Psilocybin Therapy: Independent Evidence on Depression & Safety

Table of contents

• Evidence summary
• What psilocybin therapy is, and its legal status
• How it works
• What works and what does not
• Benefits by claim
• MDMA-assisted therapy for PTSD: the related question
• Risks and all side effects
• All interactions
• Who should avoid it
• Doses studied and how a session works
• Follow the money: who makes it and who funded the evidence
• Related research
• Frequently asked questions
• Sources and funding notes

Evidence summary

Independent evidence and credibility scorecard

Independence tiers: 1 = regulator or government body; 2 = academic or Cochrane team with no declared commercial funding for the work; 3 = independent authors analysing mostly manufacturer-run trials, or minor declared industry ties; 4 = manufacturer-funded or manufacturer-authored. Credibility runs from A (highest) to D.

Most sources come from the US and UK, where the main developers and donors are also based. There are no regulator efficacy reviews yet, because no psilocybin product has completed a marketing review.

What psilocybin therapy is, and its legal status

Psilocybin is a compound found in some mushrooms. In the body it is converted to psilocin, the active form (Brown et al. 2017). "Psilocybin therapy" in trials is not the same as taking mushrooms. It means a fixed dose of synthetic psilocybin made to pharmaceutical (cGMP) standards (Usona Institute), given in a clinic. Preparation sessions come first, trained staff watch the person throughout a session that lasts several hours, and follow-up support comes after. The FDA classes psilocybin as a classic psychedelic, a 5-HT_2A receptor agonist, and groups MDMA with it as an "entactogen" (FDA guidance 2026).

• Main products in development: COMP360, Compass Pathways' "proprietary psilocybin formulation" of crystalline psilocybin, for TRD (Compass 2025 annual report). Usona Institute's psilocybin, for major depressive disorder (Usona).
• Approval status: no regulator has approved a psilocybin medicine. Usona describes its product as "an investigational drug that has not been approved" by the FDA (Usona).

Legal and regulatory status by country (checked 6 October 2026)

How it works

Proven in humans: psilocybin's mind-altering effects come mainly from activating serotonin 5-HT_2A receptors. In healthy volunteers, ketanserin (a 5-HT_2A blocker) and risperidone blocked psilocybin's psychosis-like effects in a dose-dependent way, while haloperidol increased them (Vollenweider et al. 1998). Psilocybin itself was not detected in blood. It is converted to psilocin, whose half-life was about 3 hours in one study (Brown et al. 2017) and 1.8 hours in another, "consistent with the short duration of action" (Becker et al. 2022).

Not proven: why a few hours of drug effect might ease depression for weeks or months. Compass's own annual report describes a hypothesis that psilocybin briefly decouples a brain network (the default mode network), which "could lead to longer-term changes, such as altered emotional processing" (Compass 10-K). Ideas such as increased brain plasticity come mainly from imaging and animal work. None has been shown to explain the clinical effect.

The therapy part is also unmeasured. The FDA states that "the contribution of the psychotherapy component to any efficacy observed with psychedelic drug treatment has not been characterized" (FDA guidance 2026). Trials give the drug alongside support, so they cannot say how much of the benefit comes from each.

What works and what does not

Benefits by claim

Treatment-resistant depression

The phase 2b trial randomised 233 adults whose current depressive episode had not responded to at least two antidepressants. They received a single dose of 25 mg, 10 mg or 1 mg (the control) with psychological support. At week 3, MADRS scores fell by 12.0 points on 25 mg, 7.9 on 10 mg and 5.4 on 1 mg. The 25 mg vs 1 mg difference was −6.6 (95% CI −10.2 to −2.9). The 10 mg dose did not separate from 1 mg. Response and remission at 3 weeks supported the main result, "but not sustained response at 12 weeks" (Goodwin et al., NEJM 2022).

