Decreases in Suicidality Following Psychedelic Therapy: A Meta-Analysis of Individual Patient Data Across Clinical Trials

Objective: Suicide is a global health concern, and innovative interventions that target suicidality are needed. While psychedelic therapy shows promise for a range of mental health concerns, including suicidality, not all psychedelic therapy trials have published their suicidality results and no meta-analysis has been published on the topic. Therefore, we completed the first meta-analysis of patientlevel data on the effects of psychedelics on suicidality. Data Sources: We conducted a systematic search of MEDLINE, PsycINFO, and PubMed for all psychedelic therapy clinical trials (last search: November 5, 2020). Study Selection: We identified all psychedelic therapy trials that included a measure or measure-item that assesses suicidality. Data Extraction: Suicidality data were requested from study authors and extracted using a data extraction form developed for this study. Results: We identified 8, and successfully collected data from 7, relevant trials. Analysis of standardized mean differences (SMDs) indicated that, relative to baseline, psychedelic therapy was associated with large effect sizes for acute (80-240 min) and sustained (1 day, 1-8 weeks, and 3-4 months) decreases in suicidality (SMD range=-1.48 to -236; 95% CI range, -4.30 to 0.23). At 6 months, the effect size was medium (MID =-0.65; 95% CI, -1.14 to -0.16). Reductions in suicidality were significant at all time points except for 7-8 weeks. Acute and post-acute elevations in suicidality were rare (6.5% and 3.0%, respectively). Conclusions: Limitations Include heterogeneous samples and interventions, as well as limited sample size and number of studies. Results provide preliminary support for the safety of psychedelic therapy and its positive effect on suicidality. Controlled trials that specifically evaluate the effect of psychedelic therapy on suicidality may be warranted.