Moderated mediation of motivation and self-efficacy in a brief motivational interviewing intervention to reduce youth alcohol use

Abstract

Background Adolescent alcohol use is a significant public health concern, particularly in Latin America where rates are high. Despite the increasing use of evidence-based interventions in this region, there is a need for further research to understand how and for whom the programs work best. Objectives This study examines at how motivation and self-efficacy affected an alcohol prevention intervention among students in Zacatecas, Mexico. We tested whether motivation mediated the relationship between alcohol use risk and the success of the intervention, and whether self-efficacy moderated this relationship. Methods We analyzed data from 5,955 middle school students using correlation and mediation analyses to assess the indirect effects of motivation. We then conducted a moderated mediation analysis to see if the indirect effect differed between students with low and high self-efficacy. Results Students with higher motivation had lower risk for alcohol use and were more successful in achieving the intervention outcome. Motivation was a stronger mediator in the high self-efficacy group compared to the low self-efficacy group. Conclusions This study deepened our understanding of the mechanisms of change for the program and emphasized the importance of personal self-efficacy in targeting motivation. It also highlights the need for testing mechanisms in Latin America.