Increasing numbers of adolescents approve of and use marijuana, and report that marijuana is relatively easy to obtain. Because marijuana use is associated with a host of negative consequences, many prevention campaigns have been implemented over the years, but most have been proven ineffective. We believe the failure of many campaigns is due to the common practice of assuming that the same message will successfully persuade a diverse audience of adolescents. This application seeks to prevent marijuana use by developing and testing a theory-based Tailored Interactive Media Intervention (TIMI) that avoids this common shortcoming. This intervention combines two theories that individually have been shown to have powerful effects on attitude change. In combination, they provide the means necessary to stem the accelerated tide of adolescent marijuana use that is evident in today's social statistics. The approach begins by either reinforcing anti-marijuana beliefs or weakening pro-marijuana beliefs. A second message, tailored to account for each participant's view of the normative nature of peer marijuana use, is then delivered. For pro-marijuana youth, this message attacks an attitude weakened by the first communication. Our approach is based on the resistance appraisals model (RAM), which specifies strategies to reduce resistance to persuasion, and the deviance regulation model (DRM), which guides the ways messages should be framed to account for differences in adolescents'perceptions of peer norms. Experiment 1 tests the utility of these theories separately in a marijuana prevention context. Experiment 2 tests the effects of combining the theories in developing a TIMI, and follows with a test of the effect of administering the TIMI repeatedly over the course of a school year. Outcomes include attitude toward marijuana, attitude certainty, intention to use marijuana, and actual usage. This approach overcomes resistance by reducing attitude certainty, and it creates maximally persuasive messages by accounting for and capitalizing on individually perceived peer norms, to which adolescents are exquisitely attuned. It outlines a feasible and cost- effective way of preventing adolescent marijuana use on a large scale by weakening and then directly targeting pro-drug attitudes in a manner that is widely applicable for all school-attending adolescents, a group in which marijuana use has risen significantly and dramatically over the past 4 years.

Public Health Relevance

Adolescent marijuana use is associated with a range of harmful consequences, including long-term cognitive deficits and a five-fold increase in the likelihood of drug and alcohol problems later in life. Marijuana use is prevalent and on the rise-i 2009 16% of 8th graders, 32% of 10th graders, and 42% of 12th graders had used marijuana. Adolescent disapproval and perceived risk of using has also decreased from 2008 to 2009. Worse, a majority of 10th through 12th graders described the drug as easy or very easy to obtain. This pattern of increased use, ready availability, and low disapproval is a cause for serious concern, especially when considering the harmful consequences of use. Several mass media campaigns have attempted to prevent adolescent marijuana use, but evaluations of these major campaigns have indicated that they are ineffective at best and even harmful to some sub-populations. This is likely because in these campaigns, the same preventive messages are applied to all potential users. Our own research has shown that messages that influence some users can fall flat with others, in predictable ways. This application is based on the premise that persuading youth to adopt and maintain anti-marijuana attitudes may require messages tailored to their specific beliefs. Tailored messages are more effective than generic health messages, and can be easily delivered in today's classrooms through an interactive computer program. The proposed research seeks to deliver tailored persuasive messages to adolescents based on the use of two complementary models, the Resistance Appraisal Model and the Deviance Regulation Model. These models account for and capitalize on two critical variables: resistance to persuasion and social norms. The intervention developed from this application has the potential to be placed online and made available to adolescents nationwide. The strategy used in developing this model of mediated prevention can be generalized across a range of public health issues, and hence this research may contribute both to theory development and practical application in many different areas of research on factors that affect the public welfare.

National Institute of Health (NIH)
National Institute on Drug Abuse (NIDA)
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Community-Level Health Promotion Study Section (CLHP)
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Diana, Augusto
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Claremont Graduate University
Other Domestic Higher Education
United States
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Crano, William D; Alvaro, Eusebio M; Tan, Cara N et al. (2017) Social mediation of persuasive media in adolescent substance prevention. Psychol Addict Behav 31:479-487
Hohman, Zachary P; Crano, William D; Niedbala, Elizabeth M (2016) Attitude ambivalence, social norms, and behavioral intentions: Developing effective antitobacco persuasive communications. Psychol Addict Behav 30:209-19
Handren, Lindsay M; Donaldson, Candice D; Crano, William D (2016) Adolescent Alcohol Use: Protective and Predictive Parent, Peer, and Self-Related Factors. Prev Sci 17:862-71
Donaldson, Candice D; Handren, Lindsay M; Crano, William D (2016) The Enduring Impact of Parents' Monitoring, Warmth, Expectancies, and Alcohol Use on Their Children's Future Binge Drinking and Arrests: a Longitudinal Analysis. Prev Sci 17:606-14
Donaldson, Candice D; Siegel, Jason T; Crano, William D (2016) Nonmedical use of prescription stimulants in college students: Attitudes, intentions, and vested interest. Addict Behav 53:101-7
Lac, Andrew; Handren, Lindsay; Crano, William D (2016) Conceptualizing and Measuring Weekend versus Weekday Alcohol Use: Item Response Theory and Confirmatory Factor Analysis. Prev Sci 17:872-81
Siegel, Jason T; Tan, Cara N; Navarro, Mario A et al. (2015) The power of the proposition: frequency of marijuana offers, parental knowledge, and adolescent marijuana use. Drug Alcohol Depend 148:34-9
Donaldson, Candice D; Nakawaki, Brandon; Crano, William D (2015) Variations in parental monitoring and predictions of adolescent prescription opioid and stimulant misuse. Addict Behav 45:14-21
Nakawaki, Brandon; Crano, William (2015) Patterns of substance use, delinquency, and risk factors among adolescent inhalant users. Subst Use Misuse 50:114-22
Lamb, Christopher S; Crano, William D (2014) Parents' beliefs and children's marijuana use: evidence for a self-fulfilling prophecy effect. Addict Behav 39:127-32

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