Psilocybin for Cancer Distress: What the Trials Found

Before psilocybin was tested for everyday depression, researchers tested it on people with life-threatening cancer. The results from Johns Hopkins, NYU and a community cancer practice in Maryland are some of the most durable in the field. Here's what each trial found, the caveats that come with them, and why a patient in Canada can get it legally while one in the U.S. mostly can't.

In November 2021, a routine colonoscopy found late-stage colon cancer in Roland Griffiths, the Johns Hopkins scientist who had spent two decades running psilocybin trials, several of them in people with cancer. He died in October 2023. A few weeks before his death, he told WebMD's Paul Frysh: "I'm just overwhelmed with gratitude and joy and love for how I'm experiencing the world despite everything."

That sense of meaning in the face of death is what the cancer trials were trying to measure. People with a serious cancer diagnosis often live with a specific kind of suffering: fear of death, hopelessness, and a sense that life has lost its meaning. Researchers call this existential distress. Standard antidepressants weren't built for it. Psilocybin, it turns out, may help with it.

The Trials, Side by Side

Study	Who	Design	What happened	The catch
Johns Hopkins (Griffiths et al., 2016)	51 people with life-threatening cancer	High dose vs. very low dose, double-blind, crossover	About 80% still had clinically significant drops in depressed mood and anxiety six months later	Crossover design: everyone eventually got the high dose
NYU (Ross et al., 2016)	29 people with advanced cancer	One dose of psilocybin vs. niacin, plus psychotherapy, crossover	Fast, large drops in anxiety and depression	Small; niacin is a weak placebo
NYU follow-up (Agin-Liebes et al., 2020)	15 of the 16 surviving participants	Follow-up at 3.2 and 4.5 years	About 60–80% still met criteria for a clinically significant response	No control group by then
Sunstone Therapies (JAMA Oncology, 2023)	30 people with cancer and major depression	Open-label, 25mg dose, given in small groups	Depression scores fell 19.1 points at 8 weeks; 80% had a sustained response, 50% full remission	Everyone knew they got psilocybin
Sunstone two-year follow-up (Cancer, 2025)	28 of the same patients	Long-term follow-up	50% still had a sustained reduction in depression	Still open-label, still small
Fred Hutch / UW group retreats (2026)	52 people with metastatic cancer	Groups of 5–8 over three-day retreats	Meaningful drops in anxiety and depression lasting at least six months; no unattended distress	Phase 1/2, no placebo

"Clinically significant" means a drop large enough that doctors consider it a real improvement, not just a statistical one. Response and remission rates come from each study's own measures and aren't directly comparable across rows.

What Stands Out

One dose, long effect. Most people in these trials received one or two doses of psilocybin, with therapy before and after. Antidepressants are typically taken daily, often for years. That's why these results got so much attention: the effects lasted months, and in NYU's small follow-up group, years. We compared those durability numbers to standard antidepressants here.

It's about meaning, not just mood. The Hopkins trial found that a stronger mystical-type experience during the session predicted better outcomes. Participants also reported less fear of death and more sense of meaning in life, things standard depression scales don't fully capture.

Groups may work. Sunstone and the Fred Hutch team both treated patients several at a time. That matters for cost: one-on-one psychedelic therapy often ties up one or two therapists for a full day per patient. Sunstone's trial used COMP360, the same psilocybin formulation Compass Pathways has now submitted to the FDA for treatment-resistant depression.

What These Trials Can't Tell You Yet

They're small. The largest completed trial here enrolled 52 people. That's why none of these results has led to an FDA approval for cancer patients.
Blinding is hard. People usually know whether they got a psychedelic, which can inflate results. The newer Sunstone and Fred Hutch studies didn't use a placebo at all.
The patients were screened. Trials typically exclude people with a personal or family history of psychosis or bipolar disorder, and some heart conditions. Results may not apply to everyone.
It doesn't treat cancer. These trials measured anxiety, depression and distress. Nothing here suggests psilocybin affects the cancer itself.

The Trials That Could Settle It

The biggest test underway is a 200-person randomized, double-blind trial led by NYU Langone with the University of Colorado Anschutz Medical Campus, with the National Cancer Institute as a collaborator. It compares a single 25mg dose with an active placebo and is expected to finish around early 2027. If it confirms the earlier results at four times the size, it would be the strongest evidence yet.

Our trials tracker follows several others, including Sunstone's Phase 2 study in cancer-related depression, M.D. Anderson's trial in cancer survivors, and a University Hospital Basel trial testing LSD for distress in serious illness. A Toronto trial called PEARL, which pairs psilocybin with a therapy focused on relationships and meaning, is listed as starting soon.

Who Can Get It Now

In Canada, Thomas Hartle, a Saskatoon man with stage 4 colon cancer, became the first person to legally receive psilocybin therapy in 2020. He got there through a special exemption from the health minister, known as a Section 56 exemption, with help from the nonprofit TheraPsil. Others have followed, though critics say the process is so slow that some patients die waiting.

In the U.S., the main attempt failed. Seattle palliative-care doctor Sunil Aggarwal asked the DEA to let him give psilocybin to terminally ill patients under federal Right to Try law. On February 13, 2025, the Ninth Circuit sided with the DEA: Right to Try lets patients skip FDA approval but doesn't override the DEA's controlled-substance rules. For now, Americans with cancer can get psilocybin legally mainly through clinical trials or the state-regulated programs in Oregon and Colorado. New Mexico's medical psilocybin program, which lists end-of-life care as a qualifying condition, is aiming to enroll its first patients by the end of 2026. Here's which states would let doctors prescribe it once the FDA approves a psilocybin drug.

The Bottom Line

The cancer trials are small, mostly older, and harder to blind than researchers would like. But they found something unusual: one guided session, followed by relief that in many patients lasted months or years. The 200-person NYU and Colorado trial is the one to watch. We'll cover its results when they're published.

This article is for educational purposes only and is not medical advice. Psilocybin is a Schedule I substance under U.S. federal law. Anyone with cancer considering psilocybin should talk to their oncology team first, especially about heart conditions, psychiatric history and medications. If you're in crisis, call or text 988 in the U.S.

One Dose, Years of Relief? What Psilocybin Trials Found in People With Cancer