Psychedelic-assisted therapy for treating anxiety, depression, and existential distress in people with life-threatening diseases

Abstract

Implications for practice Psychedelic-assisted therapy with classical psychedelics (psilocybin, LSD) may be effective for treating anxiety, depression, and possibly existential distress, in people facing a life-threatening disease. Psychedelic-assisted therapy seemed to be well tolerated, with no treatment-emergent serious adverse events reported in the studies included in this review. However, the certainty of evidence is low to very low, which means that we cannot be sure about these results, and they might be changed by future research. At the time of this review (2024), psychedelic drugs are illegal in many countries. Implications for research The risk of bias due to 'unblinding' (participants being aware of which intervention they are receiving) could be reduced by measuring expectation bias, checking blinding has been maintained before cross-over, and using active placebos. More studies with larger sample sizes are needed to reduce imprecision. As the US Drug Enforcement Administration (DEA) currently classifies psychedelics as Schedule I substances (i.e. having no accepted medical use and a high potential for abuse), research involving these drugs is restricted, but is steadily increasing.

In the evidence

This study is part of the evidence base for a synthesis in the library. Here is how each one recorded it.

• State of the evidence: End-of-life distress ↑Supports

  Psilocybin or LSD-assisted therapy may be effective for anxiety, depression, and possibly existential distress in people with life-threatening disease and appeared well tolerated, but certainty of evidence is low to very low.

  Synthesized September 20, 2026

Comparable studies

Other systematic reviews and meta-analyses on end-of-life distress, most cited first.