Research Findings - Epidemiology and Etiology Research
Effect of Early Versus Deferred Antiretroviral Therapy for HIV on Survival
The optimal time for the initiation of antiretroviral (ARV) therapy for asymptomatic individuals with HIV infection is uncertain. For this study, researchers conducted two parallel analyses involving a total of 17,517 asymptomatic individuals with HIV infection in the U.S. and Canada who received medical care during the period 1996 through 2005. None of the participants had undergone previous ARV therapy. In each group, they stratified individuals according to the CD4+ count (351 to 500 cells per cubic millimeter or >500 cells per cubic millimeter) at the initiation of ARV therapy. In each group, they compared the relative risk of death for those who initiated therapy when the CD4+ count was above each of the two thresholds of interest (early-therapy group) with that of those who deferred therapy until the CD4+ count fell below these thresholds (deferred-therapy group). In the first analysis, which involved 8,362 subjects, 2,084 (25%) initiated therapy at a CD4+ count of 351 to 500 cells per cubic millimeter, and 6,278 (75%) deferred therapy. After adjustment for calendar year, cohort, and demographic and clinical characteristics, among persons in the deferred-therapy group there was an increase in the risk of death of 69%, as compared with that in the early-therapy group (relative risk in the deferred-therapy group, 1.69; 95% confidence interval [CI], 1.26 to 2.26; P<0.001). In the second analysis involving 9,155 subjects, 2,220 (24%) initiated therapy at a CD4+ count of more than 500 cells per cubic millimeter and 6,935 (76%) deferred therapy. Among those in the deferred-therapy group, there was an increase in the risk of death of 94% (relative risk, 1.94; 95% CI, 1.37 to 2.79; P<0.001). These findings show that early initiation of ARV therapy before the CD4+ count fell below two prespecified thresholds significantly improved survival, as compared with deferred therapy. Kitahata M, Gange S, Abraham A, Merriman B, Saag M, Justice A, et al., Effect of early versus deferred antiretroviral therapy for HIV on survival. N Engl J Med. 2009; 360(18):1815-1826.
Genetics of Nicotine Dependence (NICSNP) in an Adoption Sample
Nicotine dependence results from a complex interplay of genetic and environmental factors. Over the past several years, a large number of studies have been performed to identify distinct gene loci containing genetic vulnerability to nicotine dependence. Two of the most prominent studies were conducted by the Collaborative Study of the Genetics of Nicotine Dependence (NICSNP) Consortium using both candidate gene and high-density association approaches. In this publication, the investigators attempted to confirm and extend the most significant findings from the high-density association study and the candidate gene study using the behavioral and genetic resources of the Iowa Adoption Studies (N= 516); phenotypic data were drawn from follow up interviews conducted between 199 and the present. Mean age of males and females were 47 and 45 respectively. The investigators found evidence that genetic variation at CHRNA1, CHRNA2, CHRNA7, and CHRNB1 alters susceptibility to nicotine dependence, but did not replicate any of the most significant single nucleotide polymorphism associations from the NICSNP high-density association study. Further examination of the NICSNP findings in other population samples is indicated. Philibert R, Todorov A, Andersen A, Hollenbeck N, Gunter T, Heath A, Madden P. Examination of the Nicotine Dependence (NICSNP) Consortium findings in the Iowa Adoption Studies Population. Nicotine Tob Res. 2009;11(3):286-292.
Genetic Influences on Young Black Women Using Drugs
This study assessed overlap in heritable and environmental influences on the timing of initiation for alcohol, cigarettes, and cannabis in African-American women, using a sample of 462 female twins (100 monozygotic and 131 dizygotic pairs) from wave 5 (begun in 2005) or wave 4 (begun in 2002) of the Missouri Adolescent Female Twin Study. Mean age at the time of interview was 25.1 years. Ages at first use of alcohol, cigarettes, and cannabis were gathered in diagnostic interviews administered over the telephone. Standard genetic analyses were conducted with substance use initiation variables categorized as never, late, and early onset. Variance in the timing of first use was attributable in large part to genetic sources: 44% for alcohol, 62% for cigarettes, and 77% for cannabis. Genetic correlations across substances ranged from 0.25 to 0.70. Shared environmental influences were modest for alcohol (10%) and absent for cigarettes and cannabis. Findings contrast with reports from earlier studies based on primarily Caucasian samples, which have suggested a substantial role for shared environment on substance use initiation when measured as lifetime use. By characterize-ing onset as timing of first use, this study may be tapping a separate construct. Differences in findings may also reflect a distinct etiological pathway for substance use initiation in African-American women that could not be detected in previous studies. Sartor C, Agrawal A, Lynskey M, Bucholz K, Madden P, Heath A. Common genetic influences on the timing of first use for alcohol, cigarettes, and cannabis in young African-American women. Drug Alc Dep. 2009;102(1-3):49-55.
Longitudinal Community Plasma HIV-1 RNA Concentrations and Incidence of HIV-1 Among Injecting Drug Users: Prospective Cohort Study
Researchers examined the relationship between plasma HIV-1 RNA concentrations in the community and HIV incidence among injecting drug users. They used data from a prospective cohort study of injection drug users (IDUs) living in an inner-city community of Vancouver, Canada. The IDU, with and without HIV, were followed up every six months between 1 May 1996 and 30 June 2007. Estimated community plasma HIV-1 RNA was measured in the six months before each HIV negative participant's follow-up visit as well as associated HIV incidence. Among 622 IDU with HIV, 12,435 measurements of plasma HIV-1 RNA were obtained. Among 1429 injecting drug users without HIV, there were 155 HIV seroconversions, resulting in an incidence density of 2.49 (95% confidence interval 2.09 to 2.88) per 100 person years. In a Cox model that adjusted for unsafe sexual behaviors and sharing used syringes, the estimated community plasma HIV-1 RNA concentration remained independently associated with the time to HIV seroconversion (hazard ratio 3.32 (1.82 to 6.08, P<0.001), per log(10) increase). When the follow-up period was limited to observations after 1 January 1988 (when the median plasma HIV RNA concentration was <20 000 copies/ml), the median viral load was no longer statistically associated with HIV incidence (1.70 (0.79 to 3.67, P=0.175), per log (10) increase). A longitudinal measure of community plasma HIV-1 RNA concentration was correlated with the community HIV incidence rate and predicted HIV incidence independent of unsafe sexual behaviors and sharing used syringes. These findings have importance for informing both HIV prevention and treatment interventions. Wood E, Kerr T, Marshall B, Li K, Zhang R, Hogg R, Harrigan P, Montaner J. Longitudinal community plasma HIV-1 RNA concentrations and incidence o HIV-1 among injecting drug users: prospective cohort study. BMJ. 2009;338:1191-1195.
Features of Men With Anabolic-Androgenic Steroid Dependence: A Comparison With Nondependent AAS Users and With AAS Nonusers
The authors note that anabolic-androgenic steroid (AAS) dependence has been a recognized syndrome for some 20 years, but remains poorly understood. To better understand this syndrome, this study evaluated three groups of experienced male weightlifters: (1) men reporting no history of AAS use (N=72); (2) nondependent anabolic-androgenic steroid (AAS) users reporting no history of AAS dependence (N=42); and (3) men meeting adapted DSM-IV criteria for current or past AAS dependence (N=20). Data assessed include demographic indices, lifetime history of psychiatric disorders by the Structured Clinical Interview for DSM-IV, variables related to AAS use, and results from drug tests of urine and hair. Analysis revealed that nondependent AAS users showed no significant differences from AAS nonusers on any variable assessed. Dependent AAS users, however, differed substantially from both other groups on many measures. Notably, they reported a more frequent history of conduct disorder than nondependent AAS users (odds ratio [95% CI]: 8.0 [1.7, 38.0]) or AAS nonusers (13.1 [2.8, 60.4]) and a much higher lifetime prevalence of opioid abuse and dependence than either comparison group (odds ratios 6.3 [1.2, 34.5] and 18.6 [3.0, 116.8], respectively). Men who exhibited AAS dependence, unlike nondependent AAS users or AAS nonusers, showed a distinctive pattern of comorbid psychopathology, overlapping with that of individuals with other forms of substance dependence. AAS dependence showed a particularly strong association with opioid dependence. The authors note that this observation recalls recent animal data suggesting similarities in AAS and opioid brain reward mechanisms. The study findings provide support for the existence of AAS dependence and suggest that individuals with AAS dependence and individuals with "classical" substance dependence may possibly harbor similar underlying biological and neuropsychological vulnerabilities. Kanayama G, Hudson J, Pope H. Features of men with anabolic-androgenic steroid dependence: A comparison with nondependent AAS users and with AAS nonusers. Drug Alcohol Depend. 2009;102(1-3):130-137.
Elevated HIV Risk Behavior Among Recently Incarcerated Injection Drug Users In A Canadian Setting: A Longitudinal Analysis
While incarceration has consistently been associated with a higher risk of HIV infection for individuals who use injection drugs (IDU), the effect of incarceration on the post-release risk environment remains poorly described. Researchers sought to assess the impact of incarceration on risk factors for HIV infection after release from prison in a sample of active IDU in Vancouver, Canada. Using a prospective cohort of community-recruited IDU followed from May 1, 1996 to November 30, 2005, they examined contingency tables and performed linear growth curve analyses to assess changes in the prevalence of independent risk factors for HIV infection from before to after a period of incarceration among participants reporting incarceration and a matched control group. Of the 1603 participants followed-up over the study period, 147 (9.2%) were eligible for an analysis of post-incarceration risk behaviors and 742 (46.3%) were used as matched controls. Significant differences were found in one or both groups for the prevalence of frequent cocaine injection, requiring help injecting, binge drug use, residence in the HIV outbreak epicenter, sex-trade participation, and syringe sharing (all p < 0.05) after incarceration. In linear growth curve adjusted for age, gender and ethnicity, syringe sharing was significantly more common in those recently released from prison (p = 0.03) than in the control group. In a sample of Canadian IDU, any effect of incarceration was observed on the prevalence of several behaviors that are risk factors for HIV infection, including intensity of drug use or participation in the sex trade. However, those recently released from prison were more likely to report syringe sharing than those in a matched control group. Milloy M, Buxton J, Wood E, Li K, Montaner J, Kerr T. Elevated HIV risk behavior among recently incarcerated injection drug users in a Canadian setting: A longitudinal analysis. BMC Public Health. 2009;9:156-163.
