USA: A new article published in the Journal of Psychopharmacology suggests that in certain individuals, the significant antidepressant benefits of psilocybin-assisted treatment are durable and may last at least 12 months after the acute intervention.
Major depressive disorder (MDD) affects about 260 million individuals globally and is a primary source of disability and healthcare costs. First-line therapies, such as medication and psychotherapy, can take weeks or months to generate clinically important symptom reduction, and patients may struggle to adhere to treatment. Preliminary studies show that psilocybin-assisted therapy delivers significant and immediate antidepressant benefits in individuals with major depressive disorder (MDD), but long-term consequences are unknown. As a result, Natalie Gukasyan and colleagues undertook this study to investigate the effectiveness and safety of psilocybin over a 12-month period in people with moderate to severe MDD who were given psilocybin.
In this randomized, waiting-list controlled trial, 27 patients with varying severity of unipolar depression (GRID-Hamilton Depression Rating Scale (GRID-HAMD) ⩾ 17) were included. Participants were randomly assigned to one of two treatment conditions: immediate (8 weeks) or delayed (8 weeks), in which they received two doses of psilocybin along with supportive psychotherapy. Twenty-four subjects completed both psilocybin sessions and were monitored for a year after their second dosage.
The key findings of this study were as follows:
1. Throughout the 12-month period, all 24 participants attended all follow-up appointments.
2. At 1-, 3-, 6-, and 12-month follow-up, GRID-HAMD scores decreased significantly from baseline (Cohen d = 2.3, 2.0, 2.6, and 2.4, respectively).
3. At 12 months, treatment response (50 percent reduction in GRID-HAMD score from baseline) and remission were 75% and 58%, respectively.
4. During the long-term follow-up period, there were no major adverse events attributed to psilocybin, and no individuals reported psilocybin usage outside of the setting of the research.
5. Personal significance, spiritual experience, and mystical experience evaluations following sessions indicated higher well-being at 12 months but did not predict depression recovery.
In conclusion, The current study demonstrates that two doses of psilocybin administered as part of supportive treatment for MDD had substantial and durable antidepressant effects over a 12-month period.
Reference:
Gukasyan, N., Davis, A. K., Barrett, F. S., Cosimano, M. P., Sepeda, N. D., Johnson, M. W., & Griffiths, R. R. (2022). Efficacy and safety of psilocybin-assisted treatment for major depressive disorder: Prospective 12-month follow-up. In Journal of Psychopharmacology (Vol. 36, Issue 2, pp. 151–158). SAGE Publications. https://doi.org/10.1177/02698811211073759