Two phase 3 trials followed, both funded by Compass (Compass SEC 8-K, 17 February 2026):

• COMP005 (US, 258 people dosed: 171 on 25 mg, 87 on placebo). One dose. Week 6 MADRS difference −3.6 (95% CI −5.7 to −1.5), p<0.001.
• COMP006 (North America and Europe, 581 people: 296 on 25 mg, 142 on 10 mg, 143 on 1 mg). Two doses three weeks apart. Week 6 difference for 25 mg vs 1 mg was −3.8 (95% CI −5.8 to −1.8), p<0.001. The company has not published the 10 mg result in the filings we read.

What do 4 points mean? The MADRS runs from 0 to 60, and people in these trials started at about 32 (Goodwin 2022). A 4-point average advantage is real but modest. Compass reports that 39% (COMP006) and 25% (COMP005) of the 25 mg group had a "clinically meaningful reduction". It defines this as a drop of 25% or more (Compass, August 2026), which is a lower bar than the conventional definition of response, a 50% drop, used in its own phase 2b paper (Goodwin 2022). Compass itself warns investors that "concerns about functional unblinding, expectancy bias" could "hinder interpretability or regulatory acceptability" of its data (Compass 10-K).

Major depressive disorder

Usona's phase 2 trial randomised 104 adults with major depression to 25 mg psilocybin or 100 mg niacin, which causes flushing and was meant to act as an active placebo. At day 43, psilocybin lowered MADRS by 12.3 points more than niacin (95% CI −17.5 to −7.2). The separation was already visible by day 8. More people on psilocybin had a sustained response, but not sustained remission. There were no serious treatment-emergent adverse events, but overall and severe adverse events were more common with psilocybin (Raison et al., JAMA 2023). Usona's phase 3 trial, uAspire (25 mg vs 5 mg vs placebo), enrolled 238 people and finished its primary data collection on 5 January 2026. When we checked, no results were posted (ClinicalTrials.gov NCT06308653).

A smaller Johns Hopkins trial randomised 27 people to immediate treatment or an 8-week wait. It reported very large effects (Cohen's d 2.5 to 2.6), with 54% in remission at week 4 (Davis et al., JAMA Psychiatry 2021). Waiting-list controls get no placebo at all, and an independent meta-analysis found such designs give inflated results. In trials using an active drug as placebo, psilocybin's pooled effect (g 0.71, 95% CI −0.01 to 1.43) was not statistically significant (Li et al. 2025).

Psilocybin versus an SSRI

Imperial College London randomised 59 people with moderate to severe depression. One group had two 25 mg psilocybin doses plus daily placebo. The other had two 1 mg doses plus daily escitalopram. The primary outcome, a self-rated depression score at week 6, showed no significant difference: 2.0 points (95% CI −5.0 to 0.9), P = 0.17. Remission was 57% vs 28%, but the authors note that secondary analyses "were not corrected for multiple comparisons" (Carhart-Harris et al., NEJM 2021). At 6 months, both groups had held their improvements, and the difference was still not significant: 1.51 points (95% CI −1.35 to 4.38). Psilocybin scored better on functioning, connectedness and meaning in life (Erritzoe et al. 2024). A later analysis found patients expected much more from psilocybin than from escitalopram, though expectancy did not predict response to psilocybin (Szigeti et al. 2024).

How big is the effect, really? Blinding and expectancy

The FDA puts the problem plainly. The "intense perceptual changes" increase "the potential for bias due to functional unblinding of patients, therapists, monitors, or raters", and a traditional placebo "can be problematic" (FDA guidance 2026). Independent analyses point the same way:

• A 2021 review found psychedelic trials had generally not measured expectancy or whether blinding held. The authors argued that effect sizes "are likely over-estimated" (Muthukumaraswamy et al. 2021).
• The BMJ meta-analysis first reported a large pooled effect (g 1.64, 95% CI 0.55 to 2.73), but the journal has since issued an expression of concern and a correction about effect-size calculations, so we do not rely on its size. Effects were larger on self-rated scales and in people who had used psychedelics before, which is consistent with expectancy (Metaxa & Clarke 2024).
• People on control in psilocybin trials improved much less (standardised change 0.50) than control groups in SSRI trials (1.00) or esketamine trials (1.12). Response rates in control groups were 14 and 23 percentage points higher in SSRI and esketamine trials. The authors concluded that psilocybin may not be as broadly effective for depression as estimated (Hieronymus et al. 2025). In plain terms, part of psilocybin's apparent advantage may come from people on control feeling let down, rather than from extra benefit on the drug.
• When the network meta-analysis used the placebo response from antidepressant trials, high-dose psilocybin still beat placebo, but the effect was small (standardised mean difference 0.31) (Hsu et al. 2024).

