BACKGROUND: Psilocybin with varying degrees of psychotherapy has emerged as a promising treatment for major depressive disorder. Little attention has been paid to the psychotherapy that adjoins the psilocybin. Providing an adjunctive psychotherapy is a manualized, evidence-based therapy may make psilocybin treatment more acceptable and effective. We examined the acceptability, feasibility, and clinical outcomes associated with psilocybin paired with cognitive behavioral therapy (CBT) for major depressive disorder.
METHODS: Participants were adults with moderately severe or severe depressive symptoms who were enrolled in psilocybin-assisted CBT (PA-CBT). Treatment consisted of two psilocybin doses (10 mg and 25 mg separated by one month) interspersed with 12 psychotherapy sessions in four months. Participants' depressive symptoms, psychosocial functioning, and cognitive-affective responses were collected at the study's baseline, at the completion of PA-CBT, and at 3-months post-treatment.
RESULTS: Sixteen participants were retained through the 7-month study. PA-CBT was rated as highly acceptable by participants and study clinicians, with no serious adverse events reported. Based on independent assessments, 13 of 16 showed at least moderate (≥ 25%) improvement by 3 months, and 9 had fully remitted. Pre-to-post treatment improvement in depressive symptoms and psychosocial functioning were sustained at a 3-month follow-up (Hedges' gs = 1.9-2.7). Changes in depressive severity during the treatment were associated with improvements in emotion regulation and positive and negative cognitions.
CONCLUSIONS: CBT appears to be a feasible, well-accepted, and beneficial adjunct to psilocybin treatment. Future randomized trials are needed to compare the efficacy of PA-CBT with psilocybin-assisted therapy that contains more minimal psychotherapy.
Psychedelic Science