Ketamine-assisted psychotherapy (KAP) produces sustained reductions in anxiety, depression, and PTSD symptoms lasting up to 5 months after the last session. In a retrospective study of adults with treatment-resistant major depressive disorder, generalized anxiety disorder, or PTSD who received KAP across 11 North American clinics, large treatment effects were detected at 3 months (Cohen's d = 0.75-0.86) and sustained at 6 months (d = 0.61-0.73). Case reductions ranged from 39% to 41% at 3 months and 29% to 37% at 6 months. However, high attrition rates (82% at 3 months, 95% at 6 months) may limit validity of the results.
People who use cannabis expect that a cannabis-assisted psychotherapy session, modeled on psychedelic-assisted psychotherapy, would reduce depression. Over 500 participants in each of two studies imagined such a session and reported expected antidepressant effects. Expected reductions in depression were linked to anticipated psychedelic-like subjective experiences, such as mystical-type feelings, and also to expected changes in dysfunctional attitudes—a separate pathway that resembles how cognitive therapy works. These findings support calls for clinical trials of cannabis-assisted psychotherapy and indicate that users anticipate it would work through mechanisms similar to both psychedelics and cognitive therapy.