Brief interventions for cannabis use in emerging adults: A systematic review, meta-analysis, and evidence map

Abstract

PurposeThis systematic review summarizes and critically appraises the existing literature on brief interventions (BIs) for cannabis use among emerging adults. MethodsEligible BIs were operationalized as 1–2 sessions focused exclusively on cannabis use for samples with mean ages between 15 and 30. Outcomes related to cannabis use, other substance use, mental health, help-seeking, or functional status were included. Two independent reviewers screened a total of 3638 records, identifying 244 studies for full-text screening. In total, 32 BIs in 26 primary studies with 6318 participants were included. ResultsParticipants were typically not seeking treatment and using cannabis at least once a month. Most interventions were motivational, single sessions, and delivered in person. Few discussed concurrent psychiatric conditions. Pooling results at 1–3 months post-intervention, BIs compared to passive control slightly reduced symptoms of cannabis use disorder (SMD −0.14 [95% CI −0.26 to −0.01]) and increased the odds of abstinence (OR 1.73 [95% CI 1.13–2.66]). Other outcome results often favored BIs but were not significant. Results of studies comparing types of BIs (k = 8) or BIs to longer interventions (k = 1) are discussed narratively. Quality assessment suggested low to very low-quality evidence. ConclusionsThis review indicates that BIs targeting non-treatment seeking emerging adults result in significant reductions in symptoms of cannabis use disorder and an increased likelihood of cannabis abstinence, however evidence is of low quality.