Measuring the Risk for Substance Abuse Disorders
The inability to quantify the risk for disorders, such as substance use disorders (SUD), hinders etiology research and the development of targeted and effective interventions. Based on the concept of common transmissible liability to SUD related to illicit drugs, a method enabling quantification of this latent trait has been developed, utilizing high-risk design and item response theory. This study examined properties of a SUD transmissible liability index (TLI) derived using this method. Sons of males with or without SUD were studied longitudinally from preadolescence to young adulthood. The properties of TLI, including its psychometric characteristics, longitudinal risk assessment and ethnic variation, were examined. A pilot twin study was conducted to analyze the composition of TLI's phenotypic variance. The data suggest that TLI has concurrent, incremental, predictive and discriminant validity, as well as sensitivity to ethnic differences. The data suggest a high heritability of the index in males. The results also suggest applicability of the method for genetic and other etiology-related research, and for evaluation of individual risk. Vanyukov M, Kirisci L, Moss L, Tarter R, Reynolds M, Maher B, et al., Measurement of the risk for substance use disorders: Phenotypic and genetic analysis of an index of common liability. Behav Genet. 2009;39(3):233-244.
Neighborhood Quality and Development of Cannabis Use Disorder In Boys
This prospective investigation examined the contribution of neighborhood context and neurobehavioral disinhibition to the association between substance use disorder (SUD) in parents and cannabis use disorder in their sons. It was hypothesized that both neighborhood context and son's neurobehavioral disinhibition mediate this association. Two hundred and sixteen boys were tracked from ages 10-12 to age 22. The extent to which neighborhood context and neurobehavioral disinhibition mediate the association between parental SUD and son's cannabis use disorder was evaluated using structural equation modeling. The best fitting model positioned neighborhood context and neurobehavioral disinhibition as mediators of the association between parental SUD and cannabis use disorder in sons. Neurobehavioral disinhibition also was a mediator of the association between neighborhood context and son's cannabis use. The implications of this pattern of association between parental SUD, neighborhood context, and individual risk for SUD for improving prevention are discussed. Ridenour T, Tarter R, Reynolds M, Mezzich A, Kirisci L, Vanyukov M. Neurobehavioral disinhibition, parental substance use disorder, neighborhood quality and development of cannabis use disorder in boys. Drug Alcohol Depend. 2009;102(1-3):71-77.
Clarifying the Phenotype and Environtype of Cannabis Use Disorder In Boys To Young Adults
Employing a prospective paradigm, this investigation derived the childhood phenotype and the environtype associated with risk for cannabis use disorder. Two hundred and sixteen boys were evaluated between age 10-12 on a comprehensive protocol using self, mother, and teacher reports, and later followed up at ages 19 and 22 to determine the presence of cannabis use disorder. The Transmissible Liability Index (TLI) and Non-Transmissible Liability Index (NTLI) were derived using item response theory. Logistic regression was conducted to evaluate the accuracy of the indexes, singly and in combination, to predict cannabis use disorder. The TLI and NTLI together predicted with 70% and 75% accuracy cannabis use disorder manifest by age 19 and age 22. Sensitivity was 75% at both ages 19 and 22, whereas specificity was respectively 51% and 64%. The findings pertaining to sensitivity indicate that SUD risk for cannabis use disorder can be screened in childhood; however, the specificity scores demonstrate that a low score on the TLI does not inevitably portend a good prognosis up to 10 years later. Kirisci L, Tarter R, Mezzich A, Ridenour T, Reynolds M, Vanyukov M. Prediction of cannabis use disorder between boyhood and young adulthood: Clarifying the phenotype and environtype. Am J Addict. 2009;18(1):36-47.
Gender Differences In Risk Factors of HIV In South African Drug Users
South Africa continues to be the global epicenter of HIV infection. Further, extensive gender disparities in HIV infection exist with females four times as likely to be infected with HIV/AIDS as males. A cross-sectional collection of drug users recruited in the Pretoria region of South Africa (N = 385) was used to model HIV infection as a function of sexual risk behaviors and drug use as modified by gender. Receiving money from illicit sources and knowing someone with AIDS were loosely associated with HIV. Gender interactions were observed for age, cocaine use and condom use. Gender stratified analyses revealed that males who used condoms, were younger and tested negative for cocaine use were less likely to test positive for HIV. Findings suggest that males may have more control of risk behaviors and support the need for gender specific prevention strategies. Hedden S, Whitaker D, Floyd L, Latimer W. Gender differences in the prevalence and behavioral risk factors of HIV in South African drug users. AIDS Behav. 2009;13(2):288-296.
Injection Drug Use Among Street-Involved Youth In A Canadian Setting
Street-involved youth contend with an array of health and social challenges, including elevated rates of blood-borne infections and mortality. In addition, there has been growing concern regarding high-risk drug use among street-involved youth, in particular injection drug use. This study examined the prevalence of injecting and associated risks among street-involved youth in Vancouver, Canada. From September 2005 to November 2007, baseline data were collected as part of a prospective cohort study of street-recruited youth aged 14 to 26. Using multiple logistic regression, youth with and without a history of injection were compared. The sample included 560 youth among whom the median age was 21.9 years; 179 (32%) were female; and 230 (41.1%) reported prior injection drug use. Factors associated with injection drug use in multivariate analyses included age >or= 22 years (adjusted odds ratio [AOR] = 1.18, 95% CI: 1.10-1.28); sex work involvement (AOR = 2.17, 95% CI: 1.35-3.50); non-fatal overdose (AOR = 2.10, 95% CI: 1.38-3.20); and hepatitis C (HCV) infection (AOR = 22.61, 95% CI: 7.78-65.70). These findings highlight a high prevalence of injection drug use among street-involved youth in Vancouver and demonstrate its association with an array of risks and harms, including sex work involvement, overdose, and HCV infection. The data underscore the need for a broad set of policies and interventions to prevent the initiation of injection drug use and address the risks faced by street-involved youth who are actively injecting. Kerr T, Marshall B, Miller C, Shannon K, Zhang R, Montaner J, Wood E. Injection drug use among street-involved youth in a Canadian setting. BMC Public Health. 2009;9:171-178.
Functional Impairment and Substance Use In Youth Three Years After Detention
This study examines functional impairment across global and specific dimensions among youth 3 years after their detention. Functional impairment was assessed using the Child and Adolescent Functional Assessment Scale (CAFAS) in a large, stratified, random sample of formerly detained youth (N = 1653). More than one-fifth of the individuals in the sample were scored as having marked impairment that required, at minimum, "multiple sources of care" (CAFAS Total Score of > or =100); 7.0% required "intensive intervention" (CAFAS Total Score > or =140). Most of the sample had impairment; only 7.5% had "no noteworthy impairment" (CAFAS Total Score < or =10). Significantly more males were impaired than females. Among males living in the community at follow-up, African Americans and Hispanics were more likely to be impaired than non-Hispanic whites. In comparison to males living in the community, males who were incarcerated at follow-up were significantly more likely to have impaired thinking and impaired functioning at home (if incarcerated, "home" is the correctional facility) but less likely to have substance use problems. Three years after detention, most youth struggle in one or more life domains; more than one in five have marked impairment in functioning. These findings underscore the ongoing costs, to both youth and society, of failing to provide effective rehabilitation to youth after detention. Abram K, Choe J, Washburn J, Romero E, Teplin L. Functional impairment in youth three years after detention. J Adolesc Health. 2009;44(6):528-535.
Modification of the Association Between Serotonin Transporter Genotype and Risk of Posttraumatic Stress Disorder In Adults By County-Level Social Environment
Although both genetic factors and features of the social environment are important predictors of posttraumatic stress disorder (PTSD), there are few data examining gene-social environment interactions in studies of PTSD. The researchers examined whether features of the social environment (county-level crime rate and unemployment) modified the association between the serotonin protein gene (SLC6A4) promoter variant (5-HTTLPR) and risk of current PTSD in a sample of 590 participants from the 2004 Florida Hurricane Study. Interviews conducted in 2005 were used to obtain individual-level risk factor measures and Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, PTSD diagnoses. DNA was extracted from salivary samples. County-level crime and unemployment rates were assessed from Federal Bureau of Investigation and US Census data, respectively. There was a significant interaction between 5-HTTLPR genotype and both crime rate (odds ratio = 2.68, 95% confidence interval: 1.09, 6.57) and unemployment rate (odds ratio = 3.67, 95% confidence interval: 1.42, 9.50) in logistic regression models predicting PTSD risk, after adjustment for individual-level determinants of PTSD. Stratified analyses indicated that the "s" allele of the 5-HTTLPR polymorphism was associated with decreased risk of PTSD in low-risk environments (low crime/unemployment rates) but increased risk of PTSD in high-risk environments. These results suggest that social environment modifies the effect of 5-HTTLPR genotype on PTSD risk. Koenen K, Aiello A, Bakshis E, Amstadter A, Ruggiero K, Acierno R, Kilpatrick D, Gelernter J, Galea S. Modification of the association between serotonin transporter genotype and risk of posttraumatic stress disorder in adults by county-level social environment. Am J Epidemiol. 2009;169(6):704-711.
The Harm Inside: Injection During Incarceration Among Male Injection Drug Users In Tijuana, Mexico
Limited access to sterile syringes and condoms in correctional facilities make these settings high risk environments for HIV transmission. Although incarceration among injection drug users (IDUs) is common, there is limited information regarding specific IDU risk behaviors inside. Researchers examined correlates of incarceration, injection inside and syringe sharing inside among male IDUs recruited in Tijuana, Mexico, using respondent driven sampling (RDS) (n=898). An interviewer administered survey collected data on sociodemographic, behavioral and contextual characteristics. Associations with (a) history of incarceration, (b) injection inside, and (c) syringe sharing inside were identified using univariate and multiple logistic regression models with RDS adjustment. Seventy-six percent of IDUs had been incarcerated, of whom 61% injected inside. Three quarters (75%) of those who injected shared syringes. U.S. deportation [adjusted odds ratio (AOR) =1.61; 95% confidence interval (CI): 1.07, 2.43] and migration (AOR=1.81; 95% CI: 1.12, 2.95) were independently associated with incarceration. Injection inside was independently asso-ciated with recent receptive syringe sharing (AOR=2.46; 95% CI: 1.75, 3.45) and having sex with a man while incarcerated (AOR=3.59; 95% CI: 1.65, 7.83). Sharing syringes inside was indepen-dently associated with having sex with a man while incarcerated (AOR=6.18; 95% CI: 1.78, 21.49). A majority of incarcerated IDUs reported injecting and syringe sharing during incarceration, and these IDUs were more likely to engage in sex with other men. Findings indicate the great need for corrections-based interventions to reduce injection and syringe sharing and risk reduction inter-ventions for male IDUs who have sex with men while incarcerated. Pollini R, Alvelais J, Gallardo M, Vera A, Lozada R, Magis-Rodriquez C, Strathdee S. The harm inside: Injection during incar-ceration among male injection drug users in Tijuana, Mexico. Drug Alc Dep. 2009;103(1-2):52-58.
