John Hopkins University researchers have published the results of a follow-up study of patients with major depressive disorder (MDD) who had previously received psilocybin-assisted therapy where they were able to validate that the positive effects of the treatment were present for some of the participants one year later.
The initial randomized clinical trial included 24 participants diagnosed with MDD who had been experiencing depressive symptoms consistently for a minimum of two years. Eighty-eight percent had previously received standard antidepressant medications, and 58% reported using antidepressants during current depressive episodes.
Participants were assigned to either a group that received treatment immediately or after an 8-week waiting period. Participants were provided preparatory sessions by trained facilitators followed by two separate psilocybin sessions conducted two weeks apart. Follow-up assessment visits were conducted one day and one week after each session and one, three, six, and twelve months after the second session. 24 participants completed both psilocybin sessions.
The researchers found significant decreases in depression across the board and observed low severity of symptoms one, three, six, and twelve months after treatment. Depressive symptoms were assessed using the GRID-Hamilton Depression Rating Scale, a standard depression assessment tool, in which a score of 24 or more indicates severe depression, 17–23 moderate depression, 8–16 mild depression, and 7 or less no depression.
Results of the 12-month follow-up assessments demonstrated a remarkable 75% treatment response (defined as over 50% reduction in symptoms) and a 58% remission. No serious adverse side effects were identified and the participants had not reported psilocybin consumption outside of the initial two administrations.
“Psilocybin not only produces significant and immediate effects, it also has a long duration, which suggests that it may be a uniquely useful new treatment for depression,” says Roland Griffiths, Ph.D., the Oliver Lee McCabe III, Ph.D., Professor in the Neuropsychopharmacology of Consciousness at the Johns Hopkins University School of Medicine, and founding director of the Johns Hopkins Center for Psychedelic and Consciousness Research. “Compared to standard antidepressants, which must be taken for long stretches of time, psilocybin has the potential to enduringly relieve the symptoms of depression with one or two treatments.”
Further research and follow up is required to assess whether the positive treament responses last longer than the currently verified 12-month period post administration.
This finding provides yet another point of validation for accellerating decriminalization efforts, expanding access, and taking active steps to reduce the monumental human, healthcare, and productivity costs associated with long-term depression.