Health and Developmental Consequences of Youth Drug Abuse

Research Findings from September, 1998 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.

Differential Cognitive Functioning in 9-12 Years Olds Relative to Prenatal Cigarette and Marijuana Exposure

In an examination of cognitive performance of 131 9-12 year-old children participating in a Carleton University longitudinal study since birth, discriminant function analysis indicated a dose-dependent association between higher prenatal cigarette exposure in utero and lower performance on global intelligence test scores, with the verbal subtests of the intelligence test discriminating maximally among levels of in utero exposure. In contrast, prenatal marijuana exposure was not associated with global intelligence or the verbal subtests, but rather was negatively related to executive function tasks that require impulse control and visual analysis/hypothesis testing, and with a number of the intelligence subtests requiring these same abilities. The cigarette results extend observations made in this sample and others at earlier ages. The marijuana findings, combined with results observed at earlier ages, lead the authors to suggest that in utero exposure to marijuana may have a negative impact on aspects of neurocognitive competence that fall under the domain of executive function. Fried, P.A., Watkinson, B.M. and Gray, R. Neurotoxicology and Teratology, 20 (3), pp. 293-306, 1998.

Maternal Smoking in Pregnancy, Child Behavior Problems, and Adolescent Smoking

This study used a longitudinal sample of mother-child dyads to examine the role of child behavior problems in explaining the effect of maternal prenatal smoking on adolescent daughter's smoking. Maternal smoking during pregnancy is associated with higher levels of child behavior problems, particularly among girls. Childhood behavior problems increase the likelihood of lifetime smoking among daughters but do not explain the effect of prenatal maternal smoking on their current smoking. Maternal smoking in pregnancy, especially heavy use of a pack or more a day, retains a unique effect on girls' current smoking with controls for current maternal smoking, child behavior problems, and maternal monitoring of the child. The effect of maternal prenatal smoking is suggestive of a biological component, which may have direct or indirect influences on adolescent smoking. The small number of cases in the study calls for the replication of these findings in large samples that would incorporate prospective measures of prenatal nicotine exposure from mother and father and additional biological and psychosocial covariates. Griesler, P.C., Kandel, D.B., Davies, M. Journal of Research on Adolescence, 8(1), pp. 159-185, 1998.

Social Context Predictors of Adolescent Substance Use Development

This study examined the form of growth in alcohol, cigarette, and marijuana use among adolescents and covariates influencing this growth. Participants were 664 male and female adolescents (ages 14 to 17 years) assessed at three time points. A common trajectory existed across the developmental period with significant increases in all three substances. Second-order multivariate extensions of the basic latent growth modeling framework indicated that associations among the individual differences parameters representing growth in the various substance use behaviors, could be adequately modeled by a higher-order substance use construct. Inept parental monitoring, parent-child conflict, peer deviance, academic failure, gender, and age, were significant predictors of initial levels and the trajectory of substance use. Results indicate considerable similarity in the development of alcohol, cigarettes and marijuana during adolescence, and suggest that it may be possible to reduce the upward trajectory of adolescent substance use if we improve the prevalence of effective parental monitoring, reduce parent-child conflict and associations with deviant peers, and increase academic success. Duncan, S.C., Duncan, T.E., Biglan, A., and Ary, D.V. Contributions of the Social Context to the Development of Adolescent Substance Use: A Multivariate Latent Growth Modeling Approach. Drug and Alcohol Dependence, 50, pp. 57-71, 1998.

Behavioral and Emotional Problems Among Children of Cocaine and Opiate Dependent Parents

Children of cocaine and opiate dependent parents are compared with demographically matched referred and nonreferred children. Cocaine and opiate dependent parents completed the Child Behavior Checklist for 410 children (218 boys, 192 girls) between the ages of 2 and 18 years (mean=7.9 years). Children of drug abusers (CDAs) were matched to referred (RCs) and nonreferred children (NCRs) on age, gender, informant, ethnicity, and SES. RCs scored lower than CDAs and NCRs on all competence scales, and higher than CDAs and NRCs on all problem scales. CDAs scored lower than NRCs on social, school, and total competence, and higher than NRCs on withdrawn, thought problems, delinquent behavior, aggressive behavior, internalizing, externalizing, and total problems. More CDAs than NRCs also scored in the clinical range on school and total competence, withdrawn, anxious/depressed, thought problems, delinquent behavior, aggressive behavior, internalizing, externalizing, and total problems. Preschool CDAs were at risk of both internalizing and externalizing problems, and adolescent CDAs were at greatest risk of externalizing problems. CDAs were at risk of internalizing and externalizing psychopathology relative to demographically matched NRCs, but showed significantly less psychopathology than shown by matched RCs. Stanger, C., Higgins, S.T., Bickel, W.K., Elk, R., Grabowski, J., Schmitz, J., Amass, L., Kirby, K.C., Seracini, A. Journal of the American Academy of Child and Adolescent Psychiatry, 1998.

