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.

Keywords:

• Parental substance use
• peer influence
• adolescent drug use
• latent class analysis

Acknowledgments

The authors are thankful for the technical team from the Ministry of Health, the State and Municipal Secretariats of Health and Education and all the teachers and adolescents who participated in the study. Also, we would like to thank Editage (www.editage.com) for English language editing.

Ethical approval

The research in this paper does not require ethics board approval.

Author Contributions

The submitted manuscript has been read and approved by all authors. All authors acknowledge that they have exercised due care in ensuring the integrity of the work. RGC was responsible for drafting all sections of the article and literature review. LFMR assisted the statistical analysis and its interpretation, and reviewed the full article. ZMS designed the study, wrote the grant protocol and was responsible for the final approval of the version to be published.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was funded by the Brazilian Ministry of Health through TED 89-2014. RGC is thankful to the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) PhD scholarship (process number 140272/2019-4). The study was registered in the Brazilian Registry of Clinical Trials (REBEC) (protocol number #RBR-4mnv5g).