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

Psychedelic-assisted therapy using psilocybin or LSD may help treat anxiety, depression, and existential distress in people with life-threatening diseases, and appears well tolerated with no serious adverse events reported in reviewed studies. However, the evidence is low to very low certainty, meaning results are uncertain and could change with future research. As of 2024, these drugs remain illegal in many countries. Blinding issues and small sample sizes limit confidence; more rigorous studies with active placebos and larger samples are needed. Research is restricted in the US due to Schedule I classification but is increasing.

Study at a glance

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.