'I decide': prevention program for marijuana use in Peruvian high school students

In Peru, the prevalence of consumption of marijuana over the years has increased and the age of the first consumption is decreasing. Preventions programs are carried out; nevertheless, they are adaptations of programs developed in other contexts, such as the United States or Spain; and are not evaluated to determine if the interventions are effective. Therefore, the objective of this study was the design, implementation and evaluation of a prevention program for the use of marijuana in high school students in Lima, based on the risk factors that were identified as the most important in a previous investigation with the same population (Chau, Romero, Otiniano, & Olivo, 2017) and of the literature consulted.

The prevention program "Yo decido” (“I decide" in English) consists of six sessions of an hour and a half each. The program has the following objectives: (1) the students are autonomous to make decisions, (2) the students modify their expectations regarding the effects of marijuana use, and (3) they are able to reject the use of marijuana. There is a guide that presents the details of the activities that are carried out in each of the sessions.

In 2018, the pilot of the program was held in a private school in Lima and 55 students participated. Their ages ranged from 13 to 17 years (M = 14.20; SD = .94). In relation to the consumption of substances, the prevalence of life of alcohol consumption was 71% (age of first consumption: M=12.38; SD = 2.23) and of tobacco was 20% (age of first consumption: M = 13.33; SD = 1.23). In addition, it was found that only one student had used marijuana, having started consumption at age 13. He indicated that he had used marijuana only once with friends. However, 20% of the sample have been offered marijuana in the last year. Added to this, 20% indicated that they are curious to try it.

In order to have a first evaluation of the program, a protocol was applied that consisted of a sociodemographic data sheet and four psychological instruments. The questionnaires measured the central constructs on which the program focuses: assertive behavior was measured with the ADCA-1 (García & Magaz, 1992); the expectations of the effects of marijuana use with the MEEQ (Schafer & Brown, 1991); the self-efficacy for the rejection of consumption with the DURSE (Carpenter, 2006); and decision-making with the DMQ-II. The protocol was applied before and after the implementation of the program. As a result, it was found that the students improved the expression of their feelings, values, tastes and preferences. Likewise, positive expectations towards the effects of marijuana decreased and self-efficacy for the rejection of consumption increased.

In 2019, in August and September the "I decide" program will be applied again in another private school to 90 students. In this opportunity, there will be a control group. For October, the results of the pre and post application will be available and will be presented.