The effect of prenatal marijuana exposure on offspring marijuana use and cannabis use disorder in young adulthood

Marijuana is the most commonly-used illicit substance among pregnant women. Few studies have been conducted on the long-term effects of prenatal marijuana exposure (PME) on offspring. This dissertation examines the association between PME and offspring marijuana use and cannabis use disorder (CUD) in young adulthood. First, the association between PME and offspring frequency of marijuana use at 22 years of age was evaluated. PME was defined as a continuous measure of the average daily joints and frequency of use by the offspring was defined as no use, using less than three times per week, and using three times per week or more. An ordinal logistic regression model was used. Results showed that PME was initially significant but this association was attenuated to non-significance after adjusting for covariates. Childhood maltreatment, but not race or gender, moderated the association between PME and offspring use. PME was associated with offspring frequency of use at low levels of childhood maltreatment, but not at high levels of childhood maltreatment. Second, a path analysis was used to evaluate pathways from PME to frequency of marijuana use in offspring. Results showed a significant indirect path through early initiation of marijuana. There was also a significant indirect path through depressive symptoms and early initiation of marijuana. In addition, PME predicted early marijuana initiation but maternal marijuana use during the offspring’s childhood did not. Third, a path analysis was used to evaluate pathways from PME to CUD. Results showed a significant indirect path of PME on CUD through early initiation of marijuana. There was also a significant indirect path of PME on CUD through depressive symptoms in childhood and early initiation of marijuana. In summary, PME may create a biologic vulnerability in offspring. In addition, aspects of the offspring’s environment also contribute to marijuana use and CUD in young adulthood. The findings of this dissertation are significant to public health. Healthcare professionals should encourage pregnant women to abstain from marijuana and public health programs should target youth to delay marijuana initiation