Johns Hopkins and NYU Psilocybin Cancer Anxiety Studies

Psilocybin for Cancer Patients

78–83% clinical response rate at 6 months

In the Johns Hopkins 2016 RCT, 78% of cancer patients showed clinically significant depression reduction and 83% showed anxiety reduction after a single psilocybin session, with effects sustained at 6.5-month follow-up. The NYU trial published simultaneously found comparable reductions plus improvements in spiritual well-being and demoralization.

Griffiths et al., Journal of Psychopharmacology, 2016

n=80

total patients across both 2016 landmark trials (Hopkins n=51, NYU n=29)

4.5 years

sustained follow-up period confirmed by Agin-Liebes et al. 2020 NYU long-term study

1 session

single psilocybin session produced the effects measured across all follow-up periods

Griffiths et al., Journal of Psychopharmacology, 2016

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In December 2016, two research teams published their results in the same issue of the Journal of Psychopharmacology on the same day. Both had run randomized controlled trials of psilocybin for cancer patients experiencing anxiety and depression. Both found the same thing: large, rapid, and sustained reductions in distress after a single guided session. The journal published 11 expert editorials alongside the two papers. The coverage was described as a landmark moment in both psychiatry and psychedelic research. These Johns Hopkins and NYU psilocybin cancer anxiety study results are now the most cited body of evidence in the emerging field of psychedelic-assisted therapy for oncology patients. This article explains what each trial actually tested, what they found, how their methodologies differed, and what the 4.5-year follow-up data added. For the broader overview of how psilocybin therapy works in this population, see Psilocybin for Cancer Patients: Reducing Existential Anxiety.

Before 2016: What Grob's Pilot Study Established

Before the Hopkins and NYU results, the modern evidence base for psilocybin in cancer patients rested on a single small trial.

Charles Grob and colleagues published a double-blind crossover pilot in the Archives of General Psychiatry in 2011 using 12 patients with advanced-stage cancer.^[1] The design was psilocybin versus niacin as the control. Participants received one session of each in counterbalanced order. The results showed significant reductions in trait anxiety at the 1-month and 3-month follow-up periods. Most importantly, there were no serious adverse events. The study established that psilocybin could be administered safely in a medically ill population, which was not obvious given that cancer patients often take multiple medications, may have cardiac complications from their treatments, and have elevated baseline psychological stress.

The Grob pilot was necessary but inconclusive. Twelve patients is not enough to establish efficacy. The effect sizes were small, the crossover design complicated interpretation, and the study was underpowered for most outcomes. It was, in the researchers' own framing, a proof-of-concept: important enough to justify larger trials, not sufficient to support clinical conclusions on its own.

Hopkins and NYU each built on Grob's pilot independently, running trials large enough to generate reliable effect size estimates. Both published in the same month.

December 2016: A Simultaneous Publication That Made History

The coordination between Hopkins and NYU was deliberate. Both research teams knew the other was running trials on the same question with similar designs. They agreed to publish together, and the journal arranged simultaneous peer review. The December 2016 issue of the Journal of Psychopharmacology included both full papers plus 11 invited editorials from researchers, clinicians, ethicists, and psychiatrists commenting on the findings.

This publication structure was itself an editorial statement about the significance of the work. Journal editors do not typically commission 11 editorials for a single research topic in one issue. The editorials ranged from enthusiastic endorsement to careful methodological critique, but the consensus was that these trials represented a meaningful advance in understanding how psilocybin might address a clinical need that existing treatments serve poorly.

What makes existential distress in cancer patients distinctly difficult to treat with conventional pharmacotherapy is the specific nature of the problem. Benzodiazepines reduce acute anxiety symptoms but do not address the underlying confrontation with mortality. SSRIs take 4 to 6 weeks to work and have limited evidence for anxiety specifically in the context of terminal illness. The psychological suffering these patients experience is often described as "demoralization" in the clinical literature: a distinct syndrome characterized by loss of meaning, loss of purpose, hopelessness, and changed relationship to the future, different from primary depression or generalized anxiety disorder. Psilocybin's proposed mechanism addresses something different from what these drugs target.

The Hopkins Trial: Griffiths 2016, n=51

The Hopkins trial enrolled 51 adults with a life-threatening cancer diagnosis who also had a DSM-IV diagnosis of a depressive or anxiety disorder related to their cancer experience.^[2] The design was a randomized double-blind crossover: each participant received both a high-dose session and a low-dose control session, separated by at least five weeks, in randomized order.