High Prevalence of Latent Tuberculosis Infection Among Injection Drug Users In Tijuana, Mexico
Researchers studied prevalence and correlates of latent tuberculosis infection (LTBI) among injection drug users (IDUs) in Tijuana, Mexico, where tuberculosis (TB) is endemic. IDUs aged > or =18 years were recruited via respondent-driven sampling (RDS) and underwent standardized interviews, human immunodeficiency virus (HIV) antibody testing and LTBI screening using Quanti-FERON((R))-TB Gold In-Tube, a whole-blood interferon-gamma release assay (IGRA). LTBI prevalence was estimated and correlates were identified using RDS-weighted logistic regression. Of 1020 IDUs, 681 (67%) tested IGRA-positive and 44 (4%) tested HIV-positive. Mean age was 37 years, 88% were male and 98% were Mexican-born. IGRA positivity was associated with recruitment nearest the US border (aOR 1.64, 95%CI 1.09-2.48), increasing years of injection (aOR 1.20/5 years, 95%CI 1.07-1.34), and years lived in Tijuana (aOR 1.10/5 years, 95%CI 1.03-1.18). Speaking some English (aOR 0.38, 95%CI 0.25-0.57) and injecting most often at home in the past 6 months (aOR 0.68, 95%CI 0.45-0.99) were inversely associated with IGRA positivity. Increased LTBI prevalence among IDUs in Tijuana appears to be associated with greater drug involvement. Given the high risk for HIV infection among Tijuana's IDUs, interventions are urgently needed to prevent HIV infection and treat LTBI among IDUs before these epidemics collide. Garfein R, Lozada R, Liu L, Laniado-Laborin R, Rodwell T, Deiss R, Alvelais J, Catanzaro A, Chiles P, Strathdee S. High prevalence of latent tuberculosis infection among injection drug users in Tijuana, Mexico. Int J Tuberc Lung Dis. 2009;13(5):626-632.
Peptic Ulcers and Mental Disorders In Smokers and Alcoholics
Previous studies have documented links between peptic ulcer disease (PUD) and mood and anxiety disorders among adults in the community. Several substance use disorders (e.g., nicotine and alcohol dependence) are highly comorbid with mood/anxiety disorders and have been also linked with PUD. No previous study has examined the potentially explanatory role of substance use disorders in the link between mood and anxiety disorders and PUD. The objective of the study is to examine relationships between a range of mental disorders and PUD among adults in the United States and to examine the potential explanatory role of substance use disorders in these links. Data were drawn from the National Epidemiologic Survey on Alcohol and Related Conditions, a nationally representative sample of US adults 18 years of age and over (N= 43,098). Diagnostic and Statistical Manual for Mental Disorders IV diagnoses of mood, anxiety, and substance use disorders were assessed using the Alcohol Use Disorder and Associated Disabilities Interview Schedule-DSM-IV, and PUD status was assessed via self-report. Findings show that mood/anxiety disorders were associated with PUD. Specifically, generalized anxiety disorder (GAD) (Odds Ratio (OR) = 3.43) was most strongly associated with PUD, followed by panic disorder (OR = 3.11), dysthymia (OR = 3.59), and bipolar disorder (OR = 2.91). The relationships between most mood/anxiety disorders and PUD were substantially attenuated after adjusting for nicotine and alcohol dependence. Mood/anxiety disorders are associated with increased rates of PUD; nicotine and alcohol dependence seem to play a substantial role in explaining the link with PUD. Goodwin R, Keyes K, Stein M, Talley N. Peptic ulcer and mental disorders among adults in the community: The role of nicotine and alcohol use disorders. Psychosom Med. 2009;71(4):463-468.
Influence of Drinking Quantity on Alcohol Dependence
Recent research suggests that adding a quantity/frequency alcohol consumption measure to the diagnoses of alcohol use disorders may improve construct validity of diagnoses using the Diagnostic and Statistical Manual of Mental and Behavior Disorders (DSM-V). This study explores the epidemiological impact of including weekly at-risk drinking (WAD) in the DSM-IV diagnostic definition of alcohol dependence via three hypothetical reformulations of the current criteria. The sample was the National Epidemiologic Survey on Alcohol and Related Conditions, a nationally representative sample with 43,093 adults aged >18 in the U.S interviewed with the Alcohol Use Disorder and Associated Disabilities Interview Schedule IV. The current (DSM-IV) definition of alcohol dependence was compared with four hypothetical alcohol dependence reformulations that included WAD: (1) WAD added as an eighth criteria; (2) WAD required for a diagnosis; (3) adding abuse and dependence criteria together, and including WAD with a 3 of 12 symptom threshold; (4) adding abuse and dependence criteria together, and including WAD with a 5 of 12 symptom threshold. The inclusion of at-risk drinking as an eighth criterion of alcohol dependence has a minimal impact on the sociodemo-graphic correlates of alcohol dependence but substantially increases the prevalence of dependence (from 3.8% to 5.0%). At-risk drinking as a required criterion or as part of a diagnosis that combines abuse with dependence criteria with a higher threshold (5+ criteria) decreases prevalence and has a larger impact on sociodemographic correlates. Blacks, Hispanics, and women are less likely to be included in diagnostic reformulations that include WAD, whereas individuals with low-income and education are more likely to remain diagnosed. Including WAD as either a requirement of diagnosis or as an additional criterion would have a large impact on the prevalence of alcohol dependence in the general population. The inclusion of a quantity/frequency requirement may eliminate false positives from studies of alcohol disorder etiology and improve phenotype definition for genetic association studies by reducing heterogeneity in the diagnosis, but may also reduce eligibility for treatment services among women and racial/ethnic minorities. Keyes K, Geier T, Grant B, Hasin, D. Influence of a drinking quantity and frequency measure on the prevalence and demographic correlates of DSM-IV alcohol dependence. Alcohol Clin Exp Res. 2009;33(5):761-771.
Association Between Neurobehavioral Disinhibition and Peer Environment on Illegal Drug Use
Individual and contextual factors jointly participate in the onset and progression of substance abuse; however, the pattern of their relationship in males and females has not been systematically studied. Male and female children and adolescents were compared to determine the relative influence of individual susceptibility (neurobehavioral disinhibition or ND) and social environment (deviancy in peers) on use of illegal drugs. Boys (N = 380) and girls (N = 127) were prospectively tracked from age 10-12 to age 16 to delineate the role of ND and peer deviancy on use of illegal drugs. Girls exhibited lower ND scores than boys in childhood and were less inclined to affiliate with deviant peers. These differences were reduced or disappeared by mid-adolescence. In boys only, peer deviancy in childhood mediated the association between ND and illegal drug use at age 16. In both genders, peer deviancy in mid-adolescence mediated ND and substance abuse at age 16. Individual and contextual risk factors promoting substance abuse are more salient at a younger age in boys compared to girls. These results point to the need for earlier screening and intervention for boys. Kirisci L, Mezzich A, Reynolds M, Tarter R, Aytaclar S. Prospective study of the association between neurobehavioral disinhibition and peer environment on illegal drug use in boys and girls. Am J Drug Alcohol Abuse. 2009;35(3):145-150.
Opportunities To Use Drugs and Stages of Drug Involvement Outside the United States: Evidence From the Republic of Chile
The research team sought to replicate North American research findings regarding the earliest stages of drug involvement by studying youthful drug involvement in the Republic of Chile. In particular, they assessed initial opportunities for licit drug use and transitions leading toward illegal drug use. The researchers surveyed a nationally representative probability sample of middle and high school students in Chile; 30,490 youths completed surveys that assessed age at first drug exposure opportunities and first actual drug use. An estimated 39% of the students had an opportunity to use cannabis, and 70% of these transitioned to actual cannabis use. The probability of cannabis use and the conditional probability of cannabis use were greater for users of alcohol only, tobacco only, and alcohol plus tobacco, as compared to non-users of alcohol and tobacco. Male-female differences in cannabis use were traced back to male-female differences in drug exposure opportunities. The findings suggest that in Chile as in North America, when cannabis use follows alcohol and tobacco use, the mechanism may be understood in two parts: users of alcohol and tobacco are more likely to have opportunities to try cannabis, and once the opportunity occurs, they are more likely to use cannabis. Male-female differences do not seem to be operative within the mechanism that governs transition to use, once the opportunity to use cannabis has occurred. Caris L, Wagner F, R’os-Bedoya C, Anthony J. Opportunities to use drugs and stages of drug involvement outside the United States: Evidence from the Republic of Chile. Drug Alcohol Depend. 2009;102(1-3):30-34.
Lifetime Alcohol Abuse, Dependence, and Binge Drinking
Questions relevant to DSM-V alcohol use disorders (AUD) include whether dimensional measures provide more information than categorical diagnoses, whether to combine abuse and dependence criteria, and whether to add a new diagnostic criterion, binge drinking. Binary and dimensional models of three versions of AUD criteria were investigated: (1) dependence criteria; (2) abuse and dependence criteria combined; and (3) abuse and dependence criteria combined, with an added binge drinking criterion. In a national sample of lifetime drinkers (N=27,324), the models of AUD criteria were investigated in relation to two well-established risk factors for AUD, family history and early drinking onset. Logistic or Poisson regression modeled the relationships between the validating variables and dependence in categorical, dimensional, and hybrid forms; Wald tests were used to assess differences between the dimensional, categorical, and hybrid models. Alcohol dependence criteria represented a single continuum (family history Wald=9.93, p=0.13; early drinking Wald=7.62, p=0.27) with no support for a categorical or hybrid version of alcohol dependence. Adding four abuse criteria produced similar results for family history (Wald=15.4, p=0.12) although with early drinking, this model showed a trend towards deviating from the data (Wald=16.7, p=0.08). No support was found for any diagnostic threshold at 3, 4, 5, 6, or 7 criteria when abuse and dependence were combined. Adding binge drinking resulted in a significant departure from linearity for family history (Wald=21.8, p=0.03) and early drinking (Wald=23.9, p=0.01). The number of alcohol dependence and abuse criteria met should be explored further as a useful AUD severity indicator or phenotype. Hasin D, Beseler C. Dimensionality of lifetime alcohol abuse, dependence and binge drinking. Drug Alcohol Depend. 2009;101(1-2):53-61.