Using 1 mg or 10 mg doses as controls, as Compass did, partly addresses this. It may be one reason the phase 3 effects are smaller and, arguably, more believable.

Depression and anxiety in serious physical illness

A Cochrane review included 6 trials (149 people) of psychedelic-assisted therapy in people with life-threatening illness such as cancer. Classic psychedelics "may" reduce depression compared with an active placebo or low-dose psychedelic, and the review rates the certainty as low. We could not confirm the pooled depression effect size from the text we could access, so we do not quote a number for it. For anxiety, the review reports a mean difference of −8.41 points on the STAI-Trait scale (95% CI −12.92 to −3.89; 5 studies, 122 people; low certainty) (Schipper et al., Cochrane 2024).

MDMA-assisted therapy for PTSD: the related question

MDMA works differently from psilocybin. It is an entactogen rather than a classic psychedelic, but it is usually discussed in the same breath (FDA guidance).

• The trials: in MAPP1 (90 people with severe PTSD), MDMA-assisted therapy cut CAPS-5 scores by 24.4 points against 13.9 with placebo plus the same therapy (d = 0.91) (Mitchell et al. 2021). In MAPP2 (104 people), the figures were −23.7 vs −14.8 (d = 0.7). Severe adverse events occurred in 9.4% vs 3.9% (Mitchell et al. 2023). MAPS "fully funded" MAPP1 "from private donations", and its subsidiary MAPS PBC designed and analysed it (MAPP1 full text).
• FDA advisers said no: on 4 June 2024 the FDA's advisory committee voted 9–2 that the data did not show effectiveness and 10–1 that benefits did not outweigh risks. Members cited functional unblinding, expectation bias, missing abuse-potential and cardiac data, and the risk of "boundary violations" by therapists (FDA minutes).
• Rejection: on 9 August 2024 the FDA issued a complete response letter and asked for another phase 3 trial (Psychiatric Times).
• Independent appraisal: ICER concluded that "functional unblinding in the trials and additional concerns around trial design and conduct" made the evidence "insufficient to assess the balance of benefits and harms" (ICER 2024).
• Retractions: in August 2024 the journal Psychopharmacology retracted three MAPS-linked phase 2 analyses. The reason was "protocol violations amounting to unethical conduct" at one trial site, which the authors knew of but did not disclose, plus incompletely declared competing interests (retraction 1; retraction 2; retraction 3).
• Now: the developer, renamed Resilient Pharmaceuticals, resubmitted its application in August 2026 without new phase 3 data (MAPS statement; Psychedelics Today). In Australia, authorised psychiatrists may already prescribe MDMA for PTSD (TGA).

Risks and all side effects

On the day of dosing

A meta-analysis of 6 randomised trials (528 people) found therapeutic doses raised the risk of nausea (RR 8.85, 95% CI 5.68 to 13.79), dizziness (RR 5.81), raised blood pressure (RR 2.29), anxiety (RR 2.27) and headache (RR 1.99). These effects resolved within 48 hours (Yerubandi et al. 2024). In Compass's phase 3 trials, most adverse events happened on dosing day and most resolved within a day. The commonest were headache, nausea, anxiety and visual hallucination (Compass).

Source: sponsor-posted results for NCT03775200 (Compass Pathways). In the phase 3 trials, serious adverse events over 26 weeks were 5.7% on 25 mg and 6.3% on 1 mg in COMP006 (Compass, July 2026).

