Brief Interventions in Medical Settings Did Not Reduce Cannabis Use | Research

The takeaway

A meta-analysis of 17 RCTs found no evidence that brief drug interventions delivered in general medical settings reduced cannabis use, consumption levels, or severity, though emergency department delivery showed some promise.

Primary care providers, emergency medicine physicians, addiction intervention researchers, health system planners

No significant effect of brief interventions on cannabis use across 17 RCTs

What the researchers found

Across 17 RCTs, brief drug interventions showed no significant short-term effects on cannabis use (OR=1.20), consumption level (g=0.01), or severity (g=0.13). Long-term effects were also non-significant. However, sensitivity analyses found that interventions delivered specifically in emergency departments showed small but significant reductions in long-term cannabis consumption.

Why it matters

Brief interventions work well for alcohol, so they have been widely adapted for cannabis. This meta-analysis shows they are not effective for cannabis in most medical settings, redirecting efforts toward settings (like EDs) where they may work.

The numbers in context

17 RCTs synthesized. Short-term cannabis use: OR=1.20 (NS). Short-term consumption: g=0.01 (NS). Short-term severity: g=0.13 (NS). Long-term use: OR=1.19 (NS). Long-term consumption: g=0.04 (NS). ED-delivered interventions showed small significant long-term effect.

How the study worked

Systematic review and meta-analysis of 17 randomized controlled trials comparing brief drug interventions to control conditions in general medical settings. Mixed effects meta-regression examined variability across intervention characteristics including booster sessions, delivery setting, target, and population.

What this study cannot tell us

Heterogeneity in intervention designs across studies. Some trials had small sample sizes. Could not fully assess all potential moderators. The ED finding came from sensitivity analyses and needs confirmation.

How to read the evidence

Strong: meta-analysis of 17 randomized controlled trials with sensitivity analyses and moderation testing

When this study was published

Published in 2025

The bigger picture

The assumption that what works for alcohol will work for cannabis does not hold for brief interventions. Cannabis use may require different intervention approaches, or may respond better in specific settings like emergency departments where motivation for change is higher.

Questions still open

Why do brief interventions work for alcohol but not cannabis? What makes emergency departments a more effective setting? What alternative intervention approaches should be developed?

Common questions

Don't brief interventions work for substance use?

They work well for alcohol, but this meta-analysis found no evidence they reduce cannabis use, consumption, or severity when delivered in general medical settings. The finding that ED-based interventions showed some promise suggests the setting matters.

Should doctors still screen for cannabis use?

Screening can still identify people who may benefit from more intensive interventions. However, the brief counseling that typically follows screening does not appear effective for cannabis on its own. Alternative approaches may be needed.

Read the original research

Brief Drug Interventions Delivered in General Medical Settings: a Systematic Review and Meta-analysis of Cannabis Use Outcomes.

Prevention science : the official journal of the Society for Prevention Research, 26(6), 985-998

View on PubMed ↗Publisher’s paper ↗

Citation

Berny, Lauren M; Nichols, Lindsey M; Schweer-Collins, Maria L; Tanner-Smith, Emily E. (2025). Brief Drug Interventions Delivered in General Medical Settings: a Systematic Review and Meta-analysis of Cannabis Use Outcomes.. Prevention science : the official journal of the Society for Prevention Research, 26(6), 985-998. https://doi.org/10.1007/s11121-025-01826-7