Linking Adolescent Nicotine Dependence and Common Latent Continuum
Using the theoretical model of nicotine dependence (ND) within the Diagnostic and Statistical Manual of Mental Disorder, 4th Edition (DSM-IV) as a frame of reference, investigators used methods based on item response theory to link alternative instruments assessing adolescent nicotine dependence severity to a common latent continuum. A multi-ethnic cohort of 6th-10th graders selected from the Chicago Public Schools completed 5 household interviews over 2 years. Youth who reported at least some cigarette use in the last 30 days prior to the interviews at waves W3-W5 completed measures of DSM-IV ND, the Modified Fagerstrom Tolerance Questionnaire (mFTQ), and the Nicotine Dependence Syndrome Scale (NDSS), yielding samples of 253, 241, and 296 respondents at W3-W5, respectively. Confirmatory factor analysis supported a primary dimension of ND. Each instrument's items had complementary and stable relationships to ND across multiple waves of assessment. By aligning symptoms along a common latent ND continuum, researchers were able to evaluate the consistency of symptoms from different instruments that target similar content. These methods allowed for an examination of the DSM-IV as a continuous index of ND, the evaluation of the degree of heterogeneity in levels of ND within groups above and below diagnostic thresholds, and the assessment of the utility in using the pattern or particular DSM-IV symptoms that led to each score in further differentiating levels of ND. They also made it possible to examine the concurrent validity of the ND continuum and levels of current of smoking at each wave of assessment. Strong D, Kahler C, Colby S, Griesler P, Kandel D. Linking measures of adolescent nicotine dependence to a common latent continuum. Drug Alcohol Depend. 2009;99(1-3):296-308.
Early-Onset Drug Use and Risk for Drug Dependence Problems
There is substantial evidence that alcohol, tobacco, and cannabis dependence problems surface more quickly when use of these drugs starts before adulthood, but the evidence based on other illicit drugs (e.g., cocaine) is meager. Using existing data from the National Survey on Drug Use and Health (NSDUH), a large-scale population-based study which includes adolescents and adults, researchers examined drug-specific and age-specific variation in profiles of emerging clinical features associated with drug dependence. The risk of experiencing drug dependence problems was found to be robustly greater for adolescent recent-onset users of cocaine, psychostimulant drugs other than cocaine, analgesics, anxiolytic medicines, inhalants drugs, and cannabis, as compared to adult recent-onset users (odds ratio=1.5-4.3, p<0.05). This was not the case for the NSDUH hallucinogens group (e.g., LSD). The findings suggest promoting earlier detection and interventions for drug use, as well as greater parent and peer awareness of drug dependence clinical features that may develop early among young people who have just started using drugs. Chen C, Storr C, Anthony J. Early-onset drug use and risk for drug dependence problems. Addict Behav. 2009;34(3):319-322.
Simultaneous Cannabis and Tobacco Use In Women
Compared to those who reported a lifetime co-occurrence of cannabis and tobacco use, individuals who report simultaneous use of cannabis and tobacco are more likely to also report higher rates of substance-related problems and psycho-pathology. A study of a sample of young women (N=3427) examined (a) co-occurring use, or whether regular cigarette smoking is associated with increased cannabis involvement; (b) simultan-eous use, a special form of co-occurring use where cannabis and cigarettes are typically used on the same occasion (to determine if those who use cannabis and tobacco simultaneously are also more likely to report greater cannabis involvement); and (c) the extent to which latent genetic and environmental factors may contribute to simultaneous use in those with a history of co-occurring cannabis use and regular cigarette smoking. Womenwho reported regular cigarette smoking were 4.5-9.5 times more likely to report co-occurring cannabis use and other stages of cannabis involvement, including DSM-IV cannabis abuse and dependence. In those women who reported co-occurring regular cigarette smoking and lifetime cannabis use (N=1073), simultaneous use of cannabis and tobacco was associated with increased likelihood of negative cannabis-related outcomes. Simultaneous users were 1.6 times more likely to meet criteria for DSM-IV cannabis abuse, even after controlling for early covariates and for prior stages of cannabis involvement. Simultaneous use was not heritable; twin similarity was attributable to shared environmental factors (31%). While this study does not determine causality between simultaneous tobacco-cannabis use and cannabis involvement, results indicate that simultaneous use is potentially a marker for more severe psychosocial consequences associated with cannabis use. Agrawal A, Lynskey M, Madden P, Pergadia M, Bucholz K, Heath A. Simultaneous cannabis and tobacco use and cannabis-related outcomes in young women. Drug Alcohol Depend. 2009;101(1-2):8-12.
Tobacco and Cannabis Co-Occurrence
Qualitative research suggests that a shared route of administration (i.e., inhalation) for common forms of tobacco (i.e., cigarettes) and cannabis (i.e., joints) may contribute to their co-occurring use. Investigators examined data on 43,093 U.S. adults who participated in the 2001-2002 National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) to examine whether cannabis use and abuse/dependence were associated with smoked (cigarettes, cigars, pipes) versus smokeless (snuff, chewed tobacco) forms of tobacco use, after controlling for socio-demographic, psychiatric, and substance-related covariates. They found that tobacco smoking was associated with a 3.3-4.5 times increased risk for cannabis use and abuse/dependence, respectively. After covariate adjustment for nicotine dependence, tobacco smoking (but not smokeless tobacco) was significantly associated with cannabis use (multinomial odds-ratio (MOR) 1.99) as well as cannabis dependence (MOR 1.55). By contrast, use of smokeless tobacco was not significantly correlated with elevated rates of cannabis use (MOR 0.96) or abuse/ dependence (MOR 1.04). These findings suggest that route of administration may play a role in the observed association between tobacco and cannabis use. This may represent a physiological adapta-tion of the aero-respiratory system and/or an index of social and cultural influences surrounding the use of smoked vs. smokeless forms of tobacco. Agrawal A, Lynskey M. Tobacco and cannabis co-occurrence: Does route of administration matter? Drug Alcohol Depend. 2009;99(1-3):240-247.
Cigarette-By-Cigarette Satisfaction During Ad Libitum (As Desired) Smoking
Smoking is thought to produce immediate reinforcement, and subjective satisfaction with smoking is thought to influence subsequent smoking. The authors used ecological momentary assessment to assess cigarette-by-cigarette smoking satisfaction in 394 heavy smokers who subsequently attempted to quit. Across 14,882 cigarettes rated, satisfaction averaged 7.06 (0-10 scale), with considerable variation across cigarettes and individuals. Women and African American smokers reported higher satisfaction. More satisfied smokers were more likely to lapse after quitting (Hazard Ratio (HR) =1.1, p < .03), whereas less satisfied smokers derived greater benefit from patch treatment to help them achieve abstinence (HR = 1.23, p<.001). Cigarettes smoked in positive moods were more satisfying, correcting for mood at the time of rating. The best predictor of subsequent smoking satisfaction was the intensity of craving prior to smoking. Understanding subjective smoking satis-faction provides insight into sources of reinforcement for smoking. Shiffman S, Kirchner T. Cigar-ette-by-cigarette satisfaction during ad libitum smoking. J Abnorm Psych. 2009;118(2):348-359.
Mortality Among Injection Drug Users In Chennai, India (2005-2008)
Injection drug users (IDUs) have estimated mortality rates over 10 times higher than the general population; much of this excess mortality is HIV-associated. Few mortality estimates among IDUs from developing countries, including India, exist. In this study, IDUs (1158) were recruited in Chennai from April 2005 to May 2006; 293 were HIV positive. Information on deaths and causes was obtained through outreach workers and family/network members. Mortality rates and standardized mortality ratios were calculated; multivariate Poisson regression was used to identify predictors of mortality. There were 85 deaths over 1998 person-years (p-y) of follow-up [mortality rate (MR) 4.25 per 100 p-y; 95% confidence interval (CI) = 3.41-5.23]. The overall standardized mortality ratio was 11.1; for HIV-positive IDUs, the standardized mortality ratio was 23.9. Mortality risk among HIV-positive IDUs (MR: 8.88 per 100 p-y) was nearly three times that of negative IDUs (MR: 3.03 per 100 p-y) and increased with declining immune status (CD4 cells > 350: 5.44 per 100 p-y vs. CD4 cells < or = 200: 34.5 per 100 p-y). This association persisted after adjustment for confounders. The leading causes of mortality in both HIV negative and positive IDUs were overdose (n = 22), AIDS (n = 14), tuberculosis (n = 8) and accident/trauma (n = 9). Substantial mortality was observed in this cohort with the highest rates among HIV-positive IDUs with CD4 counts of less than 350 cells/microl. Although non-AIDS deaths outnumbered AIDS-related deaths, the relative contribution of AIDS-associated mortality is likely to increase with advancing HIV disease progression. These data reinforce the need for interventions to reduce the harms associated with drug use and increase HAART access among IDUs in Chennai. Solomon S, Celentano D, Srikrishnan A, Vasudevan C, Anand S, Kumar M, Solomon S, Lucas G, Mehta S. Mortality among injection drug users in Chennai, India (2005-2008). AIDS. 2009;23(8):997-1004.