The methodological choice that drew the most commentary was the control condition. Rather than a clearly inactive placebo, the Hopkins team used a very low dose of psilocybin (1 to 3 mg per 70 kg body weight) as the comparator against the high dose (22 to 30 mg per 70 kg). The rationale was that this produced some perceptible drug effects, maintaining blinding integrity. The criticism was that a "low dose of the same drug" is not an inert control, and that positive expectation effects might inflate the apparent benefit of the high dose.

The high dose produced perceptible psychedelic effects in all participants. The primary outcome measures were clinician-rated depression (HAM-D) and anxiety (HAM-A) at the 5-week assessment point, with follow-up extending to 6.5 months.

At 6.5 months:

• 78% of participants showed a clinician-rated clinical response on depression measures
• 83% showed a clinical response on anxiety measures
• 60% met remission criteria for depression

The mystical experience finding was important. The team used the Mystical Experience Questionnaire (MEQ30) to measure the quality of the psilocybin session. They found that the strength of the mystical experience during the session was a significant predictor of the therapeutic outcome: participants who reported a more complete mystical experience during the session showed larger and more durable reductions in distress. This suggests the mechanism is not simple serotonergic pharmacology. The drug's acute effect on subjective experience mediates the long-term psychological change.

The NYU Trial: Ross 2016, n=29

The NYU trial, led by Stephen Ross, enrolled 29 adults with DSM anxiety or depression related to cancer diagnoses.^[3] The control condition was niacin, an active placebo that produces physical flushing, warmth, and prickling sensations that participants might mistake for early drug effects. This addresses a limitation of the Hopkins design: niacin creates an expectation-consistent physical experience without any psychedelic effect, making blinding more robust for participants.

The dose was 0.3 mg per kg body weight for psilocybin in the active arm.

At 7 weeks:

• 83% of participants in the psilocybin group showed reduced depression, versus 14% in the niacin group
• Anxiety, spiritual well-being, and quality of life all significantly improved in the psilocybin group

The NYU trial measured outcomes that Hopkins did not include as primary endpoints. The Functional Assessment of Chronic Illness Therapy Spiritual Well-Being scale (FACIT-Sp) captured dimensions of meaning and peace specifically. The Demoralization Scale measured the clinical syndrome of demoralization in terminal illness. Both showed significant improvements in the psilocybin group. In qualitative reporting, participants described recurring themes: a sense of reconciliation with death, an emotional uncoupling from the physical cancer diagnosis, and a feeling that their identity extended beyond the illness.

The key difference in findings between the two trials was not the magnitude of the effect but the measurement breadth. Hopkins demonstrated powerful effects on clinician-rated depression and anxiety with a larger sample. NYU added evidence that psilocybin addressed spiritual well-being and demoralization specifically, dimensions that conventional psychiatric medication does not reach.

Side-by-Side Comparison: Hopkins vs. NYU 2016

The key methodological difference is in the control strategy. Hopkins' very low-dose control may have produced some active effects in participants, which could inflate the apparent high-dose benefit through mechanisms other than expectation alone. NYU's niacin control was more physically convincing as a sham treatment, potentially providing cleaner separation between pharmacological and expectation effects. Neither design is unambiguously superior; both represent genuine methodological compromises in a field where blinding psilocybin trials is inherently difficult.

4.5 Years Later: The Agin-Liebes Follow-Up

The most important evidence that emerged after the two 2016 trials was not from a new study. It was from the same NYU participants, followed for 4.5 years.

Agin-Liebes et al. (2020) traced 15 of the 16 surviving participants from the Ross 2016 trial, conducting structured clinical interviews at both 3.2-year and 4.5-year timepoints.^[4] At both assessment points, the reductions in anxiety, depression, hopelessness, demoralization, and death anxiety were sustained. No long-term adverse effects were reported.

The phenomenological finding was striking: 70 to 100% of participants described the psilocybin experience as among the most personally meaningful or spiritually significant experiences of their lives, even 4 to 4.5 years later. A large fraction reported it as the single most meaningful experience. These were patients with late-stage cancer. The psilocybin session had taken place years before. Their cancers had progressed. They were, in some cases, nearer to death than they had been at enrollment. And yet the session continued to provide what they described as a psychological anchor.

