Parental Cannabis Use Is Associated with Cannabis Initiation and Use in Offspring

To assess, before legalization in Canada, whether parental cannabis use is associated with initiation of use in adolescent offspring or with use in young-adult offspring.

Data were available in 2 longitudinal studies in Montréal, Canada. In AdoQuest, 1048 parents with children in grade 6 reported past-year cannabis use. Cannabis initiation among offspring was measured in grade 7, 9, and/or 11. In the Nicotine Dependence in Teens study, cannabis use data were available for 584 participants (mean age 24 years) and their parents (ie, 542 offspring-mother pairs, 438 offspring-father pairs). The association between parental and offspring cannabis use was estimated using multivariable logistic regression in both studies.

In AdoQuest, grade 6 never-users were 1.8 times more likely to initiate cannabis during high school if their parents reported past-year use. In the Nicotine Dependence in Teens study, the aORs (95% CI) for past-year cannabis use among adult offspring were not different for "mother uses cannabis" (2.8 [1.4-5.8]) or "father uses cannabis" (2.1 [1.2-3.8]). Participants with 1 or 2 cannabis-using parents were 1.7 and 7.1 times more likely to use cannabis, respectively, than participants with non-using parents.

To enable informed decision-making about their own cannabis use, parents need to be aware that children of cannabis users are more likely to use cannabis in adolescence and young adulthood.