Research Findings - Epidemiology and Etiology Research
Drug Use as a Complex Phenotype: A Review
Drug use is a complex behavior influenced by multiple biological, family, and socio-cultural factors. The concurrent use/misuse of multiple drugs is often seen and drug use also co-occurs with other psychiatric conditions. Behavior and molecular genetic studies support an important posited role of genes in drug use. This posited genetic risk does not appear to be conferred by one or two major genes manifesting large effects, but rather by a number of genes manifesting smaller effects. Genetic factors explain, on average, only about half of the total variability in drug use, with the remaining variability influenced by environmental factors. Also, genetic risk may be differentially expressed in the presence vs. absence of particular environmental conditions. Thus, investigation of environmental factors and their interaction with genetic risk is a necessary component of genetic research. While the full potential of genetic investigations for the prevention of drug misuse has yet to be realized, an example of the impact of risk factor modification under various conditions of gene-environment interaction is provided, and the implications for use of genetic information in drug-misuse prevention are discussed. The multifactorial nature of drug use necessitates coordinated investigation from multiple disciplines and timely dissemination of scientific findings. In addition, this work demands adherence to the highest standards of confidentiality and ethical use of genetic information to best inform future prevention efforts. Lessov, C.N., Swan, G.E., Ring, H.Z., Khroyan, T.V. and Lerman, C. Genetics and Drug Use as a Complex Phenotype. Substance Use and Misuse 39, pp. 1515-1569, 2004.
Cognitive and Contextual Mediators of Substance Use
This study examined the cognitions thought to mediate the impact of context on adolescent substance use and also the extent to which context moderates the relations between these cognitions and use. Risk cognitions and behaviors were assessed in a panel of 746 African American adolescents (M age 10.5 at Wave 1, 12.2 at Wave 2). Results indicated that adolescents living in high-risk neighborhoods were more inclined toward substance use and more likely to be using at Wave 2. These context effects were mediated by the adolescents' risk cognitions, their risk images, willingness to use, and intentions to use. Also, context moderated the relation between willingness and use (the relation was stronger in high-risk neighborhoods) but it did not moderate the intentions to use relation. Gibbons, F.X., Gerrard, M., Lune, L.S.V., Wills, T.A., Brody, G. and Conger, R.D. Context and Cognitions, Environmental Risk, Social Influence, and Adolescent Substance Use. Personality and Social Psychology Bulletin 30, pp. 1048-1061, 2004.
Caregiver Factors Buffer Effects of Violence Exposure on Adjustment Problems
This short-term, longitudinal interview study used an ecological framework to explore protective factors within the child, the caregiver, the caregiver-child relationship, and the community that might moderate relations between community violence exposure and subsequent internalizing and externalizing adjustment problems and the different patterns of protection they might confer. Participants included 101 pairs of African American female caregivers and one of their children (56% male, M = 11.15 yrs, SD = 1.28) living in high-violence areas of a mid-sized southeastern city. Child emotion regulation skill, felt acceptance from caregiver, observed quality of caregiver-child interaction, and caregiver regulation of emotion each were protective, but the pattern of protection differed across level of the child's ecology and form of adjustment. Kliewer, W., Cunningham, J.N., Diehl, R., Parrish, K.A., Walker, J.M, Atiyeh, C., Neace, B., Duncan, L., Taylor, K. and Mejia, R. Violence Exposure and Adjustment in Inner-city Youth: Child and Caregiver Emotion Regulation Skill, Caregiver-child Relationship Quality, and Neighborhood Cohesion as Protective Factor. J Clin Child Adolesc Psychol. 33(3), pp. 477-487, 2004.
Shared Environment, Genetics and Sibling Social Connectedness Predict Adolescent Smoking
Using a genetically informative sample of adolescents, this study assessed whether sibling effects on smoking reflect social rather than genetic processes. A combined twin-sibling design, with 1421 sibling pairs, was employed to disentangle genetic and non-genetic effects. These sibling pairs represent a spectrum of genetic relatedness and include monozygotic twins, dizygotic twins, biological siblings, half-siblings and unrelated siblings. Main effects of both shared environment and genetics were found on adolescent smoking frequency. Social connectedness between siblings moderated shared environmental influences on smoking frequency at each time period, as well as on change in smoking frequency. Shared environmental effects were more pronounced when siblings reported high levels of social connectedness. These environmental sibling effects on smoking were significant after controlling for parent and peer smoking. This report extends prior research on sibling effects on smoking by identifying specific relationship dynamics that underlie transmission of risk within sibships and providing evidence that such relationship dynamics represent social rather than genetic processes. Slomkowski, C., Rende, R., Novak, S., Lloyd-Richardson, E. and Niaura, R. Sibling Effects On Smoking In Adolescence: Evidence For Social Influence From A Genetically Informative Design. Addiction 100(4), pp. 430-438, 2005.
