For years, the big question hanging over psychedelic medicine wasn’t whether psilocybin could lift depression. It was whether that lift would last, six months, a year, long after the drug had left the body.
Compass Pathways, a biotech company developing a synthetic, pharmaceutical-grade version of psilocybin called COMP360, just answered that question.
Milestone
On July 7, Compass released new results from one of its two major clinical trials testing COMP360 as a treatment for treatment-resistant depression (TRD). This particular trial is called COMP006, and it’s a big deal because it’s one of the last major steps before a company can apply to get a drug approved.
Here’s how drug trials generally work: a company runs a series of tests, called phases, that get progressively larger and stricter. Phase 3 is the final and most rigorous stage before a medicine can be submitted to a regulator, in this case the US Food and Drug Administration (FDA), for approval. Getting strong Phase 3 results is one of the biggest milestones a drug can hit.
Compass now has two separate Phase 3 trials (COMP005 and this new one, COMP006) both showing that psilocybin can work quickly and the benefit sticks around for months.
The Numbers
This trial tested people who had been depressed for over three years on average, and had already been through more than six separate depressive episodes in their lives. In other words, these were people who’d tried the usual treatments and gotten nowhere.
Despite that, 39 out of every 100 participants who got two doses of COMP360 showed a real, meaningful improvement in their symptoms within six weeks, and most of them were still doing better six months later. That’s notably higher than the 25 out of 100 seen in the earlier trial, which only used a single dose, suggesting a second dose may help more people.
Even more impressive, nearly 30 out of every 100 people who improved after their first two doses went on to have their depression symptoms disappear almost entirely after a further treatment. In medical terms this is called “remission,” and it’s rare language to use around a condition this stubborn.
Most side effects were mild and short-lived, mainly happening on the day people took the dose, and included nausea, headaches, anxiety, and visual hallucinations (which is expected with a psychedelic). Serious side effects were uncommon, showing up in roughly 6 out of 100 people regardless of which dose they received, and that rate has stayed steady across the trials.
What Happens Next?
Compass is now in the process of formally submitting COMP360 to the FDA for approval, a process it expects to finish by the end of 2026. If approved, the company is aiming to launch the treatment in the first half of 2027.
There’s one more hurdle beyond FDA approval. Psilocybin is currently classed in the US as a Schedule I drug, the same legal category as heroin, meaning it’s officially considered to have no accepted medical use. Before COMP360 could actually reach patients, the US Drug Enforcement Administration (DEA) would need to reclassify it to reflect that it does have a legitimate medical use.
Compass’s CEO, Kabir Nath, described the bigger ambition behind all this: moving mental health treatment away from pills taken every day, toward something closer to just a few sessions a year that could meaningfully change someone’s life.
Why This Matters
Depression is already one of the biggest health burdens in the world, and it’s expected to become the single biggest cause of illness worldwide by 2030, according to the World Health Organization. In the US alone, an estimated 4 million people are living with the treatment-resistant kind Compass is targeting, meaning they’ve tried two or more standard antidepressants without success.
What makes this moment significant isn’t just one company’s results. It’s that two large, independent trials have now both shown psilocybin can work fast, the benefit can last for months, and it’s safe. For the first time, “psilocybin as an FDA-approved medicine” has an actual date attached to it: the first half of 2027.
Source: Compass
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