Research Findings - Epidemiology and Etiology Research
Genetic and Environmental Influences on Initiation and Progression of Substance Use
This study sought to examine the genetic and environmental contributions to the initiation of use and progression to more serious use of alcohol, cigarettes and marijuana during adolescence, and to examine the relationship between initiation and progression of substance use, using a twin-based design and a new theoretical model, the causal-common-contingent (CCC) model, which allows modeling of the relationship between initiation of use and progression to heavier use as a two-stage model and the examination of genetic and environmental influences on both stages, while taking into account their relationship. The participants consisted of 1214 twin pairs aged 11-19 years sampled from the UK population-based Cardiff Study of All Wales and North-west of England Twins. Data on adolescent initiation and progression to more serious use of alcohol, cigarettes and marijuana were obtained using self-report questionnaires. The investigators found that initiation of alcohol and progression to heavier alcohol use had separate but related underlying etiologies. For cigarette and marijuana use the relation between initiation and progression to heavier use was stronger, suggesting greater overlap in etiology. For all three substances, environmental influences that make twins more similar (common environment) tended to be greater for initiation, while genetic influences were stronger for heavier use. The authors conclude that their findings have implications for prevention: that it may be more efficacious to focus alcohol interventions on risk factors for the development of heavier use rather than initiation of use while interventions aimed at reducing the initiation of cigarettes and marijuana use may be more appropriate. Fowler, T., Lifford, K., Shelton, K., Rice, F., Thapar, A., Neale, M., McBride, A., and Van den Bree, M. Exploring the Relationship Between Genetic and Environmental Influences on Initiation and Progression of Substance Use. Addiction, 102(3), pp. 413-422, 2007.
Increasing Trend in DXM Abuse
The investigators analyzed indicator data on dextromethorphan (DXM) abuse in California and compared findings with national trends. The investigators conducted a review of data from 1999 through 2004 on DXM abuse cases from the California Poison Control System (CPCS), American Association of Poison Control Centers (AAPCC), and Drug Abuse Warning Network (DAWN). All DXM abuse cases reported to the CPCS, AAPCC, and DAWN were included in the analyses. The data on DXM abuse cases included date of exposure, age, acute vs. long-term use, coingestants, product formulation, and clinical outcome. The main outcome examined was the annual proportion of DXM abuse cases among all exposures reported to the CPCS, AAPCC, and DAWN databases. A total of 1382 CPCS cases were included in the study. A 10-fold increase in CPCS DXM abuse cases from 1999 (0.23 cases per 1000 calls) to 2004 (2.15 cases per 1000 calls) (odds ratio, 1.48; 95% confidence interval, 1.43-1.54) was identified. Of all CPCS DXM abuse cases, 74.5% were aged 9 to 17 years; the frequency of cases among this age group increased more than 15-fold during the study (from 0.11 to 1.68 cases per 1000 calls). Similar trends were seen in the AAPCC and DAWN databases. The highest frequency of DXM abuse occurred among adolescents aged 15 and 16 years. The most commonly abused product was Coricidin HBP Cough & Cold Tablets. This study revealed an increasing trend of dextromethorphan abuse cases reported to the CPCS that is paralleled nationally as reported to the AAPCC and DAWN. This increase was most evident in the adolescent population. Bryner, J., Wang, U., Hui, J., Bedodo, M., MacDougall, C., and Anderson, I. Dextromethorphan Abuse in Adolescence: An Increasing Trend: 1999-2004. Arch Pediatr Adolesc Med, 160(12), pp. 1217-1222, 2006.
Diagnosing Substance Use Disorders: Examination of DSM-IV and ICD-10
Two major nomenclatures, Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) and International Classification of Diseases, tenth edition (ICD-10), currently define substance use disorders for broad audiences of users with different training, experience and interests. A comparison of these definitions and their implications for DSM-V and ICD-11, not previously available, was provided by these authors in a special issue of Addiction. The authors found reliability and psychometric validity evidence for substance dependence was consistently strong, but more mixed for abuse and harmful use. Findings on the genetics of alcohol disorders supported the validity of the dependence concept, while animal studies underscored the centrality of continued use despite negative consequences to the concept of dependence. While few studies on substance-induced disorders have been conducted, those published show good reliability and validity when elements of DSM-IV and ICD-10 are combined. The authors concluded that dependence in DSM-V and ICD-11 should be retained, standardizing both criteria sets and adding a severity measure. They included several recommendations; consequences of heavy use should be measured independently of dependence; add cannabis withdrawal if further research supports existing evidence; conduct further studies of the substance-induced psychiatric categories; standardize their criteria across DSM-V and ICD-11; develop a theoretical basis for better remission criteria; consider changing substance ''abuse'' to substance ''dysfunction disorder''; and conduct clinician education on the value of the diagnostic criteria. Hasin, D., Hatzenbuehler, M., Keyes, K., and Ogburn, E. Substance Use Disorders: Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) and International Classification of Diseases, Tenth Edition (ICD-10). Addiction, 101 Suppl 1, pp. 59-75, 2006.
