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Objective: Clinical trials of cannabinoids for chronic pain have mixed and often inconclusive results. In contrast, many prospective observational studies show the analgesic effects of cannabinoids. This survey study aimed to examine the experiences/attitudes of individuals with chronic pain who are currently taking, have previously taken, or never taken cannabinoids for chronic pain to inform future research., Methods: This study is based on a cross-sectional, web-based survey of individuals with self-reported chronic pain. Participants were invited to participate through an email that was distributed to the listservs of patient advocacy groups and foundations that engage individuals with chronic pain., Results: Of the 969 respondents, 444 (46%) respondents reported currently taking, 213 (22%) previously taken, and 312 (32%) never taken cannabinoids for pain. Participants reported using cannabinoids to treat a wide variety of chronic pain conditions. Those currently taking cannabinoids (vs previously) more frequently reported: (1) large improvements from cannabinoids in all pain types, including particularly difficult-to-treat chronic overlapping pain conditions (eg, pelvic pain), (2) improvements in comorbid symptoms (eg, sleep), and (3) lower interference from side effects. Those currently taking cannabinoids reported more frequent and satisfactory communication with clinicians regarding cannabinoid use. Those never taken cannabinoids reported a lack of suggestion/approval of a clinician (40%), illegality (25%), and lack of FDA regulation (19%) as reasons for never trying cannabinoids., Conclusion: These findings underscore the importance of conducting high-quality clinical trials that include diverse pain populations and clinically relevant outcomes that if successful, could support FDA approval of cannabinoid products. Clinicians could then prescribe and monitor these treatments similarly to other chronic pain medications., Competing Interests: GW Pharmaceuticals (Cambridgeshire, UK) provided funds to support the conduct of the survey, including consulting fees too. The analyses and writing of this manuscript were supported by NIH (Bethesda, MD) grant K24NS126861. R.F., J.S.G., K.P.H., R.R.E., and A.D.W. received consulting fees from GW to design the survey. B.L.F. has obtained funding from Pfizer Inc. (GRAND Awards, including salary support) for investigator-initiated projects; Indivior for a clinical trial sponsored by Indivior. B.L.F. has in-kind donations of cannabis products from Aurora Cannabis Enterprises Inc. and study medication donations from Pfizer Inc. (varenicline for smoking cessation) and Bioprojet Pharma. He was also provided a coil for a Transcranial magnetic stimulation (TMS) study from Brainsway. B.L.F. has obtained industry funding from Canopy Growth Corporation (through research grants handled by the Centre for Addiction and Mental Health and the University of Toronto), Bioprojet Pharma, Alcohol Countermeasure Systems (ACS), Alkermes and Universal Ibogaine. He has participated in a session of a National Advisory Board Meeting (Emerging Trends BUP-XR) for Indivior Canada and has been consultant for Shinogi. He is supported by CAMH, Waypoint Centre for Mental Health Care, a clinician-scientist award from the department of Family and Community Medicine of the University of Toronto, and a Chair in Addiction Psychiatry from the department of Psychiatry of University of Toronto. The remaining authors declare no conflict of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Aims/objectives/background: Studies have associated chronic low back pain (cLBP) with grey matter thinning. But these studies have not controlled for important clinical variables (such as a comorbid affective disorder, pain medication, age, or pain phenotype), which may reduce or eliminate these associations., Methods: We conducted cortical thickness and voxel-based morphometry (VBM) analyses in 14 cLBP patients with a discogenic component to their pain, not taking opioids or benzodiazepines, and not depressed or anxious. They were age and gender matched to 14 pain-free controls (PFCs). An ROI-driven analysis (regions of interest) was conducted, using 18 clusters from a previous arterial spin labeling study demonstrating greater regional cerebral blood flow (rCBF) in these cLBP subjects than the PFCs. Cortical thickness and VBM-based gray matter volume measurements were obtained from a structural MRI scan and group contrasts were calculated., Results: Multivariate analysis of variance showed a trend toward cortical thickening in the right paracentral lobule in cLBP subjects (F1,17=3.667, P<0.067), and significant thickening in the right rostral middle frontal gyrus (F1,17=6.880, P<0.014). These clusters were non-significant after including age as a covariate (P<0.891; P<0.279). A whole-brain cortical thickness and VBM analysis also did not identify significant clusters of thinning or thickening. Exploratory analyses identified group differences for correlations between age and cortical thickness of the right rostral middle frontal gyrus (cLBP: R=-0.03, P=0.9; PFCs: R=-0.81, P<0.001), that is, PFCs demonstrated age-related thinning while cLBP patients did not., Conclusions: Our pilot results suggest that controlling for affect, age, and concurrent medications may reduce or eliminate some of the previously reported structural brain alterations in cLBP.

Background: Many cannabinoid medications are approved in North America or in phase III trials, such as dronabinol, nabilone, or nabiximols. Little is known about their subjective psychoactive effects when used for pain management. We hypothesized that when used for pain, dronabinol has psychoactive effects in a dose-response relationship, whose peak effects are comparable with smoking marijuana., Methods: This was a randomized controlled trial of single dose placebo, 10 or 20 mg dronabinol in 30 chronic noncancer pain patients taking opioids and not using marijuana. Participants completed the Addiction Research Center Inventory (ARCI) hourly for 8 hours during 3 monitored sessions. Comparison sample was the ARCI ratings in participants with no pain (N=20), monitored every 30 minutes after smoking a 1.99% THC (low) and a 3.51% (high strength) marijuana cigarette., Results: The 10 and 20 mg dronabinol doses had significantly elevated scores over time on 4/5 subscales versus placebo (P<0.05). Average daily morphine use, total pain relief (TOTPAR), age, sex, and baseline pain level were not significant covariates. ARCI peak effects at 2 hours were similar to peak effects of smoked marijuana at 30 minutes (P=0.80, 10 mg=low strength, 20 mg=high strength)., Conclusions: In pain patients, oral dronabinol has similar psychoactive effects to smoking marijuana. This risk must be considered in any decision to prescribe cannabinoid medications for pain.