Magic mushrooms aren’t just another recreational drug. An increasing number of studies are supporting the psychedelic drug’s value in treating depression, addiction, and PTSD. Now, a new study involving patients with major depression reiterates the power of psilocybin — the active ingredient in magic mushrooms. Just two doses of the psychoactive substance were enough to produce a fast and significant reduction in depressive symptoms.

“The magnitude of the effect we saw was about four times larger than what clinical trials have shown for traditional antidepressants on the market,” said Alan Davis, Ph.D., adjunct assistant professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine.

“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.”

The study involved 24 participants suffering from major depression, all of whom underwent two five-hour psilocybin sessions. The patients weren’t allowed to trip by themselves but rather under the supervision of a professional.

For most people, taking meds or going to psychological counseling (i.e. psychotherapy) eases depression symptoms. However, some patients with major depression symptoms don’t respond to standard treatment. According to the National Institute of Mental Health, more than 17 million Americans and 300 people worldwide have experienced major depression symptoms at least once in their lifetimes.

In 2016, the Johns Hopkins researchers showed that psilocybin in conjunction with psychotherapy significantly relieved anxiety and depression in people with a life-threatening cancer diagnosis.

Coupled with similar studies from other research groups, Davis and colleagues embarked on a study that explored psilocybin’s effects in the broader population. The patients recruited into the study had a history of depression, with persisting symptoms for approximately two years before enrolling in the study. Each patient received two doses of psilocybin two weeks apart while the participant was lying on a couch wearing eye shades and headphones that played music.

Each participant completed the GRID-Hamilton Depression Rating Scale – a standard depression assessment tool — once on enrollment, and again at one and four weeks following the completion of their treatment.

On the GRID scale, a score of 24 or more indicates severe depression, 17-23 moderate depression, 8-17 mild depression, and 7 or less no depression. At enrollment, the patients had an average depression score of 23, but one week and up to four weeks after treatment the score dropped to 8. Overall, the patients showed a 71% reduction in depression symptoms at the four-week follow-up.

Although half of the patients went into remission, the fact that most experienced such an improvement in their quality of life after only one week is remarkable. For some patients with major depression and suicidal thoughts, psilocybin treatment may mean the difference between life and death, especially for those who have treatment-resistant depression symptoms.

In the future, the researchers plan on following up the participants of the study for an entire year to see just how long the antidepressant effects of psilocybin last.

The findings appeared in the journal JAMA Psychiatry.