Most patients achieved remission in small bipolar trial, and no hypomania episodes occurred
Synthetic psilocybin with psychotherapy was effective and safe for patients with treatment-resistant bipolar depression, a small nonrandomized controlled trial suggested.
Among 15 people with bipolar type II disorder with a current major depressive episode who received a single dose of psilocybin, Montgomery-Åsberg Depression Rating Scale (MADRS) scores decreased by 24 points at 3 weeks (Cohen d 4.08, P<0.001), reported Scott T. Aaronson, MD, of the Sheppard Pratt Health System in Baltimore, and colleagues.
Repeat measures analysis of variance showed lower MADRS scores at all analyzed post-treatment time points, including the endpoint (Cohen d 3.39, adjusted P<0.001). At 3 weeks, 12 participants met the response criterion (50% decrease in MADRS), and 11 met remission criterion (MADRS score ≤10), they wrote in JAMA Psychiatryopens in a new tab or window.
“Psychedelics have the potential to ease the suffering of many patients with difficult-to-treat mood disorders, and some folks with a cyclical mood disorder could benefit,” Aaronson told MedPage Today, noting that these participants have failed multiple previous medication trials.
While psilocybin has been previously tested in trials of major depressive disorderopens in a new tab or window, treatment-resistant depressionopens in a new tab or window, and anorexiaopens in a new tab or window, this is the first report on the use of a psychedelic within the underserved population of people with bipolar II depression, Aaronson said.
The study was “done carefully with standard preparatory therapy prior to dosing and therapeutic integration sessions after dosing, along with a well-supervised dosing session,” he noted.
Aaronson and colleagues noted that the intensity of the psychedelic experience correlated with clinical benefit. “In particular, individuals in whom psilocybin administration had little subjective impact showed little clinical benefit,” they wrote. “The necessity of a distinct psychedelic experience for response remains a point of debate within the field, and the findings of this study suggest that the degree of psychedelic experience is predictive of longer-term antidepressant effects.”
In an accompanying editorialopens in a new tab or window, David Yaden, PhD, of Johns Hopkins University School of Medicine in Baltimore, and colleagues pointed out that while the efficacy here is impressive, the safety is “far more compelling.”
“Contrary to this study’s findings, we suspect that most clinicians and researchers would have guessed that 1 or more patients would have developed hypomania – given clinical experience, many anecdotal reports, and the fact that most, if not all, antidepressant interventions can precipitate mania,” they wrote.
However, no participants experienced any significant adverse events related to psilocybin. The most common adverse event was headache, occurring in four of 15 participants, but all resolved within a day.
“The favorable safety profile of this study strongly justifies a larger randomized clinical trial of psilocybin for bipolar II depression,” Yaden and team noted. Not only does this give weight to including patients with bipolar II in these sorts of studies, but it also re-evaluates the common practice of excluding patients with a family history of bipolar II out of fear of triggering a hypomanic episode, they added.
In this open-label trial, participants with a primary diagnosis of bipolar disorder II according to DSM-5 criteria who were currently experiencing a depressive episode lasting longer than 3 months were given a 25-mg dose of synthetic psilocybin at Sheppard Pratt Hospital during an 8-hour dosing day, developed by COMPASS Pathways, between April 2021 and January 2023. They met with a therapist for three sessions prior to treatment, during the 8-hour dosing session, and for three sessions after treatment.
Mean patient age was 37.8, and 60% were women. All participants were resistant to at least two pharmacologic treatments. Those with bipolar disorder I, schizophrenia, psychosis, delusions, paranoia, schizoaffective disorder, borderline personality disorder, and substance use disorder were excluded.
All participants withdrew from antidepressants and mood stabilizers at least 2 weeks before psilocybin dosing. Nine patients stayed off of these agents throughout the trial.
In addition to objective measures, there were also improvements in the self-rated Quick Inventory of Depression Symptoms-Self Rating and the self-rated Quality of Life Enjoyment and Satisfaction Questionnaire-Short Form. Columbia Suicide Severity Rating Scale and Young Mania Rating Scale scores did not change significantly post-treatment compared with baseline.
Aaronson noted that these findings cannot be extrapolated to a bipolar disorder I population, who have a higher risk for mania and psychosis, nor to non-professional or recreational psychedelic use.