Latent Class Analysis of Drug Abuse/Dependence: Results from NESARC
This study used data from the National Epidemiological Survey on Alcohol and Related Conditions (NESARC) to examine the co-occurrence of abuse/dependence across different illicit drugs and test associations between these classes and major psychiatric disorders. Latent class analyses were used to characterize polysubstance abuse/dependence (AB/D) in 43,093 individuals who participated in the NESARC. Multinomial logistic regression was performed to examine the association between the classes of life-time illicit drug AB/D and gender, age and race, as well as life-time Diagnostic and Statistical Manual version IV (DSM-IV) alcohol abuse/dependence, nicotine dependence, major depressive disorder, generalized anxiety disorder, panic disorder, social phobia and antisocial personality disorder. The investigators found five latent classes: no AB/D (class 1: 92.5%), cannabis AB/D only (class 2: 5.8%), stimulants + hallucinogen AB/D (class 3: 0.6%), prescription drug AB/D (class 4: 0.6%) and polysubstance AB/D (class 5: 0.5%). Major depressive disorder and nicotine dependence were associated most strongly with class 5. Anxiety disorders were associated strongly with the prescription drug AB/D class while alcohol AB/D and ASPD were associated with classes 2, 3, 4 and 5 when compared to the reference class (class 1). The authors conclude that significant heterogeneity exists in this US population for polysubstance AB/D patterns, with evidence for a subgroup with high rates of sedative, tranquilizer and opiate AB/D and a history of anxiety disorders; a stimulant/hallucinogens group; a high-risk group with elevated rates of all psychiatric disorders; and a milder cannabis AB/D only group. Replication of such classes across other samples is recommended, which may help in characterizing risk groups that may be etiologically diverse and therefore requiring different preventive and treatment interventions. Agrawal, A., Lynskey, M., Madden, P., Bucholz, K., and Heath, A. A Latent Class Analysis of Illicit Drug Abuse/Dependence: Results from the National Epidemiological Survey on Alcohol and Related Conditions. Addiction, 102(1), pp. 94-104, 2006.
Marker or Mediator? The Effects of Adolescent Substance Use on Young Adult Educational Attainment
The purpose of this study was to test the effects of adolescent substance use on college attendance and completion by young adulthood in the context of the behavioral and familial risk factors that influence substance use. Longitudinal data were collected from a community sample of children of alcoholics (248) and matched controls (206) at three adolescent assessments (micro(age) = 13-15) and a long-term follow-up in young adulthood (micro(age) = 25). College attendance and degree completion by age 25 were self-reported in young adulthood. During adolescence, self-reports of alcohol and drug use were assessed with log-transformed quantity/frequency measures; substance use risk factors [e.g. parental monitoring, externalizing and internalizing symptoms and Diagnostic and Statistical Manual version III (DSM-III) diagnosis of parental alcoholism] were assessed by both self- and parent-report, and adolescent reading achievement was assessed using a standardized assessment of reading achievement (Wide Range Achievement Test). Growth curve modeling results suggest that mean levels and growth in adolescent substance use mark, or identify those adolescents who are at risk for reduced odds of attending and completing college. Moreover, adolescent substance use was not merely a marker of risk, in that growth in drug use (but not alcohol use) significantly mediated the effects of parental alcoholism and early externalizing behavior on later college completion, partially explaining the effects of these risk factors on college completion. The authors concluded that the current study provides evidence for both the marker and the mediator hypotheses, and identifies multiple pathways to higher educational attainment. Furthermore, the findings point to the importance of studying the effects of adolescent substance use in a broader developmental context of its correlated risk factors to specify more effectively the key pathways to later developmental outcomes. King, K., Meehan, B., Trim, R., and Chassin, L. Marker or Mediator? The Effects of Adolescent Substance Use on Young Adult Educational Attainment. Addiction, 101(12), pp. 1730-1740, 2006.
Adolescents' Motivations to Abuse Prescription Drugs
This study examines (1) adolescents' reasons for engaging in the nonmedical (illicit) use of 4 classes of prescription medications and (2) whether motivations were associated with a higher risk for substance abuse problems. Students in 7th - 12th grades (N=1086) from one ethnically diverse school district in southeastern Michigan were surveyed in 2005 using a self-administered, Web-based questionnaire. Risk of substance abuse was assessed with a modified version of the Drug Abuse Screening Test (DAST), a self-report instrument that can be used in nonclinical settings to screen for potential abuse and dependence to various drugs. Twelve percent of the respondents reported nonmedical use of opioid pain medications in the past year: 3% for sleeping, 2% as a sedative and/or for anxiety, and 2% as stimulants. The reasons for engaging in the nonmedical use of prescription medications varied by drug classification. For opioid analgesics, when the number of motives increased, so too did the likelihood of a positive DAST score. For every additional motive endorsed, the DAST increased by a factor of 1.8. Two groups of students were compared (at-risk versus self-treatment); those who endorsed multiple motivations for nonmedical use of opioids (at-risk group) were significantly more likely to have elevated DAST scores when compared with those who were in the self-treatment group. Those in the at-risk group also were significantly more likely to engage in marijuana and alcohol use. The findings indicate that multiple motivations for the nonmedical use of prescription medications seem associated with a greater likelihood of substance abuse problems. Boyd, C., McCabe, S., Cranford, J., and Young, A. Adolescents' Motivations to Abuse Prescription Medications. Pediatrics, 118(6), pp. 2472-2480, 2006.
Medical and Nonmedical Prescription Drug Use among Secondary Student
The objectives of this study were to: (1) assess the prevalence of medical and nonmedical use of four categories of prescription drugs (opioid, stimulant, sleeping, and sedative/anxiety medication) in a racially diverse sample of secondary public school students, and (2) examine the association between the use of four categories of prescription medications and illicit drug use and probable drug abuse. Students in 7th - 12th grades (N=1086) one school district in southeastern Michigan were surveyed in 2005 using a self-administered, Web-based questionnaire. The Drug Abuse Screening Test (DAST-10), a self-report instrument that can be used in nonclinical settings, was used to screen for probable drug abuse and dependence. The sample consisted of 54% female, 52% White, 45% African American, and 3% from other racial categories. Forty-eight percent of the sample reported no lifetime use of four categories of prescription drugs (nonusers), 31.5% reported medically prescribed use only (medical users), 17.5% reported both medical and nonmedical use (medical/nonmedical users) and 3.3% reported nonmedical use only (nonmedical users). Multivariate analyses indicated that medical/nonmedical users and nonmedical users were significantly more likely than nonusers to report illicit drug use and probable drug abuse. Medical users generally reported similar or increased odds of illicit drug use and probable drug abuse than non-users. These findings provide evidence that nonmedical use of prescription drugs represents a problem behavior among secondary school students. McCabe, S., Boyd, C., and Young, A. Medical and Nonmedical use of Prescription Drugs among Secondary School Students. J Adolesc Health, 40(1), pp. 76-83, 2007.
