This page lists PDF documents that are freely and legally available from the institutions and organizations that produced them. Every item below links to its original source. No files are hosted on this site. Where a document is behind a paywall, a publicly accessible preprint or author-accepted manuscript link is noted instead.
Clinical Treatment Manuals
MAPS Treatment Manual for Psilocybin-Assisted Psychotherapy
The clinical protocol manual developed by the Multidisciplinary Association for Psychedelic Studies for trained therapists and researchers. Covers session preparation, the therapeutic framework, facilitator roles, and post-session integration. Freely available at maps.org under open access.
Access at MAPS.orgZendo Project Psychedelic Peer Support Manual
The volunteer training manual produced by the Zendo Project, a MAPS-affiliated crisis support program operating at festivals and public events. Covers the four key principles of psychedelic harm reduction: safe space, sitting not guiding, talking through rather than talking down, and difficult is not the same as bad. Available via MAPS.
Access at Zendo ProjectRegulatory and Policy Documents
FDA Breakthrough Therapy Designation for Psilocybin
The FDA granted Breakthrough Therapy Designation to psilocybin for treatment-resistant depression in 2018 (COMPASS Pathways) and for major depressive disorder in 2019 (Johns Hopkins / Usona Institute program). The designation letters and supporting documentation are available through the FDA's public database and from COMPASS Pathways' investor disclosures. This designation signals that early clinical evidence shows substantial improvement over existing therapies.
FDA Breakthrough Therapy pageLandmark Clinical Research Papers
The following peer-reviewed papers are available as free full-text through PubMed Central, university open-access repositories, or via author-provided PDFs at the journals listed. Always verify you are reading the final published version rather than an early preprint when citing for medical or legal purposes.
Griffiths et al. (2016) — Psilocybin Produces Substantial and Sustained Decreases in Depression and Anxiety in Patients with Life-Threatening Cancer
Published in the Journal of Psychopharmacology. A randomized, double-blind crossover trial (n=51) at Johns Hopkins University showing that a single high dose of psilocybin produced clinically significant decreases in depressed mood and anxiety in patients with life-threatening cancer. At 6-month follow-up, approximately 80 percent of participants continued to show clinically significant reductions. Full text freely available via PubMed Central (PMC5367557).
Full text on PubMedDavis et al. (2021) — Effects of Psilocybin-Assisted Therapy on Major Depressive Disorder
Published in JAMA Psychiatry. A randomized clinical trial at Johns Hopkins (lead author Alan Davis) in adults with MDD. Psilocybin-assisted therapy produced a 71 percent response rate and a 54 percent remission rate four weeks after treatment, compared to 48 percent response and 28 percent remission in the delayed-treatment control group. Open access via JAMA network.
Full text on PubMedCarhart-Harris et al. (2021) — Trial of Psilocybin versus Escitalopram for Depression (NEJM)
A head-to-head randomized, controlled trial from Imperial College London comparing two doses of psilocybin against six weeks of the SSRI escitalopram (20 mg/day) in 59 patients with major depressive disorder. Primary outcomes on the Quick Inventory of Depressive Symptomatology were similar between groups, but secondary measures of emotional processing and well-being favored psilocybin. Full text available open access through the NEJM.
Full text at NEJMCarhart-Harris & Friston (2019) — REBUS and the Anarchic Brain: Toward a Unified Model of the Brain Action of Psychedelics
Published in Pharmacological Reviews. This paper from Robin Carhart-Harris and Karl Friston at Imperial College London presents the Relaxed Beliefs Under Psychedelics (REBUS) model, proposing that psychedelics flatten the brain's prior-belief hierarchy, enabling bottom-up sensory signals to exert greater influence on perception and cognition. This theoretical framework underpins much current psilocybin research. Open access via PMC.
Full text on PubMedJohnson et al. (2014) — Pilot Study of the 5-HT2AR Agonist Psilocybin in the Treatment of Tobacco Addiction
Published in the Journal of Psychopharmacology. A Johns Hopkins open-label pilot study (n=15) of psilocybin-facilitated smoking cessation. At 6-month follow-up, 80 percent of participants were confirmed abstinent by biochemical verification. At 12-month follow-up, 67 percent remained abstinent. These figures compare favorably with best available pharmacotherapy outcomes. Available open access via PMC.
Full text on PubMedBogenschutz et al. (2015) — Psilocybin-Assisted Treatment for Alcohol Dependence
Published in the Journal of Psychopharmacology. A proof-of-concept trial at the University of New Mexico (n=10) evaluating psilocybin-assisted therapy for alcohol use disorder. Drinking days decreased significantly following psilocybin sessions and improvements were maintained through the 36-week follow-up period. An important early paper establishing proof of concept for addiction treatment. Available via PMC.
Full text on PubMedEthnobotany and Natural History
Stamets (1996) — Psilocybin Mushrooms of the World (Excerpt and Species Descriptions)
Paul Stamets' definitive field guide to psilocybin-containing fungi covers more than one hundred species across multiple genera. Chapter excerpts and species-level data sheets have been made available by Fungi Perfecti for educational use. The full book is commercially published, but Stamets has released substantial supplementary ethnobotanical survey data as open PDFs through his organization. These documents cover habitat, geographic range, macroscopic and microscopic identification features, and historical ethnomycological use.
Articles at Fungi PerfectiHarm Reduction Guides
DanceSafe Psychedelic Harm Reduction Guide
DanceSafe is a 501(c)(3) nonprofit focused on health and safety within the nightlife and festival community. Their harm reduction literature on psilocybin covers dosage ranges, risk factors, drug interaction warnings, symptoms of a difficult experience, and guidance on supporting someone through psychological distress. Freely downloadable from DanceSafe's website. DanceSafe also provides drug-checking services at events using reagent testing kits.
DanceSafe Psilocybin InfoErowid Psilocybin Mushroom Vault — Reference Pages
Erowid's reference section for psilocybin mushrooms includes pharmacology summaries, chemistry reference documents, dosage charts, effects classification tables, law summaries by jurisdiction, and a curated library of experience reports used by researchers studying subjective effects. While Erowid content is primarily web-based, most pages are printer-friendly and the factual reference sections are cited in peer-reviewed literature. The chemistry and pharmacology pages cite primary sources throughout.
Erowid Mushroom VaultHow to Access Academic Papers Without a Subscription
Many of the clinical trials listed above are published in journals that require institutional access. The following legitimate routes provide free access:
- PubMed Central (PMC) at ncbi.nlm.nih.gov/pmc — a free full-text archive of biomedical literature funded by the US National Institutes of Health. Most NIH-funded psilocybin trials are required to be deposited here.
- Author personal pages and ResearchGate — corresponding authors frequently post the accepted manuscript on their university profiles or on ResearchGate. Look for a "Request full-text" link or the author's institutional page.
- Open access journals — JAMA Psychiatry, the New England Journal of Medicine, and Frontiers in Psychiatry have published several key psilocybin trials under open-access terms, meaning anyone can download them directly.
- Preprint servers — bioRxiv and medRxiv host preprints of many psilocybin studies before or alongside journal publication. Preprints have not undergone peer review, so they should be distinguished from final published versions when cited for clinical or policy purposes.
If you are a practitioner, researcher, or policy professional seeking specific papers not listed here, the Johns Hopkins Center for Psychedelic and Consciousness Research maintains a publications list at hopkinspsychedelic.org, and Imperial College London's Centre for Psychedelic Research publishes its full output at imperial.ac.uk/psychedelic-research-centre.