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Andrew D Penn

Department of Psychiatry and Behavioral Sciences, Weill Institute for Neurosciences, University of California, San Francisco, CA, USA.

4 papers in the library · 592 citations · publishing 2022-2025

Papers

Single-Dose Psilocybin Treatment for Major Depressive Disorder

JAMA August 31, 2023 Charles L Raison, Gerard Sanacora, Joshua Woolley et al. 493 citations

A single 25-mg dose of synthetic psilocybin, administered with psychological support, produced a clinically significant and sustained reduction in depressive symptoms and functional disability over 43 days in adults with major depressive disorder. In a phase 2 trial of 104 participants, those receiving psilocybin showed a mean 12.3-point greater improvement on the Montgomery-Asberg Depression Rating Scale at day 43 compared with those receiving a niacin placebo. Psilocybin also improved daily functioning and led to more sustained response, though not remission. No serious adverse events occurred, but psilocybin was associated with more overall and severe adverse events.

Effects of Naturalistic Psychedelic Use on Depression, Anxiety, and Well-Being: Associations With Patterns of Use, Reported Harms, and Transformative Mental States.

Frontiers in psychiatry January 1, 2022 Charles L Raison, Rakesh Jain, Andrew D Penn et al. 75 citations

In a large online survey of 2,510 adults who had used psychedelics at least once, psychedelic use was linked to significant improvements in depression, anxiety, and emotional well-being. The benefits grew with more use but showed a ceiling effect; even a single use was associated with improvements. No single psychedelic agent proved clearly superior, but increases in mystical experiences and prosocial perspective-taking were tied to better mental health. However, 13% of participants (330 people) reported at least one harm from psychedelic use, and those individuals experienced less mental health benefit. The findings suggest that naturalistic psychedelic use may offer mental health benefits similar to those in clinical trials, while also posing some risk of harm for a minority.

Psilocybin therapy for mood dysfunction in Parkinson's disease: an open-label pilot trial.

Neuropsychopharmacology : official publication of the American College of Neuropsychopharmacology April 9, 2025 Ellen R Bradley, Kimberly Sakai, Gisele Fernandes-Osterhold et al. 23 citations

In an open-label pilot trial, 12 people with mild to moderate Parkinson's disease plus depression or anxiety received psilocybin (10 mg then 25 mg) with psychotherapy. No serious adverse events occurred, and no worsening of Parkinson's symptoms was observed. Non-motor and motor symptoms improved, and gains in some cognitive domains were sustained one month later. Depression and anxiety scores improved to a clinically meaningful degree and remained improved three months after dosing. These first results in any neurodegenerative disease suggest psilocybin therapy for Parkinson's disease warrants further study.

Health-related behavioral changes following the use of psychedelics in naturalistic settings.

Preventive medicine reports August 1, 2025 Pedro J Teixeira, Rakesh Jain, Andrew D Penn et al. 1 citation

A survey of 2,510 U.S. adults who had used psychedelics at least once found that most reported lasting improvements in health behaviors after their experiences. Specifically, 66% reduced alcohol use, 49% cut tobacco use, 49% improved their diet, and 48–72% reported fewer impulsive behaviors. People who used psychedelics more often or microdosed were especially likely to report these positive changes. Although some participants experienced harms, the majority perceived lasting benefits. The findings suggest that psychedelic use may be linked to broad behavioral shifts in areas like diet and substance use, not just mental health.