Much discussion has taken place on effects of marijuana and alcohol, especially on young adults. This study specifically looks at moderate and heavy drinking’s effect on marijuana use in college-aged youth. This relationship is important because it could give insight into potentially useful regulation and policies around these substances. The study conducted used data from the National Longitudinal Survey of Youth 97.

Data was collected from 8,984 participants from the ages of 12-18 starting in 1997. They were then followed until 2009 with ages ranging from 18-24. The researchers used a logistic model which helped to predict the probability of participants drinking habits and marijuana use. The survey asked about marijuana use in the past 30 days, the drinking habits including binge drinking, as well as demographic questions. It was found that those who had the heaviest drinking habits had the highest probability of marijuana use along with females being less likely to use marijuana. Young adults with moderate drinking habits were also found to have an increased probability of marijuana use, but not as high as heavy drinkers.

Another interesting finding was that turning 21 was associated with approximately 35% increase in probability of heaving drinking and a 15% increase in probability of marijuana use.  The researchers found that there was no significant effect on marijuana use when participants drank moderately before the age of 21. Overall, this study shows that college-aged youth with heavy drinking habit may be more likely to use marijuana and moderate drinking over time increases likeliness of using marijuana. This information is important to predict young adults’ trajectories of marijuana use. It can provide helpful insight when regulations and policies are being created around these two substances. It can also be used by counselors and other college staff to better educate them on the substance use risks on college students.

Take Away: While there has been much discussion on alcohol and marijuana use in college-aged youth, this study focuses primarily on how alcohol use may predict marijuana use. The researchers used the National Longitudinal Survey of Youth 97 to follow 8,984 participants over 12 years. The study shows that heavy drinkers have the highest probability of marijuana use. Also, moderate drinking over time is also associated with a higher probability of marijuana use. This information can be used when creating regulations and policies around these substances as well as when educating college staff on substance use risks in students.

Bai, Z. (2019). The impact of different drinking habits on marijuana use among college-aged youths. The Social Science Journal. doi: 10.1016/j.soscij.2019.08.002