Cannabis use neither helped nor hurt opioid treatment outcomes in people with opioid use disorder

A meta-analysis of 10 studies with 8,367 participants found no significant association between cannabis use and return to non-medical opioid use during opioid use disorder treatment.

Costa, Gabriel P A et al.·The American journal of drug and alcohol abuse·2024·highMeta-Analysis
RTHC-05230Meta Analysishigh2024RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Meta-Analysis
Evidence
high
Sample
N=8,367

What This Study Found

The pooled odds ratio was 1.00 (95% CI: 0.97-1.04, p=.98), indicating no association between cannabis use and non-medical opioid use during OUD treatment. This null finding held across treatment types (methadone, buprenorphine, naltrexone). Average follow-up was 9.7 months.

Key Numbers

10 studies, 8,367 participants. 38% female. Pooled OR: 1.00 (95% CI: 0.97-1.04). Average follow-up: 9.7 months. Treatment: methadone 76.3%, buprenorphine 21.3%, naltrexone 2.4%. Moderate heterogeneity.

How They Did This

Systematic review and meta-analysis of 10 longitudinal studies found across multiple databases. Random-effects model with restricted maximum likelihood. Sensitivity analysis by OUD treatment modality. 8,367 participants (38% female), mostly receiving methadone (76.3%).

Why This Research Matters

Some treatment programs require cannabis abstinence for opioid use disorder medication. This meta-analysis found no evidence that cannabis use worsens opioid treatment outcomes, challenging the rationale for mandatory cannabis abstinence policies.

The Bigger Picture

The question of whether cannabis helps or hinders opioid recovery is politically charged. This meta-analysis provides the most definitive answer yet: neither. This supports individualized approaches rather than blanket policies requiring cannabis abstinence for OUD treatment.

What This Study Doesn't Tell Us

Moderate heterogeneity and evidence of publication bias. Mostly methadone patients (76.3%), limiting generalizability to other medications. Cannot distinguish between different cannabis use patterns (frequency, quantity, method). Does not assess cannabis for OUD treatment, only concurrent use.

Questions This Raises

  • ?Should cannabis abstinence requirements be removed from OUD treatment programs?
  • ?Would heavy versus occasional cannabis use show different associations?
  • ?Could certain cannabis use patterns actually improve OUD treatment adherence through stress reduction?

Trust & Context

Key Stat:
OR 1.00: cannabis had zero association with opioid relapse during treatment
Evidence Grade:
High-quality meta-analysis of longitudinal studies with large pooled sample. Limited by moderate heterogeneity, publication bias, and heavy methadone representation.
Study Age:
Published in 2024 in the American Journal of Drug and Alcohol Abuse, searching through April 2023.
Original Title:
The impact of cannabis on non-medical opioid use among individuals receiving pharmacotherapies for opioid use disorder: a systematic review and meta-analysis of longitudinal studies.
Published In:
The American journal of drug and alcohol abuse, 50(1), 12-26 (2024)
Database ID:
RTHC-05230

Evidence Hierarchy

Meta-Analysis / Systematic ReviewCombines many studies into one answer
This study
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / Observational
Case Report / Animal Study

Combines results from multiple studies to find an overall pattern.

What do these levels mean? →

Frequently Asked Questions

Does cannabis use interfere with opioid addiction treatment?

This meta-analysis of over 8,000 patients found no association between cannabis use and return to non-medical opioid use during treatment. The odds ratio was exactly 1.00, meaning cannabis use neither helped nor hurt.

Should opioid treatment programs require cannabis abstinence?

The authors suggest these findings challenge the requirement of cannabis abstinence to maintain OUD treatment, arguing for individualized approaches rather than blanket policies that could prevent people from accessing life-saving medications.

Read More on RethinkTHC

Cite This Study

RTHC-05230·https://rethinkthc.com/research/RTHC-05230

APA

Costa, Gabriel P A; Nunes, Julio C; Heringer, Daniel L; Anand, Akhil; De Aquino, Joao P. (2024). The impact of cannabis on non-medical opioid use among individuals receiving pharmacotherapies for opioid use disorder: a systematic review and meta-analysis of longitudinal studies.. The American journal of drug and alcohol abuse, 50(1), 12-26. https://doi.org/10.1080/00952990.2023.2287406

MLA

Costa, Gabriel P A, et al. "The impact of cannabis on non-medical opioid use among individuals receiving pharmacotherapies for opioid use disorder: a systematic review and meta-analysis of longitudinal studies.." The American journal of drug and alcohol abuse, 2024. https://doi.org/10.1080/00952990.2023.2287406

RethinkTHC

RethinkTHC Research Database. "The impact of cannabis on non-medical opioid use among indiv..." RTHC-05230. Retrieved from https://rethinkthc.com/research/costa-2024-the-impact-of-cannabis

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.