Residential Segregation and Injection Drug Use Prevalence Among Black Adults in US Metropolitan Areas
Researchers analyzed the relationship between two 1990 dimensions of racial residential segregation (isolation and concentration) and 1998 injection drug use prevalence among Black adult residents of 93 large US metropolitan statistical areas (MSAs). The authors estimated injection drug use prevalence among Black adults in each MSA from three databases documenting IDU encounters with the health care system. Multiple linear regression methods were used to investigate the relationship of isolation and concentration to the natural logarithm of Black adult injection drug use prevalence, controlling for possible confounders. The findings indicate that median injection drug use prevalence was 1,983 per 100,000 Black adults (interquartile range: 1,422 to 2,759 per 100,000). The median isolation index was 0.48 (range: 0.05 to 0.84): in half the MSAs studied, the average Black resident inhabited a census tract where 48% or more of the residents were Black. The multiple regression model indicates that an increase of 0.50 in the isolation index was associated with a 23% increase in injection drug use prevalence among Black adults. Concentration was unrelated to the outcome. These findings show that residential isolation is positively related to injection drug use prevalence among Blacks in U.S. MSAs. The pathways that link isolation to injection drug use remain as yet poorly understood, however, indicating the need for further research. Cooper, H., Friedman, S., Tempalski, B., and Friedman, R. Residential Segregation and Injection Drug Use Prevalence among Black Adults in US Metropolitan Areas. Am J Public Health, 97(2), pp. 344-352, 2007.
Diagnostic Criteria for Substance Abuse in Adolescents
This study used Item Response Theory to characterize the psychometric properties of Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) alcohol and cannabis use disorder symptoms among 472 clinical adolescents. Item response theory has advantages over classical test theory in evaluating diagnostic criteria. For both substances, DSM-IV symptoms fit a model specifying a unidimensional latent trait of problem severity. Threshold (severity) parameters did not distinguish abuse and dependence symptoms. Abuse symptoms of legal problems and hazardous use, and dependence symptoms of tolerance, unsuccessful attempts to quit, and physical-psychological problems, showed relatively poor discrimination of problem severity. There were gender differences in thresholds for hazardous use, legal problems, and physical-psychological problems. The results illustrate limitations of DSM-IV criteria for alcohol and cannabis use disorders when applied to adolescents. The authors recommend that the development process for the fifth edition (DSM-V) should be informed by statistical models such as those used in this study. Martin, C., Chung, T., Kirisci, L., and Langenbucher, J. Item Response Theory Analysis of Diagnostic Criteria for Alcohol and Cannabis Use Disorders in Adolescents: Implications for DSM-V. J Abnorm Psychol, 115(4), pp. 807-814, 2006.
Models of Genetic Co-morbidity for Cannabis and Other Illicit Drugs
The authors investigated the co-morbidity between cannabis use (experimentation, early and repeated use, and problems) and experimentation and problems with other illicit drugs (OID) using genetic models proposed by Neale and Kendler. Using data from a sample of 4152 same-sex male and female adult Australian twins, they fit 13 genetically informative models of co-morbidity to data on experimentation, early use, repeated use of cannabis and co-morbid OID experimentation, and to abuse/dependence (A/D) problems with cannabis and OIDs. Model-fitting results suggest that common genetic, shared and unique environmental factors are responsible for the association between cannabis experimentation, early use, repeated use and A/D problems and OID experimentation or problems. The liability causation model, which is a reduced form of the correlated vulnerabilities model, also fit very well. In women, authors found evidence for high-risk cannabis experimenters and repeated users to be at increased risk for OID experimentation, despite being below the risk threshold on the liability distribution for OID experimentation. The authors conclude that co-morbid cannabis and OID use and misuse are due partly to a common predisposition to substance use disorders, but causal effects could not be ruled out. These models warrant further research, so that features of the correlated vulnerabilities model and the gateway models can be studied jointly. Agrawal, A., Lynskey, M., Bucholz, K., Martin, N., Madden, P., and Heath, A. Contrasting Models of Genetic Co-morbidity for Cannabis and Other Illicit Drugs in Adult Australian Twins. Psychol Med, 37(1), pp. 49-60, 2007.
Convergence of HIV Seroprevalence Among Injecting and Non-injecting Drug Users in New York City
HIV infection has historically been higher among injecting drug users because the virus is efficiently transmitted through the sharing of drug-injecting equipment. In this study, researchers sought to compare HIV prevalence among injecting and non-injecting heroin and cocaine users in New York City by analyzing data from 2 separate cross-sectional surveys, both with HIV counseling and testing and drug use and HIV risk behavior questionnaires. Participants included injecting and non-injecting heroin and cocaine users recruited at detoxification and methadone maintenance treatment from 2001-2004 (n = 2121) and through respondent-driven sampling from a research storefront in 2004 (n = 448). In both studies, HIV prevalence was nearly identical among current injectors (injected in the last 6 months) and heroin and cocaine users who had never injected: 13% [95% confidence interval (CI), 12-15%] among current injectors and 12% (95% CI, 9-16%) among never-injectors in the drug treatment program study, and 15% (95% CI, 11-19%) among current injectors and 17% (95% CI, 12-21%) among never injectors in the respondent driven sampling storefront study. The 95% CIs overlapped in all gender and race/ethnicity subgroup comparisons of HIV prevalence in both studies. These findings indicate that the very large HIV epidemic among drug users in New York City may be entering a new phase, in which sexual transmission is increasingly important. Additional prevention programs are needed to address this transition. Des Jarlais, D., Arasteh, K., Perlis, T., Hagan, H., Abdul-Quader, A., Heckathorn, D., McKnight, C., Bramson, H., Nemeth, C., Torian, L., and Friedman, S. Convergence of HIV Seroprevalence Among Injecting and Non-injecting Drug Users in New York City. AIDS, 21(2), pp. 231-235, 2007.
