Cannabis is a commonly used drug in the United States as its popularity grows. It has also been found that its highest use is among young adults from 17-25 years of age.    Because of this, there is a need for brief interventions (BIs) that adopt a motivational interviewing (MI) or enhancement (MET) approach. This study is a systematic review, meta-analysis, and evidence on previous literature to discover the nature and efficacy of   MI and BI for young adults.  

The literature search included randomized controlled trials, quasi-experimental trials, and pre-post designs. The search was conducted in several electronic databases including MEDLINE, PsycoINFO. ClincalTrials.gov, etc. Unpublished trials were found using resources such as Google Scholar and OpenGrey. The studies were reported narratively and random effects meta-analyses with subgroup analyses and meta regression were performed when appropriate. The researchers used 26 studies which included 6,318 participants with a mean age of 15-29. They found that from 14 studies, there were no significant difference in frequency of marijuana use in individuals that underwent a BI compared to those who didn’t. The data also showed that cannabis use consequences were lower for participants that underwent a BI. There was also a small significant reduction in risk of individuals having cannabis use disorder if they underwent a BI.

The studies showed that individuals who receive a BI are more likely to stop using marijuana when assessed at a short-term follow-up. Finally, when looking at BIs compared to other interventions, brief motivational interventions may be better than psychoeducational brief interventions. Overall the review found that brief interventions for cannabis users may reduce the risk for cannabis use disorder and increase likelihood of abstinence but may not impact frequency of use or consequences. This information is important when colleges are compiling resources to provide prevention or intervention resources to at risk students.

Take Away: Cannabis use is a growing concern, especially in the young adult population. This study completed a systematic review of studies looking at brief interventions specifically focused on cannabis use. What they found was that brief interventions may reduce the risk for cannabis use disorder and increase likelihood of abstinence at short-term follow-ups. However, they found no difference in brief intervention and no intervention when it came to frequency of marijuana use or consequences. This information can be used with colleges are providing prevention and intervention resources for at risk college students.

Halladay, J., Petker, T., Fein, A., Munn, C., & Mackillop, J. (2018). Brief interventions for cannabis use in emerging adults: protocol for a systematic review, meta-analysis, and evidence map. Systematic Reviews, 7(1). doi: 10.1186/s13643-018-0772-z