Health and Developmental Consequences of Youth Drug Abuse

Research Findings from May, 2002 Director's Report

This section lists selected summaries from NIDA funded research projects that investigate the developmental implications of drug use. The summaries provided were selected from recent issues of the Director's Report to the National Advisory Council on Drug Abuse. For a more comprehensive listing of NIDA funded projects see the Director's Report.

Current and Former Marijuana Use: Effects on IQ in Young Adults

Studying a cohort of young individuals who have been followed since birth, Peter Fried and colleagues have been able to assess IQ before and after onset of marijuana use. Seventy individuals aged 17-20 years old were involved in the analyses, using self-report of drug use and urinalysis. IQ in the 17-20 year-old period was compared with IQ in the 9-12 year-old period (pre-marijuana use). In addition, IQ differences across the two time periods were compared for current heavy users (at least 5 joints per week), current light users (less than 5 joints per week), former users (had not smoked regularly for at least 3 months), and non-users (never smoked more that once per week and no smoking in the past 2 weeks). Among the factors controlled for in the analyses are socioeconomic status variables (e.g., family income and parental education), education level of participant, age, sex, maternal use of cigarettes, marijuana and alcohol during pregnancy, participant's exposure to secondhand marijuana smoke, and participant's use of alcohol and tobacco. Current marijuana use was negatively associated with global IQ score only in the current heavy users (average decrease of 4.1 points over the time periods, current average IQ of 105.1). A negative effect was not found among subjects who had been heavy users but were no longer using marijuana. The authors caution that the negative effects of current heavy use and the lack of long-term effects found in this study should be interpreted carefully. The relatively small number of subjects for whom data were available, the length of time that the drug was used, the estimated total number of joints smoked, and the young age of the subjects all may serve to moderate effects. The authors also emphasize that broad intellectual functioning was examined in this report (i.e., only overall IQ), and it remains to be ascertained whether the absence of a residual marijuana effect of past use would also be evident in more specific cognitive domains such as memory and attention. Fried, P., Watkinson, B., James, D., and Gray, R. Current and Former Marijuana Use: Preliminary Findings from a Longitudinal Study of Effects on IQ in Young Adults. Canadian Medical Association Journal, 166, pp. 887-891, 2002.

Effects of Fetal and Adolescent Nicotine Exposure on CNS Vulnerability

It is widely believed that nicotine is a neuroteratogen that targets synaptic function during critical developmental stages. Recent studies indicate that central nervous system (CNS) vulnerability extends into adolescence, the time that smoking typically commences. In the past year, NIDA supported researchers, Dr. Theodore Slotkin and his associates at Duke University Medical Center have demonstrated that nicotine administration during development alters the functioning of the serotonergic (5-HT) systems, the neurotransmitter pathway closely associated with depression, throughout the brain. Dr. Slotkin examined indices of the development of 5-HT projections and 5-HT presynaptic activity following prenatal and adolescent nicotine exposure of rats. These studies used the nicotine dose rates that replicate the plasma nicotine levels found in smokers. Fetal nicotine exposure (gestational days 4-21) showed a decrease in the cerebrocortical binding of paroxetine (PXT), a marker for the 5-HT transporter, indicative of a decrease in nerve terminals in that region. This effect lasted into adulthood. There was a corresponding increase in PXT binding in the midbrain and brainstem, the region containing the 5-HT cell bodies that project to the cerebral cortex, a pattern typical of reactive sprouting in response to nerve terminal damage. After adolescent nicotine treatment (postnatal days 30-47), PXT binding was reduced in the hippocampus and striatum instead of the cerebral cortex, again accompanied by increased binding in the midbrain and brainstem. These effects within each region were gender selective, although both males and females displayed abnormalities. Superimposed on this overall effect, there were transient changes of 5-HT transporter expression likely due to the acute stimulant effects of nicotine. Additional studies showed that withdrawal from adolescent nicotine treatment led to suppression of activity in the cerebral cortex and activation in the midbrain. These results indicate that both fetal and adolescent nicotine exposure elicit apparent damage to 5-HT projections with reactive increases in regions containing 5-HT cell bodies. These findings are important as long-term changes in 5-HT innervation and /or synaptic activity may play a role in the subsequent development of depression in the offspring of women who smoke during pregnancy or in adolescent smokers. Xu, Z., Seidler, F.J., Ali, S.F., Slikker Jr., W., and Slotkin, T.A. Fetal and Adolescent Nicotine Administration: Effects on CNS Serotonergic Systems. Brain Research, 914, pp.166-178, 2001.