Effects of Parent and Peer Support on Adolescent Substance Use
This research tested comparative effects of parent and peer support on adolescent substance use (tobacco, alcohol, and marijuana) with data from 2 assessments of a multiethnic sample of 1,826 adolescents, mean age 12.3 years. Multiple regression analyses indicated that parental support was inversely related to substance use and that peer support was positively related to substance use, as a suppression effect. Structural modeling analyses indicated that effects of support were mediated through pathways involving good self-control, poor self-control, and risk-taking tendency, parent and peer support had different patterns of relations to these mediators. The mediators had pathways to substance use through positive and negative recent events and through peer affiliations. Effects for gender and ethnicity were also noted. Mechanisms of operation for parent and peer support are discussed. Wills, T.A., Resko, J.A., Ainette, M.G. and Mendoza, D. Role of Parent Support and Peer Support in Adolescent Substance Use, A Test of Mediated Effects. Psychology of Addictive Behaviors 18, pp. 122-134, 2004.
Positive Adult Behavior Predicts Crime and Substance Use
Drawing on diverse approaches to the study of youth development and adult functioning, as well as social capital and citizenship, this investigation identified measures of positive adult behavior, which has been given less attention in research. Analyses included 765 participants from the Seattle Social Development Project interviewed at age 21. Seven measures of positive adult behavior were identified: volunteerism, group involvement, neighborliness, interpersonal connection, constructive engagement, financial responsibility, and honesty. Measures related to distal social relationships (group involvement and neighborliness) had relatively weak associations with crime and substance use. In contrast, the measures of constructive engagement, financial responsibility, and honesty had significant negative associations with multiple measures of crime and substance use. Results indicate that the seven measures provide relatively independent variables useful for assessing positive adult behavior. These measures can be used to assess positive outcomes in adulthood of intervention studies, or to assess the prevalence of positive adult behavior in different populations or groups. Kosterman, R., Hawkins, J.D., Abbott, R.D., Hill, K.G., Herrenkohl, T.I. and Catalano, R.F. Measures of Positive Adult Behavior and their Relationship to Crime and Substance Use. Prevention Science 6(1), pp. 21-33, 2005.
Neighborhood Social Disorder as a Determinant of Drug Injection Behaviors
Neighborhood environments are increasingly recognized as a contextual determinant of health, behaviors, and disease; however, the pathways through which neighborhood characteristics impact health behaviors are poorly understood. This article examines pathways to elucidate how neighborhood social disorder may lead to HIV transmission. Data are from a baseline survey of 701 IDUs from the Self-Help in Eliminating Lethal Diseases (SHIELD) Study, an HIV prevention intervention in Baltimore. Structural equation modeling was used to examine the pathways among social disorder, psychological distress, and drug injection behaviors. The relationship between disorder and injection behaviors in the models tested suggests that psychological distress is higher in more socially disordered neighborhoods; that distress leads to greater injection frequency and equipment sharing; and that injection frequency predicts equipment sharing. Latkin, C., Williams, C. and Wa. J. Neighborhood Social Disorder as a Determinant of Drug Injection Behaviors: A Structural Equation Modeling Approach. Health Psychology, 24(1), pp. 96—100, 2005.
Gang Membership Associated with Increased Drug Involvement
This study examined whether gang membership is associated with higher levels of delinquency and drug involvement because boys predisposed to delinquent activity are more likely than others to join. Ten years of longitudinal data from 858 participants of the Pittsburgh Youth Study were used to identify periods before, during and after gang membership. This study builds on prior research by controlling for ages and calendar time, by better accounting for gang memberships that occurred before the study began, and by using fixed effects statistical models. Findings show that boys who join gangs are more delinquent before entering the gang than those who do not join. Even with such selective differences, however, studies replicate prior research showing that drug selling, drug use, violent behaviors and vandalism of property increase significantly when a youth joins a gang. The delinquency of peers appears to be one mechanism of socialization. These findings are clearest in youth self-reports, but are also evident in reports from parents and teachers on boys' behavior and delinquency. After adjusting for time trends, the increase in delinquency is temporary and delinquency falls to pre-gang levels when boys leave gangs. Gordon, R.A., Lahey, B.B., Kawai, E., Loeber, R., Stouthamer-Loeber, M. and Farrington, D.P. Antisocial Behavior and Youth Gang Membership, Selection and Socialization. Criminology, 42, pp. 55-87, 2004.
