Depressive DisordersAnxiety DisordersSubstance Use Disorders (SUD)LSDPsilocybinDMTAyahuasca5-MeO-DMTMescaline

Insights on Psychedelics: A Systematic Review of Therapeutic Effects

This systematic review (s=98) examining psychedelic-catalysed insight found that 86% of studies showed insight was linked to therapeutic improvement, with insight being dose-dependent and significantly higher than placebo in 93% of comparative studies, suggesting insight may be a key mechanism in psychedelic therapy.

Authors

  • David Yaden
  • Paul Liknaitzky
  • Ruben Laukkonen

Published

Neuroscience and Biobehavioral Reviews
meta Study

Abstract

Background

Insight - a sudden change in understanding or perspective that feels true or reliable - is a common occurrence during psychedelic experiences, and often considered by clinicians and patients to be central to their therapeutic value. However, their occurrence and role has not been systematically assessed.

Objectives

We reviewed all peer-reviewed studies that published data on insight catalysed by a classic psychedelic at psychoactive levels, to elucidate several aspects of psychedelic-catalysed insight, including its prevalence, relationship to dose, time-course, and relationship to therapeutic outcomes. Risk of bias was assessed regarding selection, reliability, causality, and transparency.

Findings

The final database and key bibliography searches were completed on July 13, 2024. We screened 741 abstracts and included 98 studies (40 survey, 58 interventional). Insight was positively correlated with psychedelic dose, and was significantly higher following psychedelics in 43 of 46 (93%) studies that presented a comparison to a placebo condition. Crucially, 25 of 29 studies (86%) found that insight was associated with therapeutic improvement, and this relationship was often stronger than mystical-type experience, which has received more research attention.

Interpretation

This review indicates that psychedelic-catalysed insight is associated with therapeutic improvement, suggesting its importance for clinical practice and for understanding the mechanisms of psychedelic therapy.

Limitations

Heterogeneous study designs and operationalisations of insight precluded a meta-analytic summary. Publication bias and selective reporting is possible, given insight was typically not a primary outcome of the included studies.

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Research Summary of 'Insights on Psychedelics: A Systematic Review of Therapeutic Effects'

Introduction

Psychedelic-assisted experiences at psychoactive doses commonly produce a range of acute subjective effects that have been linked to therapeutic benefit, including connectedness, emotional breakthrough, ego-dissolution and mystical-type experiences. Among these subjective changes, many users and clinicians report sudden, confidence‑laden changes in understanding—termed "insight"—which the authors define here as the sudden emergence of a change in perspective accompanied by clarity or certainty. Earlier studies have reported correlations between acute insight ratings and improvements in wellbeing, depression, anxiety and substance use, but insight itself has not been the subject of a comprehensive, systematic synthesis. Kugel and colleagues set out to fill that gap by conducting the first systematic review focused on psychedelic‑catalysed insight. The review aimed to characterise the prevalence of insight after psychoactive doses of classic serotonergic psychedelics, its relationship to dose, its time-course, and its association with therapeutic outcomes, and to compare insight with mystical‑type experiences as predictors of clinical benefit. The investigators also assessed risk of bias across included studies and made their protocol and materials openly available.

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Study Details

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