Early Adolescent Marijuana Use: Risks for the Transition to Young Adulthood

This study assessed the relationship of early adolescent marijuana use to performance of developmental tasks integral to the transition to young adulthood. The tasks concerned intimacy, education, and work and social conformity. African American (N = 617) and Puerto Rican (N = 531) youths completed questionnaires in their classrooms. Five years later they were individually interviewed. Logistic regression analysis estimated the increased likelihood that early marijuana users would make an inadequate transition to young adult social roles. Analyses examining the association between early marijuana use and 20 outcome variables found significant relationships for 10 of them: (a) having lower educational and occupational expectations; (b) being suspended or expelled from school, fired from jobs, 'high' at school or work, collecting welfare; and (c) rebelliousness, not participating in productive activities, not attending church, and being an unmarried parent. Marijuana use was not related to any of the intimate relationship measures. These findings emerged with controls on gender, ethnicity, age and mother's education. The authors conclude that among African Americans and Puerto Ricans, early marijuana use predicts less adequate performance on some developmental tasks integral to becoming an independent young adult. Marijuana is not a benign drug and is associated with future risks for the individual and society at large. Brook, J.S., Adams, R.E., Balka, E.B., and Johnson, E. Psychol Med, 32(1), pp. 79-91, January 2002.

Persistence of Violence In The Transition To Adulthood

Researchers examined violent behavior from ages 13-21 yrs and identified predictors at age 10. Logistic regression was used to assess predictors of developmental patterns of violence. The sample is from a study of 808 youth interviewed annually from age 10 to 16 yrs, and again at ages 18 and 21. Over 28% of the youth in the sample reported nonviolence throughout adolescence and into early adulthood. Most youth (55%) engaged in violence in adolescence but desisted from violence in early adulthood, while 16% persisted in violent behavior at age 21. Violence in adolescence was best predicted by male gender, Asian American ethnicity (a protective factor), childhood fighting, early individual characteristics, and early antisocial influences. Adult persistence of violence was best predicted by male gender, early school achievement (which was protective), and early antisocial influences. Early prosocial development was also protective against violence persistence for females. Implications for prevention are discussed. Kosterman, R., Graham, J.W., Hawkins, J.D., Catalano, R.F., and Herrenkohl, T.I., Violence & Victims,16(4), pp. 355-369, 2001.

Test of the Plausibility of Adolescent Substance Use Playing a Causal Role in Developing Adulthood Antisocial Behavior

DSM-IV antisocial personality disorder diagnosis requires that conduct disorder be exhibited before age 15. However, recent studies have reported on men and women without conduct disorder before age 15 but qualified for the adulthood antisocial personality criterion (AAB). This general-population, retrospective study investigated the plausibility of causal relationships between adolescent drug and alcohol misuse (ADAM) and AAB among subgroups who reported childhood-onset conduct problems (CP), adolescent-onset CP, or no more than one conduct problem. Data from the Epidemiological Catchment Area Study (N=8,724) suggested that persons with childhood-onset CP are at much greater risk for AAB than persons with adolescent-onset CP. Nevertheless, large proportions of men and women with AAB had adolescent-onset CP or no CP. Regardless of CP history, being drunk by age 18 or having a drug use-related symptom before age 18 increased AAB risk, even after controlling for having a substance use-related disorder in adulthood. Mechanisms that potentially explain these associations are discussed. Ridenour, T.A, Cottler, L.B, Robins, L.N., Compton, W.M., Spitznagel, E.L., Cunningham-Williams, R.M. Journal of Abnormal Psychology, 111(1), pp. 144-155, 2002.

Influence of a Substance-Abuse-Prevention Curriculum on Violence-Related Behavior

The objective of this work was to test the impact of a school-based substance-abuse prevention program, Project Towards No Drug Abuse (TND), on risk for violence. Logistic regression analyses tested whether victimization, perpetration, or weapon carrying differed for intervention students relative to control students within a sample of 850 continuation high school students followed over 12 months. Data indicate a higher risk for victimization (OR=1.57) among male control students. No intervention effect was observed for female students or for perpetration among males. The findings provide limited support for a generalization of TND's preventive effect. Simon, T.R., Sussman, S., Dahlberg, L.L., and Dent, C.W. Influence of a Substance-Abuse-Prevention Curriculum on Violence-Related Behavior. American Journal of Health Behavior, 26(2), pp. 103-110, 2002.

