A new study investigating a single dose of psilocybin for the treatment of major depressive disorder (MDD) has shown clinically significant levels of reduction in depressive symptoms.
The Phase 2 randomised clinical trial, published in JAMA, involved 104 participants with MDD who were administered a 25-mg dose of psilocybin in combination with psychological support.
The results showed that the treatment was associated with a rapid and sustained antidepressant effect, was well tolerated and caused no serious treatment-emergent adverse events.
The authors now suggest that psilocybin administered in combination with psychotherapy may hold promise as a treatment for major depressive disorder when combined with psychological support.
The authors write: ‘Psilocybin treatment was associated with a clinically significant sustained reduction in depressive symptoms and functional disability, without serious adverse events. These findings add to increasing evidence that psilocybin—when administered with psychological support—may hold promise as a novel intervention for MDD.’
The study
The study was carried out across 11 research sites in the US between December 2020 and June 2022 with participants aged between 21 and 65 years old, all of whom had a diagnosis of MDD or at least 60 days duration, with moderate or greater symptom severity.
Those who were excluded from the trial included MDD patients with a history of psychosis or mania, an active substance use disorder, and those with active suicidal ideation with intent. Additionally, participants taking psychotropic agents were able to be included in the study following a medication taper.
Participants were randomized in a 1:1 ratio to receive either a single dose of psilocybin or niacin placebo, both of which were administered with psychological support.
The researchers state that primary and secondary outcomes and adverse events were assessed at baseline, conducted within seven days before dosing, and at two, eight, 15, 29, and 43 days following dosing.
The primary outcome was measured as change in central rater–assessed Montgomery-Asberg Depression Rating Scale (MADRS) score from baseline to day 43, with the secondary outcome measured as change in MADRS score from baseline to day 8, with further secondary outcomes measured as change in Sheehan Disability Scale score from baseline to day 43 and MADRS-defined sustained response and remission.
