Do parents' marital circumstances predict young adults' DSM-IV cannabis use disorders? A prospective study.

AIMS: To determine whether parental marital status and marital quality in adolescence are associated with cannabis use disorders in young adults.

DESIGN: Prospective birth cohort study.

SETTING: A 21-year follow-up of 4815 mothers and their children who participated at 14 years after the child's birth in Queensland, Australia.

PARTICIPANTS: Cohort of 2303 young adults who completed the life-time version of the Composite International Diagnostic Interview-computerized version (CIDI-Auto) at the 21-year follow-up.

MEASUREMENTS: Young adults' cannabis use disorders were assessed using the CIDI-Auto. Marital status and quality (marital circumstances) and potential confounding factors such as socio-economic status (SES), maternal mental health and maternal substance use were measured when the child was 14 years of age.

FINDINGS: Marital circumstances of the mother when child was aged 14 years predicted risk of cannabis use disorders in their offspring. After adjustment for potential confounding factors, adolescents who grew up in step-father families were more likely to have cannabis use disorders in early adulthood and a moderate association was found for those children who experienced maternal marital disagreement [odds ratio (OR) = 1.7; 95% confidence interval (CI): 1.0, 2.9]. There was no significant increase in subsequent risk of cannabis use disorders for children whose mothers were unpartnered at 14 years.

CONCLUSIONS: Maternal marital status and marital quality are associated with young adults' subsequent cannabis use disorders. This association is independent of suspected confounding factors measured at 14 years. However, at least part of the association is explained by changes in marital status before 14 years.