Does number of dosing sessions and type of adjunctive psychotherapy affect outcomes in psychedelic-assisted-psychotherapy for depressive disorders and anxiety disorders? A systematic review and meta-analysis.
Journal of affective disorders February 15, 2026 Tomas Lindegaard, Anton Käll
Psychedelic-assisted psychotherapy (PAP) shows large to very large effects on symptoms of depression and anxiety at post-treatment and follow-up, with Hedge's g values ranging from 0.98 to 1.83. A meta-analysis of 23 clinical trials found some evidence that two dosing sessions produce larger between-group effects than one session, though this finding was not robust across all analyses and needs replication. Only three studies used evidence-based psychotherapy protocols, limiting analysis of that moderator. The field would benefit from more thorough reporting of psychotherapy protocols to enable comparison between studies.