Grandmother and Parent Influences on Child Self-Esteem
This study tests a model of intergenerational influences on childhood self-esteem that proposes paths from grandmothers' drug problems to grandchildren's self-esteem via parents' drug problems and parental adaptive child rearing and from grandmothers' maternal acceptance to grandchildren's self-esteem via parents' unconventionality and adaptive child rearing. This longitudinal study uses data obtained from interviews with a New York City sample of black and Puerto Rican children (N = 149) and 1 of their parents and from mailed questionnaires or comparable interviews with those parents' mothers. Structural equation modeling was used to test the proposed model. The LISREL analysis found that, with 3 exceptions, all of the hypothesized paths were significant. The total effects analysis indicated that parents' adaptive child rearing was the strongest latent construct, a finding that was consistent with this construct's proximal position in the model. This study suggests that mothers' drug problems are not just near-term risks for their children, but also pose long-term risks for their children's future functioning as parents and thereby for their grandchildren. The authors conclude that the relative strength of parents' adaptive child rearing in this intergenerational model indicates that this area should be the focus of therapeutic intervention efforts, but addressing future grandmothers' drug problems may have positive effects on multiple generations. Brook, J., Ning, Y., Balka, E., Brook, D., Lubliner, E., and Rosenberg, G. Grandmother and Parent Influences on Child Self-Esteem. Pediatrics, 119(2), pp. 444-451, 2007.
Women Who Gave Birth as Unmarried Adolescents: Trends in Substance Use from Adolescence to Adulthood
The purpose of this study was to determine whether adolescent childbearing mothers "mature out" of substance use as they transition into adulthood; how their substance use compares to that of typical young women of the same ages; and whether there are different patterns of substance use evident in this vulnerable population. The data come from an ongoing longitudinal study of 240 young women who were unmarried, pregnant, and under age 18 at enrollment. They have been interviewed regularly from pregnancy through 11.5 years postpartum. The data are based on self-reported substance use verified by random urinalysis for drug metabolites. Substance use did not decline during the transition to adulthood nor into early adulthood. With the exception of alcohol, the prevalence of substance use was higher than that of a nationally representative sample of same-aged women. Three distinct patterns of substance use were identified: licit users (cigarettes and/or alcohol), marijuana users, and "hard" drug users. Based on these findings, the authors suggest that clinicians should routinely assess substance use among young mothers who bore children as teenagers, and make referrals for appropriate treatment. Cigarette smoking is especially a cause for concern, given its widespread use and harmful effects for both mothers and their children. Although only a small proportion (about 5%) of young mothers used hard drugs consistently over time, this group will likely require comprehensive interventions that address multiple issues such as mental health and contextual factors to be effective. Future research should address reasons for continued substance use in this population. Gillmore, M., Gilchrist, L., Lee, J., and Oxford, M. Women who Gave Birth as Unmarried Adolescents: Trends in Substance Use from Adolescence to Adulthood. J Adolesc Health, 39(2), pp. 237-243, 2006.
Predictors of Non-fatal Overdose among a Cohort of Polysubstance-Using Injection Drug Users
Non-fatal overdose is a major determinant of morbidity among injection drug users (IDU). Researchers sought to evaluate factors associated with non-fatal overdose among IDU participating in the Vancouver Injection Drug Users Study. Correlates of non-fatal overdose occurring between 1996 and 2004 were identified using generalized estimating equations (GEE). There were 1,587 participants included in the analysis, including 576 (36%) women. At baseline, 750 (47%) reported a history of non-fatal overdose. In total, 985 reports of non-fatal overdose were made during follow-up by 519 (32.7%) participants. In multivariate GEE analyses, factors independently associated with non-fatal overdose included: heroin injection (AOR=2.67), cocaine injection (AOR=2.01), benzodiazepine use (AOR=2.00), requiring help injecting (AOR=1.58), binge drug use (AOR=1.52), homelessness (AOR=1.38), alcohol use (AOR=1.32), street injecting (AOR=1.22), non-injectable opiate use (AOR=1.16), speedball use (AOR=1.15), and recent incarceration (AOR=1.14). Younger age (AOR=0.99) and methadone use (AOR=0.51) were protective. Non-fatal overdose was common among local IDU in the study, and was associated with several factors that may be amenable to intervention, including opiate and stimulant use, and the characteristic of requiring help with injecting. These findings indicate the need for the ongoing development of structural interventions to address this common cause of morbidity among IDU. Kerr, T., Fairbairn, N., Tyndall, M., Marsh, D., Li, K., Montaner, J., and Wood, E. Predictors of Non-Fatal Overdose among a Cohort of Polysubstance-Using Injection Drug Users. Drug Alcohol Depend, 87(1), pp. 39-45, 2007.
Maternal Cigarette Smoking During Pregnancy and Child Aggressive Behavior
This study's objective was to examine the association between maternal smoking during pregnancy and childhood aggressive behavior in African-American and Puerto Rican children, as well as the relationship between maternal unconventional behavior, low maternal affection, and offspring aggression. Participants consisted of African-American and Puerto Rican children (N = 203; mean age = 8.6, SD = 0.87) and their mothers living in an inner city community. An interview consisting of a structured questionnaire was administered to the mothers and their children. Scales with adequate psychometric properties were adapted from previous validated measures. They included maternal smoking during pregnancy, maternal education, unconventionality, and warmth. Controlling for demographic factors, maternal unconventional behavior, and low maternal warmth, maternal smoking during pregnancy was associated with having offspring who were aggressive. Maternal unconventionality and warmth were independently related to childhood aggression. The authors suggest that although causal limitations are noted, it may be that a decrease in smoking during pregnancy is associated with a reduction in aggression in the offspring. Brook, D., Zhang, C., Rosenberg, G., and Brook, J. Maternal Cigarette Smoking during Pregnancy and Child Aggressive Behavior. Am J Addict, 15(6), pp. 450-456, 2006.