Trends in Recall and Appraisal of Anti-smoking Advertising among American Youth: National Survey Results, 1997-2001
Data from the Monitoring the Future Study (MTF) were analyzed to provide (a) a description of the overall extent of exposure to anti-smoking media among American youth from 1997 to 2001, (b) an appraisal of general youth reactions to such advertising, and (c) an examination of how exposure levels and reactions vary by socio-demographic characteristics. MTF data were collected each year from nationally representative school samples of 8th, 10th, and 12th grade students (N = 29,724; 24,639; and 12,138, respectively). Self-reported levels of recalled exposure to both electronic and print anti-smoking advertising were measured, as well as the judged impact and perceived exaggeration of such advertising. Data indicate that significant increases in overall exposure to anti-smoking advertising occurred over the study time period. These increases were associated with (a) increases in the self-reported likelihood that anti-smoking advertising diminished the probability of individual smoking behaviors, and (b) increases in the perceived level to which anti-smoking advertising exaggerates the risks associated with smoking. Further, these trends were significantly associated with various characteristics-most notably, ethnicity, smoking behaviors, and residence in a state with an ongoing tobacco-control program having a media component. The findings of this study suggest that current anti-smoking media efforts may be positively impacting youth behaviors, however the ramifications of the level to which ads are perceived to exaggerate behavior risks are not clear. Johnston, L.D., Terry-McEllrath, Y.M., O'Malley, P.M. and Wakefield, M. Prevention Science 6(1), pp. 1-19, 2005.
The Internet and Substance Abuse Among Adolescents
Recognizing that the Internet contains a large amount of information on the use of psychoactive substance, the investigators analyzed preliminary data from a cross-sectional survey of adolescents to examine the effect of the Internet on their drug-use knowledge, attitudes, and behaviors. Of 12 patients (9 male, 3 female) who had used the Internet to learn about psychoactive substances, 100% reported that Internet-based information had affected the ways in which they had used psychoactive substances. Eight of the respondents described adopting behaviors intended to minimize the risks associated with psychoactive substance use. Respondents also reported changes in the use of a wide variety of illicit substances as well as over-the-counter and prescription pharmaceuticals. Analysis of respondents' knowledge, attitudes and behaviors towards drugs suggested that the youth were influenced by Internet information. These preliminary findings suggest that Web-based data on psychoactive substances may influence a broad range of drug-use behaviors in adolescents. The authors conclude that information on the ways in which the Internet is being used by adolescents should be considered in the design of Web sites to prevent the initiation and use of psychoactive substances. Boyer, E.W., Shannon, M. and Hibberd, P.L. The Internet and Psychoactive Substance Use among Innovative Drug Users. Pediatrics 115(2), pp. 302-305, 2005.
The Influence of Substance Abuse on Desistance in Antisocial Behavior among Young Adults
Using data collected at ages 18, 21, and 26 from male participants in the Dunedin Multidisciplinary Health and Development Study (N=406), the "snares" and "launch" hypotheses about the developmental relation between substance abuse and individual differences in desistance from antisocial behaviors during young adulthood were examined. The "snares" hypothesis posits that substance abuse should result in time-specific elevations in antisocial behavior relative to an individual's own developmental trajectory of antisocial behavior, whereas the "launch" hypothesis posits that substance abuse early in young adulthood slows an individual's overall pattern of crime desistance related to the population norm during his developmental period. Based on latent trajectory analyses, significant individual variability was found in initial levels and rates of change in antisocial behavior over time as well as support for both the snares hypothesis and the launch hypothesis as explanations for the developmental relation between substance abuse and crime desistance in young men. Hussong, A.M, Curran, P.J., Moffitt, T.E., Caspi, A and Carrig, M.M. Substance Abuse Hinders Desistance in Young Adults' Antisocial Behavior. Development and Psychopathology 16, pp. 1029-1046, 2004.
Support for Contextual Models of Smoking Onset
This is a study examining smoking — specific and contextual models of smoking onset. Data was collected in 4 waves from a sample of 1,364 adolescents. Cluster analysis identified experimenters and abstainers, as well as early (7th grade), intermediate (9th grade), and late (10th grade) smoking onset groups. Predictor variables derived from stress-coping, social influence, and problem-behavior theories discriminated smokers from abstainers. The onset groups were discriminated by Group X Time interactions, showing differential changes in risk and protective factors, which occurred just prior to smoking onset. Findings support a contextual model of the smoking onset process. Wills, T.A., Resko, J.A., Ainett, M.G. and Mendoza, D. Smoking Onset in Adolescence: A Person-centered Analysis with Time-varying Predictors. Health Psychology 23, pp. 158-167, 2004.