The durability data from Agin-Liebes 2020 is the finding most often omitted from popular summaries of this research. Most coverage highlights the 78% and 83% response rates. The less-cited finding is that 60 to 80% of those participants were still maintaining clinically significant reductions in distress 4.5 years later, from a single session.

What Independent Meta-Analyses Found

Two meta-analyses synthesized the evidence from the 2016 trials and subsequent studies independently.

Yu et al. (2021) conducted a meta-analysis of five studies including 132 participants total.^[5] Using Hedges' g as the effect size measure, they found psilocybin outperformed placebo for state anxiety at day 1 (g = -0.70) and month 1 (g = -0.73). For trait anxiety, the effects were larger: day 1 (g = -0.71), month 1 (g = -1.04), month 3 (g = -0.60), and month 6 (g = -1.03). No serious adverse events were reported across all included studies. The only consistent physiological finding was transient blood pressure elevation during the session itself. Meta-analytic synthesis confirmed that the Hopkins and NYU findings were not outliers, but rather consistent with the entire available literature at the time.

Bader et al. (2024) updated the meta-analysis with seven studies and 132 participants, finding pooled STAI anxiety scores declining from 35.15 at 4 to 4.5 months to 33.06 at 6 to 6.5 months, with approximately 60 to 80% of participants maintaining clinically significant reductions in depression or anxiety at follow-up.^[6] Quality of life and pain control also showed improvement in the pooled analysis.

Where the Research Stands: Ross 2025 Phase 2b

The most recent data comes from a Phase 2b randomized controlled trial led by the NYU group and published in General Hospital Psychiatry in 2025.^[7] Phase 2b represents a more rigorous and larger-scale replication of the 2016 findings, designed specifically to satisfy regulatory requirements for clinical development. The results confirmed significant reductions in depression and anxiety, extending and replicating the Ross 2016 findings in a more methodologically stringent design.

The existence of a Phase 2b trial signals that this research has moved beyond academic exploration into a clinical development pathway. Phase 3 trials, which would be required for regulatory approval, have not yet been completed.

Honest Limitations of the 2016 Evidence Base

The 2016 trials are well-designed for their era and publication context. They are not without important limitations.

Sample sizes are small. The Hopkins trial had 51 participants and the NYU trial had 29. These samples are adequate for detecting large effect sizes, but they limit the precision of estimates and the generalizability of findings. Both trials drew from relatively homogeneous populations: mostly white, college-educated, and comfortable with psychological introspection. Whether the results generalize to patients without these characteristics is not established.

Both trials involved a single psilocybin session. The treatment model in real-world deployment might look different: multiple sessions, different durations of preparatory therapy, or different support structures. The single-session design is internally consistent but may not represent optimal clinical practice.

The crossover design in both trials means some participants received psilocybin first and some received the control first. Any carryover effect from the psilocybin session (an experience described as among the most meaningful in people's lives) would contaminate subsequent control session ratings. Both teams controlled for this statistically, but it remains a structural concern.

These limitations do not undermine the findings. Large, robust, sustained effects with consistent replication across two independent teams and confirmed by meta-analysis are the strongest signal available at this evidence level. They do mean the evidence base is not yet equivalent to a multi-center Phase 3 program.

The Bottom Line

The 2016 Hopkins and NYU psilocybin trials remain the landmark evidence in this field: n=51 and n=29 respectively, different control designs, and consistent findings of 78-83% clinical response rates for depression and anxiety in cancer patients after a single guided session, with effects persisting to 6.5 months. The Agin-Liebes 2020 follow-up extended this to 4.5 years in the NYU cohort, with 60-80% maintaining clinically significant improvements. Two meta-analyses and a 2025 Phase 2b RCT have since confirmed and extended the original findings. The evidence is robust for effect size and durability; generalizability remains limited by small, demographically narrow samples.

Frequently Asked Questions

What did the Johns Hopkins psilocybin cancer study find?

The Hopkins 2016 trial (n=51, Griffiths et al.) found that a single high-dose psilocybin session produced clinically significant reductions in depression in 78% of participants and anxiety in 83% at 6.5-month follow-up. Approximately 60% met remission criteria. The study also found that the strength of the mystical experience during the psilocybin session significantly predicted the therapeutic outcome.

What was the NYU psilocybin cancer study?

