Potential Therapeutic Effects of Psilocybin: A Systematic Review

Acute Adverse Effects of Therapeutic Doses of Psilocybin: A Systematic Review and Meta-Analysis

Importance

Psilocybin has been studied in the treatment of depression and anxiety disorders. Clinical studies have mainly focused on efficacy, with systematic reviews showing favorable efficacy; however, none have primarily focused on psilocybin safety.

Objective

To evaluate the acute adverse effects of psilocybin at therapeutic doses in the treatment of depression and anxiety.

Data Sources

MEDLINE via PubMed, Web of Science, and ClinicalTrials.gov were searched for publications available between 1966 and November 30, 2023.

Study Selection

Randomized, double-blind clinical trials that reported adverse effects of psilocybin in patients treated for depression and anxiety were screened.

Data Extraction and Synthesis

Data were independently extracted by 2 authors and verified by 2 additional authors following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline. The inverse variance method with the Hartung-Knapp adjustment for the random-effects model was used, with a continuity correction of 0.5 for studies with 0 cell frequencies. Sensitivity analysis was conducted by sequentially removing 1 study at a time to assess the robustness of the results.

Main Outcomes and Measures

The primary outcome was considered as the adverse effects of psilocybin at high and moderate (ie, therapeutic) dose regimens and compared with placebo, low-dose psilocybin, or other comparator in the treatment of depression and/or anxiety.

Results

Six studies met the inclusion criteria with a total sample of 528 participants (approximately 51% female; median age 39.8 years; IQR, 39.8-41.2). Seven adverse effects were reported in multiple studies and included in the analysis. Among these, headache (relative risk [RR], 1.99; 95% CI 1.06-3.74), nausea (RR, 8.85; 95% CI, 5.68-13.79), anxiety (RR, 2.27; 95% CI, 1.11-4.64), dizziness (RR, 5.81; 95% CI, 1.02-33.03), and elevated blood pressure (RR, 2.29; 95% CI, 1.15- 4.53) were statistically significant. Psilocybin use was not associated with risk of paranoia and transient thought disorder.

Conclusions and Relevance

In this meta-analysis, the acute adverse effect profile of therapeutic single-dose psilocybin appeared to be tolerable and resolved within 48 hours. However, future studies need to more actively evaluate the appropriate management of adverse effects.

Psilocybin, an Effective Treatment for Major Depressive Disorder in Adults - A Systematic Review

Psilocybin is a classical psychedelic which has been utilised for healing purposes for millenia. However, with its classification as a Schedule I substance, research into this compound is scarce with few FDA-approved clinical studies. Despite this, profound findings into its antidepressant effects (largely through its action on 5-HT1a receptors) in mental illnesses such as major depressive disorder have rapidly increased interest back into their potential therapeutic benefits. This systematic review provides an analysis of the studies examining the clinical use of psilocybin for major depressive disorder. In total 6 studies were selected, including 319 participants, with half being randomised controlled trials and half open label trials. In every study psychological support was included as an integral part of the treatment. It was found that every study significantly favoured the use of psilocybin in reducing depressive symptoms, with few side effects. This gives psilocybin an advantage over commonly prescribed selective serotonin reuptake inhibitors (SSRIs), which carry more risk and cause more adverse effects. This drug therefore shows promise for being used as a clinical treatment for major depressive disorder, however future research should develop a paradigm for its use, with the timing of sessions and type of psychological support specified to allow for more precise analysis of the clinical effects of the drug. Additionally, more studies into its clinical efficacy are needed for appropriate detection of any publication bias. With this, psilocybin could prove to be revolutionary in treating depression and become an alternative medication to SSRIs.

Psychedelic Drug Microdosing Practices: A Qualitative Online Exploration

"Microdosing," defined as the consumption of small, sub-hallucinogenic quantities of psychedelic drugs, has gained recent popularity. Microdosing is a relatively new concept, therefore no scientific recommendations exist on how to prepare and consume microdoses. Many consumers obtain microdosing information online. Few studies have investigated the content of this information; thus, the present study aimed to do so by collecting a large set of online microdosing information. A qualitative approach was taken to compile and characterize online microdosing information. Medical databases, video websites, online forums, drug-specific websites and forums, search engines, and social media websites were searched. A total of 174 unique resources were found, detailing the types of substances, preparation methods, doses, schedules, and safety strategies used by people who microdose. Future research is recommended to further explore how people prepare microdoses through in-person interviews and sample collection.

Predictors of Medical Students' Perceptions of Psilocybin-Assisted Therapy for Use in Medical Practice

Background Psilocybin use, along with other psychedelics, has seen an increased interest among professionals in the medical community due to its potential therapeutic benefits for psychiatric disorders, substance use disorders (SUD), and palliative care. While it is certain that more research is necessary as psychedelic-assisted therapy becomes more prevalent, it will most likely be future physicians at the forefront of this neoteric care. Currently, physicians receive minimal training because of psilocybin's contextual information and its current enlistment as a Schedule 1 drug per the United States Drug Enforcement Administration. Schedule 1 drugs, substances, or chemicals are defined as drugs with no currently accepted medical use and a high potential for abuse. As a rule, formal education on psilocybin is not included in medical school curricula, and very little is known about how medical students perceive it. The aim of this study was thus to assess current medical students' perceptions of their knowledge, concern for possible negative effects, and perceptions about medical psilocybin to provide a deeper understanding of which factors may predict their overall perceptions of its future therapeutic use. Methods Medical students' knowledge, concern for potential adverse effects, and perceptions of medical psilocybin were investigated using a cross-sectional survey study design. Data were collected in January 2023 from a convenience sample of United States medical students in years one to four of their program using a 41-item anonymous quantitative online survey. Multivariate linear regression modeling was performed to determine if perceived knowledge and beliefs about legalization would predict medical students' attitudes about psilocybin use for therapeutic purposes. Results Two hundred and thirteen medical students completed the survey. Seventy-three percent (n=155) were osteopathic medical students (OMS), and 27% (n=58) were allopathic medical students (MDS). Regression modeling produced a statistically significant equation: (F(3, 13) = 78.858, p < .001), with an R² = 0.573 (adjusted R² = 0.567), indicating that greater (perceived) knowledge about medical psilocybin, less concern for its possible adverse effects, and greater belief in the legalization of psilocybin for recreational use significantly contributed to positive perceptions of psilocybin use in medical practice. Conclusions In this sample, medical students with greater self-assessment of their knowledge about medical psilocybin, less concern for its potential adverse effects, and more positive views about recreational psilocybin legalization predicted positive attitudes about its medical use. Interestingly, although some participants had positive perceptions about the legalization of psilocybin for medical use, endorsing its legalization for recreation was related to greater positive attitudes toward medical psilocybin in general, a finding that appears to be somewhat counterintuitive. More research is warranted to further explore medical trainees' attitudes toward it, as psilocybin is a promising therapeutic intervention. If medicinal psilocybin continues to gain attention among patients and physicians alike, it will be imperative to evaluate its therapeutic efficacy, proper use, dosing, and potential for negative effects, in addition to preparing students to endorse therapeutic psilocybin when warranted.