William B. Hansen

Preventing alcohol, marijuana, and cigarette use among adolescents: Peer pressure resistance training versus establishing conservative norms☆

BACKGROUND Two strategies for preventing the onset of alcohol abuse, and marijuana and cigarette use were tested in junior high schools in Los Angeles and Orange Counties, California. The first strategy taught skills to refuse substance use offers. The second strategy corrected erroneous normative perceptions about prevalence and acceptability of use among peers and established conservative groups norms regarding use. METHODS Four experimental conditions were created by randomly assigning schools to receive (a) neither of the experimental curricula (placebo comparison), (b) resistance skill training alone, (c) normative education alone, or (d) both resistance skill training and normative education. Students were pretested prior to the program and post-tested 1 year following delivery of the program. RESULTS There were main effects of normative education for summary measures of alcohol (P = 0.0011), marijuana (P = 0.0096), and cigarette smoking (P = 0.0311). All individual dichotomous measures of alcohol, marijuana, and tobacco use indicated significant reductions in onset attributable to normative education. There were no significant main effects of resistance skill training. CONCLUSION These results suggest that establishing conservative norms is an effective strategy for preventing substance use.

Adolescents at Risk

Adolescence is a developmental period of rapid physical, psychological, sociocultural, and cognitive changes characterized by efforts to confront and surmount challenges and to establish a sense of identity and autonomy. While many adolescents navigate the sometimes turbulent course from childhood to adulthood to become productive and healthy adults, there is growing concern that far too many others may not achieve their full potential as workers, parents, and individuals. Unfortunately, adolescence is also a period fraught with many threats to the health and well-being of adolescents, many of whom suffer substantial impairment and disability. Much of the adverse health consequences experienced by adolescents are, to a large extent, the result of risk behaviors (Ginzberg, 1991). As such, they are preventable.

Affective and Social Influences Approaches to the Prevention of Multiple Substance Abuse among Seventh Grade Students: Results from Project SMART

Two drug abuse prevention curricula were tested to determine their efficacy in preventing the onset of tobacco, alcohol, and marijuana use among adolescents. The first program focused on prevention through social pressure resistance training. The second featured affective education approaches to prevention. Curricula were tested on seventh grade students. Subjects were pretested just prior to the program and were post-tested at 12 and 24 months. Post-test analyses indicated that the social program delivered to seventh grade subjects was effective in delaying the onset of tobacco, alcohol, and marijuana use. No preventive effect of the affective education program was observed. By the final post-test, classrooms that had received the affective program had significantly more drug use than controls.

Testing the Generalizability of Intervening Mechanism Theories: Understanding the Effects of Adolescent Drug Use Prevention Interventions

Outcome research has shown that drug prevention programs based on theories of social influence often prevent the onset of adolescent drug use. However, little is known empirically about the processes through which they have their effects. The purpose of the present study was to evaluate intervening mechanism theories of two program models for preventing the onset of adolescent drug use. Analyses based on a total of 3077 fifth graders participating in the Adolescent Alcohol Prevention Trial revealed that both normative education and resistance training activated the causal processes they targeted. While beliefs about prevalence and acceptability significantly mediated the effects of normative education on subsequent adolescent drug use, resistance skills did not significantly predict subsequent drug use. More impressively, this pattern of results was virtually the same across sex, ethnicity, context (public versus private school students), drugs (alcohol, cigarettes, and marijuana) and levels of risk and was durable across time. These findings strongly suggest that successful social influence-based prevention programs may be driven primarily by their ability to foster social norms that reduce an adolescents social motivation to begin using alcohol, cigarettes, and marijuana.