Familial Aggregation of Alcohol, Drug, and Psychiatric Disorders: Evidence of Shared Vulnerability
This study analyzed data from the family collection of the Collaborative Study on the Genetics of Alcoholism to quantify familial aggregation of substance use disorders and other psychiatric disorders. Age-corrected lifetime morbid risk was estimated in adult first-degree relatives of affected probands and control subjects for selected disorders. Diagnostic data were gathered by semistructured interview (the Semi-Structured Assessment for the Genetics of Alcoholism) family history, and medical records. Rates of illness were corrected by validating interview and family history reports against senior clinicians' all sources best estimate diagnoses. Sex ethnicity, comorbidity, cohort effects, and site of ascertainment were also taken into account. Results from data from 8296 relatives of alcoholic probands and 1654 controls indicate lifetime risk rates of 28.8% and 14.4% for DSM-IV alcohol dependence in relatives of probands and controls, respectively, respective rates were 37.0% and 20.5% for the less stringent DSM-III-R alcohol dependence, 20.9% and 9.7% for any DSM-III-R diagnosis of nonalcohol nonnicotine substance dependence, and 8.1% and 5.2% for antisocial personality disorder. Rates of specific substance dependence were markedly increased in relatives of alcohol-dependent probands for cocaine, marijuana, opiates, sedatives, stimulants, and tobacco. Aggregation was also seen for panic disorder, obsessive-compulsive disorder, posttraumatic stress disorder, and major depression. These results suggest that the risk of alcohol dependence in relatives of probands compared with controls is increased about 2-fold, and shared familial vulnerability with antisocial personality disorder, drug dependence, anxiety disorders, and mood disorders. Nurnberger, J.I., Wiegand, R., Bucholz, K., O'Connor, S., Meyer, E.T., Reich, T., Rice, J., Schuckit, M., King, L., Petti, T., Bierut, L., Hinrichs, A.L., Kuperman, S., Hesselbrock, V. and Porjesz, B. A Family Study of Alcohol Dependence - Coaggregation of Multiple Disorders in Relatives of Alcohol-dependent Probands. Archives of General Psychiatry 61, pp. 1246-1256, 2004.
Attenuated P300 Amplitude and Substance Use Disorders
This investigation examined whether P300 amplitude in late childhood is a predictor of SUD outcome by age 19, and whether neurobehavior disinhibition (ND) mediates this association. Boys (aged 10-12) were recruited through proband biological fathers with either a lifetime DSM-III-R diagnosis of SUD (N = 67) or no adult psychiatric disorder (N = 94). P300 amplitude was recorded during an auditory oddball task. Neurobehavior disinhibition was evaluated using tests of executive cognitive function, behavior undercontrol, and emotion dysregulation. Results indicate that substance use disorder by age 19 was significantly predicted by P300 amplitude and ND score measured at age 10 to 12. P300 amplitude also significantly correlated with ND severity. Low P300 amplitudes were observed in children who succumbed to SUD by age 19. These results suggest that ND mediates the association between attenuated P300 amplitude in childhood and SUD at age 19, however, P300 amplitude is not a specific childhood marker of SUD. Habeych, M.E., Charles, P.J., Sclabassi, R.J., Kirisci, L. and Tarter, R.E. Direct and Mediated Associations Between P300 Amplitude in Childhood and Substance Use Disorders Outcome in Young Adulthood. Biological Psychiatry 57, pp. 76-82, 2005.
Cognitive Distortions, Neurobehavior Disinhibition, and Substance Use Disorders
Previous research has demonstrated that neurobehavior disinhibition increases the risk for a diagnosis of substance use disorder (SUD). This investigation tested the hypothesis that a deficiency in the capacity to appraise the effects of alcohol and drugs and interpret social interactions mediates the relation between neurobehavior disinhibition in childhood and SUD by early adulthood. Boys with fathers having lifetime SUD (N = 88) and no SUD or other psychiatric disorder (N = 127) were prospectively tracked from ages 10-12 to 19 years. Neurobehavior disinhibition was evaluated at baseline followed by assessments of cognitive distortions and substance use involvement in early and mid-adolescence. SUD outcome was evaluated up to age 19 years. Results showed that cognitive distortions (age 12-14 years) mediated the association between neurobehavior disinhibition (age 10-12 years) and marijuana use (age 16 years) which, in turn, predicted SUD by age 19 years. Cognitive distortions in early adolescence did not directly predict SUD by young adulthood. These results indicate that cognitive processes, in conjunction with psychological self-regulation, comprise important components of the individual liability to SUD. Kirisci, L., Tarter, R.E., Vanyukov, M., Reynolds, M. and Habeych, M. Relation Between Cognitive Distortions and Neurobehavior Disinhibition on the Development of Substance Use during Adolescence and Substance Use Disorder by Young Adulthood, A Prospective Study. Drug and Alcohol Dependence 76, pp. 125-133, 2004.
