Intergenerational Continuity in Cannabis Use: The Role of Parent's Early Onset and Lifetime Disorder on Child's Early Onset.

Purpose: Children's early onset of cannabis use was examined as a function of their parent's early onset of cannabis and subsequent incidence of a lifetime cannabis abuse or dependence disorder.

Methods: Prospective, longitudinal data from the Rochester Youth Development Study and the Rochester Intergenerational Study for 442 parent-child dyads (274 father-child, 168 mother-child) were used. The children were evenly split by sex. Logistic regression models and a path analysis were estimated to assess the effect of parent's cannabis use on child's onset of cannabis by age 15.

Results: Fathers who began using cannabis by age 15 were more likely to meet the criteria for a lifetime cannabis disorder (odds ratio = 5.66, 95% confidence interval = 1.89-16.90). The offspring of fathers who met the criteria for a disorder had higher odds of early initiation of cannabis use (odds ratio = 9.70, 95% confidence interval = 3.00-31.34). Early-onset cannabis use by father was indirectly associated with their child's onset of cannabis use via father's lifetime cannabis disorder. No significant effects for mothers were observed, although analyses were limited due to the low rate of mothers who met the criteria for a lifetime cannabis disorder.

Conclusions: This study provides evidence of intergenerational continuity in cannabis use among fathers and their children and confirms the need to consider timing of use and intervening mechanisms in the study of continuity in cannabis use across generations.