Differential influence from family and best friend on adolescent drug use: a prospective cohort study with latent classes

Abstract

We aimed to analyze the association between latent classes of drug use of the ‘closest psychosocial network’ (CPN) (i.e. parents, siblings, and best friend) of adolescents, and adolescents’ lifetime drug use practices (tobacco, alcohol, and binge drinking). A prospective cohort study, nested in a randomized controlled trial, was performed among public school students in six Brazilian cities (N = 3,148; 51.4% girls; M age=12.6 years), for 21 months. Latent class analyses and multilevel mixed-effect logistic regressions were performed. Regressions were clustered at the school and individual levels and adjusted for sex, age, socioeconomic status, and relatives with whom the adolescents lived. The three-class model was the best solution for the three drug use practices, ranging from minimum to high exposure of drug use influence. Those adolescents with high exposure were more likely to use tobacco and practice binge drinking. In the alcohol model, a gradient of association was observed as the exposure increased. CPN’s drug use may predict substance use in adolescents. It was observed that if the mother’s drug use is similar to that of the father, it may predict higher drug use in the other CPN characters. Our results support the idea that preventive actions in adolescence should be comprehensive, i.e. including components targeting the family (e.g. parenting and communication skills) and peers (e.g. refusal skills and perception of use). Mainly, integrating family-based components in the curriculum of school-based prevention programs is recommended.