This meta-study reviewed 17 Randomized Controlled Trials (RCTs) published through 2/1/2021 studying the effects of THC, CBD, CBDV, and some synthetic cannabinoids on chronic neuropathic pain (NP). It was published in the Journal of Dental Anesthesia and Pain Medicine in December 2021.
The study included patients ages 21 to 77, and included all forms of administration including smoking, vaping, and oral administration.
"Meta-analysis showed that there was a significant reduction in pain intensity for THC/CBD by -6.624 units, THC by -8.681 units, and dronabinol by -6.0 units compared to placebo on a 0–100 scale. CBD, CBDV, and CT-3 showed no significant differences".
The authors concluded that patients taking THC+CBD were 1.7 times more likely to see a 30% reduction in pain and 1.4 times more likely to see a 50% reduction in pain than the placebo group. Patients taking only THC were 1.8 times more likely to see a reduction in pain than the placebo group.
The full-text article is here at the Journal of Dental Anesthesia and Pain Medicine website.