Predictors of Injection Drug Use Cessation and Relapse in a Prospective Cohort of Young Injection Drug Users In San Francisco, CA (UFO Study)
Studies of injection drug use cessation have largely sampled adults in drug treatment settings. Little is known about injection cessation and relapse among young injection drug users (IDU) in the community. This study included 365 HCV-negative IDU under age 30 years recruited by street outreach and interviewed quarterly for a prospective cohort between January 2000 and February 2008. Participants were followed for 638 person-years and 1996 visits. Survival analysis techniques were used to identify correlates of injection cessation (> or =3 months) and relapse to injection. Sixty-seven percent of subjects were male, the median age was 22 years (interquartile range (IQR) 20-26) and the median years injecting was 3.6 (IQR 1.3-6.5); 28.8% ceased injecting during the follow-up period. Among those that ceased injecting, nearly one-half resumed drug injection on subsequent visits, one-quarter maintained injecting cessation, and one-quarter were lost to follow-up. Participating in a drug treatment program in the last 3 months and injecting less than 30 times per month were associated with injection cessation. Injecting heroin or heroin mixed with other drugs, injecting the residue from previously used drug preparation equipment, drinking alcohol, and using benzodiazepines were negatively associated with cessation. Younger age was associated with relapse to injection. These results suggest that factors associated with stopping injecting involve multiple areas of intervention, including access to drug treatment and behavioral approaches to reduce injection and sustain cessation. The higher incidence of relapse in the younger subjects in this cohort underscores the need for earlier detection and treatment programs targeted to adolescents and transition-age youth. Evans J, Hahn J, Lum P, Stein E, Page K. Predictors of injection drug use cessation and relapse in a prospective cohort of young injection drug users in San Francisco, CA (UFO Study). Drug Alcohol Depend. 2009;101(3):152-157.
Development of Substance Abuse in Adolescents With Bipolar Disorder
Recent work has highlighted important relationships among conduct disorder (CD), substance use disorders (SUD), and bipolar disorder in youth. However, because bipolar disorder and CD are frequently comorbid in the young, the impact of CD in mediating SUD in bipolar disorder youth remains unclear. To help clarify this, a sample of 105 adolescents with DSM-IV bipolar disorder (mean +/- SD age=13.6 +/- 2.50 years) and 98 controls (mean +/- SD age = 13.7 +/- 2.10 years) was comprehensively assessed with a structured psychiatric diagnostic interview for psychopathology and SUD. The study was conducted from January 2000 through December 2004. Among bipolar disorder youth, those with CD were more likely to report cigarette smoking and/or SUD than youth without CD. However, CD preceding SUD or cigarette smoking did not significantly increase the subsequent risk of SUD or cigarette smoking. Adolescents with bipolar disorder and CD were significantly more likely to manifest a combined alcohol plus drug use disorder compared to subjects with bi-polar disorder without CD. While bipolar disorder is a risk factor for SUD and cigarette smoking in a sample of adolescents, comorbidity with preexisting CD does not increase the risk for SUD. Further follow-up of this sample through the full risk of SUD into adulthood is necessary to confirm these findings. Wilens T, Martelon M, Kruesi M, Parcell T, Westerberg D, Schillinger M, Gignac M, Biederman J. Does conduct disorder mediate the development of substance use disorders in adolescents with bipolar disorder? A case-control family study. J Clin Psych. 2009;70(2):259-265.
Quantitative Measurements of Alcoholic Consumption
The purpose of this study was to develop a quantitative measure of alcohol consumption for gene-mapping studies. Using a sample of 3,787 young-adult twin women and an independent sample of 489 men and women from a college drinking study, researchers developed an alcohol-consumption factor score indexed by (1) maximum typical consumption (log-transformed quantity frequency [LQNTFRQ]), (2) maximum drinks in a 24-hour period (LMAXALC), (3) frequency of drinking five or more drinks per day (FIVE), and (4) frequency of drinking to intoxication (INTOX). The investigators tested (1) for factorial and psychometric equivalence across samples and genders; and (2) for construct validity and its equivalence across samples and genders, using measures of tobacco and cannabis use and family history of alcoholism. They then determined the heritability of the alcohol-consumption factor score using a genetic psychometric model. A single-factor model fit well with factor loadings ranging from .60 to .90. With rare exception, they found support for measurement invariance across the two samples and across genders. Measures of nicotine and cannabis use as well as family history of alcoholism were associated to a similar extent across samples and genders, with the underlying alcohol-consumption factor. Psychometric twin modeling revealed that each of the alcohol-consumption measures (h2=34%-47%) and the underlying factor score (h2=50%) were heritable, with the remainder of the variance attributable to individual-specific environmental factors. The moderately heritable alcohol-consumption factor also accounted for a majority of the genetic variance in LQNTFRQ, LMAXALC, FIVE, and INTOX. The findings suggest that quantitative measures of alcohol consumption with the favorable attributes of measurement invariance, construct validity, and moderate heritability can enhance future gene-mapping efforts, supplementing information afforded by conventional diagnostic measures of alcohol abuse/dependence. Agrawal A, Grant J, Littlefield A, Waldron M, Pergadia M, Lynskey M, Madden P, Todorov A, Trull T, Bucholz K, Todd R, Sher K, Heath A. Developing a quantitative measure of alcohol consumption for genomic studies on prospective cohorts. J Stud Alcohol Drugs. 2009;70(2):157-168.
Multiple Distinct Risk Loci for Nicotine Dependence
Tobacco smoking continues to be a leading cause of preventable death. Recent research has underscored the important role of specific cholinergic nicotinic receptor subunit (CHRN) genes in risk for nicotine dependence and smoking. To detect and characterize the influence of genetic variation on vulnerability to nicotine dependence, 226 single nucleotide polymorphisms (SNPs) covering the complete family of 16 CHRN genes, which encode the nicotinic acetylcholine receptor (nAChR) subunits, were analyzed in a sample of 1,050 nicotine-dependent cases and 879 non-dependent controls of European descent. After correcting for multiple tests across this gene family, significant associations were found for two distinct loci in the CHRNA5-CHRNA3-CHRNB4 gene cluster, one locus in the CHRNB3-CHRNA6 gene cluster, and a fourth, novel locus in the CHRND-CHRNG gene cluster. The two distinct loci in CHRNA5-CHRNA3-CHRNB4 are represented by the non-synonymous SNP rs16969968 in CHRNA5 and by rs578776 in CHRNA3, respectively, and joint analyses show that the associations at these two SNPs are statistically independent. Nominally significant single-SNP association was detected in CHRNA4 and CHRNB1. This is the most comprehensive study of the CHRN genes for involvement with nicotine dependence to date, revealing significant evidence for at least four distinct loci in the nicotinic receptor subunit genes that influence the transition from smoking to nicotine dependence. The findings are discussed with regard to their implications for the development of improved smoking cessation treatments and prevention initiatives. Saccone N, Saccone S, Hinrichs A, Stitzel J, Duan W, Pergadia M, et al., Multiple distinct risk loci for nicotine dependence identified by dense coverage of the complete family of nicotinic receptor subunit (CHRN) genes. Am J Med Genet B Neuropsychiatr Genet. 2009;150B(4):453-466.
Genes Linked To Alcohol Consumption
Previous studies have identified evidence of genetic influence on alcohol use in samples selected to be informative for alcoholism research. However, there are a growing number of genome-wide association studies (GWAS) using samples unselected for alcohol consumption (i.e., selected on other traits and forms of psychopathology), which nevertheless assess consumption as a risk factor. Is it reasonable to expect that genes contributing to variation in alcohol consumption can be identified in such samples? An exploratory approach was taken to determine whether linkage analyses for heaviness of alcohol consumption, using a sample collected for heterogeneous purposes, could replicate previous findings. Quantity and frequency measures of consumption were collected in telephone interviews from community samples. These measures, and genotyping, were available for 5,441 individuals (5,067 quasi-independent sibling pairs). For 1,533 of these individuals, data were collected on two occasions, about 8.2 years apart, providing two datasets that maximize data collected at either a younger or an older age. Analyses were conducted to address the question of whether age and heavier levels of alcohol consumption effects outcome. Linkage results were compared in the younger and older full samples, and with samples in which approximately 10, 20, and 40 of drinkers from the lower end of the distribution of alcohol consumption were dropped. Linkage peaks varied for the age differentia-ted samples and for percentage of light drinkers retained. Larger peaks (LOD scores >2.0) were typically found in regions previously identified in linkage studies and/or containing proposed candidate genes for alcoholism including AGT, CARTPT, OPRD1, PIK3R1, and PDYN. The results suggest that GWAS assessing alcohol consumption as a covariate for other conditions will have some success in identifying genes contributing to consumption-related variation. However, sample characteristics, such as participant age, and trait distribution, may have substantial effects on the strength of the genetic signal. These results can inform forthcoming GWAS where the same restrictions apply. Hansell N, Agrawal A, Whitfield J, Morley K, Gordon S, Lind P, et al., Can we identify genes for alcohol consumption in samples ascertained for heterogeneous purposes? Alcohol Clin Exp Res. 2009;33(4):729-739.
Early Cannabis Use and DSM-IV Nicotine Dependence
Evidence suggests that cannabis users are at increased risk for cigarette smoking. If so, this may be the single most alarming public health challenge posed by cannabis use. Investigators examined whether cannabis use prior to age 17 years is associated with an increased likelihood of DSM-IV nicotine dependence and the extent to which genetic and environmental factors contribute to this association in a population-based cohort of 24-36-year-old Australian male and female twins (N=6257; 286 and 229 discordant pairs). The co-twin-control method, with twin pairs discordant for early cannabis use, was used to examine whether, after controlling for genetic and familial environmental background, there was evidence for an additional influence of early cannabis use on DSM-IV nicotine dependence. Bivariate genetic models were fitted to the full data set to quantify the genetic correlation between early cannabis use and nicotine dependence. The early cannabis-using twin was about twice as likely to report nicotine dependence when compared to their co-twin who had experimented with cigarettes but had never used cannabis. Even when analyses were restricted to cannabis users, earlier age of cannabis use onset conferred greater risk (1.7 times greater) for nicotine dependence than did later onset. This association was governed largely by common genetic liability to early cannabis use and nicotine dependence as demonstrated by genetic correlations of 0.41-0.52. The findings suggest that early-onset cannabis users are at increased risk for nicotine dependence, and that this risk is attributable largely to common genetic vulnerability. There is no evidence for a causal relationship between cannabis use and nicotine dependence. Agrawal A, Lynskey M, Pergadia M, Bucholz K, Heath A, Martin N, Madden P. Early cannabis use and DSM-IV nicotine dependence: A twin study. Addiction. 2008;103(11):1896-1904.
