A systematic review of 16 clinical trials found that psilocybin is generally well tolerated in patients with psychiatric or substance-dependence conditions. The most common side effects were temporary nausea and headache. Some participants experienced transient anxiety, and three received a benzodiazepine for severe anxiety during the session. Psilocybin caused modest increases in blood pressure and heart rate, with one participant requiring an antihypertensive for sustained high blood pressure. No cases of psilocybin-induced psychosis or Hallucinogen Persisting Perception Disorder were reported. The evidence suggests psilocybin has a favorable safety profile and may offer an alternative treatment for patients who do not respond to standard therapies.
Psychedelics may reduce anxiety and depression in patients with cancer, based on five randomized, double-blind, placebo-controlled trials. Two trials showed significant reductions in anxiety on the State-Trait Anxiety Inventory, and one trial found reductions on two additional anxiety scales. Two trials reported significant reductions in depression on the Hospital Anxiety and Depression Scale and Beck Depression Inventory, and one trial found reductions on another depression scale. Clinically relevant improvements were more common in psychedelic-treated patients than placebo. Benefits may last 6 to 12 months, but studies were small, had methodological limitations, and included increased blood pressure and heart rate.