Other risks

• Serious events in vulnerable groups: across 114 studies (3,504 participants), serious adverse events occurred in about 4% of people with existing psychiatric disorders and in no healthy volunteers. They included worsening depression, suicidal behaviour, psychosis and seizures. Only 23.5% of studies since 2005 described systematic adverse-event checks, so harms may be under-counted (Hinkle et al. 2024).
• Hallucinogen persisting perception disorder (HPPD): perceptual effects that linger or recur after use, ranging from mild to "severely burdening" (Neven & Blom 2025). No HPPD cases were reported after high-dose psilocybin or LSD in modern research settings (Hinkle 2024), but cases are described after non-clinical use.
• Heart valves: the FDA notes that the 5-HT_2B receptor "has been linked to heart valvulopathy in humans". It asks sponsors to exclude people with valve disease or pulmonary hypertension from repeated-dose studies until the risk is characterised (FDA guidance 2026). Psilocybin is a partial 5-HT_2B agonist, but no study has been designed to test valve risk in people (Tagen et al. 2023). This matters most for repeated dosing and microdosing, not for one or two doses.
• Vulnerability during the session: the FDA requires consent forms to warn of "increased vulnerability and suggestibility" during sessions, and two monitors throughout (FDA guidance). Advisers on the MDMA application raised therapist boundary violations as a specific risk (FDA minutes).
• Misuse: the FDA expects every psychedelic drug programme to include an abuse-potential assessment (FDA guidance). Health Canada warns of "bad trips" with "paranoia, loss of boundaries and a distorted sense of self" (Health Canada).

All interactions

If you take any psychiatric medicine, do not stop it to qualify for a trial or programme without your prescriber. Antidepressant withdrawal can be significant (see our guide to antidepressant withdrawal and dependence).

Who should avoid it

• People with a personal history of psychosis or bipolar disorder: excluded from Compass's phase 3 trials ("prior or ongoing bipolar disorder, any psychotic disorder") (COMP005 criteria) and from Usona's trial (NCT03866174).
• People with a family history of psychosis or bipolar disorder: the Johns Hopkins trial excluded anyone with a "personal or family history (first or second degree) of psychotic or bipolar disorders" (Davis 2021 full text).
• Heart disease: uncontrolled high blood pressure, coronary disease, heart failure, long QT, recent heart attack, stroke or TIA were exclusions (NCT03866174). Valve disease and pulmonary hypertension rule people out of repeated-dose studies (FDA guidance).
• Epilepsy, or taking lithium: epilepsy was an exclusion in Usona's trial (NCT03866174), and there are seizure reports with lithium (Nayak 2021).
• Pregnancy and breastfeeding: excluded from trials, so there are no safety data (NCT03866174).
• Children and teenagers: the main trials enrolled adults only, aged 18 and over (COMP005) or 21 to 65 (Usona).
• Moderate to severe alcohol or drug use disorder, or liver impairment: exclusions in Usona's trial (NCT03866174).
• Psychotic depression: Compass's trials required "major depression without psychotic features" (COMP005). See our guide to depression with psychotic features.

Trial participants were carefully screened, so results may not apply to the wider group of people who might seek this treatment.

Doses studied and how a session works

These are doses used in research, not a guide to use. Psilocybin is illegal to possess in most places, and wild or home-grown mushrooms vary in strength.

What happens in a session

Under the FDA's 2026 guidance, a trial session needs two monitors for its full length. The lead must be a licensed clinician with psychotherapy training. If the lead is not a doctor, a physician must be able to reach the site within 15 minutes (FDA guidance). Effects "can last for several hours or days", and sponsors are asked to study effects on driving. Usona required each participant to have a support person to take them home after dosing (NCT03866174). Oregon and Colorado use licensed facilitators under state rules instead of a medical model (OHA; Colorado DORA).

