Hypnotic cognitive therapy reduces pain intensity in adults with spinal cord injury

BACKGROUND AND OBJECTIVES: Chronic pain is highly prevalent, disabling, and difficult to treat in people with spinal cord injury (SCI). Our objective was to determine whether hypnotic cognitive therapy (HYP-CT) significantly reduces average pain intensity. METHODS: This single-blind, randomized, parallel-group trial investigated the efficacy of HYP-CT in treating moderate-to-severe chronic pain in community-residing adults with SCI. Participants were recruited nationwide through SCI organizations and randomized 1:1 to HYP-CT vs usual care (UC). We used computerized permuted block randomization with variable block sizes and stratified by sex and worst pain type. HYP-CT was delivered by a psychologist over the telephone or through Zoom and consisted of 6 weekly 60-minute sessions plus instructions to practice self-hypnosis daily independently by listening to session recordings. Controls were encouraged to continue current treatments or seek additional pain treatments. The primary outcome was average pain intensity assessed 4 times per week on a 0-10 numerical rating scale and averaged. The primary end point was at 6 weeks after randomization, with a follow-up assessment at 12 weeks. All outcomes were assessed through structured telephone interviews performed by blinded assessors. RESULTS: A total of 127 participants were randomized to HYP-CT (n = 64) vs UC (n = 63). Forty-eight percent were treated over the telephone and 52% through Zoom. The group was 42% female, had a mean age of 51.3 years (15.4 years after SCI), and had a mean baseline pain intensity of 5.93. The worst pain was neuropathic in 57% of cases. The primary outcome, average pain intensity, decreased more in the HYP-CT group compared with UC controls at 6 (-0.55, 95% CI -1.04 to -0.06) and 12 (-0.79, 95% CI -1.28 to -0.29) weeks. Depression declined significantly more in the HYP-CT vs UC groups at 6 and 12 weeks. Planned exploratory analyses suggested that the effect of HYP-CT on pain intensity was similar when delivered over the telephone vs through Zoom, and that pain intensity decreased more in those with all neuropathic pain vs those with mixed pain at 12 weeks. DISCUSSION: The study suggests that HYP-CT is an effective adjunctive treatment for SCI-related pain. Replication studies are needed. TRIAL REGISTRATION INFORMATION: The study was registered on ClinicalTrials.gov (NCT03857672) on February 28, 2019 and study enrollment commenced on April 24, 2019. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that, in patients with SCI, HYP-CT improves average pain intensity at 6 weeks compared with UC.