Early marijuana initiation: The link between prenatal marijuana exposure, early childhood behavior, and negative adult roles

- A longitudinal study of prenatal substance exposure was used to investigate influences on adult roles at 22 years.
- Behavior problems at age 3 were significantly related to early onset of marijuana use (< 15 years).
- Early onset of marijuana and maladjustment to adulthood roles were highly correlated.
- Prenatal marijuana exposure and early behavior problems were significantly related to adult roles.
- These associations with adult roles were mediated through early onset of marijuana use.

We investigated the associations among gestational factors including prenatal marijuana exposure (PME), child behavior at age 3, early age of onset of marijuana use (EAOM, < 15 years), and adult roles at 22 years. Participants were drawn from the Maternal Health Practices and Child Development (MHPCD) Project, a longitudinal study of prenatal substance exposure in offspring who have been studied for over 22 years since the prenatal phase. Data from the prenatal, birth, 3-, and 22-year phases (N = 608) were used in the present study. Age of onset of offspring substance use was determined based on data from the 14-, 16-, and 22-year phases. The subjects were of lower socioeconomic status, 43% were Caucasian and the remaining were African-American, and 48% were males. Early childhood behavior was significantly (p < 0.05) related to EAOM after controlling for PME, birth and childhood environmental risk factors, and Conduct Disorder. EAOM was significantly associated with negative adult roles including increased risk of being arrested (p < 0.001), lower educational attainment (p < 0.001), having a child without being married (p < 0.05), and unemployment at 22 years (p < 0.001). The correlations between PME and negative adult roles and between early childhood behavior and negative adult roles were also statistically significant. Pathway analysis demonstrated that EAOM significantly mediated the associations between PME and fulfillment of adult roles and between early childhood behavior and adult roles. There are a number of intervention points that could be targeted that would have a long-term impact on lowering the probability of EAOM and less success in adult roles.