Deviant Peer Association and Aggression toward Female Partner

Deviancy training was examined as a risk factor for physical and psychological aggression toward a female partner among boys and young men in the Oregon Youth Study. Hostile talk about women during videotaped male friendship interaction was hypothesized to indicate a process by which aggression toward women is reinforced within male peer networks. Both antisocial behavior and hostile talk were predicted to be associated with later aggression toward a female partner. Prospective developmental models were tested from 9-10 years of age through young adulthood. Findings indicated that the relation of deviant peer association in adolescence and later aggression toward a partner was mediated by antisocial behavior; observed hostile talk about women with male peers explained additional variance in aggression toward a partner. Capaldi, D.M., Dishion, T.J., Stoolmiller, M., and Yoerger, K. Aggression Toward Female Partners by at-risk Young Men: The Contribution of Male Adolescent Friendships. Developmental Psychology, 37(1), pp. 61-73, 2001

Binge Drinking Trajectories from Adolescence to Emerging Adulthood in a High-Risk Sample: Predictors and Substance Abuse Outcomes

This study describes binge-drinking trajectories from adolescence to emerging adulthood in 238 children of alcoholics and 208 controls. Mixture modeling identified three trajectory groups: early-heavy (early onset, high frequency), late moderate (later onset, moderate frequency), and infrequent (early onset, low frequency). Nonbingers were defined a priori. The early-heavy group was characterized by parental alcoholism and antisociality, peer drinking, drug use, and (for boys) high levels of externalizing behavior, but low depression. The infrequent group was elevated in parent alcoholism and (for girls) adolescent depression, whereas the nonbinger and late-moderate groups showed the most favorable adolescent psychosocial variables. All 3 drinking trajectory groups raised risk for later substance abuse or dependence compared with the nonbingers, with the early-heavy group at highest risk. Chassin, L., Pitts, S.C., Prost, J. Journal of Consulting & Clinical Psychology, 70(1), pp. 67-78, 2002.

Emotional Distress Both Contributes To And Is Influenced By Cigarette Smoking

Empirical evidence regarding the causal nature of the relationship between emotional distress and tobacco use in male and female adolescents provides support for both the distress-to-use and the use-to-distress hypotheses. Using a cross-lagged model with 3 waves of data from 2,961 adolescents followed into young adulthood, the authors tested the hypothesis that this relationship changes over time. As hypothesized, emotional distress in Grade 10 was associated with increased smoking in Grade 12 for both boys and girls. Smoking in Grade 12 was, in turn, associated with increased emotional distress in young adulthood. The addition of 3 factors (rebelliousness, deviance, and family problems) to the model did not alter the results. Results suggest that the relationship between tobacco use and emotional distress is a dynamic one in which distress initially leads to use but then becomes exacerbated by it over time, Orlando, M., Ellickson, P.L., and Jinnett, K., Journal of Consulting & Clinical Psychology, 69(6), pp. 959-970, 2001.

High-Risk Behaviors Associated With Early Smoking

This study compared problem behaviors of 7th grade nonsmokers, experimenters, and smokers at baseline and at 5-yr follow-up. 4,327 7th grade students completed questionnaires concerning academic difficulties, substance use, and delinquent behavior at baseline and at 5-yr follow-up. Subjects were classified as nonsmokers, experimenters, or smokers. Results showed that, compared with nonsmokers, early smokers were 3+ times more likely by 12th grade to regularly use tobacco and marijuana, use hard drugs, sell drugs, have multiple drug problems, drop out of school, and experience early pregnancy and parenthood. These subjects were also at higher risk for low academic achievement and behavioral problems at school, stealing and other delinquent behaviors, and use of predatory and relational violence. Early experimenter subjects were at significantly greater risk for these problems as well, although to a lesser extent than smokers. The higher risk of many of these problems was evident for experimenters and smokers as early as 7th grade. It is concluded that early experimenters and smokers are more likely than nonsmokers to experience various problem behaviors by 12th grade, with many of these problems evident as early as 7th grade. Ellickson, P.L., Tucker, J.S., and Klein, D.J., Journal of Adolescent Health, 28(6), pp. 465-473, 2001.