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A Phase I trial to inform clinical protocols for the safe administration of psilocybin-assisted psychotherapy

Jennifer Bennett, Michael D. Blough, Ian Mitchell, Lyle Galloway, Ravinder Bains

medRxiv April 19, 2023 preprint DOI: 10.1101/2023.04.12.23288325 (opens in new tab)

Study at a glance

AI-extracted from the abstract
Characteristics Phase I clinical trial
Sample size 14
Population Healthy individuals
Intervention psilocybin extract
Dose 25 mg
Duration Two-month follow-up
Topics Psilocybin Psychedelic-assisted therapy
Keywords Adverse effect Blood pressure Heart rate Clinical trial Vital signs Depression economics Anesthesia Cardiology Pharmacology Hallucinogen
Citations 3
Key findings Psilocybin extract caused transient, clinically insignificant rises in blood pressure and heart rate that resolved without long-term adverse effects in healthy individuals.

Abstract

Abstract This Phase I trial aims to inform the development of safety protocols for psilocybin-assisted therapy. Psychedelics, including psilocybin, are increasingly being recognized as a successful treatment option for many mental health concerns. In order to decrease the risks associated with its clinical use, more data is required regarding its physiological effects in healthy individuals. Safety assessments (heart rate, blood pressure, temperature, and ECG data), as well as adverse event evaluations were the primary outcome measures used to assess the physiological effects of 25 mg of psilocybin extract administered to 14 healthy individuals. We hypothesized that there would be a transient, clinically insignificant rise in both blood pressure and heart rate that would not result in any long-term adverse effects. No unexpected effects were observed, blood pressure and heart rate returned to normal as drug effects waned, and all participants had normal two-month follow-ups. Mean peak systolic and diastolic blood pressures during the psilocybin session were 145.93 ( SD = 19.01) and 93.93 ( SD = 9.75), respectively. While this represents a significant increase from baseline ( p < 0.0001), a healthy cardiovascular system is capable of tolerating such levels for a longer time period than the brief duration of drug effects. Therefore, we suggest implementing focused and limited screening protocols to balance patient safety and accessibility. Secondary outcomes of this trial centered on the subjective effects of psilocybin, assessed via the QIDS-SR16 and the MEQ-30. There was a statistically significant decrease in QIDS-SR16 scores from baseline scores ( M = 3.50, SD = 2.35) to eight-week follow-up scores ( M = 1.86, SD = 0.86), p = 0.018. Mean MEQ-30 scores, assessed on day two and seven after the psilocybin session, indicate participants had full mystical experiences.

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