Product quality

Trial psilocybin is synthesised under cGMP conditions; Usona says it does not use mushrooms to make it (Usona). Compass's COMP360 is a specific crystalline form "optimized for stability and purity" (Compass 10-K). Colorado's regulated system licenses testing facilities for natural medicine products (Colorado Natural Medicine Division). Illicit products have no such checks.

Follow the money: who makes it and who funded the evidence

Compass Pathways (developer of COMP360)

• Company: a public limited company registered in England and Wales and listed on Nasdaq (ticker CMPS). Its 2020 prospectus said its operations were "headquartered in our offices in London, UK" (IPO prospectus; 2026 filing). Its American depositary shares were priced at $17.00 at the September 2020 IPO.
• Early owners (pre-IPO, September 2020): press reports describe Compass as backed by Peter Thiel and lead investor Christian Angermayer when it filed for its US IPO (Bloomberg). We could not verify the percentage stakes in the prospectus sections we could access, so we do not quote them (IPO prospectus).
• Owners now: the April 2026 proxy lists only two holders above 5%, RTW Investments and entities affiliated with Deep Track (9.99% each). ATAI and Thiel-affiliated entities are not listed above 5%. The chief executive since August 2022 previously ran Otsuka's North American pharmaceutical business (2026 proxy).
• Finances: no revenue to date. Net loss was $287.9 million in 2025, with an accumulated deficit of $822.6 million (10-K). Cash was $433.3 million at 30 June 2026. The company expects to launch in the first half of 2027 if approved and rescheduled (Q2 2026 results).
• Authors: Guy Goodwin, lead author of the NEJM phase 2b paper, has been Compass's chief medical officer since August 2021 (proxy). In a 2023 Compass paper, he and other authors disclosed shares or options in the company (Goodwin 2023).

The patent dispute

Compass holds US patents on its crystalline psilocybin and its use. One petition for post-grant review was dismissed in 2020. In December 2021 a group called Freedom to Operate, Inc. challenged two further patents (10,947,257 and 10,954,259). The US Patent Trial and Appeal Board denied review on 22 June 2022 and refused rehearing in May 2023 (Compass 10-K). Critics argued that patenting a crystal form of a naturally occurring compound could restrict access. The board did not reach a final ruling on validity; it declined to start a review. Separately, the nonprofit Usona has published its own research on producing psilocybin crystal forms (polymorphs) (Usona press releases).

Usona Institute (developer of psilocybin for MDD)

Usona is a 501(c)(3) nonprofit medical research organisation in Madison, Wisconsin. It was founded in 2014 by Bill Linton and Malynn Utzinger and "relies on a number of generous donors" (Usona FAQ). Its JAMA paper names grants to Usona from Dr. Bronner's All-One, the Fournier Family Foundation, Good Ventures, the Steven and Alexandra Cohen Foundation, the Tiny Blue Dot Foundation, the Turnbull Family Foundation and William A. Linton. Usona "designed the study", supplied the drug, "interpreted study data, wrote the manuscript" and decided to publish (Raison et al. 2023). It received a national priority voucher in April 2026. Psychedelic Alpha, a specialist industry publication, expects Usona to file on the basis of its single phase 3 trial (Psychedelic Alpha).

MAPS and Resilient Pharmaceuticals (MDMA)

MAPS is a US nonprofit active since 1986. It says it funded the MDMA research programme with philanthropic donations from the early 1990s to 2022, and that donors and grantors have given it more than $150 million since its founding for research, drug policy and culture work. It incubated the company now called Resilient Pharmaceuticals (formerly MAPS PBC, then Lykos Therapeutics), but says it has "no active role" in Resilient's drug development programme (MAPS, August 2026). MAPP2 was funded by MAPS "with support from the Steven and Alexandra Cohen Foundation" (Mitchell 2023). A magazine report says investor Antonio Gracias became a major shareholder after a 2025 takeover (DoubleBlind). We could not confirm the terms in a primary filing.