The NYU 2016 trial (n=29, Ross et al.) enrolled cancer patients with anxiety or depression and randomized them to psilocybin versus niacin as an active placebo. At 7 weeks, 83% of the psilocybin group showed reduced depression versus 14% of the niacin group. The trial also showed significant improvements in spiritual well-being (FACIT-Sp), demoralization, and quality of life, dimensions not captured as primary outcomes in the Hopkins trial.

What is the difference between the Hopkins and NYU psilocybin studies?

Both trials showed similar effects but used different control conditions. Hopkins compared high-dose psilocybin against very low-dose psilocybin as a control, which addresses blinding but means the control may have some active effects. NYU used niacin as an active placebo (produces flushing and warmth without psychedelic effects), providing a more inert control. Hopkins had a larger sample (n=51 vs n=29), while NYU measured additional outcomes including spiritual well-being and demoralization.

How many patients were in the psilocybin cancer studies?

The two 2016 landmark trials enrolled 80 patients total: 51 in the Hopkins trial and 29 in the NYU trial. Including Grob's 2011 pilot (n=12) and subsequent trials, the 2021 meta-analysis by Yu et al. included 132 participants across five studies. The 2025 Phase 2b trial by Ross et al. expanded the evidence base further, though the exact sample size of that trial is not yet fully reported in publicly available summaries.

Are the results of psilocybin cancer studies reliable?

The evidence is stronger than what is available for many psychiatric treatments at a comparable stage of development. The 2016 findings were confirmed by two independent meta-analyses (Yu 2021 and Bader 2024) covering up to 132 patients across multiple studies. The NYU cohort showed sustained effects at 4.5-year follow-up. A Phase 2b RCT was published in 2025. The main reliability limitation is sample size and demographic homogeneity: both 2016 trials enrolled small, mostly white, college-educated populations, limiting generalizability.

What dose of psilocybin was used in the cancer studies?

The Hopkins trial used 22 to 30 mg per 70 kg body weight as the high dose and 1 to 3 mg per 70 kg as the low-dose control. The NYU trial used 0.3 mg per kg as the active dose. These are moderate to high doses by the standards of human psilocybin research. Both trials administered the sessions in a specially prepared clinical environment with trained therapists present throughout the 6-8 hour session duration.

Who funded the Hopkins and NYU psilocybin cancer trials?

Both trials were funded primarily through private philanthropy and non-profit research foundations, as federal funding for Schedule I substance research has historically been difficult to obtain. The Heffter Research Institute, which specifically supports psilocybin research, was among the funders for the Hopkins work. Both teams operated within university medical center frameworks, with their IRB-approved protocols providing additional institutional support. Neither trial received primary NIH funding, which reflects the regulatory classification challenge for this type of research.

Sources & References

1. 1RTHM-00397·Grob, Charles S et al. (2011). “Pilot study of psilocybin treatment for anxiety in patients with advanced-stage cancer..” Archives of general psychiatry.Study breakdown →PubMed →↩
2. 2. Source details for this reference are not yet available.
3. 3RTHM-00445·Ross, Stephen et al. (2016). “Rapid and sustained symptom reduction following psilocybin treatment for anxiety and depression in patients with life-threatening cancer: a randomized controlled trial..” Journal of psychopharmacology (Oxford.Study breakdown →PubMed →↩
4. 4RTHM-01160·Agin-Liebes, Gabrielle I et al. (2020). “Long-term follow-up of psilocybin-assisted psychotherapy for psychiatric and existential distress in patients with life-threatening cancer..” Journal of psychopharmacology (Oxford.Study breakdown →PubMed →↩
5. 5RTHM-01466·Yu, Chia-Ling et al. (2021). “Psilocybin for End-of-Life Anxiety Symptoms: A Systematic Review and Meta-Analysis..” Psychiatry investigation.Study breakdown →PubMed →↩
6. 6RTHM-01856·Bader, Husam et al. (2024). “Investigating the therapeutic efficacy of psilocybin in advanced cancer patients: A comprehensive review and meta-analysis..” World journal of clinical oncology.Study breakdown →PubMed →↩
7. 7RTHM-00949·Ross, Margaret L et al. (2025). “Psilocybin-assisted psychotherapy for depression and anxiety associated with life threatening illness: A phase 2b randomized controlled trial..” General hospital psychiatry.Study breakdown →PubMed →↩