Initial Sensitivity to the Pharmacological Effects of Nicotine
To validate reports of early experiences with nicotine, this study assessed 34 smokers who had contributed retrospective data on early experiences with smoking. Half had reported experiencing a buzz from smoking their first cigarette (the "yes" group), the other half had not (the "no" group). To simulate initial sensitivity to nicotine, participants were asked to remain abstinent from smoking for 5 days to allow for the dissipation of tolerance. They then participated in a laboratory session in which they were reexposed to nicotine in an unfamiliar form (nicotine nasal spray) and asked to indicate pleasurable responses by depressing a foot pedal if and when they experienced a "pleasurable buzz." Smokers in the "yes" group were marginally more likely to be male. The two groups did not differ significantly on age or race. The "yes" group smoked significantly more cigarettes/day than the "no" group. When the two groups were compared for response to nasal spray following 5 days' abstinence, smokers in the "yes" group were marginally more likely to have signaled experiencing at least one pleasurable buzz and rated "pleasurable sensation from spray" on a 100-mm visual analogue scale administered 10 min after nicotine dosing significantly higher than were those in the "no" group. To the extent that several days' abstinence can serve as a model for initial sensitivity to nicotine, findings validate retrospective reports of pleasurable sensations upon early smoking experimentation. Pomerleau, O.F., Pomerleau, C.S., Mehringer, A.M., Snedecor, S.M. and Cameron, O.G. Validation of Retrospective Reports of Early Experiences with Smoking. Addictive Behaviors 30, pp. 607-611, 2005.
Reliability of Proxy Reports of Parental Smoking
To investigate the accuracy of offspring assessments of parental smoking status, this study assessed 116 parents and 151 adult children (276 parent-child dyads) who provided data on both their own and their parents' smoking status. All currently smoking and all ex-smoking parents were correctly classified as ever-smokers by their offspring (n=79 and 100, respectively). Of the 97 offspring who reported on never-smoking parents, 88 correctly classified their parents as never-smokers. Thus, sensitivity for detecting ever-smoking in parents was 100%, and specificity, 91%. Because all incorrect classifications involved never-smoking parents, further analyses focused on this group. Too few parents were misclassified to permit testing of parental characteristics. Offspring who misclassified their parents were significantly older than those who did not; neither sex nor smoking status of the offspring was associated with the increased likelihood of misclassification. No significant differences were discovered for dyadic factors (concordance/discordance for sex; parent-offspring age difference). Overall, these results support the utility of proxy reports of parental smoking phenotype by adult informants when self-report is unavailable. Pomerleau, C.S., Snedecor, S., Ninowski, R., Gaulrapp, S., Pomerleau, O.F. and Kardia, S.L. Differences in Accuracy of Offspring Assessment Based on Parental Smoking Status. Addictive Behaviors 30, pp. 437-441, 2005.
Reliability of Retrospective Reports of Nicotine Dependence
Information about levels of nicotine dependence in ex-smokers when they smoked, or in current smokers at an earlier date, is useful for clinical and research purposes. To estimate the accuracy of retrospective reports of dependence, 28 individuals who completed either the Fagerstrom Tolerance Questionnaire (FTQ) or Fagerstrom Test for Nicotine Dependence (FTND) in smoking cessation trials conducted 5 to 12 years earlier were asked to respond again to the same questions, thinking back to their smoking behavior just prior to their on-study quit attempt. Concordance and Kappa values for the items ranged from 50.0% to 95.0% and 0.00 to 0.92, respectively. The mean difference between the baseline and follow-up total scale scores was 0.05 for the FTQ and 0.38 for the FTND, and the correlation between these assessments was 0.62 for the FTQ (p<0.005) and 0.72 for the FTND (p<0.05). These preliminary results suggest that retrospectively assessed FTQ/FTND scale scores have acceptable reliability. Suchanek Hudmon, K., Pomerleau, C.S., Brigham, J., Javitz, H. and Swan, G.E. Validity of Retrospective Assessments of Nicotine Dependence: A Preliminary Report. Addictive Behaviors 30, pp. 613-617, 2005.