Academic centres and their donors

• Imperial College London: its Centre for Psychedelic Research launched in April 2019 with "more than £3 million from five founding donors" (not named in the announcement). Its psilocybin trial was funded by the Alexander Mosley Charitable Trust (Imperial). Compass supplied COMP360 for the escitalopram trial and, under contract with Imperial, had access to its safety data (Erritzoe 2024).
• Johns Hopkins: its Center for Psychedelic and Consciousness Research "is funded by the Steven and Alexandra Cohen Foundation and has received support from Tim Ferriss, Matt Mullenweg, Craig Nerenberg, and Blake Mycoskie". The depression trial was funded partly by a public fundraising campaign organised by Tim Ferriss and by the Riverstyx Foundation (Davis 2021).
• A shared donor: the Steven and Alexandra Cohen Foundation appears as a funder of the Hopkins centre, of Usona and of the MAPS MDMA trial. That is a documented pattern, not evidence of wrongdoing, but it means much of the field's evidence traces back to a small circle of philanthropists who want psychedelic treatments to succeed.

Government money

Executive Order 14401 directs the US health department to put at least $50 million of existing ARPA-H funds into partnerships with states running psychedelic programmes. It also directs the FDA to give priority vouchers to psychedelics with Breakthrough designation (EO 14401). The third voucher went to Transcend Therapeutics for methylone (TSND-201) for PTSD. Otsuka has since completed its acquisition of Transcend, though reports differ on the deal value, so we do not quote one (Fierce Biotech; Otsuka acquisition report). Smaller public grants appear in some papers, such as US NIDA training and research grants that supported investigators on the Hopkins trial (Davis 2021).

Documented integrity events

• Retractions (August 2024): three MAPS-linked MDMA papers in Psychopharmacology were retracted for undisclosed "unethical conduct" at a trial site and incomplete competing-interest declarations (notice).
• Regulatory rejection (August 2024): FDA complete response letter for MDMA-assisted therapy, after a 9–2 advisory vote against efficacy (FDA minutes).
• Patent challenges (2020–2023): petitions against Compass patents, all denied review (Compass 10-K).
• Unpublished results: as of 6 October 2026, the main phase 3 psilocybin results exist only as company summaries. Usona's phase 3, whose main data collection ended in January 2026, had no posted results (NCT06308653).

Who pays the referees

ICER says life-science companies and insurers contribute dues to its policy forum totalling "less than 25%" of its annual revenue. The rest comes from non-profit foundations and individual donors (ICER). The Cochrane review notes its included trials were funded by groups that "promote psychedelic-assisted therapy" (Cochrane 2024). The BMJ meta-analysis had no funding received (Metaxa 2024). The psychosis meta-analysis includes an author who has consulted for Compass and for dozens of other drug companies (Sabé 2025).

What this means: the efficacy evidence comes almost entirely from developers and from donors who want psychedelic treatments to work. The most independent work (the FDA, ICER and unfunded meta-analyses) does not say psilocybin fails. It says the benefit is probably smaller than early trials suggested and hard to measure cleanly. That is consistent with what Compass's own larger trials found.

Related research

• Esketamine (Spravato): independent evidence on TRD, side effects and risks
• Treatment-resistant depression
• Major depressive disorder
• Brain stimulation for depression
• Escitalopram: independent evidence
• Antidepressant withdrawal and dependence
• Bipolar depression
• Depression with psychotic features
• Post-traumatic stress disorder
• Trauma-focused therapy
• Complex PTSD
• Mental health crisis warning signs

