Self-Reported Use of Alcohol, Marijuana, and Hard Drugs and Aggression: A Structural Equation Modeling Analysis of an Internet Survey of Long-Term Marijuana Users

In the largest study to date investigating aggressive behavior among long-time adult concomitant marijuana and alcohol users, respondents completed an Internet survey on substance use and aggressive behavior. Aggressive acts following alcohol consumption were more frequent than aggressive acts following marijuana consumption. Structural equation modeling demonstrated that there was no relationship between marijuana and aggression once recent alcohol use, hard drug history, gender, and age were taken into account. Alcohol use and history of hard drug use were associated with increased aggression. It also appears that increased aggression among males is partially mediated by alcohol use. This model fit the data better than plausible alternative models. Although the sample characteristics limit the generalizability of these findings, our data suggest that marijuana use does not lead to aggressive behavior in adults, even among frequent, long-time users.