Ketamine assisted psychotherapy to reduce chronic neuropathic pain: A mixed-methods randomized pilot trial.

BACKGROUND: Intravenous ketamine can provide short-term analgesia in chronic neuropathic pain but benefits often wane after treatment. We conducted a randomized pilot trial to assess the feasibility of combining ketamine infusions with psychotherapy to inform future efficacy trials. METHODS: In this single-center, randomized, outcome-assessor-blinded pilot trial at a Canadian tertiary pain clinic, adults with moderate-to-severe chronic neuropathic pain were randomly assigned in 1:1:1 ratio to the ketamine, psychotherapy, or combined ketamine plus psychotherapy arm. Ketamine was delivered as three intravenous infusions over 16 weeks; psychotherapy consisted of 16 weekly cognitive behavioral therapy and mindfulness-based meditation sessions. The primary outcome was feasibility, assessed using prespecified progression criteria. Exploratory outcomes included changes in pain interference (PROMIS 6a T-score), pain intensity, mood, and qualitative interview findings at week 20 (ClinicalTrials.gov: NCT05639322). FINDINGS: Between October 23, 2023, and March 31, 2025, 30 participants were randomized, and 26 (87%) completed 20-week follow-up. Most feasibility criteria, including consent, retention, data completeness, and absence of study-related serious adverse events, were met; adherence targets were partially met. Exploratory pain outcomes showed numerical improvement across groups, with clinically meaningful reductions observed for pain interference and pain intensity. Sixty-four adverse events were recorded, mostly mild and in ketamine-containing groups; no serious study-related adverse events occurred. CONCLUSIONS: Combined ketamine and psychotherapy was feasible and acceptably safe in this pilot trial, supporting evaluation in a larger efficacy-powered study. FUNDING: The study was funded by the St. Michael's Hospital Innovation Fund, The Canadian Pain Society Early Investigator Award and the Physician Services Incorporation Early Career Researcher Award.