Epidemiology of Youth Drug Abuse

Research Findings from February, 2000 Director's Report

This section lists selected summaries from NIDA funded research projects that investigate the epidemiology, etiology, and prevention research. 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.

Gender Differences in Drug Use Traced to Differences in Opportunity to Use

Researchers at Johns Hopkins University used data from the 1979-1994 National Household Surveys on Drug Abuse to examine whether male-female differences in rates of drug use could be traced back to differences in rates of exposure to initial opportunities to try drugs, rather than to sex differences in the probability of making a transition to use, once opportunity has occurred. Survey respondents were 131,226 US residents aged 12 years and older. The investigators estimated proportion of males and females with an opportunity to use marijuana, cocaine, hallucinogens and heroin; proportions reporting use among those having an opportunity to use each drug; proportion making a "rapid transition" from initial opportunity to initial use. They found that males were more likely than females to have an initial opportunity to use drugs. Once an opportunity had occurred, however, few male-female differences were observed in the probability of making a transition into drug use,. These results suggest that the previously documented male excess in rates of drug use may be due to greater male exposure to opportunities to try drugs, rather than to greater chance of progressing from initial opportunity to actual use. This suggests that sex differences in drug involvement emerge early in the process. Van Etten, M.L., Neumark, Y.D., and Anthony, J.C. Male-Female Differences in the Earliest Stages of Drug Involvement. Addiction, 94(9), pp. 1413-1419, 1999.

The Epidemiology of Alcohol, Tobacco, and Other Drug Use Among Black Youth

This study examined the patterns, trends, and sociodemographic correlates of alcohol, tobacco, and other drug use within the black youth population. The data indicate that the drug most prevalent among black secondary students is alcohol, followed by tobacco and marijuana. By twelfth grade, 7 in 10 black secondary students have used alcohol, less than 50 percent have smoked cigarettes, 25 percent have used marijuana, and less than 2 percent have used cocaine. Trend data indicate that there were significant declines in drug use among black (and other) youth throughout the 1980s, but tobacco, alcohol, and marijuana have been on the increase throughout the 1990s. Data on the sociodemographic correlates of black students' drug use reveal that levels of substance use are, on average, higher among males than females and among students who do not live with either of their parents than among those who live with one or both parents. Although there is a trend toward lower levels of drug use among youth as parents' level of education increases, the relationship varies across drugs and grade level. The relationship between urbanicity and drug use varies considerably by drug. Finally, cigarette use is highest in the Northeast followed by the North Central region, the South, and the West; alcohol use is highest in the North Central region; and marijuana and cocaine prevalence rates vary by region, with use generally being lowest in the South. Wallace, J.M., Jr., Forman, T.A., Guthrie, B.J., Bachman, J.G., O'Malley, P.M., and Johnston, L.D. The Epidemiology of Alcohol, Tobacco and Other Drug Use among Black Youth. Journal of Studies on Alcohol, 60(6), pp. 800-809, 1999.

Psychiatric Comorbidity Among Adolescents

This study analyzed rates of comorbid psychiatric disorders among adolescents with substance use disorders (SUD) in a community-based sample from the MECA (Methods for the Epidemiology of Child and Adolescent Mental Disorders) Study, and compared the results with findings from other community-based studies of adolescents and adults. Diagnoses were established using the DISC. Three quarters of the subjects with an SUD had a comorbid anxiety, mood or disruptive behavior disorder, compared with one quarter of adolescents without SUD. The relationship with disruptive behavior disorder was the strongest and remained significant after controlling for other co-occurring disorders. Rates of comorbidity were comparable with those found in other studies of adolescents and adults, including some studies of adolescent treatment populations. The cross-sectional data did not shed light on sequence of development of the disorders. Kandel, D.B., Johnson, J.G., Bird, H.R., Weissman, M.M., Goodman, S.H., Lahey, B.B., Regier, D.A., and Schwab-Stone, M.E. Psychiatric Comorbidity Among Adolescents With Substance Use Disorders: Findings From the MECA Study. Journal of the American Academy of Child and Adolescent Psychiatry, 38, pp. 693-699, 1999.

Cigarette and Smokeless Tobacco Use Among Minority Youth

Increases in smoking/tobacco-related diseases among the Hispanic population call for an examination of its use among this population. This study examined the relationship between gender, cultural identification, migrant status, and grade level and the use of tobacco and perception of harmfulness among Mexican American youth. Results showed that when grade, cultural identification, and migrant status of parents was held constant, males more likely to use cigarettes (occasional and daily) and smokeless tobacco than females. No gender effect was found for lifetime cigarette use. The odds of using cigarettes and smokeless tobacco increase substantially across grades. Effects were found for Mexican American/Spanish and Anglo/White American cultural identification and daily cigarette use. Youths who belonged to nonmigrant families or who identified with a traditional Mexican American/Spanish culture were more likely to consider regular tobacco use harmful. Casas, J.M., Bimbela, A., Corral, C.V., Yanez, I., Swaim, R.C., Wayman, J.C., and Bates, S. Cigarette and Smokeless Tobacco Use among Migrant and Nonmigrant Mexican American Youth. Hispanic Journal of Behavioral Sciences, 20, pp. 102-121, 1998.

Developmental Differences in Beliefs About How Alcohol and Cocaine Affect Behavior

This study examines age group differences in children's knowledge and understanding of how drugs affect behavior. African-American and White children ages 5-7, 8-10, 11-14 years, and a comparison group of college students were asked about alcohol and cocaine. In descriptions of the routes drugs take in the body, mention of gastrointestinal sites decreased across age groups for cocaine but increased for alcohol; mention of vital organs peaked among 8 to 10 year olds; emphasis on peripheral body parts decreased across age groups; and emphasis on blood and brain increased. Knowledge of key elements of a physiological theory of how drugs affect behavior was greater among college students than among younger children. Understanding (causal complexity of explanations) increased with age for cocaine, though not for alcohol. Knowledge and understanding were moderately correlated, suggesting that they represent distinct aspects of thinking about drugs. This study provides data about when children come to know about and understand the effects of drugs. It suggests that younger children think at a more concrete level. They understand that drugs damage the body but are unable to provide coherent and specific physiological explanations of what happens. Sigelman, C.K., Alyson S., Goldberg, F., Davies, E.P., Dwyer, K.M., Leach, D. and Mack, K. Developmental Differences in Beliefs about How Alcohol and Cocaine Affect Behavior. Journal of Applied Developmental Psychology, 20, pp. 1-18, 1999.

A Conceptual Framework to Explain Race Differences in Drug Use

Based upon a study that investigated the influence of race and religion on drug use among Black and White youth conducted by researchers at the University of Michigan, a theoretical framework for explaining variations in drug use between the two racial groups has been proposed. Despite a growing literature on race differences in drug use, few studies have offered theoretical explanations for their existence. The central argument advanced by the investigator of this study is that in order for researchers to understand race differences in drug use outcomes, developmental processes, and mean level differences of antecedent influences on drug use, they must understand the ways in which social systems influence individual, interpersonal, and community risk and protective mechanisms that are linked to race and that, in turn, are responsible for racial variation in drug use. Wallace, J.M. Jr., Explaining Race Differences in Adolescent and Young Drug Use: The Role of Racialized Social Systems, Drugs and Society, 14 (1/2), pp. 21-36, 1999.