Attrition in prevention research

Selective attrition can detract from the internal and external validity of longitudinal research. Four tests of selective attrition applicable to longitudinal prevention research were conducted on data bases from two recent studies. These tests assessed (1) differences between dropouts and stayers in terms of pretest indices of primary outcome variables (substance use), (2) differences in change scores for dropouts and stayers, (3) differences in rates of attrition among experimental conditions, and (4) differences in pretest indices for dropouts among conditions. Results of these analyses indicate that cigarette smokers, alcohol drinkers, and marijuana users are more likely to drop out than nonusers, limiting the external validity of both studies. For one project, differential rates of attrition among conditions suggested a possible attrition artifact which will interfere with interpretation of outcome results, possibly masking true program effectiveness. Recommendations for standardizing reports of attrition and for avoiding attrition through second efforts are made.

Effects of Program Implementation on Adolescent Drug Use Behavior The Midwestern Prevention Project (MPP)

This study evaluated the relationship between level of program implementation and change in adolescent drug use behavior in the Midwestern Prevention Project (MPP), a school- and community-based program for drug abuse prevention. Trained teachers implemented the pro gram with transition year students. Implementation was measured by teacher self-report and validated by research staff reports. Adolescent drug use was measured by student self-report; an expired air measure of smoking was used to increase the accuracy of self-reported drug use. Regression analyses were used to evaluate adherence; exposure, or amount of implementation; and reinvention. Results showed that all schools assigned to the program condition adhered to the research by implementing the program. Exposure had a significant effect on minimizing the increase in drug use from baseline to one year. Exposure also had a larger magnitude of intervention effect than experimental group assignment. Reinvention did not affect drug use. Results are discussed in terms of research assumptions about quality of program implementation, and possible school-level predictors of implementation.

The Consistency of Peer and Parent Influences on Tobacco, Alcohol, and Marijuana Use among Young Adolescents

The purpose of this study was to determine the degree to which the use of tobacco, alcohol, and marijuana by young adolescents can be described using a common theoretical model. Structural models were created in which psychosocial variables hierarchically predicted the use of each substance. The fit of a model in which paths from predictor variables were constrained to be equal was not inferior in any meaningful way to that of a model in which all path coefficients were freely estimated, thus suggesting that use of tobacco, alcohol, and marijuana by young adolescents may be considered to be a unitary phenomenon. A simplified model, in which these substances were combined into a single latent variable, showed a good fit. The results of these analyses suggest that it may be beneficial to consider adolescent substance use to be a unitary phenomenon.

Reliability of Self-Report Measures of Drug Use in Prevention Research: Evaluation of the Project SMART Questionnaire via the Test-Retest Reliability Matrix.

The present article describes an evaluation of a self-report questionnaire administered to whole classrooms of 7th graders. Using the test-retest reliability matrix (based on concepts of Cronbach [1] and Campbell and Fiske [2]), eight of nine drug-use indices appeared to have acceptable to good reliability. The three measures included in the test-retest reliability matrix provide stronger evidence for good reliability than could any single measure.

Attrition in Substance Abuse Prevention Research

A meta-analysis of substance abuse prevention studies revealed that the mean proportion of subjects retained dropped from 81.4% at 3-month to 67.5% at 3-year follow-ups. Time from pretest alone accounted for less than 5% of the variance. Other available predictors of retention were not significant. Researchers are encouraged to interpret their results in light of these normative data and to adopt second-effort strategies to reduce attrition.

Modeling transitions in latent stage-sequential processes: a substance use prevention example

This article illustrates the use of latent transition analysis (LTA), a methodology for testing stage-sequential models of individual growth. LTA is an outgrowth of latent class theory and is a particular type of latent Markov model emphasizing the use of multiple manifest indicators. LTA is used to compare the fit of two models of early adolescent substance use onset and to assess the effects of a school-based substance use prevention program on Ss measured in 7th grade and again in 8th grade. Several interesting findings emerged. First, a model of substance use onset including both alcohol and tobacco use as possible starting points fit better than a model that included alcohol use as the only starting point. Second, Ss who had tried tobacco but not alcohol in in 7th grade seemed to be on an accelerated onset trajectory. Third, the normative education prevention program was generally successful, except for the students who had tried only tobacco in 7th grade.