Personality Risk Factors Associated with Trajectories of Tobacco Use
The purpose of this longitudinal, prospective study was to evaluate trajectories of smoking in a cohort of African-American and Puerto Rican young adults and describe personality and behavioral factors associated with specific smoking trajectory group membership. Participants consisted of African-American and Puerto Rican male and female young adults (N = 451, mean age 26) from an inner-city community. Data were collected at four time points over a period of 13 years using structured interviews. Interviews took place within the schools and the participants' homes. Scales with adequate psychometric properties were adapted from previously validated measures. Variables that were examined for this study came from the domains of internalizing behaviors, externalizing behaviors, drug use, and demographic information. Data were analyzed using latent growth mixture modeling to explore discrete smoking trajectories. Logistic regression analyses were then used to examine the risk factors associated with the various smoking trajectory groups. Four trajectory groups were determined to best fit the data: nonsmokers, maturing-out smokers, late-starting smokers, and early-starting continuous smokers. Subjects who were unconventional, experienced intrapersonal distress, and used alcohol and illegal drugs were more likely to belong to one of the smoking trajectory groups than to the nonsmoking group. The early-starting continuous group scored highest on these personal risk attributes. The long-term impact of unconventional behavior, intrapersonal distress, and drug use on developmental trajectories of smoking support the importance of early intervention and prevention. Brook, J., Ning, Y., and Brook, D. Personality Risk Factors Associated with Trajectories of Tobacco Use. Am J Addict, 15(6), pp. 426-433, 2006.
Severe Anxiety Symptomatology and HIV Risk Behavior among Hispanic Injection Drug Users in Puerto Rico
Despite an overall decrease in AIDS incidence in Puerto Rico, research continues to show high prevalence of HIV risk behaviors among injection drug users (IDUs). This study seeks to evaluate whether the occurrence of injection-related and sex-related HIV risk behaviors among IDUs in Puerto Rico varies with the presence of anxiety symptomatology. Subjects included 557 IDUs, recruited from street settings in poor neighborhoods in Puerto Rico. Symptoms of severe anxiety were reported by 37.1% of the study sample. Participants with severe anxiety symptoms were more likely to share needles, cotton, and rinse water; to pool money to buy drugs; and to engage in back loading, than those without severe anxiety symptoms. Participants with severe anxiety symptomatology were also more likely to practice unprotected vaginal or oral sex. The findings from this study alert HIV prevention and treatment programs to the need to address anxiety disorders within their programs. Reyes, J., Robles, R., Colon, H., Marrero, C., Matos, T., Calderon, J., and Shepard, E. Severe Anxiety Symptomatology and HIV Risk Behavior among Hispanic Injection Drug Users in Puerto Rico. AIDS Behav, 11(1), pp. 145-150, 2007.
A Multiwave Multi-informant Study of the Specificity of the Association Between Parental and Offspring Psychiatric Disorders
The present study was conducted to investigate the specificity of the association between parental and offspring psychiatric disorders using epidemiological data from a series of parent and offspring interviews. A community-based sample of 593 mothers and their offspring from upstate New York were interviewed during the adolescence and early adulthood of the offspring. The children of parents with generalized anxiety disorder were at specifically elevated risk for anxiety disorders when co-occurring psychiatric disorders were controlled. The associations between parental and offspring antisocial, conduct, depressive, and substance use disorders were characterized by modest specificity. Children of parents with externalizing disorders were nearly as likely to develop internalizing disorders as they were to develop externalizing disorders. Children of parents with internalizing disorders were somewhat, but not significantly, more likely to develop internalizing disorders. These findings support the inference that children of parents with generalized anxiety disorder may be more likely to develop anxiety disorders than they are to develop other psychiatric disorders. However, when co-occurring psychiatric disorders are accounted for, the children of parents with depressive, disruptive, and substance use disorders may be as likely to develop other disorders as they are to develop the same type of disorder that their parents have had. Johnson, J., Cohen, P., Kasen, S., and Brook, J. A Multiwave Multi-Informant Study of the Specificity of the Association between Parental and Offspring Psychiatric Disorders. Compr Psychiatry, 47(3), pp. 169-177, 2006.
Prescription Drug Abuse and Diversion among Adolescents
The aims of this study were to determine the prevalence of medical use of 4 classes of prescription medications relative to nonmedical use (illicit use) and to assess whether gender differences exist in the trading, selling, loaning, or giving away of medications. A Web-based survey was administered to 7th- to 12th-grade students residing in 1 ethnically diverse school district in 2005. There were 1086 secondary students, including 586 girls, 498 boys, 484 black students, and 565 white students. Students were asked about their medical and nonmedical use of sleeping, sedative or anxiety, stimulant, and pain medications. Diversion of prescription medication was assessed by determining who asked the student to divert his or her prescription and who received it. Thirty-six percent of students reported having a recent prescription for 1 of the 4 drug classes. A higher percentage of girls reported giving away their medications than boys (27.5% vs. 17.4%, respectively; chi(2)(1) = 6.7; P = .01); girls were significantly more likely than boys to divert to female friends (64.0% vs. 21.2%, respectively; chi(2)(1) = 17.5; P<.001) whereas boys were more likely than girls to divert to male friends (45.5% vs. 25.6%, respectively; chi(2)(1) = 4.4; P = .04). Ten percent diverted their drugs to parents. These findings provide evidence of the need for physicians to discuss the proper use of prescription medications with their patients and their patients' families. Boyd, C., McCabe, S., Cranford, J., and Young, A. Prescription Drug Abuse and Diversion among Adolescents in a Southeast Michigan School District. Arch Pediatr Adolesc Med, 161(3), pp. 276-281, 2007.
