Adverse effects of psychedelics: From anecdotes and misinformation to systematic science.

Classic psychedelics carry minimal medical risks such as toxicity and overdose, and many persistent negative perceptions of psychological risks—including abuse liability and dependence—are unsupported by current scientific evidence when use occurs in regulated or medical contexts. Most reported adverse effects are not observed under these conditions. The review underscores the need for clinicians and therapists to maintain high safety and ethical standards and for balanced media reporting to avoid future controversies and allow continued research.

Study at a glance

Abstract

BACKGROUND: Despite an increasing body of research highlighting their efficacy to treat a broad range of medical conditions, psychedelic drugs remain a controversial issue among the public and politicians, tainted by previous stigmatisation and perceptions of risk and danger. OBJECTIVE: This narrative review examines the evidence for potential harms of the classic psychedelics by separating anecdotes and misinformation from systematic research. METHODS: Taking a high-level perspective, we address both psychological and psychiatric risks, such as abuse liability and potential for dependence, as well as medical harms, including toxicity and overdose. We explore the evidence base for these adverse effects to elucidate which of these harms are based largely on anecdotes versus those that stand up to current scientific scrutiny. RESULTS: Our review shows that medical risks are often minimal, and that many - albeit not all - of the persistent negative perceptions of psychological risks are unsupported by the currently available scientific evidence, with the majority of reported adverse effects not being observed in a regulated and/or medical context. CONCLUSIONS: This highlights the importance for clinicians and therapists to keep to the highest safety and ethical standards. It is imperative not to be overzealous and to ensure balanced media reporting to avoid future controversies, so that much needed research can continue.