A nationwide register-based cohort study in Denmark was published in October 2021 in the European Journal of Pain, and examined 1817 neuropathic pain patients, and 924 patients with unspecified pain disorders.
They found that the neuropathic-pain patients that used either CBD, THC, or combined CBD + THC used less gabapentin (standard pharmceutical treatment for decreasing abnormal excitement in the brain), and were hospitalized fewer days than the control group. There was not the same improvement in the "other pain disorders" group.
"CBM/MC [medical cannabis medicines] were generally safe and even displayed some positive effects among patients with neuropathic pain. We conclude that CBM/MC are safe and possibly efficacious for patients with neuropathic pain but not patients with other pain disorders."
The link to the abstract at PubMed is here.