Are Some Reasons for Marijuana Use Linked to Later Problems?

Can we look at motives for marijuana use among young adults and predict who is more likely to develop later marijuana-related problems? Megan Patrick and other researchers at the Institute for Social Research recently published a study on this topic, filling out our understanding of marijuana use and providing a resource for future study and intervention efforts.

 

Marijuana use has been rising slowly and steadily in recent years. It ranks second in substance use by young adults in the US (alcohol use is first). Data from Monitoring the Future show that 32 percent of young adults have used marijuana in the past year.

 

This study looks at 19- and 20-year-old marijuana users who graduated from high school between 1976 and 1997 (Monitoring the Future). At age 19/20 they were asked to give reasons for their marijuana use and at age 35 (from 1994 to 2014; weighted n=2,288) they reported on their marijuana use and problems. The study accounts for respondents who dropped from the study by age 35. It also takes into consideration other factors that may influence later marijuana use and problems like gender, high school grades, and other substance use.

 

At age 19/20, respondents identified any of 13 reasons for using marijuana, including to experiment, to feel good or get high, to get away from my problems, or to get through the day. An interesting issue here is that people often have multiple reasons for a behavior and this applies to marijuana use. To deal with this complexity, the researchers use latent class analysis (LCA) to find clusters of reasons and to divide the study population into unique categories of types of reasons that are not directly observable (latent classes).

 

– LCA shows five latent classes that have higher likelihood of some reasons and lower likelihood of other reasons for using marijuana:

– Experimental reasons (to experiment)

– Get High + Relax reasons (to feel good or get high, have a good time, relax)

– Typical reasons (the four most typical reasons: to feel good or get high, have a good time, experiment, and relax)

– Typical + Escape reasons (typical reasons plus to get away from my problems)

– Coping + Drug Effect reasons (most reasons including coping and increasing the effects of other drugs)

 

At age 35, respondents were asked if their marijuana use caused them any problems like behaving in ways they later regretted or hurting a relationship. The reasons they were given cover 8 of the 11 criteria for cannabis use disorder in the DSM-5.

 

Results: Overall, the study finds that these person-centered clusters of reasons for marijuana use at age 19/20 are strongly related to marijuana use and problems at age 35. The highest risk for later marijuana use and problems is among people with either Coping + Drug Effect reasons or Get High + Relax reasons in young adulthood. Those with Experimental reasons have the lowest risk for later marijuana use and problems. These results replicate and extend existing findings on the importance of coping reasons in predicting later marijuana use and problems. But in this study respondents are also at risk with Get High + Relax reasons and even with Typical reasons. In fact, having any appreciable reason for using marijuana, other than experimenting, puts young people at higher risk for later use and problems. Future research should help us understand the shift from experimenting with marijuana to using marijuana for other reasons.

 

Patrick, M. E., Bray, B. C., & Berglund, P. (2016). Reasons for marijuana use among young adults and long-term associations with marijuana use and problems. Journal of Studies on Alcohol and Drugs, 77(6), 881-888. doi: 10.15288/jsad.2016.77.881.