Young adults dependent on marijuana and alcohol are less likely to achieve adult life goals, according to new research by UConn Health scientists presented today at the American Public Health Association 2017 Annual Meeting & Expo.

Chronic marijuana use in adolescence was negatively associated with achieving important developmental milestones in young adulthood. — Elizabeth Harari

UConn Health researchers examined data from the Collaborative Study on the Genetics of Alcoholism (COGA) to track the effect teenage alcohol and marijuana use has on the achievement of life goals, defined as educational achievement, full-time employment, marriage, and social economic potential. The study includes 1,165 young adults from across the United States whose habits were first assessed at age 12 and then at two-year intervals until they were between 25 and 34 years old. Most of the study participants had an alcoholic grandparent, parent, aunt, or uncle.

Overall, individuals who were dependent on either marijuana or alcohol during their teen years achieved lower levels of education, were less likely to be employed full time, were less likely to get married, and had lower social economic potential.

“This study found that chronic marijuana use in adolescence was negatively associated with achieving important developmental milestones in young adulthood. Awareness of marijuana’s potentially deleterious effects will be important moving forward, given the current move in the U.S. toward marijuana legalization for medicinal and possibly recreational use,” says UConn Health psychiatry resident Elizabeth Harari, author of the study.

The researchers also found that dependence may have a more severe effect on young men. Dependent young men achieved less across all four measures, while dependent women were less likely than non-dependent women to obtain a college degree and had lower social economic potential, but were equally likely to get married or obtain full-time employment.

Previous research had shown that heavy use of alcohol or marijuana in adolescence affects people developmentally. This study followed up on that, to look at what happens after age 18. The life outcomes seem to show that the differences are meaningful into adulthood.

The study is ongoing.

“COGA investigators are following many subjects over the years, and are using this extensive and growing database to examine several significant research topics,” says assistant professor Grace Chan, a statistician in the UConn Health Department of Psychiatry.

Chan, Harari, and UConn Health Alcohol Research Center director Victor Hesselbrock are currently looking at whether there are different outcomes between young people dependent on alcohol versus marijuana, as well as why there were marked differences in outcomes between the sexes.

Harari’s research was supported by Hesselbrock and Chan. The Collaborative Study on the Genetics of Alcoholism is funded by the National Institute of Alcohol Abuse and Alcoholism.