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.
Comparable studies
Other non-randomized and open-label trials on psilocybin and psychedelic-assisted therapy, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| Psilocybin with psychological support for treatment-resistant depression: six-month follow-up. Patients with severe, unipolar, treatment-resistant major depression | 2017 | Open-label trial | n = 20 |
| Psilocybin therapy increases cognitive and neural flexibility in patients with major depressive disorder. Patients with major depressive disorder | 2021 | Open-label study | n = 24 |
| HOPE: A Pilot Study of Psilocybin Enhanced Group Psychotherapy in Patients With Cancer. Cancer patients with a DSM-5 depressive disorder (major depressive disorder or... | 2023 | Open-label feasibility and safety pilot study | n = 12 |
| Group psychedelic therapy: empirical estimates of cost-savings and improved access Adults with PTSD or major depressive disorder eligible for psychedelic-assisted therapy... | 2023 | Comparative cost analysis using trial data and published estimates | |
| Increased low-frequency brain responses to music after psilocybin therapy for depression. Patients with treatment-resistant depression | 2023 | Open-label trial | n = 19 |