Maternal Cannabis Use During a Child's Lifetime Associated With Earlier Initiation

Introduction: Earlier cannabis initiation is associated with more severe neuropsychiatric and social consequences. The authors investigated whether mothers' cannabis use is associated with earlier cannabis initiation by their children.

Methods: Mother and child data were from the National Longitudinal Survey of Youth 1979 (1980-1998 waves) and Child and Young Adults (1988-2014 waves) cohorts, respectively. Cox proportional hazard models assessed the effect of maternal cannabis use prior to a child's adolescence on the child's risk of subsequent cannabis initiation. Models were stratified by race and child's age category (6-16, 17-24, ≥25 years). Adjusted analyses controlled for sociodemographic variables. Analyses were conducted in 2017.

Results: Median age of cannabis initiation for children of maternal ever users was age 16years compared with age 18years among children of maternal never users. Children of 1-year and multiple-year users were at increased risk of cannabis initiation between ages 6 and 16years (hazard ratio=1.38, p<0.001, and hazard ratio = 1.45, p<0.001, respectively). Effects were slightly stronger among non-Hispanic non-black children.

Conclusions: As cannabis legalization expands across the U.S., adult use may become increasingly normative. This study indicates that maternal cannabis use may be a risk factor for early initiation among their offspring. Preventive interventions should consider strategies to delay initiation among children of cannabis users.