Association Between DSM-IV Nicotine Dependence and Stressful Life Events
Nicotine dependence (ND) is a pervasive public health concern and a leading cause of preventable mortality. Stressful life events (SLEs), which severely disrupt the lives of individuals experiencing such events, have been posited as correlates of persisting ND. While both ND and SLEs have been studied extensively in relation to other variables, there are few instances in which they have been investigated in concert. In this study, researchers used data on 18,013 smokers from the 2001-2002 data set of the National Epidemiological Survey on Alcohol and Related Conditions (NESARC; N= 43,093) to examine whether experiencing a SLE in the past 12 months was associated with meeting criteria for ND in the same past 12 months. Logistic regression analyses were conducted while accounting for a variety of covariates. A majority of the SLEs were associated with past 12 month ND, even after controlling for poverty, psychiatric and substance use disorders, and a prior history of ND (odds-ratios 1.35-2.20). The rates of past 12 month ND were considerably greater in those experiencing more than one SLE. While these data do not allow for making causal interpretations, they suggest an association between SLE and ND. It appears that individuals experiencing SLEs may find it particularly difficult to quit smoking; alternatively, directly or via correlated risks (e.g., living in a high risk neighborhood), smoking may increase the likelihood of exposure to SLEs. Balk E, Lynskey M, Agrawal A. The association between DSM-IV nicotine dependence and stressful life events in the national epidemiologic survey on alcohol and related conditions. Am J Drug Alcohol Abuse. 2009;35(2):85-90.
Distress and Academic Achievement Among Adolescents of Affluence
The main objectives of this study were to prospectively examine the relationship between externalizing (substance use and delinquency) and internalizing (depression and anxiety) dimensions and academic achievement (grades and classroom adjustment), as well as continuity over time in these domains within a sample of wealthy adolescents followed from 10th-12th grades (N = 256). Cluster analyses were used to group participants at 10th grade and then group differences were evaluated on adjustment outcomes over time. Problem behavior clusters revealed differences on academic indices, with the two marijuana using groups-marijuana users and multi-problem youth- exhibiting the worst academic outcomes at all three waves. The two lowest achieving groups reported the highest distress across all externalizing dimensions over time. Stability across the three waves was found for both personal and academic competence as well as the associations between these two domains. Based on youth tracked from sophomore year through the end of high school, these findings indicate strong associations between problem behavior activity and academic underachievement among relatively affluent suburban youth. The findings run counter to others, which indicate that it is cigarette, and not marijuana, use that is a more potent force for academic risk. These results highlight the difficulty of concluding that there is a robust temporal sequence in the complex relationship shared between distress domains and academic achievement. In all likelihood, once the cycle has started, it may be nearly impossible to tease apart which came first. These findings suggest the need for school-based interventions focusing on marijuana use as well as academic problems as related if not bi-directionally influencing one another. Ansary N, Luthar S. Distress and academic achievement among adolescents of affluence: A study of externalizing and internalizing problem behaviors and school performance. Dev Psychopathol. 2009;21(1):319-341.
Vulnerability To Drug-Related Infections and Co-Infections Among Injecting Drug Users In Budapest, Hungary
Drug-related infectious diseases are among the major health consequences of drug use and any existing drug-related infection may predispose injecting drug users (IDUs) to other infections. This study assessed among IDUs in Budapest, Hungary the prevalence of and vulnerability to selected drug-related infections and co-infections. The sample consisted of 186 participants recruited between October 2005 and December 2006. Researchers found 0% HIV, 37% HCV, 24% HAV, and 14% past HBV infection. Infections with Herpes 1 or 2, tuberculosis, Chlamydia, syphilis, and gonorrhea were 79%, 12%, 7%, 4%, and 0%, respectively. Co-infection with HAV/HCV was 12%, HBV/HCV 9%, HAV/HBV 7%, and HAV/HBV/HCV 4%. Those over age 30, the ethnic Roma, and the homeless were more likely to have any hepatitis and a higher number of drug-related infections. Amphetamine injectors were more likely to have a higher number of drug-related infections and those who travelled within Hungary were more likely to have any STI. However, those who worked at least part time and those who were in treatment were less likely to have drug-related infections. These results highlight the need of interventions in Hungary to reach and focus on marginalized (Roma or homeless) IDUs and address not only injecting and sex risk, but also hygienic living and injecting conditions. Furthermore, structural interventions to increase social integration (working or being in treatment) may improve welfare and decrease drug use and infection risk tied to drug use/injection among disadvantaged, marginalized, mostly minority populations. Gyarmathy V, Neaigus A, Ujhelyi E. Vulnerability to drug-related infections and co-infections among injecting drug users in Budapest, Hungary. Eur J Public Health. 2009;19(3):260-265.
Social Influences Upon Injection Initiation Among Street-Involved Youth In Vancouver, Canada: A Qualitative Study
Street-involved youth are a population at risk of adopting injection as a route of drug administration. Preventing the transition to injection drug use among street youth represents a major public health priority. To inform epidemiological research and prevention efforts, researchers conducted a qualitative study on the initiation of injection drug use among street-involved youth in Vancouver, Canada. Qualitative interviews with street youth who inject drugs were used to elicit descriptions of the adoption of injection as a route of administration. Interviewees were recruited from the At-Risk Youth Study (ARYS), a cohort of street-involved youth who use illicit drugs in Vancouver, Canada. Researchers transcribed audio recorded interviews verbatim and then conducted thematic analysis of their content. Of 26 youth aged 16 to 26 who participated in this study, just under half (12) were females. Among the participants, the first injection episode frequently featured another drug user who facilitated the initiation of injecting. Youth narratives indicate that the transition into injecting is influenced by social interactions with drug using peers and evolving perceptions of injecting, and rejecting identification as an injector was important among youth who did not continue to inject. It appears that social conventions discouraging initiating young drug users into injection exist among established injectors, although this ethic is often ignored. The importance of social relationships with other drug users within the adoption of injection drug use highlights the potential of social interventions to prevent injection initiation of injecting in young people. Developing strategies to engage current injectors who are likely to initiate youth into injection could also be important and beneficial to prevention efforts. Small W, Fast D, Krusi A, Wood E, Kerr T. Social influences upon injection initiation among street-involved youth in Vancouver, Canada: A qualitative study. Subst Abuse Treat Prev Policy. 2009;4:1-8.
Homelessness and Unstable Housing Associated With an Increased Risk of HIV and STI Transmission Among Street-Involved Youth
The role that environmental factors play in driving HIV and STI transmission risk among street-involved youth has not been well examined. The authors examined factors associated with number of sex partners using quasi-Poisson regression and consistent condom use using logistic regression among participants enrolled in the At Risk Youth Study (ARYS). Among 529 multi-ethnic participants ages 16 to 26 years, 253 (47.8%) reported multiple partners while only 127 (24.0%) reported consistent condom use in the past 6 months. Homelessness was inversely associated with consistent condom use (adjusted odds ratio [aOR]=0.47, p=0.008), while unstable housing was positively associated with greater numbers of sex partners (adjusted incidence rate ratio [aIRR]=1.44, p=0.010). These findings highlight the need for interventions and services to modify social and environmental factors that influence risks of unsafe sexual behaviors and HIV/STIs among young street-involved populations. Marshall B, Kerr T, Shoveller J, Patterson T, Buxton J, Wood E. Homelessness and unstable housing associated with an increased risk of HIVand STI transmission among street-involved youth. Health Place. 2009;15(3):753-760.
Structural and Environmental Barriers To Condom Use Negotiation With Clients Among Female Sex Workers: Implications For HIV-Prevention Strategies & Policy
Researchers investigated the relationship between environmental-structural factors and condom-use negotiation with clients among female sex workers. They used baseline data from a 2006 Vancouver, British Columbia, community-based cohort of female sex workers to map the clustering of "hot spots" for being pressured into unprotected sexual intercourse by a client and assess sexual HIV risk. They also used multivariate logistic modeling to estimate the relationship between environmental-structural factors and being pressured by a client into unprotected sexual intercourse. In multivariate analyses, being pressured into having unprotected sexual intercourse was independently associated with having an individual zoning restriction (odds ratio [OR] = 3.39; 95% confidence interval [CI] = 1.00, 9.36), working away from main streets because of policing (OR = 3.01; 95% CI = 1.39, 7.44), borrowing a used crack pipe (OR = 2.51; 95% CI = 1.06, 2.49), client-perpetrated violence (OR = 2.08; 95% CI = 1.06, 4.49), and servicing clients in cars or in public spaces (OR = 2.00; 95% CI = 1.65, 5.73). These findings highlight the growing global concern surrounding the failings of prohibitive sex-work legislation on sex workers' health and safety. Shannon K, Strathdee S, Shoveller J, Rusch M, Kerr T, Tyndall M. Structural and environmental barriers to condom use negotiation with clients among female sex workers: implications for HIV-prevention strategies and policy. Am J Public Health. 2009;99(4):659-665.
Integrative Data Analysis of Multiple Sets
There are both quantitative and methodological techniques that foster the development and maintenance of a cumulative knowledge base within the psychological sciences. Most noteworthy of these techniques is meta-analysis, which allows for the synthesis of summary statistics drawn from multiple studies when the original data are not available. However, when the original data can be obtained from multiple studies, many advantages accrue from the statistical analysis of the pooled data. The authors define integrative data analysis (IDA) as the analysis of multiple data sets that have been pooled into one. Although variants of IDA have been incorporated into other scientific disciplines, the use of these techniques is much less evident in psychology. In this paper, the authors provide an overview of IDA as it may be applied within the psychological sciences, discuss the relative advantages and disadvantages of IDA, describe analytic strategies for analyzing pooled individual data, and offer recommendations for the use of IDA in practice. Curran P, Hussong A. Integrative data analysis: The simultaneous analysis of multiple data sets. Psychol Methods. 2009;14(2):81-100.
