Minimal Intervention Could Reduce Teen Marijuana Use

Many teens use marijuana regularly and believe that it is a harmless drug with few addictive properties. Recently, however, research has been increasingly showing an association between marijuana and psychosis, and some research shows a connection between marijuana use and other risky behaviors.

A new study published in the journal Psychology of Addictive Behaviors shows that even a short, minimal intervention could significantly reduce a teen’s use of the drug. Because most high school students report that they have access to marijuana, and nearly a third report smoking it, the technique may be a powerful tool in reducing marijuana use in the United States.

Denise Walker, co-director of the University of Washington’s Innovative Programs Research Group, and colleagues examined the impact of motivational conversations with teenagers to help them reduce marijuana use. While many teens use marijuana without experiencing problems, explains Walker, there are others who use it regularly and are looking for a way to stop.

Walker and co-authors conducted two sessions of Teen Marijuana Check-Up at schools, in which they described myths and facts about marijuana, along with common reasons why teens use marijuana and the risks associated with the behavior.

As part of the presentation, Walker told the students about the study, and students could volunteer privately to become a participant. Walker says that many teens have concerns about marijuana use, even if they are not discussing these concerns with family or peers. The opportunity offered by the study gave the teens a convenient way to think through the pros and cons of drug use in a way that did not shame them for their use.

The presentation was originally given to approximately 7,100 students, of which 619 volunteered for the study and 310 met the criteria for participation. The participants, all high school students in Seattle public schools, attended two one-on-one sessions with health educators.

The students were given one of two types of approaches. One approach was motivational interviewing, which provided the student a session with a health educator. The discussion centered on the student’s marijuana use and how it might be affecting the student’s life. The health educator also shared with the student about social norms of how much others use marijuana.

The second approach featured a PowerPoint presentation which described current marijuana research, and the health and psychological effects of marijuana use.

The students who were given motivational interviewing decreased marijuana use by 20 percent, from using marijuana 40 out of the previous 60 days to using it only 32 out of 60 days. Those who observed the PowerPoint presentation had slower progress, reporting an 8 percent decrease in marijuana use.

The results of the study support the benefit of even short, minimal education and intervention plans to help reduce marijuana use among teens.