Cannabis legalization was associated with greater increases in cannabis use disorder among VA patients with chronic pain than without, with MCL attributing 8.4% and RCL 11.5% of increases.
Pain medicine researchers, health policy analysts, and VA healthcare system leaders.
0.188% absolute increasein CUD prevalence among chronic pain patients attributable to recreational cannabis laws
What the researchers found
Among chronic pain patients, MCL led to 0.135% and RCL to 0.188% absolute increases in CUD prevalence. In patients without pain, increases were much smaller (MCL: 0.037%, RCL: 0.042%).
Why it matters
This large-scale study from a major medical journal quantifies how cannabis legalization disproportionately affects a vulnerable population — chronic pain patients — with implications for clinical monitoring.
The numbers in context
3.2M-4.6M patients per year (2005-2019). Chronic pain: MCL +0.135% (8.4% attributable), RCL +0.188% (11.5% attributable). No pain: MCL +0.037% (5.7%), RCL +0.042% (6.0%). NIDA-funded.
How the study worked
Repeated cross-sectional study of VHA electronic health records (2005-2019) with staggered-adoption difference-in-difference analyses, stratified by chronic pain status.
Who was studied
VHA patients aged 18-75 with at least one qualifying visit per year, stratified by chronic pain status (2005-2019).
What this study cannot tell us
Observational design. VHA population is predominantly male. CUD diagnosis may reflect screening intensity changes. Cannot distinguish between harmful and beneficial cannabis use.
How to read the evidence
Large quasi-experimental study published in The Lancet with rigorous difference-in-difference methodology.
When this study was published
Published in Lancet covering 2005-2019 VHA data.
The bigger picture
This companion study to RTHC-04612 confirms the differential impact of cannabis legalization on chronic pain patients and highlights the need for targeted clinical monitoring as legalization continues.
Replication
Companion to RTHC-04612 and RTHC-04615; consistent findings across related analyses.
Funding
NIDA grant R01DA048860, New York State Psychiatric Institute, VA Centers of Excellence
Conflicts of interest
Not specified in abstract
Questions still open
- How should clinicians balance cannabis access for pain with CUD risk?
- Are evidence-based pain treatments sufficiently available to offset the appeal of cannabis?
Read the original research
Chronic pain, cannabis legalisation, and cannabis use disorder among patients in the US Veterans Health Administration system, 2005 to 2019: a repeated, cross-sectional study.
The lancet. Psychiatry, 10(11), 877-886
Citation
Hasin, Deborah S; Wall, Melanie M; Alschuler, Daniel M; Mannes, Zachary L; Malte, Carol; Olfson, Mark; Keyes, Katherine M; Gradus, Jaimie L; Cerdá, Magdalena; Maynard, Charles C; Keyhani, Salomeh; Martins, Silvia S; Fink, David S; Livne, Ofir; McDowell, Yoanna; Sherman, Scott; Saxon, Andrew J. (2023). Chronic pain, cannabis legalisation, and cannabis use disorder among patients in the US Veterans Health Administration system, 2005 to 2019: a repeated, cross-sectional study.. The lancet. Psychiatry, 10(11), 877-886. https://doi.org/10.1016/S2215-0366(23)00268-7