Classical psychedelics for the treatment of depression and anxiety: A systematic review.

Depression and anxiety are common and disabling, yet existing treatments often fall short. A review of seven clinical trials involving 130 patients found that, when used in a supportive setting, the psychedelics ayahuasca, psilocybin, and LSD produced immediate and lasting reductions in depression and anxiety symptoms over several months. The treatments were well tolerated; the most common side effects were temporary anxiety, headaches, nausea, and mild increases in heart rate and blood pressure. The authors note that the number of studies and patients is small, but the evidence suggests psychedelic-assisted therapy is a promising alternative for patients who do not respond to standard care.

Study at a glance

Abstract

Depression and anxiety are prevalent psychiatric disorders that carry significant morbidity. Pharmacological and psychosocial interventions are used to manage these conditions, but their efficacy is limited. Recent interest into the use of psychedelic-assisted therapy using ayahuasca, psilocybin or lysergic acid diethylamide (LSD) may be a promising alternative for patients unresponsive to traditional treatments. This review aims to determine the efficacy and tolerability of psychedelics in the management of resistant depression. Clinical trials investigating psychedelics in patients with depression and/or anxiety were searched via MEDLINE, EMBASE and PsychINFO. Efficacy was assessed by measuring symptom improvement from baseline, and tolerability was evaluated by noting the incidence and type of adverse effects reported. Risk of bias was assessed. Seven studies, with 130 patients, were analysed in this review. Three were conducted in patients with depression, two in patients with anxiety and two in patients with both. In a supportive setting, ayahuasca, psilocybin, and LSD consistently produced immediate and significant anti-depressant and anxiolytic effects that were endured for several months. Psychedelics were well-tolerated. The most common adverse effects were transient anxiety, short-lived headaches, nausea and mild increases in heart rate and blood pressure. At present, the number of studies on this subject is very limited; and the number of participating patients within these is also limited as the treatment under investigations is a relatively novel concept. Though further evidence is required, psychedelics appear to be effective in significantly reducing symptoms of depression and anxiety and are well-tolerated.