The experimental effects of psilocybin on symptoms of anxiety and depression: A meta-analysis

Highlights

•Four trials testing psilocybin for anxiety and depression were meta-analyzed.

• Within-group effects were large (Hedges’ gs = 1.16 to 1.47).•

• Placebo-controlled effects were large (gs = 0.82 to 0.83) across three trials.•

• Potential risk for bias was identified in several domains.

Abstract

The current meta-analysis examined the effects of psilocybin in combination with behavioral interventions on anxiety and depression in samples with elevated symptoms. Across four studies (one uncontrolled; three randomized, placebo-controlled; N = 117), within-group pre-post and pre-follow-up effects on anxiety and depression were large (Hedges’ gs=1.16 to 1.47) and statistically significant. Across three placebo-controlled studies, pre-post placebo-controlled effects were also large (gs = 0.82 to 0.83) and statistically significant. No serious adverse events were reported. Limitations include the small number of studies and risk for bias within studies. Results tentatively support future research on psilocybin for the treatment of anxiety and depression.

Simon B.Goldberg^a
Brian T.Pace^bc
Christopher R.Nicholas^d
Charles L.Raison^ef
Paul R.Hutson^ga

Department of Counseling Psychology, University of Wisconsin – Madison, 335 Education Building, 1000 Bascom Mall, Madison 53706, WI, USA

^bDepartment of Educational Psychology, University of Utah, Salt Lake City, UT, USA^cVA Palo Alto Health Care System, Palo Alto, CA, USA^d

Department of Family Medicine and Community Health, University of Wisconsin – Madison, Madison, WI, USA^e

School of Human Ecology, University of Wisconsin – Madison, Madison, WI, USA^f

Usona Institute, Fitchberg, WI, USA^gSchool of Pharmacy, University of Wisconsin – Madison, Madison, WI, USA

Received 9 April 2019, Revised 22 December 2019, Accepted 1 January 2020, Available online 2 January 2020.