Using Cannabis 2-4 Times a Month Was the Key Threshold for Problematic Use in Teens

Decision tree analysis identified cannabis use at least 2-4 times per month as the most important predictor of problematic use across all three indicators (unsuccessful quit attempt, excessive use, feeling addicted). For teens who used less frequently, initiating before age 14 and using alone further increased risk. No sociodemographic differences emerged among high-risk groups.

Decision tree analysis of 8,915 cannabis ever-users from the COMPASS survey of secondary school students (mean age 15.5) in Quebec, Canada. Three indicators of problematic use were examined: unsuccessful quit attempt, excessive use, and feeling addicted.

Identifying a clear frequency threshold for problematic use gives clinicians and educators a practical screening criterion. The finding that early initiation and solitary use add risk provides additional targets for prevention.

Rather than a binary use/no-use framework, this research identifies specific patterns (frequency, age of onset, social context) that predict problematic outcomes. This supports targeted harm reduction rather than abstinence-only messaging.

Cross-sectional design cannot determine whether frequency causes problematic use or vice versa. Self-reported data. Quebec-specific sample. Decision tree analysis may not capture complex interactions between predictors.