Substance Use Among Mexican Adolescents Moderators of Intervention Efficacy and Risk Profile

Adolescent substance use is a complex and significant public health concern that has received considerable attention among researchers and practitioners (Gray & Squeglia, 2018). The purpose of this dissertation was to examine factors associated with substance use intervention effects and to develop subgroups of risk factors for Mexican adolescents. This dissertation utilizes secondary data from a randomized controlled trial of the school-based substance use universal prevention program, keepin’ it REAL (kiR). The dissertation included two studies. Study 1: This study tested a model on the efficacy of the school-based substance use universal prevention program, keepin’ it REAL, among a sample of Mexican adolescents (N = 3,742, 11-17 years old). Study 1 analysis included Structural Equation Modeling and results demonstrated that participation in kiR positively predicted alcohol resistance strategies and those alcohol resistance strategies were negatively and significantly associated with alcohol use. Further, depressive symptomology was a moderator of intervention effects as the effects of kiR on resistance strategies increased as the level of depressive symptomology increased. Study 2: this study explored subgroups (classes) of Mexican adolescents (N = 5,520, 11-14 years old) based on their experiences with violence (witnessing, victimization, and perpetration), depressive symptomology, and substance use (alcohol, tobacco, and marijuana). Using Latent Class Analysis (LCA) four empirically, well-differentiated classes emerged representing adolescents various risk typologies (Moderate Risk-Violence at 55% of the sample, Low Risk at 35%, High Risk at ~8%; and Moderate Risk-Substance Use at ~2%) Implications for research and practice are discussed across both studies.