Medical cannabis improved pain, anxiety, sleep, and quality of life in complex regional pain syndrome patients
In a UK registry of 64 CRPS patients prescribed cannabis-based medicines, pain severity, anxiety, sleep quality, and overall quality of life all improved significantly over 6 months.
Quick Facts
What This Study Found
Pain severity on the Brief Pain Inventory improved from 6.69 at baseline to 5.85 at 1 month and 6.05 at 6 months. Improvements were also seen in the McGill Pain Questionnaire, pain VAS, anxiety symptoms, sleep quality, and general health-related quality of life at multiple time points.
Key Numbers
64 patients. Pain severity BPI: 6.69 baseline to 5.85 at 1 month (p<0.05). McGill Pain, VAS, anxiety, sleep, and quality of life all improved (p<0.05). 5 patients (7.8%) reported adverse events. 50 adverse events (78.1%) recorded total.
How They Did This
Case series from the UK Medical Cannabis Registry tracking patient-reported outcomes over 6 months in 64 CRPS patients, with adverse events graded using CTCAE v4.0.
Why This Research Matters
CRPS is notoriously difficult to treat and causes severe, persistent pain. This is the first study examining cannabis-based medicines specifically for CRPS, providing initial data for a condition with few effective treatments.
The Bigger Picture
CRPS affects an estimated 200,000 people in the US alone, with limited treatment options and high rates of disability. If cannabis-based medicines prove effective in controlled trials, they could fill a significant gap in CRPS management.
What This Study Doesn't Tell Us
No control group or blinding means improvement could reflect placebo response, natural disease fluctuation, or concurrent treatments. Registry data may have selection bias. Pain improvement, while statistically significant, was modest in absolute terms.
Questions This Raises
- ?Would a randomized controlled trial confirm these improvements?
- ?Is the modest absolute pain reduction clinically meaningful for CRPS patients?
Trust & Context
- Key Stat:
- Pain, anxiety, sleep, and quality of life all improved significantly over 6 months
- Evidence Grade:
- Uncontrolled case series provides initial observational data. Without a comparison group, placebo effects and natural variation cannot be excluded.
- Study Age:
- Published in 2025.
- Original Title:
- UK Medical Cannabis Registry: A Clinical Outcomes Analysis for Complex Regional Pain Syndrome.
- Published In:
- Brain and behavior, 15(9), e70823 (2025)
- Authors:
- Evans, Lilia(2), Erridge, Simon(22), Varadpande, Madhur(3), Aggarwal, Arushika, Cowley, Isaac, Clarke, Evonne, McLachlan, Katy, Coomber, Ross, Rucker, James J, Platt, Michael, Sodergren, Mikael H
- Database ID:
- RTHC-06422
Evidence Hierarchy
Describes what happened to one person or a small group.
What do these levels mean? →Frequently Asked Questions
Can medical cannabis help with complex regional pain syndrome?
This UK registry study of 64 patients found improvements in pain, anxiety, sleep, and quality of life over 6 months. However, without a control group, these improvements could reflect other factors.
What side effects did CRPS patients experience with medical cannabis?
7.8% of patients reported adverse events. The study noted 50 total adverse events among the group. The majority of effects were not severe enough to warrant treatment discontinuation.
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Cite This Study
https://rethinkthc.com/research/RTHC-06422APA
Evans, Lilia; Erridge, Simon; Varadpande, Madhur; Aggarwal, Arushika; Cowley, Isaac; Clarke, Evonne; McLachlan, Katy; Coomber, Ross; Rucker, James J; Platt, Michael; Sodergren, Mikael H. (2025). UK Medical Cannabis Registry: A Clinical Outcomes Analysis for Complex Regional Pain Syndrome.. Brain and behavior, 15(9), e70823. https://doi.org/10.1002/brb3.70823
MLA
Evans, Lilia, et al. "UK Medical Cannabis Registry: A Clinical Outcomes Analysis for Complex Regional Pain Syndrome.." Brain and behavior, 2025. https://doi.org/10.1002/brb3.70823
RethinkTHC
RethinkTHC Research Database. "UK Medical Cannabis Registry: A Clinical Outcomes Analysis f..." RTHC-06422. Retrieved from https://rethinkthc.com/research/evans-2025-uk-medical-cannabis-registry
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.