Identifying Venues for Purposive Sampling of Hard-to-reach Latino Youth
This study of recruitment venues in a Latino neighborhood was designed with the following objectives: (1) to identify venues where Latino youth at risk for unintended pregnancies and sexually transmitted infections (STIs) could be reached; (2) to describe different youth crowds, and (3) to investigate how and where youth meet their sex partners. Based on neighborhood venues mapped using Map-Info, and ethnographic interviews conducted with 62 youth recruited primarily from street sites, 3 types of "crowds" were identified, including gang related "regulars," individuals affiliated with street economy, and females. Findings suggest that gang members dominate venues in The Mission and that street sites are important venues to meet sexual partners. This qualitative assessment produced insights into research planning, outreach, and interventions with Latino youth who are at disproportionate risk for unintended pregnancies and STIs. Auerswald, C.L., Greene, K., Minnis, A., Doherty, I., Ellen, J. and Padian, N. Qualitative Assessment of Venues for Purposive Sampling of Hard-to-reach Youth. Sexually Transmitted Diseases 31, pp. 133-138, 2004.
School-level Clustering of Youthful Drug Involvement in Seven Latin American Countries
This study estimated the occurrence and school-level clustering of drug involvement among school-attending adolescent youths in each of seven countries in Latin America. During 1999-2000, anonymous self-administered questionnaires on drug involvement and related behaviors were administered to a cross-sectional, nationally representative sample that included a total of 12,797 students in the following seven countries, Costa Rica (n = 1,702), the Dominican Republic (n = 2,023), El Salvador (n = 1,628), Guatemala (n = 2,530), Honduras (n = 1,752), Nicaragua (n = 1,419), and Panama (n = 1,743). (The PACARDO name concatenates PA for Panama, CA for Centroamerica, and RDO for Republica Dominicana). Estimates for exposure opportunity and actual use of alcohol, tobacco, inhalants, marijuana, cocaine (crack/coca paste), amphetamines and methamphetamines, tranquilizers, ecstasy, and heroin were assessed via responses about questions on age of first chance to try each drug, and first use. Cumulative occurrence estimates for alcohol, tobacco, inhalants, marijuana, and illegal drug use for the overall sample were, respectively, 52%, 29%, 5%, 4%, and 5%. In comparison to females, males were more likely to use alcohol, tobacco, inhalants, marijuana, and illegal drugs, the odds ratio estimates were 1.3, 2.1, 1.6, 4.1, and 3.2, respectively. School-level clustering was noted in all countries for alcohol and tobacco use. It was also noted in Costa Rica, El Salvador, Guatemala, and Panama for illegal drug use. This report sheds new light on adolescent drug experiences in Panama, the five Spanish-heritage countries of Central America, and the Dominican Republic, and presents the first estimates of school-level clustering of youthful drug involvement in these seven countries. Placed in relation to school survey findings from North America and Europe, these estimates indicate lower levels of drug involvement in these seven countries of the Americas. For example, in the United States of America 70% of surveyed youths had tried alcohol and 59% had smoked tobacco. By comparison, in these seven countries, only 51% have tried alcohol and only 29% have smoked tobacco. Future research will help to clarify explanations for the observed variations across different countries of the world. In the meantime, strengthening of school-based and other prevention efforts in the seven-country PACARDO area may help these countries slow the spread of youthful drug involvement, reduce school-level clustering, and avoid the periodic epidemics of illegal drug use that have been experienced in North America. Dormitzer, C.M., Gonzalez, G.B., Penna, M., Bejarano, J., Obando, P., Sanchez, M., Vittetoe, K., Gutierrez, U., Alfaro, J., Meneses, G., Diaz, J.B., Herrera, M., Hasbun, J., Chisman, A., Caris, L., Chen, C.Y. and Anthony, J.C. The PACARDO Research Project, Youthful Drug Involvement in Central America and the Dominican Republic. Pan American Journal of Public Health 15, pp. 400-416, 2004.
Difference between Ever- and Never-Smokers
This study examined whether 52 same-sex sibling pairs discordant for ever-smoking differed on psychiatric cofactors, alcohol and caffeine use, and responses to initial exposure to smoking. Ever-smokers scored significantly higher on measures of novelty seeking, depression, and childhood ADHD, and on alcohol dependence, alcohol intake, and caffeine intake. They reported significantly more pleasurable experiences, dizziness, "buzz," and relaxation upon initial exposure to smoking and significantly fewer displeasurable sensations, nausea, and cough than did nicotine-exposed, never-smoking siblings. Ever-smokers had significantly fewer years of education than their never-smoking siblings, suggesting that the concentration of smokers in lower socioeconomic strata may be partly due to downward mobility among smokers, possibly because of the observed elevation in psychiatric cofactors, which may interfere with academic performance. These findings are consistent with differences previously identified in unrelated ever- and never-smokers. Because same-sex siblings typically share a large set of common environments during childhood, the findings could be due either to genetic differences among siblings and/or (excepting educational level and responses to early exposure) to differences in adult environments. Pomerleau, C.S., Pomerleau, O.F., Snedecor, S.M., Gaulrapp, S. and Kardia, S.L.R. Heterogeneity in Phenotypes Based on Smoking Status in the Great Lakes Smoker Sibling Registry. Addictive Behaviors 29, pp. 1851-1855, 2004.
