Performance Improvement 1995. Evaluating the Effects of School-Based Intervention Programs To Prevent Teenager Drug Use and Abuse



This study provided followup to a large-scale, randomized, controlled field trial of school-based training in substance abuse prevention. It examined the effectiveness of Life Skills Training (LST), an approach that teaches social resistance and other personal and coping skills. The study provides the first evidence that school-based intervention programs conducted by regular classroom teachers can produce durable reductions in tobacco, alcohol, and illicit drug use. These salutary effects were sustained 6 years after the introduction of the program, providing impetus for the widespread adoption of similar programs.


This followup study evaluated the long-term effectiveness of a New York school-based substance abuse prevention program started 6 years earlier. It surveyed high school seniors who had been trained in the seventh grade in a substance abuse prevention program called Life Skills Training. This approach teaches social resistance skills and general personal and social skills, that is, ways to improve self-esteem, decisionmaking, and problemsolving. The study also analyzed what types of adolescents were at risk for drug use.


Substance use patterns established in adolescence have serious consequences for the Nation's health. In 1993, 76 percent of high school seniors used alcohol and 31 percent used illicit and/or illegal drugs. In addition, of those seniors surveyed, 29.9 percent had smoked cigarettes within the last 30 days and 10.7 percent had used smokeless tobacco within the last 30 days. Providing students with factual information about drugs and drug abuse was the most common prevention approach up to 1985, but it did not appear to be effective in changing behaviors.

The rationale for this study was to evaluate newer approaches aimed at increasing awareness of the social influences that encourage drug use and improve social resistance, personal, and coping skills. In 1985, the National Institute on Drug Abuse (NIDA) funded a study in 56 schools in New York State to determine the long-term effectiveness of a substance abuse prevention program for students in seventh grade, with booster sessions in the eighth and ninth grades. Earlier followups (when students were in the ninth grade) revealed that LST was effective at reducing the use of gateway drugs: tobacco, alcohol, and marijuana. The use of tobacco, for example, declined by over 50 percent.

The followup study described here examined whether the training continued to be effective in the senior year of high school and whether its effectiveness extended to illicit drugs in addition to marijuana. The 6 years of followup data also enabled researchers to analyze what types of students were more prone to drug use.

The New York State study was also begun to overcome a dearth of information about the effectiveness of substance abuse prevention programs. Little evidence had been accumulated on (1) the durability of program effects more than a year afterward; (2) program effects on multiple drug use and/or use of illicit drugs other than marijuana; or (3) programs using techniques of random assignment, with the school as the unit of assignment and analysis.


The initial program, offered in 1985, consisted of 12 curriculum units taught in 15 class periods in the seventh grade, with booster classes in the eighth and ninth grades. The intervention was based on an LST curriculum that taught cognitive-behavioral skills for increasing awareness of the causes and effects of substance use, resisting peer and advertising pressure, making decisions, managing anxiety, communicating effectively, asserting one's rights, and developing personal relationships and other psychological skills. The curriculum was randomly assigned to schools under two conditions: (1) teachers received training materials, training, and staff support;
or (2) teachers received only packaged training materials. A third group of schools, the control group, did not receive any substance abuse training.

The original study, conducted by Cornell University Medical College, used a true experimental randomized design and analyzed outcomes as well as measures of curriculum implementation. To ensure comparability of results across different schools, the schools were selected on the basis of similar demographic variables such as gender, age, and ethnicity. The sample was approximately 52 percent male and 91 percent white.

Followup data presented in this part of the study were collected on a cohort of 3,597 participants (60 percent of the original 5,954 students) at the end of the 12th grade. Separate analyses were performed on a restricted sample of 2,752 students from 50 schools who received at least 60 percent of the prevention program to determine the effectiveness of the two preventive interventions when implemented with an acceptable degree of fidelity. Two questionnaires were used: the first was exactly the same as an earlier followup, and the second was a brief, anonymous survey of illicit drug use. Data on illicit drug use were collected anonymously from 454 individuals using a mailed survey.


The probability of smoking, drinking immoderately, or using marijuana was significantly lower--as much as 40 percent lower--for students who received the prevention program than for those in the control group. The strongest prevention effects were found among students who received at least 60 percent of the intervention and for students whose teachers received the most staff support.

The probability of using multiple drugs was significantly lower--by as much as 60 percent--for weekly use. Long-term prevention effects were found 6 years after initial assessment for tobacco, alcohol, and marijuana use, and after 6 \xba for illicit drug use. Booster sessions were found to contribute to the reduction in substance use.

The students least likely to engage in drug use had better knowledge of drug use prevalence, better skills for refusing drug offers, fewer expectations about the benefits of drug use, and increased life skills and psychological adjustment, among other factors.

Use of Results

The results of this long-term followup provide empirical support for the efficacy of a school-based prevention strategy based on LST in preventing drug use and abuse. Because the study population was primarily white, research is needed to determine the effectiveness of this type of program for inner-city minority students.

To produce durable prevention effects, the study revealed that school-based drug abuse prevention programs must (1) increase knowledge of drug use prevalence rates, and improve skills for refusing drug offers as well as general life skills; (2) decrease expectations and positive attitudes and beliefs about the benefits of drug use; (3) be properly and completely implemented; and (4) include booster sessions.


Botvin, Gilbert, et al. 1995. Long-term followup results of a randomized drug abuse prevention trial in a white middle-class population. Journal of the American Medical Association, 273(14): 1106-1112.

Agency sponsor:

National Institutes of Health

Federal contact:

Larry A. Seitz, Ph.D.
Division of Epidemiology and Prevention Research
National Institute on Drug Abuse
National Institutes of Health
5600 Fishers Lane, Room 9A-53
Rockville, MD 20857
(301) 443-1514 Fax: (301) 443-2636

Principal investigator:

Gilbert J. Botvin, Ph.D.
Cornell University Medical College, Ithaca, NY

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