Prevalence and predictors of "heavy" marijuana use in a Canadian youth sample

In this investigation, secondary analyses were performed on an extensive database for 473 biological and 128 adoptive families. These data, which were gathered as part of the Vancouver Family Survey, were used to examine the prevalence and predictors of "heavy" marijuana use in a Canadian youth sample aged 14-25. Results in this study showed that 12.6% of the sample reported using marijuana once a week or more. These respondents were categorized as "heavy" marijuana users. Higher levels of life problems were associated with this use pattern. Results from a series of regression analyses suggested that the family, personality, and peer domains all contributed significantly in predicting "heavy" marijuana use. Father's alcoholism and peer illicit drug use had direct relationships with heavy marijuana use in this final model. A possible mediated pathway was also suggested with the Addiction Prone Personality influencing use through its relationship with heavier peer drug use.