Psilocybin Effective For Depression a Year Post Treatment, Study Finds

The body of research supporting the therapeutic effects of psilocybin—an ingredient found in so-called “magic mushrooms”—continues to grow. 

Previous studies have found that psilocybin may be just as effective as long-established treatments for depression, and that psychedelic treatment with the compound relieved symptoms of depression for up to a month.

The latest study from a team at Johns Hopkins Medicine, published in the Journal of Psychopharmacology, says the antidepressant effects of psilocybin-assisted therapy, alongside psychotherapy, may last a year or longer for some patients. 

“A growing number of studies are demonstrating that psychedelic-assisted therapy can have rapid and significant antidepressant effects, but the long term effects of this treatment are not well characterized,” says study author Natalie Gukasyan, MD, assistant professor of psychiatry and behavioral sciences at Johns Hopkins University School of Medicine. 

“All therapies have associated risks and costs, and understanding the long-term effects is important to determine whether the potential benefits of this treatment outweigh the risks and costs,” Dr. Gukasyan adds. 

A Closer Look at the Study 

The study involved 27 participants from 21 - 75 years of age, all of whom had a long-term history of depression. The majority (25) of the group identified as white, one as African American, and one as Asian.

Participants were split into two groups, with one receiving the intervention right away and the other receiving it after eight weeks. After preparatory meetings with two treatment facilitators, participants received two doses of psilocybin approximately two weeks apart. 

One day and one week after each session, the participants returned for a follow-up assessment visit. They also had follow-up visits one, three, six, and 12 months after the second session. In total, 24 participants completed both psilocybin sessions and all follow-up assessment visits.

“We were excited to see that on average, depression severity remained low throughout the 12-month follow-up period,” Dr. Gukasyan says. “However, a third of our sample began treatment with antidepressant drugs during that time, and about 42% entered therapy at some point. That suggests that not all of the long-term improvement can be accounted for by the intervention provided in the study.” 

Nonetheless, the latest findings are significant in demonstrating the longer-term benefits of psilocybin-assisted therapy. 

“Many treatments for mental health conditions suffer from the problem that their effects are not always long-lasting, so it is important to be able to show that a new treatment has lasting benefits,” says clinical psychologist Brian Pilecki, PhD, who has been studying psychedelics for over 20 years and is passionate about the potential for psychedelic substances to treat mental health problems like anxiety and depression. 

Current evidence suggests that having therapeutic support is important for enhancing the benefit and reducing harm associated with psychedelic experiences. 

“Participants are helped to prepare for the experience and afterwards are provided support in processing their experience and translating new insights or experiences into meaningful, lasting change,” Pilecki explains. “Without proper integration, benefits experienced during psilocybin experiences are more likely to fade over time.” 

A New Mental Health Treatment Option

Psychedelic-assisted therapy represents a new paradigm in mental health treatment. “It shows early promise as being a novel method of intervention for individuals with depression,” says Pilecki. “Much more research is needed to affirm findings from early studies and to better understand scientifically how psychedelics actually work, but early clinical trials show a consistent pattern of benefit.” 

"Our findings add to evidence that, under carefully controlled conditions, this is a promising therapeutic approach that can lead to significant and durable improvements in depression," says Dr. Gukasyan. 

However, she adds that these results are observed in a research setting and require extensive preparation and structured support from trained clinicians and therapists. People should not attempt to try it on their own. 

Dr. Gukaysan hopes that the results provide preliminary data to show that psilocybin-assisted therapy may be a viable treatment that can produce long-lasting antidepressant effects in select patients.

"For this particular study, we may reach back out to participants at a later date to examine longer-term effects years after treatment,” she adds.

In the broader landscape of psilocybin research, there are currently two entities seeking approval for psilocybin that are running larger phase II and III clinical research studies.

“Once these are completed, the FDA will determine whether the data gathered from these studies is sufficient to suggest that the substances have therapeutic value,” explains Dr. Gukaysan. “This may lead to legislative action to reschedule psilocybin under the Controlled Substances Act, thereby making psilocybin available for clinical use outside of the laboratory.”