Frequently asked questions

Sources and funding notes

What we could not verify: results of Usona's phase 3 uAspire trial (none posted when checked). Full suicidality tables for either phase 3 trial (company summaries only, not peer reviewed). Headache and adverse-event rates for Usona's phase 2 (the JAMA full text was not accessible). Per-arm suicidality counts in NCT03775200 (secondary reports conflict). The pooled depression effect in the Cochrane review (Schipper 2024). The detail of the BMJ's 2025 correction for the Metaxa and Clarke review (the notice says the main messages are unchanged). The full text of Hsu et al. (BMJ 2024); the 0.31 and -3.90 figures are checked against the abstract only, and its funding and conflict details are not verified. Pre-IPO percentage stakes in Compass (ATAI, Thiel-linked entities). Current holders in Compass's 2026 proxy, which we did not re-check. The names of Imperial's five founding donors. The terms of the 2025 investment in Resilient Pharmaceuticals. Whether Czech psilocybin treatment has started. How Canada's Special Access route works under the regulations that took effect on 1 October 2026. The status of the MDMA resubmission review (we found no public FDA acceptance or decision date). Whether Compass had completed its rolling filing by 6 October 2026; the company's latest statement said the fourth quarter. The reason MAPS no longer has a role in Resilient, and whether it keeps any shareholding. A "Yan 2023" meta-analysis, which we could not identify, so it is not cited. Not re-checked in this pass: the FDA guidance and hearing dates, Canada's 1 October 2026 revocation date, and the Australian TGA dates. Several TGA and Colorado pages blocked automated access. TGA facts are taken from the TGA consumer page as indexed, and Colorado facts from the state's own pages. We did not find NICE guidance on psilocybin, but we could not access NICE's site to confirm.