Biculturality and HIV-Risk Behaviors Among Puerto Rican Drug Users In New York City
Biculturality refers to two independent processes of acculturation, one to the host society's culture and another to the culture of origin. This study examined the relationship between biculturality and HIV-related risk behaviors in a sample of injecting and noninjecting Puerto Rican drug users (N = 259), recruited in New York City in 2005-2006. Biculturality was measured by two scales: involvement in (i) American culture (AMBIC) and (ii) Puerto Rican culture Biculturality (PRBIC). The majority (78%) of the participants were males, with a mean age of 42 years. About half were born in Puerto Rico, and the average length of stay in the United States was 26 years. In multiple logistic-regression analysis, AMBIC was significantly related to lower injection risk after controlling for other factors including gender, age, and MMTP enrollment, while PRBIC was a significant predictor of higher sex risk. Involvement in the host culture and the culture of origin differed in their relationship to risk behaviors, indicating that incorporating assessments of biculturality may be useful in assessing and addressing migrants' behaviors, including HIV-risk behaviors. Kang S, Deren S, Mino M, Cortˇs D. Biculturality and HIV-risk behaviors among Puerto Rican drug users in New York City. Subst Use Misuse. 2009;44(4):578-592.
Predictors of Sexual Risk Reduction Among Mexican Female Sex Workers Enrolled In A Behavioral Intervention Study
Researchers demonstrated the efficacy of an intervention to increase condom use among female sex workers (FSWs) in Tijuana and Ciudad Juarez, situated on the Mexico-United States border and determined whether increases in condom use were predicted by social cognitive theory and injection drug user status among women randomized to this intervention. HIV-negative FSWs (N=409) aged >or=18 years having unprotected sex with clients within the prior 2 months received a brief individual counseling session integrating motivational interviewing and principles of behavior change (i.e., HIV knowledge, self-efficacy for using condoms, and outcome expectancies). Findings showed that increases in self-efficacy scores were associated with increases in percent condom use (P = 0.008), whereas outcome expectancies were not. FSWs who inject drugs (FSW-IDUs) increased condom use with clients but not to the same extent as other FSWs (P = 0.09). Change in HIV knowledge was positively associated with change in percent condom use among FSW-IDUs (P = 0.03) but not noninjection drug users. These findings indicate that increases in self-efficacy significantly predicted increased condom use among FSWs, consistent with social cognitive theory. Increased HIV knowledge was also important among FSW-IDUs, but their changes in condom use were modest. The findings suggest that enhanced interventions for FSW-IDUs are needed that take into account that substance use during sexual transactions does occur and can compromise safer sex negotiation. Strathdee S, Mausbach B, Lozada R, Staines-Orozco H, Semple S, Abramovitz D, et al., Predictors of sexual risk reduction among mexican female sex workers enrolled in a behavioral intervention study. J Acquir Immune Defic Syndr. 2009;51 Suppl 1:S42-S46.
Women Who Abuse Prescription Opioids: Findings From the Addiction Severity Index-Multimedia Version Connect Prescription Opioid Database
Evidence suggests gender differences in abuse of prescription opioids. This study aimed to describe characteristics of women who abuse prescription opioids in a treatment-seeking sample and to contrast gender differences among prescription opioid abusers. Data were collected from November 2005 to April 2008 for the Addiction Severity Index Multimedia Version Connect (ASI-MV Connect) database. The data included 29,906 assessments from 220 treatment centers, of which 12.8% (N=3821) reported past month prescription opioid abuse. Women were more likely than men to report use of any prescription opioid (29.8% females vs. 21.1% males, p<0.001) and abuse of any prescription opioid (15.4% females vs. 11.1% males, p<0.001) in the past month. Women-specific correlates of recent prescription opioid abuse were problem drinking, age <54, inhalant use, residence outside of West US Census region, and history of drug overdose. Men-specific correlates were age <34, currently living with their children, residence in the South and Midwest, hallucinogen use, and recent depression. Women prescription opioid abusers were less likely to report a pain problem although they were more likely to report medical problems than women who abused other drugs. The findings suggest that gender-specific factors should be taken into account in efforts to screen and identify those at highest risk of prescription opioid abuse. Prevention and intervention efforts with a gender-specific approach are warranted. Green T, Grimes Serrano J, Licari A, Budman S, Butler S. Women who abuse prescription opioids: Findings from the addiction severity index-multimedia version connect prescription opioid database. Drug Alcohol Depend. 2009;103(1-2):65-73.
Mental Health Services Use and Symptom Prevalence In A Cohort of Adults on Probation
This study examined the prevalence of mental disorder symptoms among adult probationers and the probability of mental health service use. Data from the 2001 National Household Survey on Drug Abuse were used to obtain information on adults reporting mental disorder symptoms who had been on probation within the past year and those who had not. Twenty-seven percent of probationers (N=311 of 1,168) and 17% of nonprobationers (N=5,830 of 34,230) had mental disorder symptoms. Mental health service use was reported by 23% of both groups. Compared with persons who had not been on probation, probationers were more likely to report psychosis, mania, and posttraumatic stress disorder; both groups were as likely to report depression. The findings suggest that the prevalence of mental disorder symptoms did not differ by probation status. However, the type and distribution of symptoms were significantly different in the two groups. These are important considerations when planning for service connection with mental health providers. Crilly J, Caine E, Lamberti J, Brown T, Friedman B. Mental health services use and symptom prevalence in a cohort of adults on probation. Psychiatr Serv. 2009;60(4):542-544.
Structural and Social Contexts of HIV Risk Among African Americans
HIV continues to be transmitted at unacceptably high rates among African Americans. Most HIV-prevention interventions have focused on behavioral change. To theorize additional approaches to HIV prevention among African Americans, the authors review the literature to describe how sexual networks and drug-injection networks are as important as behavior for HIV transmission. They discuss how higher-order social structures and processes, such as residential racial segregation and racialized policing, may help shape risk networks and behaviors. They then explore three themes in African American culture (survival, propriety, and struggle) that help to shape risk networks and behaviors. Finally, they conclude with a discussion of how these perspectives might help to reduce HIV transmission among African Americans. Friedman S, Cooper H, Osborne A. Structural and social contexts of HIV risk among African Americans. Am J Public Health. 2009;99(6):1002-1008.
Factors Associated With Event-Level Stimulant Use During Sex In A Sample of Older, Low-Income Men Who Have Sex With Men In Los Angeles
Prior research shows that stimulant use is consistently associated with high-risk sexual behavior in samples of men who have sex with men (MSM), but few studies have explored factors associated with use of crack or methamphetamine during sex during specific sexual events among older, very low-income MSM. This study examined stimulant use during the most recent sexual episodes in a sample of primarily older, very low-income MSM (n=779). Although crack use was more prevalent than methamphetamine use (33% vs. 22%), findings suggest that methamphetamine users may be at greater risk for HIV transmission. HIV prevalence was higher among methamphetamine users (49%) than among crack users (24%). Having unprotected sex (OR 2.77, 95% CI 1.46-5.26), having sex in a public sex venue (OR 3.63, 95% CI 1.52-8.64), having sex with an HIV positive rather than with an HIV negative partner (OR 6.15, 95% CI 2.14-17.62), having exchanged sex for money or drugs (OR 4.16, 95% CI 1.78-9.72), and having a higher number of sexual partners (OR 1.67, 95% CI 1.17-2.38) all were associated with increased odds of methamphetamine use during sex. Fewer high-risk behaviors were associated with increased odds of using crack during sex. Having unprotected sex was associated with increased odds of crack use during sex only when sex partners were perceived to be HIV negative rather than to be HIV positive or of unknown status. These findings on associations between stimulant use during sex and risk behaviors may be important to HIV prevention and drug treatment approaches for urban, older, very poor MSM. Ober A, Shoptaw S, Wang P, Gorbach P, Weiss R. Factors associated with event-level stimulant use during sex in a sample of older, low-income men who have sex with men In Los Angeles. Drug Alc Depend. 2009;102(1-3):123-129.
Cross-Cohort Heterogeneity Encountered While Validating A Model For HIV Disease Progression Among Antiretroviral Initiators
Researchers sought to evaluate a model for predicting time to AIDS or death among HIV-infected persons initiating highly active antiretroviral therapy (HAART). The model was constructed from 1,891 HAART initiators in the Collaborations in HIV Outcomes Research/US (CHORUS) cohort. The model's predictive ability was assessed using internal bootstrap validation techniques and data from 716 HAART initiators at Johns Hopkins HIV Clinical Cohort (JHHCC) in whom HIV disease was, in general, more advanced. The estimated concordance statistic was 0.632 with the bootstrap method and 0.625 in JHHCC. Mean predicted and observed 3-year AIDS-free survival for JHHCC was 0.76 and 0.73 (95% confidence interval [CI], 0.69-0.77), respectively; mean predicted and observed 5-year AIDS-free survival was 0.69 and 0.57 (95% CI, 0.52-0.62), respectively. Sensitivity analyses showed that the discrepancy between predicted and observed AIDS-free survival after 3 years could be due to differences in lost-to-follow-up rates between cohorts. The model was fair at using baseline characteristics to order patients' risk of disease progression, but did not accurately predict AIDS-free survival >3 years after HAART initiation. Different variable definitions, patient characteristics, and loss to follow-up highlight the challenges of using data from one cohort to predict AIDS-free survival in an independent cohort. Shepherd B, Sterling T, Moore R, Raffanti S, Hulgan T. Cross-cohort heterogeneity encountered while validating a model for HIV disease progression among antiretroviral initiators. J Clin Epidemiol. 2009;62(7):729-737.
Association Between Tobacco Dependence and Quit Attempt Length
This study examined whether Rasch modeling would yield a unidimensional withdrawal sensitivity measure correlating with factors associated with successful smoking cessation. The psychometric Rasch modeling approach was applied to estimate an underlying latent construct (withdrawal sensitivity) in retrospective responses from smokers who reported quitting for 3 or more months at least once. A randomly selected convenience sample of 1644 adult members of an e-mail invitation-only web panel was drawn from consumer databases. The Lifetime Tobacco Use Questionnaire, a self-administered computerized questionnaire was used to assess tobacco use across the life-span, demographics, and ratings of the severity of withdrawal symptoms experienced in respondents' first and most recent quit attempts lasting 3 or more months. Rasch-modeled withdrawal sensitivity was generally unidimensional and was associated with longer periods of smoking cessation. One latent variable accounted for 74% of the variability in symptom scores. Rasch modeling with a single latent factor fitted withdrawal symptoms well, except for increased appetite, for which the fit was marginal. Demographic variables of education, gender, and ethnicity were not related to changes in sensitivity. Correlates of greater withdrawal sensitivity in cessation attempts of at least 3 months included younger age at first quit attempt and indicators of tobacco dependence. The relationship between tobacco dependence symptoms and Rasch-model withdrawal sensitivity demonstrates the utility of modeling to create an individual-specific sensitivity measure as a tool for exploring relationships among sensitivity, dependence, and cessation. Javitz H, Brigham J, Lessov-Schlaggar C, Krasnow R, Swan G. Association of tobacco dependence and quit attempt duration with rasch-modeled withdrawal sensitivity using retrospective measures. Addiction. 2009;104(6):1027-1035.