HPA-axis Dysregulation among Smokers with and without Depression
To determine whether smokers with a history of depression are differentially susceptible to smoking withdrawal, depressed mood induction and/or hypothalamic-pituitary-adrenal (HPA) axis dysregulation during smoking abstinence, 24 women smokers with and without such a history were studied. During one 5-day interval, participants smoked ad libitum, during a second they abstained. On day 4, the participants were exposed to the Velten mood induction procedure (VMIP). Participants were then instructed to take 1 mg dexamethasone at 11 pm. At 4 pm on day 5, blood samples were withdrawn to determine the cortisol and ACTH response. Despite lower baseline cotinine levels, history-positive participants displayed more pronounced overall withdrawal distress than did history-negative participants, regardless of condition. The VMIP increased depression as well as negative responses on other profile of mood states subscales. Despite many overall group differences, no significant main effects for smoking condition nor interaction effects emerged. All participants evinced cortisol suppression in response to dexamethasone during both conditions, but the degree of suppression did not differ as a function of either abstinence or depression history. In history-positive smokers, however, ACTH levels trended toward overall elevation and showed almost no suppression during abstinence, thus exacerbation of HPA dysregulation in history-positive smokers during smoking abstinence cannot be ruled out. Pomerleau, O.F., Pomerleau, C.S., Snedecor, S.M., Gaulrapp, S., Brouwer, R.N. and Cameron, O.G., Depression, Smoking Abstinence and HPA Function in Women Smokers. Human Psychopharmacology-Clinical and Experimental 19, pp. 467-476, 2004.
Impact of September 11 Attacks on Young Adult Drug Abuse
The authors took advantage of their ongoing longitudinal study to assess the impact of the September 11 attacks on psychopathology in young adults who lived far from New York City. During that year, 730 rural 19-21 year olds were re-assessed, one third after the attacks. Findings differed by gender and by level of prior stress. Although men showed slightly more tendency to have one or more symptoms of posttraumatic stress disorder, their rates of substance use disorder after September 11 were lower, regardless of prior use history. Women showed increased rates of substance use and abuse after the attacks. The attacks also proved a greater stressor for those under low to moderate levels of stress than for those already under significant stress. No other psychiatric disorders showed an increase after September 11 in this sample. This "natural experiment" suggests that, if confirmed in other studies, even those who are geographically removed from a traumatic event may be vulnerable, and that interventions for those at greater risk may be indicated to prevent further costs in event of such an attack. Costello, E.J, Erkanli, A., Keeler, G., and Angold, A. Distant Trauma: A Prospective Study of the Effects of September 11th on Young Adults in North Carolina. Applied Developmental Science 8, pp. 211-220, 2004.
Elementary School Intervention Demonstrates Long-Term Effects
This study explored long-term effects of the Seattle Social Development intervention. This nonrandomized controlled trial followed up participants to 21 years of age, 9 years after the intervention ended. The investigators compared 3 intervention conditions (a full 6-year intervention (grades 1 through 6); a late 2-year intervention (grades 5 and 6 only); and a no-treatment control condition) in a sample of 605 participants. Broad significant effects on functioning in school and work and on emotional and mental health were found. Fewer significant effects on crime and substance use were found at 21 years of age. Most outcomes had a consistent dose effect, with the strongest effects in subjects in the full-intervention group and effects in the late-intervention group between those in the full-intervention and control groups. This work suggests that a theory-guided preventive intervention that strengthened teaching and parenting practices and taught children interpersonal skills during the elementary grades had wide-ranging beneficial effects on functioning in early adulthood. Hawkins, J.D., Kosterman, R., Catalano, R.F., Hill, K.G. and Abbott, R.D. Promoting Positive Adult Functioning Through Social Development Intervention in Childhood: Long-term Effects from the Seattle Social Development Project. Arch Pediatr Adolesc Med. 59(1), pp. 25-31, 2005.
COMMUNITY EPIDEMIOLOGY WORK GROUP: January 2005
The CEWG is composed of researchers from 21 metropolitan areas of the United States who meet semiannually to report on patterns and trends of drug abuse in their respective areas, emerging drugs of abuse, vulnerable populations and factors that may place people at risk for drug abuse, and negative health and social consequences. Reports are based on a variety of drug abuse indicator data such as morbidity and mortality information, treatment data and local and State law enforcement data. Additional sources of information include criminal justice, correctional, medical and community health data, local and State survey information, and findings from qualitative research studies.