Predictors of Unprotected Sex with Non-cohabitating Primary Partners among Sheltered and Low-income Housed Women in Los Angeles County
This study investigated cross-sectional associations of substance use, relationship abuse and HIV self-protective behavior with unprotected sex among 290 impoverished women with a non-cohabitating primary partner. Unprotected sex was associated with having a physically or psychologically abusive partner among low-income housed women, and having an abusive partner who also drank to intoxication among women living in shelters. Indicators of HIV self-protective behavior were associated with less frequent unprotected sex among sheltered women, even after accounting for abuse and substance use within the relationship. Results suggest the need for HIV-prevention interventions to address the problems of partner substance use and relationship abuse. Tucker, J., Wenzel, S., Elliott, M., and Hambarsoomian, K. Predictors of Unprotected Sex with Non-Cohabitating Primary Partners among Sheltered and Low-Income Housed Women in Los Angeles County. J Health Psychol, 11(5), pp. 697-710, 2006.
Psychological Correlates of Trading Sex for Money among African American Crack Cocaine Smokers
This article compares demographic characteristics, sexual practices, and psychosocial status among 193 African American female crack cocaine users who currently, previously, or never traded sex for money. Current traders were less likely to have a main sexual partner, more likely to have a casual sexual partner, and more likely to smoke larger quantities of crack. There was a significant trend towards current traders reporting lower self-esteem, greater depression and anxiety, poorer decision-making confidence, more hostility, less social conformity, greater risk taking behaviors, and more problems growing up, compared to previous and never traders. These differences suggest that interventions should address self-esteem, risk-taking practices, depression and anxiety as well as other psychosocial factors. Risser, J., Timpson, S., McCurdy, S., Ross, M., and Williams, M. Psychological Correlates of Trading Sex for Money among African American Crack Cocaine Smokers. Am J Drug Alcohol Abuse, 32(4), pp. 645-653, 2006.
Prescription Opioid Abuse among Drug-Involved Street-Based Sex Workers
National population surveys and individual studies over the past decade have documented the escalating abuse of a variety of prescription medications, particularly prescription opioids. Although surveillance data provide important information for estimating the prevalence of prescription opioid abuse in the general population, studies documenting the patterns of prescription drug abuse among chronic street-drug-using populations are extremely rare. This paper examines the abuse of prescription opioids among drug-involved street-based sex workers in Miami, Florida. The data for this study were drawn from an ongoing HIV intervention trial initiated in 2001, designed to test the relative effectiveness of two alternative HIV prevention protocols for this population. Participants in the study were recruited through traditional targeted sampling strategies, and complete data are available on 588 street-based sex workers. In terms of prescription drug abuse, 12.2 percent of the sample reported using at least one opioid analgesic in the past 90 days without having a legitimate prescription. Logistic regression analyses were conducted to examine the associations between prescription opioid abuse and its predictors. In the multivariate model, factors positively associated with prescription opioid abuse included: Caucasian race (OR = 2.53; 95 percent CI 1.30 to 4.91), current powder cocaine use (OR = 2.28; 95 percent CI 1.28 to 4.08), current heroin use (OR = 2.08; 95 percent CI 1.10 to 3.92), 90-day physical abuse/victimization (OR = 2.07; 95 percent CI 1.18 to 3.61), and shorter sex-work involvement (OR = 1.98; 95 percent CI 1.13 to 3.48). In contrast, daily crack smoking was negatively associated with prescription opioid abuse (OR = 0.61; 95 percent CI 0.33 to 1.10). This study provides some of the first empirical evidence to indicate that prescription opioid abuse is emerging in a heretofore unstudied community of marginalized drug-using sex workers. In addition, data on this population's mechanisms of access to prescription opioids clearly suggest that there is an active black market for these drugs. These findings warrant further study to determine the relative contribution of each mechanism of diversion to the illicit market. Surratt, H., Inciardi, J., and Kurtz, S. Prescription Opioid Abuse among Drug-Involved Street-Based Sex Workers. J Opioid Manag, 2(5), pp. 283-289, 2007.
Mechanisms of Prescription Drug Diversion Among Drug-Involved Club- and Street-Based Populations
Prescription drug diversion involves the unlawful channeling of regulated pharmaceuticals from legal sources to the illicit marketplace, and can occur along all points in the drug delivery process, from the original manufacturing site to the wholesale distributor, the physician's office, the retail pharmacy, or the patient. However, empirical data on diversion are limited. In an attempt to develop a better understanding of how specific drug-using populations are diverting prescription opioids and other medications, or obtaining controlled drugs that have already been diverted, qualitative interviews and focus group data were collected on four separate populations of prescription drug abusers in Miami, Florida-club drug users, street-based illicit drug users, methadone maintenance patients, and HIV positive individuals who abuse and/or divert drugs. Sources of abused prescription drugs cited by focus group participants were extremely diverse, including their physicians and pharmacists; parents and relatives; "doctor shopping"; leftover supplies following an illness or injury; personal visits to Mexico, South America and the Caribbean; prescriptions intended for the treatment of mental illness; direct sales on the street and in nightclubs; pharmacy and hospital theft; through friends or acquaintances; under-the-door apartment flyers advertising telephone numbers to call; and "stealing from grandma's medicine cabinet." While doctor shoppers, physicians and the Internet receive much of the attention regarding diversion, the data reported in this paper suggest that there are numerous active street markets involving patients, Medicaid recipients and pharmacies as well. In addition, there are other data which suggest that the contributions of residential burglaries, pharmacy robberies and thefts, and "sneak thefts" to the diversion problem may be understated. Inciardi, J., Surratt, H., Kurtz, S., and Cicero, T. Mechanisms of Prescription Drug Diversion Among Drug-Involved Club- and Street-Based Populations. Pain Med, 8(2), pp. 171-183, 2007.
