Recreational Cannabis Laws Initially Reduced Opioid Misuse, but the Effect Faded After 2-3 Years

Analysis of national survey data found recreational marijuana laws initially reduced frequent prescription opioid misuse, but the effect dissipated after only 2-3 years when using methods that account for staggered state adoption.

Ali, Mir M et al.·Health economics·2023·Moderate EvidenceRetrospective Cohort
RTHC-04360Retrospective CohortModerate Evidence2023RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Retrospective Cohort
Evidence
Moderate Evidence
Sample
Not reported

What This Study Found

Standard difference-in-differences analysis suggested RML adoption reduced frequent opioid misuse. However, a two-stage procedure accounting for staggered treatment timing showed the opposite direction. Event study estimates suggested an initial decrease in opioid misuse that dissipated after 2-3 years, indicating the benefit was temporary.

Key Numbers

Standard DD showed reduced opioid misuse; two-stage procedure showed the DD estimate became positive; event study showed initial decrease dissipating after 2-3 years

How They Did This

Analysis of National Survey on Drug Use and Health microdata examining recreational marijuana laws and prescription opioid misuse (OxyContin, Percocet, Vicodin). Used both standard difference-in-differences regression and a two-stage procedure designed for staggered treatment adoption and dynamic effects.

Why This Research Matters

The finding that the opioid substitution effect of cannabis is temporary challenges the hopeful narrative that cannabis legalization can durably reduce the opioid crisis. Initial benefits may fade as novelty wears off or as people return to prior patterns.

The Bigger Picture

Previous research celebrating opioid reductions from cannabis legalization may have been premature. If the substitution effect is temporary, relying on cannabis legalization as an opioid crisis strategy without sustained complementary interventions may not work long-term.

What This Study Doesn't Tell Us

Observational study cannot prove causation. Different statistical methods produced different results, introducing uncertainty. Self-reported substance use data may underestimate misuse. Staggered legalization across states complicates temporal comparisons.

Questions This Raises

  • ?Why does the opioid reduction effect dissipate?
  • ?Could sustained public health campaigns maintain the substitution effect?
  • ?Does the temporary reduction reflect initial curiosity about cannabis as a pain alternative that fades?

Trust & Context

Key Stat:
Effect fades after 2-3 years
Evidence Grade:
Rigorous econometric analysis of national survey data with multiple methods, though different approaches yielded different results
Study Age:
2023 study
Original Title:
Recreational marijuana laws and the misuse of prescription opioids: Evidence from National Survey on Drug Use and Health microdata.
Published In:
Health economics, 32(2), 277-301 (2023)
Database ID:
RTHC-04360

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-ControlFollows or compares groups over time
This study
Cross-Sectional / Observational
Case Report / Animal Study

Looks back at existing records to find patterns.

What do these levels mean? →

Frequently Asked Questions

Does cannabis legalization reduce opioid use?

Initially, yes. This study found recreational marijuana laws were associated with reduced opioid misuse, but the effect disappeared after 2-3 years, suggesting the benefit is temporary.

Why did different statistical methods produce different results?

Standard methods treat all state legalizations as simultaneous, which can bias results when states legalize at different times. More sophisticated methods accounting for staggered adoption showed the reduction was short-lived.

Read More on RethinkTHC

Cite This Study

RTHC-04360·https://rethinkthc.com/research/RTHC-04360

APA

Ali, Mir M; McClellan, Chandler; Mutter, Ryan; Rees, Daniel I. (2023). Recreational marijuana laws and the misuse of prescription opioids: Evidence from National Survey on Drug Use and Health microdata.. Health economics, 32(2), 277-301. https://doi.org/10.1002/hec.4620

MLA

Ali, Mir M, et al. "Recreational marijuana laws and the misuse of prescription opioids: Evidence from National Survey on Drug Use and Health microdata.." Health economics, 2023. https://doi.org/10.1002/hec.4620

RethinkTHC

RethinkTHC Research Database. "Recreational marijuana laws and the misuse of prescription o..." RTHC-04360. Retrieved from https://rethinkthc.com/research/ali-2023-recreational-marijuana-laws-and

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.