“Tetrahydrocannabinol (THC) has shown efficacy in alleviating chronic pain, particularly in disorders characterized by central sensitization. Offset analgesia (OA) and conditioned pain modulation (CPM) are key biomarkers used to evaluate central pain modulation.
This study aimed to compare the effects of THC on OA and CPM in fibromyalgia syndrome (FMS), a prototypical condition of central sensitization.
Methods
In a randomized, double-blind, placebo-controlled crossover design, 23 FMS patients participated in two experimental sessions. Each session included the McGill Pain Questionnaire, visual analogue scale (VAS) assessments, and evaluations of OA and CPM, conducted both before and after sublingual administration of either THC (0.2 mg/kg) or placebo.
Results
THC significantly reduced spontaneous pain ratings on the McGill scale compared to both baseline and placebo (P = 0.01 and P = 0.02, respectively). THC also significantly enhanced OA relative to baseline and placebo (P = 0.04 and P = 0.008), while no effect was observed on CPM (P = 0.27). Notably, baseline OA magnitude significantly predicted THC-induced pain relief (R² = 0.404, P = 0.003), whereas CPM did not show a significant association (P = 0.121).
Conclusions
This is the first study to evaluate THC’s distinct effects on central pain modulation using both OA and CPM. THC selectively enhanced OA without influencing CPM, highlighting differential neural mechanisms underlying these paradigms. Furthermore, OA predicted treatment response, suggesting its potential as a biomarker for personalized cannabinoid-based therapies in FMS and other central sensitization disorders.”
https://pubmed.ncbi.nlm.nih.gov/41199355/
“Cannabis, particularly its psychoactive component delta-9-tetrahydrocannabinol (THC), has attracted increasing attention as a therapeutic option for chronic pain management. Clinically, THC has been shown to reduce pain intensity, improve quality of life and attenuate hyperalgesia in various chronic pain conditions, including neuropathic pain and fibromyalgia “
“THC is thought to exert its analgesic effects in part by modulating disrupted pain networks. Specifically, THC interacts with the endocannabinoid system.”
“To conclude, this study corroborates the possible effectiveness of THC in alleviating experimental and spontaneous pain in FMS, a study case of central sensitization, and shows an enhancement of OA responses after THC treatment in FMS patients compared to baseline and placebo.”
“This, in turn, reinforces the potential of OA as a reliable marker of pain modulation in FMS and may pave the way for personalized cannabinoid-based therapies for chronic pain in the future.”
https://jcannabisresearch.biomedcentral.com/articles/10.1186/s42238-025-00348-x