Link between childhood problems and adult marijuana use explored

Results from a long-term study conducted in several counties in western North Carolina suggest that mental health interventions in childhood and young adulthood could help prevent problematic marijuana use in adults.

Published in the November issue of the Journal of the American Academy of Child and Adolescent Psychiatry, the findings identify common threads among individuals in the Great Smoky Mountains Study who developed problems with marijuana use. The group that was studied for this analysis was enrolled in the study as young as age 9 and is now made up of adults in their 30s.

A total of 76.3% of these individuals (there were more than 1,200 in the cohort) did not use or develop a problem with marijuana during the period in which they were tracked, from 1993 to 2015. The remainder of participants were grouped into three categories:

• Limited users (13%) had trouble with marijuana either before age 16 or in their late teens and early 20s, but the problems decreased as they aged. Surprisingly, this group reported high levels of family conflict during their childhood. “When this group of children left home, they seemed to do better,” said Sherika Hill, PhD, lead author of the study and an adjunct faculty associate at the Duke University School of Medicine.

• Persistent users (7%) had longstanding problems with marijuana that for some started before adolescence and continued into their late 20s and early 30s. These individuals had the highest rates of psychiatric disorders and justice system involvement. “This suggests that a focus on mental health and well-being could go a long way to prevent the most problematic use,” said Hill.

• Delayed users (4%) did not become habitual marijuana users until their mid-to-late 20s. This pattern was more commonly seen in African-Americans, as well as among those who had been victimized by bullying or caregiver mistreatment during childhood. “What we don't yet understand is how childhood maltreatment didn't prompt earlier problematic use of cannabis between ages 19 and 21—how individuals could be resilient to that kind of adverse experience for so long,” Hill said.