The Relationships of Early Use of Marijuana With Substance Use and Violence in Adolescent Gamblers and Non-Gamblers.

Objectives: Marijuana use (MU) and gambling are prevalent among adolescents, and marijuana products are becoming increasingly available and normalized globally. This study explored the relationships between early- (age <13 years), later- (age ≥13 years), and no-MU and substance use and violence among adolescents who gambled and did not gamble. Methods: It analyzed data from the 2019 Youth Risk Behavior Surveillance survey (n=2015) on MU, gambling, demographics, substance use, and violence, using adjusted multivariate logistic regression models. Results: The odds of current cigarette smoking, alcohol use, and heavy alcohol use; lifetime use of any substance and cocaine; current and lifetime electronic vapor product use; and physical fighting were higher across adolescents with early and later MU than those with no MU. Gambling adolescents with early-MU, compared to later- and no-MU, respectively, had greater odds of any substance use and prescription opiate misuse. Non-gambling adolescents with later-MU had higher odds of having experienced forced sexual intercourse than those with no-MU. MU by gambling status interactions were identified for prescription opiate misuse and any substance use, and having experienced bullying at school and forced sexual intercourse. However, while the simple main effects of MU on the odds of experiencing bullying among gamblers was approximately 3.9 times greater than that among non-gamblers, they were not statistically significant in either gambling group. Conclusion: Early MU is associated with risky behaviors involving the use of other substances and violence, and its relationships with several factors differ according to gambling status. Reducing early engagement in addictive behaviors may be important for preventions against substance use disorders and interpersonal violence.