Patterns of Intermittent Smoking
Non-daily smokers comprise a substantial proportion of US smokers but there has been little study of their patterns of smoking, which are often assumed to reflect "social smoking." Researchers used Ecological Momentary Assessment methods to study smoking patterns in 27 non-daily smoking adults who recorded each cigarette smoked over three weeks by leaving a voice mail message indicating their circumstances at the time of smoking. All told, 689 cigarettes were recorded over 589 person-days of observation. On average, participants smoked on 67% of days, averaging 2.1 (SD=0.91) cigarettes per day on days they smoked; 22% of all cigarettes were smoked in bouts (within an hour of another cigarette). Altogether, 19% of cigarettes were smoked when drinking alcohol and 29% when participants were socializing. Smoking patterns varied widely across participants. A pair of hierarchical cluster analyses distinguished three groups: Those who smoked primarily (81% of cigarettes) in the daytime (Early smokers; n=15, 58% of total sample), those who smoked primarily (75% of cigarettes) at night (Late smokers; n=7, 27%), and a distinct, classic "Social smoking" group (n=4, 15% of total sample), who smoked mostly at night but also primarily when socializing or drinking (86% of their cigarettes), in the evening (71% of their cigarettes), on weekends (65% of their cigarettes), and in bouts (71% of their cigarettes). Overall, results suggest that non-daily smoking patterns are heterogeneous and that non-daily smokers may not be primarily social smokers. Shiffman S, Kirchner T, Ferguson S, Scharf D. Patterns of intermittent smoking: An analysis using ecological momentary assessment. Addict Behav. 2009;34(6-7):514-519.
Secrecy and Risk Among MSM In Tbilisi, Georgia
There is concern that the tremendous economic, social, and political upheavals that the Republic of Georgia has undergone in the years since the fall of the Soviet Union may have created an environment fertile for HIV transmission. Notably absent from official statistics and HIV-related research in Georgia is discussion of men who have sex with men (MSM) and, therefore, little is known about the MSM population or its potential to acquire or transmit HIV. Data were collected from 30 MSM recruited through a testing and counseling center in Tbilisi, the capital of Georgia. Two focus groups with six men each and 18 individual in-depth interviews were conducted between October 2006 and February 2007. The study participants described a Georgian culture that is largely intolerant of sexual contact between men. In describing the various forms of discrimination and violence that they would face should their sexual identities be discovered, the MSM in this sample described a variety of behaviors that they and other Georgian MSM undertake to conceal their sexual behavior. Many of these could put these men and their partners at risk for HIV. Although official HIV rates in Georgia are still low, results from this qualitative study indicate that efforts to educate and to provide unobtrusive and anonymous testing and counseling services to MSM may be critical to the deterrence of an HIV epidemic in the Republic of Georgia. Costenbader E, Otiashvili D, Meyer W, Zule W, Orr A, Kirtadze I. Secrecy and risk among MSM In Tbilisi, Georgia. AIDS Care. 2009;21(5):591-597.
Evaluation of a Patient Referral Contact Tracing Programme For Hepatitis B and C Virus Infection In Drug Injectors
Effective contact tracing for hepatitis B virus (HBV) and hepatitis C virus (HCV) infection could enhance disease control, especially in populations with low HBV vaccination rates and high prevalence of untreated HCV infection. Researchers evaluated a low-cost approach to HBV/HCV contact tracing in injection drug users (IDUs). Index cases (n=26) were IDUs who seroconverted to HBV and/or HCV during a prospective cohort study in Seattle. Interviewers elicited index cases' recent injection partners and administered recall cues and other techniques to boost recall. Index cases received vouchers for free hepatitis testing, which they were to give to locatable partners. Persons redeeming vouchers also received small monetary incentives. Most (26/40) seroconverters participated in the paid contact interviews. Index cases reported many partners (mean=17), and in the aggregate, index cases indicated they could refer more than one third of their elicited partners for testing. Overall, only 17 persons were ultimately referred and just eight of these were confirmed as partners sought for referral. The supplementary elicitation techniques, and especially the recall cues, increased reporting of injection partners substantially. The injection network constructed from reported partnerships was mostly connected and cyclic. Successful contact tracing in IDUs likely requires active involvement by public health staff to locate and notify exposed injection partners. Brewer D, Hagan H. Evaluation of a patient referral contact tracing programme for hepatitis B and C virus infection in drug injectors. Euro Surveill. 2009;14(14):5-9.
Differences In the Drinking Behaviors of Chinese, Filipino, Korean, and Vietnamese College Students
This study examined alcohol drinking behaviors across ethnic subgroups of Asian college students by gender, foreign-born status, and college-related living arrangements. The study sample included 753 male and female undergraduates between the ages of 18 and 27 years who self-identified as Chinese, Filipino, Korean, or Vietnamese and who varied in their foreign-born status. Participants completed a self-administered questionnaire on their alcohol drinking practices. Analyses found that Korean and Filipino students reported higher levels of alcohol consumption compared with other Asian subgroups. Students living in on-campus dormitories and in off-campus apartments reported higher alcohol consumption than did those living at home. Being born in the United States was a significant predictor of higher levels of alcohol consumption for women but not for men. Results of this study indicate the need for campus alcohol education and prevention programs capable of responding to specific Asian subgroup needs. Lum C, Corliss H, Mays V, Cochran S, Lui C. Differences in the drinking behaviors of Chinese, Filipino, Korean, and Vietnamese college students. J Stud Alcohol Drugs. 2009;70(4):568-574.
Substance-Related Problems and Treatment Among Men Who Have Sex With Men In Comparison To Other Men In Chicago
This study compares a sample of urban men who have sex with men (MSM) with a general population sample of men in the same city on self-reported problems with substance use, substance dependence, and history of substance use treatment. Both samples were randomly selected using multistage probability methods and included 216 MSM and 242 men from the general population sample. All participants completed audio computer-assisted self-interviews, including questions on substance use, problems related to substance use experience-ed in the past 12 months, and substance treatment. Problem use of alcohol, marijuana, and cocaine did not differ between samples. Compared to men in the general population sample, MSM were significantly more likely to experience problems related to the use of sedatives, tranquilizers, or prescription pain relievers. Among MSM, history of substance treatment was associated with a positive HIV test, and treatment usually preceded HIV diagnosis. Findings suggest the need for further research on effective methods for integrating HIV prevention for MSM into substance treat-ment settings, including physician-administered buprenorphine treatment for opiate addiction. Mackesy-Amiti M, Fendrich M, Johnson T. Substance-related problems and treatment among men who have sex with men in comparison to other men in Chicago. J Subst Abuse Treat. 2009;36(2):227-233.
Causal Inference Methods for Estimating the Effects of Potential Public Health Interventions On Population Disease Burden
Causal inference methods allow estimation of the effects of potential public health interventions on the population burden of disease. Motivated by calls for epidemiologic research to be presented in ways that are more informative for intervention, the researchers present a didactic discussion of the steps required to estimate the population effect of a potential intervention using an imputation-based causal inference method and discuss the assumptions of and limitations to its use. An analysis of neighborhood smoking norms and individual smoking behavior is used as an illustration. The implementation steps include the following: modeling the adjusted exposure and outcome association; imputing the outcome probability for each individual while manipulating the exposure by "setting" it to different values; averaging these probabilities across the population; and bootstrapping confidence intervals. Imputed probabilities represent counterfactual estimates of the population smoking prevalence if neighborhood smoking norms could be manipulated through intervention. The degree to which temporal ordering, randomization, stability, and experimental treatment assignment assumptions are met in the illustrative example is discussed, along with ways that future studies could be designed to better meet the assumptions. With this approach, the potential effects of an intervention targeting neighborhoods, individuals, or other units can be estimated. Ahern J, Hubbard A, Galea S. Estimating the effects of potential public health interventions on population disease burden: a step-by-step illustration of causal inference methods. Am J Epidemiol. 2009;169(9):1140-1147.
The Resource Utilization of Women Who Use Violence In Intimate Relationships
Previous research has found high rates of help seeking among domestic violence victims. However, little is known about the help-seeking patterns of women who use violence (many of whom are also abused). Understanding the resources utilized by women who are violent toward their partners may aid in designing interventions that will help to reduce the women's violence as well as the victimization they may be experiencing. This study examines the resource utilization of 108 women who used violence against a male partner (94% of whom also experienced victimization). Findings revealed that almost all of the women utilized community resources in an attempt to manage the violence in their relationships; victimization was related to resource utilization via self-defense motives, avoidance coping, and posttraumatic stress symptoms; and greater resource utilization was related to lower levels of women's violence against their partners. Findings suggest that community resources may help prevent women's violence. Swan S, Sullivan T. The resource utilization of women who use violence in intimate relationships. J Interpers Violence. 2009;24(6):940-958.
Dimensions of Psychopathy In Relation To Suicidal and Self-Injurious Behavior
Externalizing psychopathology is associated with an increased risk for suicidal behavior. Within the externalizing domain, psychopathy may be an important construct for the understanding of which individuals are at particularly high risk. However, prior studies of psychopathy and suicidal behavior have not distinguished between suicide attempts and nonsuicidal self-injurious behavior (NSIB). The present study used data on 810 civil psychiatric patients from the MacArthur Violence Risk Assessment Project to examine the relationships between scores on the four dimensions of the Psychopathy Checklist: Screening Version (PCL: SV) and suicide attempts and nonsuicidal self-injurious behavior (NSIB). Results indicate that only the antisocial dimension of psychopathy is associated with suicide attempts. With regard to NSIB, an interaction was found such that, among African-Americans, NSIB was more prevalent at higher levels of antisociality. Present findings refine previous results from studies using the two-factor PCL:SV model and have important implications for the assessment of suicide risk. Swogger M, Conner K, Meldrum S, Caine E. Dimensions of psychopathy in relation to suicidal and self-injurious behavior. J Pers Disord. 2009;23(2):201-210.