Review finds endocannabinoid system alterations in fibromyalgia and some promise for cannabinoid treatments | Research

The takeaway

Patients with fibromyalgia show alterations in the endocannabinoid system, including genetic variants and elevated endocannabinoid levels, and cannabinoid treatments show promise but lack the rigorous evidence needed for clinical recommendations.

Fibromyalgia patients, rheumatologists, pain specialists, and researchers studying cannabinoid therapeutics.

Fibromyalgia patients show genetic variants and elevated endocannabinoid levels

What the researchers found

Clinical evidence shows endocannabinoid system alterations in fibromyalgia patients, including single nucleotide polymorphisms and increased circulating endocannabinoids. FAAH inhibition (boosting anandamide) showed promise in the reserpine-induced myalgia animal model. Cannabis and cannabinoid treatments reduced pain and anxiety in clinical studies, but methodological limitations prevent treatment recommendations.

Why it matters

Fibromyalgia remains a significant unmet clinical need, and evidence that the endocannabinoid system is altered in these patients provides a biological rationale for cannabinoid-based treatments beyond symptom management.

The numbers in context

The review covers multiple study types but does not provide a single pooled effect size. FAAH inhibition and cannabinoid treatments showed improvements in both pain and anxiety measures in preclinical and clinical settings.

How the study worked

Comprehensive review of preclinical and clinical studies examining the endocannabinoid system in fibromyalgia, covering animal models, genetic studies, biomarker measurements, and treatment trials with cannabis-based medicines.

What this study cannot tell us

Existing clinical studies have methodological limitations including small samples and short durations. Animal models have limited validity for the full fibromyalgia phenotype. Sex bias in preclinical research (fibromyalgia primarily affects women). No long-term efficacy or safety data.

How to read the evidence

Comprehensive review spanning preclinical and clinical evidence, but clinical trials have methodological limitations.

When this study was published

Published in 2022.

The bigger picture

The identification of endocannabinoid system alterations in fibromyalgia patients moves the field beyond simply asking "does cannabis help pain?" toward understanding why specific patients might benefit from cannabinoid-targeting therapies.

Questions still open

Could endocannabinoid biomarkers predict which fibromyalgia patients will respond to cannabis? Would FAAH inhibitors be more effective than exogenous cannabinoids? Should clinical trials stratify by endocannabinoid system genotype?

Common questions

Is the endocannabinoid system different in people with fibromyalgia?

Yes. Research has found genetic variants (single nucleotide polymorphisms) and elevated levels of circulating endocannabinoids in fibromyalgia patients, suggesting the system is altered in ways that may contribute to the condition.

Can cannabis treat fibromyalgia?

Cannabis and cannabinoid treatments show promise for reducing pain and anxiety in fibromyalgia, but current studies have methodological limitations that prevent clinical recommendations. Longer, better-designed trials are needed.

Read the original research

Cannabinoids and the endocannabinoid system in fibromyalgia: A review of preclinical and clinical research.

Pharmacology & therapeutics, 240, 108216

View on PubMed ↗Publisher’s paper ↗

Citation

Bourke, Stephanie L; Schlag, Anne Katrin; O'Sullivan, Saoirse Elizabeth; Nutt, David J; Finn, David P. (2022). Cannabinoids and the endocannabinoid system in fibromyalgia: A review of preclinical and clinical research.. Pharmacology & therapeutics, 240, 108216. https://doi.org/10.1016/j.pharmthera.2022.108216