The Importance of Clearly Defining Terms When Surveying Adolescents About Smoking
Although adolescent smoking cessation has received increased research attention, little information exists as to how adolescents define change efforts for smoking behaviors. This issue is of particular importance because surveys routinely incorporate items assessing smoking cessation, yet how adolescents interpret such items is unclear. To examine how adolescents define the terms "quit," "stop," and "cut down" when describing their smoking behavior change efforts, this research team surveyed a total of 94 adolescent smokers [average age 16.7 years (SD = 1.0), 56% female, and 71% white]. Definitions of quit and stop were categorized as (a) stop permanently, (b) stop temporarily, (c) stop except in certain situations, and (d) reduce smoking (for quit only). Definitions of cut down were categorized as (a) reduce the number of cigarettes, (b) smoke less in a time frame, (c) reduce smoking occasions, and (d) smoke less. Three trained raters sorted responses into each of the categories. Definitions of quit and stop were most frequently categorized in the stop permanently category (86% and 75%, respectively). Definitions of cut down were distributed across categories, with 51% categorized as smoke less, 25% smoking less in a time frame, and 25% reducing number of cigarettes. Different definitions of stop were related to smoking history and motivation to quit, although the other two terms were not related to adolescent individual characteristics. These findings highlight the importance of using clearly defined questionnaire items when assessing adolescent smoking change efforts. MacPherson, L., Myers, M., and Johnson, M. Adolescent Definitions of Change in Smoking Behavior: An Investigation. Nicotine Tob Res, 8(5), pp. 683-687, 2006.
A Multivariate Analysis of Neuroanatomic Relationships in a Genetically Informative Pediatric Sample
An important component of brain mapping is an understanding of the relationships between neuroanatomic structures, as well as the nature of shared causal factors. Prior twin studies have demonstrated that much of individual differences in human anatomy are caused by genetic differences, but information is limited on whether different structures share common genetic factors. Researchers performed a multivariate statistical genetic analysis on volumetric MRI measures (cerebrum, cerebellum, lateral ventricles, corpus callosum, thalamus, and basal ganglia) from a pediatric sample of 326 twins and 158 singletons. The results suggest that the great majority of variability in cerebrum, cerebellum, thalamus and basal ganglia is determined by a single genetic factor. Though most (75%) of the variability in corpus callosum was explained by additive genetic effects these were largely independent of other structures. Relatively small but significant environmental effects were observed to be common to multiple neuroanatomic regions, particularly between thalamus, basal ganglia, and lateral ventricles. These findings are concordant with prior volumetric twin studies and support radial models of brain evolution. Schmitt, J., Wallace, G., Rosenthal, M., Molloy, E., Ordaz, S., Lenroot, R., Clasen, L., Blumenthal, J., Kendler, K., Neale, M., and Giedd, J. A Multivariate Analysis of Neuroanatomic Relationships in a Genetically Informative Pediatric Sample. Neuroimage, 35(1), pp. 70-82, 2007.
Assortative Mating Explains Spousal Similarity in Cigarette and Alcohol Use and Dependence
Non-random mating affects population variation for substance use and dependence. Developmentally, mate selection leading to positive spousal correlations for genetic similarity may result in increased risk for substance use and misuse in offspring. Mate selection varies by cohort and thus, assortative mating in one generation may produce marked changes in rates of substance use in the next. This team of researchers used data from female twins and their male spouses to clarify the mechanisms contributing to spousal similarity for cigarette smoking and alcohol consumption. They found that assortative mating significantly influenced regular smoking, regular alcohol use, nicotine dependence and alcohol dependence. The bivariate models for cigarette smoking and alcohol consumption also highlighted the importance of primary assortative mating on all stages of cigarette smoking and alcohol consumption, with additional evidence for assortative mating across the two stages of alcohol consumption. They concluded that women who regularly used, and subsequently were dependent on cigarettes or alcohol were more likely to marry men with similar behaviors. After mate selection had occurred, one partner's cigarette or alcohol involvement did not significantly modify the other partner's involvement with these psychoactive substances. Agrawal, A., Heath, A., Grant, J., Pergadia, M., Statham, D., Bucholz, K., Martin, N., and Madden, P. Assortative Mating for Cigarette Smoking and for Alcohol Consumption in Female Australian Twins and their Spouses. Behav Genet, 36(4), pp. 553-566, 2006.
Heroin and Cocaine Dependence and the Risk of Accidental Non-fatal Drug Overdose
The relation between illicit drug dependence and the likelihood of drug overdose is unclear. For this analysis, researchers recruited 1,066 habitual drug users through street-based outreach in New York City, of which 99.3% used heroin in the past year and 87.1% used cocaine. They found that 819 (77.5%) heroin users and 735 (79.2%) cocaine users were severely dependent on either drug respectively. In multivariable models, among heroin users, persons who were severely heroin dependent were less likely (OR = 0.6; 95% CI = 0.4-0.9) to have overdosed on any drug in the past year; among cocaine users, those who were severely cocaine dependent were more likely (OR = 1.6; 95% CI = 1.0-2.6) to have overdosed in the past year. These findings indicate that the relationship between illicit drug dependence and risk of overdose varies for different patterns of drug dependence. These observations suggest that overdose prevention interventions, perhaps even those specifically targeting opiate overdose, may be more efficiently directed at individuals exhibiting cocaine dependence. Galea, S., Nandi, A., Coffin, P., Tracy, M., Markham Piper, T., Ompad, D., and Vlahov, D. Heroin and Cocaine Dependence and the Risk of Accidental Non-fatal Drug Overdose. J Addict Dis, 25(3), pp. 79-87, 2006.