Cocaine continued to be a widely abused illicit stimulant drug in 2003—2004. Cocaine abuse indicators remained high in 19 of the 21 CEWG areas. The exceptions were Honolulu and San Diego where methamphetamine indicators remained high. In CEWG areas in FY 2004, cocaine accounted for more than 40 percent of the drug items analyzed by police forensic labs (National Forensic Laboratory Information System) compared with 11 percent for methamphetamine. Treatment admission data show that primary cocaine admissions exceeded those for methamphetamine/amphetamine in 15 of the 20 metropolitan CEWG areas. In most CEWG areas, high percentages of primary heroin admissions reported cocaine as their secondary drug of abuse, including in New York City (35 percent). Treatment data showed that crack was the most common type of cocaine abused. In 11 of 17 reporting CEWG areas, more than 75 percent of the primary cocaine treatment admissions had smoked the drug.
In 2003—2004, methamphetamine abuse indicators increased in five CEWG areas——Atlanta, Denver, Los Angeles, Minneapolis/St. Paul, and Phoenix. In Minneapolis/St. Paul, 61 percent of the items tested by police forensic labs in FY 2004 included methamphetamine. Methamphetamine abuse indicators were stable at high or relatively high levels in four metropolitan CEWG areas——Honolulu, San Diego, San Francisco, and Seattle, with very high proportions of primary methamphetamine treatment admissions (excluding alcohol admissions) in Hawaii (58.6 percent) and San Diego (54.4 percent). Methamphetamine indicators remained at very low levels in 11 areas. Methamphetamine/amphetamine treatment admissions represented less than 1 percent of illicit drug admissions in six northeastern/Mid-Atlantic areas, Detroit, Miami, and New Orleans. Only 1 percent or less of the items analyzed by forensic labs in Baltimore, Boston, Chicago, Detroit, Miami, New Orleans, Newark, New York City, Philadelphia, and Washington, DC, included methamphetamine.
Methylenedioxymethamphetamine (MDMA or ecstasy) abuse indicators decreased in four CEWG metropolitan areas (Boston, Miami, Seattle, and St. Louis) and school surveys showed ecstasy use decreasing among students in two States (Minnesota and Texas). Most CEWG members reported that MDMA was still used primarily by White youth and young adults, but there were reports from four areas (Chicago, New York City, St. Louis and Texas) that the abuse of this drug was spreading to, or increasing in minority communities. In eight areas, there was insufficient indicator data to draw conclusions regarding changes in MDMA patterns and trends. MDMA indicators remained stable at low levels in Atlanta, Denver, and Phoenix.
Prescription Drug Abuse differs by geographic area and population group and type of drug. "Other opiate" (excluding heroin) treatment admissions increased in many CEWG areas but remained at low levels. The proportions of other opiate admissions (excluding alcohol) in 2004 were highest in Texas (6.8 percent) and Boston (6.0 percent), and between 4.1 and 4.4 percent in Detroit, Baltimore, Colorado, and New Orleans. In FY 2004, forensic labs identified 7,319 opiate/opioid items in CEWG areas. More than 35 percent of the items were hydrocodone, 23 percent were oxycodone, 19 percent were methadone, and the remainder were mostly codeine and morphine. There were 6,604 forensic lab (NFLIS) reports of benzodiazepine-type items analyzed across 18 CEWG areas and the combined 13 sites in Texas. Most (63.8 percent) of the items were alprazolam, 18.2 percent were clonazepam items, 14.7 percent were diazepam, and 3.3 percent were lorazepam items.
Heroin indicators increased in only one area and were stable or mixed (some up and some down) in 15 areas. However, heroin indicators (especially heroin treatment admissions) remained very high in nine of these areas. For example, high proportions of 2004 treatment admissions were reported in Newark (82.6 percent), Boston (74.2 percent), Baltimore (59.8 percent), Detroit (46.0 percent), San Francisco (42.8 percent), New York City (42.1 percent), Philadelphia (36.0 percent), Los Angeles (30.1 percent), and Seattle (27.0 percent). In addition, 51.2 percent of the 2003 (2004 data were not yet available) treatment admissions in Washington, DC reported heroin as their primary drug of abuse.
Marijuana abuse indicators continued at high levels in all CEWG areas. The drug is reported to be widely available. Cannabis items accounted for between 51 and 53 percent of all drug items analyzed by forensic labs in San Diego, New Orleans, and St. Louis; between 45 and 47 percent of the items in Detroit, Boston, and Chicago; and 20 to 29 percent of the items in New York, Miami, Los Angeles, Atlanta, Texas, and Baltimore. Primary marijuana admissions (excluding alcohol) were highest in Minneapolis/St. Paul (42.1 percent) and New Orleans (39.5 percent).