Cannabis use, other substance use, and co-occurring mental health concerns among youth presenting for substance use treatment services: Sex and age differences.

Cannabis use among youth is of significant concern given the potential negative health impacts on young people. This study describes the mental health characteristics, cannabis use, and substance use profiles of youth aged 14 to 24 years seen at the Youth Addiction and Concurrent Disorders Service at the Centre for Addiction and Mental Health, through an age and gender lens. Almost all participating youth indicated lifetime cannabis use. Substance use and mental health profiles among those indicating a history of cannabis use differed along sex and age. Male youth were more likely to use cannabis more frequently, while female youth were more likely to use greater variety of substances and display more co-occurring mental health problems. Adolescent problematic substance use tended to co-occur with externalizing problems whereas problematic young adult substance use tended to co-occur with internalizing problems. Implications for the integrated, coordinated care of substance use and mental health concerns, with attention to the unique needs of subgroups of youth, are discussed.