Barriers and Facilitators to Methadone Maintenance Therapy Use among Illicit Opiate Injection Drug Users in Vancouver
Methadone maintenance therapy (MMT) has been increasingly implemented as the treatment of choice for opiate-addicted individuals and has been associated with reduced harm related to opiate addiction. Barriers to MMT uptake still exist, however, and many opiate-addicted individuals do not access this form of treatment. Researchers examined barriers to and facilitators of MMT access among opiate users enrolled in a prospective cohort study of injection drug users (IDUs). They identified individuals who had initiated MMT during follow-up interviews and used generalized estimating equations to identify sociodemographic and drug-related variables associated with MMT access. Of the 1,587 participants recruited into the Vancouver Injection Drug User Study, 1,463 were eligible for the present analysis. Factors negatively associated with MMT use included male gender (odds ratio [OR] = 0.41; 95 percent confidence interval [CI], 0.32 to 0.52), Aboriginal ethnicity (OR = 0.37; 95 percent CI, 0.29 to 0.48), recent incarceration (OR = 0.82; 95 percent CI, 0.72 to 0.93), Downtown Eastside residence (OR = 0.86; 95 percent CI, 0.75 to 0.97), sex-trade involvement (OR = 0.80; 95 percent CI, 0.67 to 0.95), syringe lending (OR = 0.76; 95 percent CI, 0.66 to 0.89), denied addiction treatment (OR = 0.81; 95 percent CI, 0.68 to 0.96), heroin injection (OR = 0.51; 95 percent CI, 0.44 to 0.59), nonfatal overdose (OR = 0.59; 95 percent CI, 0.51 to 0.68), and injecting in public (OR = 0.75; 95 percent CI, 0.63 to 0.89). Older age (OR = 1.03; 95 percent CI, 1.01 to 1.04), HIV positivity (OR = 1.89; 95 percent CI, 1.52 to 2.2.3), and crack cocaine smoking (OR = 1.41; 95 percent CI, 1.22 to 1.62) were positively associated with MMT use. The study identified a large number of barriers to and facilitators of MMT use among IDUs. While some populations such as HIV-positive individuals are frequently accessing MMT, identified barriers among men and Aboriginal lDUs are of great concern. These findings indicate the need for additional interventions aimed at maximizing coverage of MMT and other treatments for opiate-addicted individuals. Callon, C., Wood, E., Marsh, D., Li, K., Montaner, J., and Kerr, T. Barriers and Facilitators to Methadone Maintenance Therapy Use among Illicit Opiate Injection Drug Users in Vancouver. J Opioid Manag, 2(1), pp. 35-41, 2007.
Multilevel Community-Based Intervention to Increase Access to Sterile Syringes among Injection Drug Users through Pharmacy Sales in New York City
Research has shown that there is minimal use of pharmacies among injection drug users (IDUs) in specific neighborhoods and among Black and Hispanic IDUs. This study developed a community-based participatory research partnership to determine whether a multilevel intervention would increase sterile syringe access through nonprescription syringe sales in pharmacies. Researchers targeted Harlem, NY (using the South Bronx for comparison), and disseminated informational material at community forums, pharmacist training programs, and counseling or outreach programs for IDUs. They compared cross-sectional samples in 3 target populations (pre- and post intervention): community members (attitudes and opinions), pharmacists (opinions and practices), and IDUs (risk behaviors). Among community members (N = 1496) and pharmacists (N = 131), negative opinions of IDU syringe sales decreased in Harlem whereas there was either no change or an increase in negative opinions in the comparison community. Although pharmacy use by IDUs (N=728) increased in both communities, pharmacy use increased significantly among Black IDUs in Harlem, but not in the comparison community; syringe reuse significantly decreased in Harlem, but not in the comparison community. These findings show that targeting the individual and the social environment through a multilevel community-based intervention reduced high-risk behavior, particularly among Black IDUs. Fuller, C., Galea, S., Caceres, W., Blaney, S., Sisco, S., and Vlahov, D. Multilevel Community-Based Intervention to Increase Access to Sterile Syringes among Injection Drug Users through Pharmacy Sales in New York City. Am J Public Health, 97(1), pp. 117-124, 2007.
Are Gay, Lesbian, and Bisexual Youth More Likely to Be Victims of Sexual and Physical Abuse?
This study was designed to examine the association between adolescent sexual orientation and risk for physical and sexual victimization. The authors conducted secondary data analyses from seven population-based high school health surveys in the US and Canada. Results suggest that sexual minority teens in nearly all surveys were significantly more likely to report sexual and physical abuse than their same-age heterosexual counterparts, with differences markedly stronger for boys. Data also suggest the disparities are worsening, particularly for bisexual teens. Case studies are provided and implications for interventions are discussed. Saewyc, E., Skay, C., Pettingell, S., Reis, E., Bearinger, L., Resnick, M., Murphy, A., and Combs, L. Hazards of Stigma: The Sexual and Physical Abuse of Gay, Lesbian, and Bisexual Adolescents in the United States and Canada. Child Welfare, 85(2), pp. 195-213, 2006.
Distribution of Influenza Vaccine to High-Risk Groups
Vaccine distribution programs have historically targeted individuals at high risk of complications due to influenza. Despite recommendations from the Advisory Committee on Immunization Practices, vaccination coverage among high-risk populations has been generally low. This review systematically summarizes the recent literature evaluating programs in different settings, from within medical settings to venue-based and community-based approaches, in an effort to identify successful program components. The published literature was identified by using the MEDLINE database from 1990 to 2006 covering studies that reported on interventions or programs aimed at vaccinating high-risk populations. The authors reviewed 56 studies. In the United States, the Healthy People 2010 goals included 90% vaccination coverage for adults aged >= 65 years and 60% for high-risk adults aged 18-64 years. Only a handful of the studies reviewed managed to meet those goals. Interventions that increased vaccination coverage to Healthy People 2010 goals included advertising, provider and patient mailings, registry-based telephone calls, patient and staff education, standing orders coupled with standardized forms, targeting of syringe exchange customers, and visiting nurses. Few studies evaluated the impact of vaccination programs by race/ethnicity and socioeconomic status. Few studies targeted individuals outside of the health-care and social services sectors. Given the growing disparities in health and health-care access, understanding the way in which interventions can remedy disparities is crucial. Danielle, O.C., and Sandro, G. Distribution of Influenza Vaccine to High-Risk Groups. Epidemiol Rev, 28(1), pp. 54-70, 2006.