Effects on secondary outcomes of the Brazilian version of the European unplugged drug use prevention program: drug knowledge, intention predictors, and life skill competencies

The drug use prevention program #<i>Tamojunto2.0</i>, a Brazilian version of the European <i>Unplugged</i>, showed effectiveness in preventing the alcohol use onset at short term. However, we aimed to evaluate the program effects on its secondary outcomes, such as drug knowledge, behavioral beliefs, attitudes, decision-making skills, and refusal skills. A cluster-randomized controlled trial (registration: RBR-8cnkwq) was conducted in 73 public middle schools in three Brazilian cities (<i>N</i> = 5,208 students; 49.4% girls; <i>M</i>_age= 13.2 years). The intervention group attended twelve #<i>Tamojunto2.0</i> lessons conducted by their own teachers previously trained. The control group received no intervention. Data were collected pre-intervention (February/March 2019) and at nine-month follow-up (November/December 2019). We used multiple imputation to handle missing data and performed multilevel mixed-effect regression models, adjusted for sex, age, socioeconomic status, and city. The #<i>Tamojunto2.0</i> program seems to have increased drug knowledge (Coef.= 0.26, 95%CI = 0.17–0.36), and negative and non-positive alcohol beliefs (Coef.= 0.24, 95%CI= 0.05–0.42), according to its logical framework. Nevertheless, it was found no evidence regarding the program’s effect on marijuana beliefs, attitudes, decision-making skills, and refusal skills. These findings could explain the effectiveness of the program in preventing the onset of alcohol consumption in adolescent participants. More research is needed to observe the long-term effects of the program on primary and secondary outcomes.