A RAND Corporation study that tracked a group of school-age youths for seven years has found that use of both marijuana and alcohol in middle and high school increased the likelihood of poor academic performance and mental health at the high school level. Yet the researchers also found that marijuana use was associated with greater problems in more areas of functioning than alcohol use, including mental health and delinquency.
“Many youth tend to think that alcohol use has more consequences than marijuana use and therefore view marijuana use as safer than drinking,” said study lead author and RAND senior behavioral scientist Elizabeth D'Amico. “However, youth need to better understand the harms of marijuana use, such as the potential effect on their developing brain and how it can affect performance in both adolescence and adulthood.”
The National Institute on Alcohol Abuse and Alcoholism (NIAAA)-supported study, published in Addiction, involved Los Angeles-area students who were asked to complete their first survey in the sixth or seventh grade. All of the students participated in a middle school substance use prevention program called CHOICE.
The study also found that non-white students fared poorer on measures of functioning than white students when they used marijuana and alcohol at the same level. “Disparities are occurring as early as high school and therefore it is crucial to address alcohol and marijuana use early on, especially for non-white youth,” D'Amico said.