Research Roundup: small study shows psilocybin effective in treating depression

Also: Israeli researchers say cannabis can be a safe and effective treatment for chronic pain


In a small-scale study, psilocybin showed effects four times larger than what clinical trials have shown for traditional antidepressants on the market. Photo by chameleonseye/iStock/Getty Images Plus.


New research published this week suggests that psilocybin can be an effective treatment for major depressive disorder (MDD).

Researchers at Johns Hopkins Bayview Medical Center in Baltimore, Maryland, recruited 24 people with long-term histories of major depression. Physicians helped wean the volunteers off of antidepressant medications before the start of the study.

Each subject then participated in two five-hour sessions in which they took doses of psilocybin and received supportive psychotherapy. The sessions took place two weeks apart. Participants completed depression assessments at the start of the study, then again one week and four weeks after treatment.

According to the study published in the journal JAMA Psychiatry, 67% of participants showed a more than 50% reduction in depression symptoms at the one-week follow-up. At the four-week follow-up, however, that number had increased to 71%. Overall, four weeks post-treatment, 54% of participants were in remission. In other words, they no longer qualified as being depressed.

Large, rapid, and sustained effects

The authors conclude:

Results of this randomized clinical trial demonstrated the efficacy of psilocybin-assisted therapy in producing large, rapid, and sustained antidepressant effects among patients with MDD. These data expand the findings of previous studies involving patients with cancer and depression as well as patients with treatment-resistant depression by suggesting that psilocybin may be effective in the much larger population of MDD. Further studies are needed with active treatment or placebo controls and in larger and more diverse populations.

Alan Davis, Ph.D., is an adjunct assistant professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine. Davis was one of the authors of the study. “The magnitude of the effect we saw was about four times larger than what clinical trials have shown for traditional antidepressants on the market,” he said in a university press release. “Because most other depression treatments take weeks or months to work and may have undesirable effects, this could be a game changer if these findings hold up in future ‘gold-standard’ placebo-controlled clinical trials.” 

Cannabis for chronic pain

Researchers at the University of Haifa surveyed Isreali patients licensed to use medical cannabis to treat chronic pain. The patients reported their weekly average pain intensity before beginning medical-cannabis treatment. They then reported on their pain related symptoms at one, three, six, nine, and 12 months following the start of treatment.

Publishing their data in the European Journal of Pain, the investigators reported long-term overall improvements:

At one-year, average pain intensity declined from baseline by 20 percent. All other parameters improved by 10 to 30 percent. A significant decrease of 42 percent from baseline in morphine equivalent daily dosage of opioids was also observed. Reported adverse effects were common but mostly non-serious.

The authors noted that reports of adverse effects declined over the course of the study period. In conclusion, they wrote: “This prospective, comprehensive and large-scale cohort demonstrated an overall mild to modest long-term improvement of all investigated measures, including pain, associated symptoms and importantly, reduction in opioid (and other analgesics) use. It seems likely that MC [medical cannabis] treatment can be safe for most patients.”

Thanks for the tip

Have you read a recent study that sheds new light on the topic of cannabis? Are you a researcher working on a clinical trial of psychedelics for treating depression? If so, send me a link and I might feature it in a future edition of CannCentral’s Research Roundup. Thanks!

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