Efficacy of psilocybin on suicidal ideation. A systematic review

Abstract

Introduction Use of classic psychedelics such as psilocybin is expanding, and psychedelic therapy as a form of psychiatric intervention is receiving increasing attention [1]. According to the world health organization, about 700,000 people die from suicide annually [2]. Since suicidal tendency is a growing public health problem, recent findings showed that psilocybin might be promising as an innovative way of preventing or decreasing suicidality [3]. This systematic review was conducted due to the growing number of studies and the inconclusive results [1]. Aim To examine whether psilocybin is effective in the treatment of suicidality. Methods The systematic literature review was carried out following PRISMA guidelines. PubMed, ScienceDirect, and Cochrane Library databases were used to search scientific literature. Keywords and combinations of possible synonyms used for the search were selected using the Medical Subject Headings dictionary. Databases were last searched on the 8th of January 2023.An electronic search with the keywords “psilocybin” and “suicide,” “suicidality,” and “suicidal behaviours” were used. Inclusion criteria were: research articles published less than ten years ago, full text, written in English, evaluating the psilocybin effect on suicidal ideation. Case reports, literature reviews, systematic reviews, and meta-analyses were excluded from this review. The risk of bias was assessed using the Cochrane Risk of Bias Tool (RoB 2). Results Initially, 253 articles were retrieved. After screening and final assessment, seven studies that investigated the effect of psilocybin on suicidal ideation were included in this review. None of the selected studies have shown high risk of bias. All patients received psychological support along with psilocybin. An association between psilocybin use and suicide ideation was found in all included studies. Two studies claim that a single dose of psilocybin may have anti‑suicidal properties in patients with life-threatening cancer [4,5]. Findings suggest that a moderate dose of psilocybin with psychological support at least may not increase the risk for suicidality [6]. Other studies have shown a significant effect of psilocybin on suicidal ideation among patients with an episode of major depression [7–9]. Although compared to the baseline visit, the number of suicidal thoughts among the patients decreased, some patients experienced a worsening of the suicidal status [10]. Conclusions Our results revealed that a single dose of psilocybin might have anti‑suicidal properties. However, study designs are created to investigate the effectiveness of treatment of the disorder, not suicidal states; also, it is difficult to compare the effect with placebo because psilocybin has a clear effect, and placebo does not cause a psychedelic effect, so double-blinded studies are contentious. Longer and larger trials are required to determine the efficacy and safety of psilocybin in the suicidal state.