A retrospective chart review of 128 participants in a 12-week ketamine-assisted group therapy program found that the treatment was well tolerated, with no dropouts. Across 448 sessions, elevated blood pressure occurred after 49.16% of sessions, while nausea affected 12.05% of participant-sessions, vomiting 2.52%, headache 3.35%, and dizziness in seven participant-sessions. Adverse events were transient and resolved with rest or medication. The findings suggest good safety and tolerability for intramuscular and sublingual ketamine dosing in a community group psychotherapy setting.
A systematic review and individual participant data meta-analysis of 12 studies (533 participants) found that higher baseline PTSD severity was the most robust predictor of symptom reduction after combined ketamine and psychotherapy. More psychotherapy sessions, more ketamine sessions, and shorter treatment duration were also associated with greater improvement, but these findings are tentative because most studies were of poor quality. The analysis showed that for each additional psychotherapy session, PTSD symptoms improved by an average of 1.03 points on the PCL-5, and for each additional ketamine session, improvement was 1.15 points. The results require confirmation in well-designed prospective trials.