Background Early substance use is associated with long-term negative health and behavioral outcomes. While extensive research has examined predictors of substance use in adolescents and adults, relatively little is known about the risk factors that drive substance use in younger children. Furthermore, most studies focus on individual substances in isolation, rather than exploring the use of multiple substances. This study aims to identify demographic, family, and peer-related factors associated with alcohol, nicotine, cannabis, and multiple substance use in children aged from 9 to 13.

Methods We analyzed longitudinal data from 11,868 children enrolled in the Adolescent Brain and Cognitive Development (ABCD) Study (version 5.1), incorporating observations collected from baseline, annual follow-ups, and mid-year phone interviews. Substance use outcomes were categorized into five mutually exclusive groups: no use, alcohol only, nicotine only, cannabis only, and use of two or more substances. We applied a generalized estimating equation model to assess the associations between substance use outcomes and demographic, family, and peer characteristics.

Results Peer substance use was consistently associated with all categories of child substance use, particularly for the use of two or more substances. Parental drug use, permissiveness toward alcohol, and lower parental education were also linked to increased risk. Older age was associated with alcohol, nicotine, and multiple substance use.

Conclusions Findings highlight the importance of peer and family environments in shaping early substance use behaviors. Early prevention efforts should consider these factors to effectively target at-risk children.

The authors have declared no competing interest.

This study did not receive any funding.

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The study used ONLY data obtained by request from the National Institute of Mental Health (NIMH) Data Archive.

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