Pot use in teens tied to later depression, suicide risk

Study design

• This meta-analysis evaluated 11 longitudinal and prospective studies (comprising 23,317 individuals) that assessed cannabis use during adolescence (
• Association between cannabis use in adolescents and development of depression in young adulthood (18-32 years old) was assessed.
• Funding: Canadian Institutes of Health Research; Quebec Network on Suicide, Mood Disorders and Related Disorders.

Key results

• Cannabis use vs nonuse during adolescence was associated with an increased risk of developing depression in young adulthood (OR, 1.37; 95% CI, 1.16-1.62; I², 0%).
• Cannabis use was also associated with increased risk for suicidal ideation (OR, 1.50; 95% CI, 1.11-2.03; I², 0%) and attempted suicide later in life (OR, 3.46; 95% CI, 1.53-7.84; I², 61.3%).
• Association between cannabis and risk of developing anxiety was not significant (OR, 1.18; 95% CI, 0.84-1.67; I², 42.0%). 

Limitations

• Strong causal association between cannabis use and later depressive disorder could not be established.
• Heterogeneity among studies in methods of detecting major depressive disorder.

Coauthored with Antara Ghosh, PhD