1. FDA. Psychedelic Drugs: Considerations for Clinical Investigations. Final guidance, July 2026 — US regulator.
2. FDA guidance page — confirms final status; draft issued June 2023.
3. FDA. Final summary minutes, Psychopharmacologic Drugs Advisory Committee, 4 June 2024 — US regulator; MDMA votes.
4. FDA press release, 24 April 2026 — national priority vouchers.
5. FDA public hearing notice, 14 September 2026 — US regulator.
6. Executive Order 14401, Accelerating Medical Treatments for Serious Mental Illness (Federal Register, 22 April 2026) — US government.
7. Health Canada. Psilocybin and psilocin (updated October 2025); SAP class exemption — Canadian regulator.
8. TGA. Access MDMA or psilocybine (consumers) — Australian regulator.
9. Misuse of Drugs Regulations 2001, Schedule 1 — UK legislation.
10. Oregon Health Authority. Oregon Psilocybin Services — US state government.
11. Colorado DORA. Natural Medicine; Colorado DOR, first healing centre licence — US state government.
12. National Institute of Mental Health (Czech Republic). Statement on psilocybin treatment availability — public institute.
13. Compass Pathways. Form 8-K, 17 February 2026 — developer; COMP005/006 results.
14. Compass. Six-month COMP006 data, 7 July 2026 — developer.
15. Compass. Rolling review and priority voucher, 24 April 2026 — developer.
16. Compass. Q2 2026 results (5 August 2026) — developer.
17. Compass. Form 10-K for 2025 — developer; scheduling, patents, risk factors, finances.
18. Compass. IPO prospectus (424B4), September 2020 — developer; principal shareholders.
19. Compass. Proxy statement, April 2026 — developer; current holders, executives.
20. Goodwin GM et al. Single-dose psilocybin for a treatment-resistant episode of major depression. NEJM 2022 — funded by COMPASS Pathfinder.
21. ClinicalTrials.gov NCT03775200 (posted results) — sponsor Compass.
22. ClinicalTrials.gov NCT05624268 (COMP005) and NCT05711940 (COMP006) — sponsor Compass.
23. Goodwin GM et al. Psilocybin for TRD in patients taking a concomitant SSRI. Neuropsychopharmacology 2023 — Compass-sponsored; authors hold Compass shares or options.
24. Raison CL et al. Single-dose psilocybin treatment for major depressive disorder. JAMA 2023 (funding and disclosures) — funded, designed and written by the Usona Institute.
25. ClinicalTrials.gov NCT06308653 (uAspire) and NCT03866174 — sponsor Usona.
26. Usona Institute FAQ, psilocybin page and press releases — developer.
27. Carhart-Harris R et al. Trial of psilocybin versus escitalopram for depression. NEJM 2021 — Alexander Mosley Charitable Trust; Imperial centre.
28. Erritzoe D et al. Six-month follow-up. eClinicalMedicine 2024 — same funders; Compass supplied COMP360.
29. Szigeti B et al. Expectancy and suggestibility in escitalopram v. psilocybin. Psychol Med 2024 — Imperial team; COI "None" in PubMed record.
30. Davis AK et al. Psilocybin-assisted therapy for MDD. JAMA Psychiatry 2021 (full text) — private donors; NIDA grants supported several investigators.
31. Metaxa AM, Clarke M. Efficacy of psilocybin for depression. BMJ 2024 — no funding; first author employed by IDEA Pharma; expression of concern and 2025 correction.
32. Hsu TW et al. Comparative oral monotherapy of psilocybin, LSD, MDMA, ayahuasca, and escitalopram for depressive symptoms. BMJ 2024;386:e078607 — Taiwan National Science and Technology Council.
33. Hieronymus F et al. Control group outcomes in trials of psilocybin, SSRIs or esketamine. JAMA Netw Open 2025 — Swedish academic team; no funding statement found; one author holds grants for two psilocybin trials; first author reported speaker fees from Lundbeck and Janssen.
34. Li JR et al. Study design and antidepressant effects in psychedelic trials. J Affect Disord 2025 — authors declared no relevant financial relationships.
35. Muthukumaraswamy SD et al. Blinding and expectancy confounds in psychedelic RCTs. Expert Rev Clin Pharmacol 2021 — COI "None" in PubMed record.
36. Schipper S et al. Psychedelic-assisted therapy in life-threatening diseases. Cochrane 2024 — Cochrane; one author reported grants from psychedelic companies.
37. Hinkle JT et al. Adverse events in studies of classic psychedelics. JAMA Psychiatry 2024 — Johns Hopkins; philanthropic support declared.
38. Yerubandi A et al. Acute adverse effects of therapeutic doses of psilocybin. JAMA Netw Open 2024 — authors reported no conflicts.
39. Sabé M et al. Psychedelic-induced psychosis: meta-analysis. Mol Psychiatry 2025 — University of Geneva open-access funding; one author has wide industry consulting including Compass.
40. Tagen M et al. Microdosing and valvular heart disease. J Psychopharmacol 2023 — COI "None"; funding not stated in PubMed record.
41. Neven A, Blom JD. Pharmacological treatment of HPPD. Harv Rev Psychiatry 2025 — COI "None".
42. Nayak SM et al. Psychedelics with lithium and seizures. Pharmacopsychiatry 2021 — Johns Hopkins; two authors employed by Erowid (data source).
43. Becker AM et al. Psilocybin after escitalopram pretreatment. Clin Pharmacol Ther 2022 — University Hospital Basel and Mind Medicine.
44. Brown RT et al. Pharmacokinetics of oral psilocybin. Clin Pharmacokinet 2017 — COI "None".
45. Vollenweider FX et al. Psilocybin and serotonin-2 agonist action. Neuroreport 1998 — academic (Switzerland).
46. Mitchell JM et al. MDMA-assisted therapy for severe PTSD. Nat Med 2021 (full text) — funded by MAPS; organised by MAPS PBC.
47. Mitchell JM et al. MDMA-assisted therapy for moderate to severe PTSD. Nat Med 2023 — MAPS with Steven and Alexandra Cohen Foundation.
48. Retraction notes (2, 3). Psychopharmacology, August 2024 — journal (Springer).
49. ICER. MDMA-assisted psychotherapy for PTSD (2024); ICER funding — US non-profit.
50. Psychiatric Times. FDA issues CRL to Lykos (9 August 2024) — trade press.
51. MAPS statement, 10 August 2026 — interested nonprofit.
52. Psychedelics Today, 18 August 2026 and DoubleBlind — specialist press.
53. Psychedelic Alpha. FDA awards priority vouchers (24 April 2026) — specialist industry press.
54. Imperial College London. Centre for Psychedelic Research launch (26 April 2019) — university.

Educational research reviewed 6 October 2026. This article is not medical advice; talk to a qualified clinician or pharmacist before starting, stopping or combining treatments.