Beliefs About Substance Use Among Pregnant and Parenting Adolescents

Substance use among pregnant and parenting adolescents has health implications for both mother and baby. Utilizing the Theory of Reasoned Action, a social psychological model, this research investigates the cognitive structure underlying substance use, based on longitudinal analyses of data from 3 waves of interviews with a cohort of young mothers who were 17 years old or younger during pregnancy. Use of cigarettes, alcohol, and marijuana were lowest during pregnancy, increased sharply at 6 months postpartum, and remained level at 12 months postpartum. Changes in intentions, attitudes, perceived social norms, outcome beliefs, and normative beliefs followed the same pattern. The content of changing beliefs about substance use is examined and implications for substance use interventions among postpartum adolescent mothers is discussed. Morrison, D., Spencer, M., and Gillmore, M. J. Res. Adoles., 8(1), pp. 69-95, 1998.

³¹P MRS and ERP Investigations of Substance Abuse Liability

Researchers at the University of Pittsburgh report two recent neurobiological studies elucidating components of liability to substance abuse. The first was an exploratory study to determine the heuristic potential of Phosphorus-31 magnetic resonance spectroscopy (MRS) employing chemical shift imaging (CSI), a procedure that reveals the presence of low molecular weight phosphorus containing metabolites critical in the transformation and use of energy by neurons and glia. Four distinct anatomic brain locations (i.e. frontal, occipital, right parietal, left parietal) were imaged in three groups of peripubertal children hypothesized to be at varying levels of familial SUD risk: children with a positive paternal history of SUD and a disruptive behavior disorder (DBD) diagnosis (SUD+/DBD+; n=10), those with a positive paternal SUD history in the absence of other psychopathology (SUD+/DBD-; n=13), and matched control children from normal families (SUD-/DBD-; n=13). In addition, investigators examined subjects' neuro- cognitive test results to determine any associations between cognitive capacities and regional ³¹P1 MRS spectra. The highest-risk sample (SUD+/DBD+) demonstrated a diminished proportion of phosphodiesters confined to the right parietal voxel. This right parietal phosphodiester proportion correlated only with the Information Scale score on a standard intelligence test for children. This suggested a relationship between general learning ability and motivation for academic achievement and right parietal physiology in the highest-risk sample. Variations in synaptic pruning could account for this observation. Moss, H.B., Talagala, S.L., and Kirisc, I.L. Phosphorus-31 Magnetic Resonance Brain Spectroscopy of Children at Risk for a Substance Use Disorder: Preliminary Results. Psychiatry Research-Neuroimaging, 76(2-3), pp. 101-112, 1997.

The second study examined event-related potentials (ERPs) in preadolescent boys at elevated risk for substance use due to paternal history of substance abuse or dependence. Sons (age 10-12) of fathers with an alcohol-use disorder (ALC, n=29) were matched by age, IQ, education and parental alcohol use with sons of fathers with a polysubstance abuse or dependence diagnosis (POLY, n=37). These two groups were matched with a low-risk comparison group (LOW, n=29) of boys whose fathers had no substance-use disorder diagnosis. No boy in the study met criteria for a substance-use disorder. ERPs were collected from midline (Fz, Ct, Pt) and parietal (P3, P4) electrode leads during an auditory oddball task. ERPs of boys from the ALC and POLY groups showed a slow negative shift prominent at Ct and Pz. This negative shift, evident by 100ms post-stimulus and lasting for the remainder of the 1000-ms recording period, overlapped temporally with N1, N2 and P3 amplitude differences distinguishing the ALC and POLY groups from the LOW group. The ALC and POLY groups differed from each other in N2 amplitude at Ct, which was larger for ALC subjects. These findings offer a possible alternative explanation for previously observed amplitude anomalies noted in children at risk for substance-use disorders and suggest new avenues of inquiry. Brigham, J., Moss, H., Murrelle, E., Kirisci, L., and Spinelli, J. Psychiatry Research, 73(3), pp. 133-146, 1997.