Personality & Trait Factors

Serotonergic psychedelics and personality: A systematic review of contemporary research

This review article (2018) summarizes the effects of psychedelics on the serotonergic system and the subsequent (therapeutic) personality changes.

Authors

  • Jamie Hallak
  • Rafael dos Santos
  • José Carlos Bouso

Published

Neuroscience and Biobehavioral Reviews
meta Study

Abstract

Serotonergic psychedelics act as agonists at cortical 5-HT2A receptors and seem to induce personality changes. We conducted a systematic review of studies assessing the effects of these drugs on personality. Papers published from 1985-2016 were included from PubMed, LILACS, and SciELO databases. Three hundred and sixty-nine studies were identified, and 18 were included. Specific personality traits, such as Absorption and Self-Transcendence, seem to influence the effects of psychedelics, and psychedelic drug users and nonusers appear to differ in some personality traits. Psychedelics administered in controlled settings may induce personality changes, such as increased Openness and Self-Transcendence. Increases in global brain entropy induced by acute psychedelic administration predicted changes in Openness, and Self-Transcendence was negatively correlated with cortical thinning of the posterior cingulate cortex in long-term religious ayahuasca users. Acute and long-term use of psychedelics is associated with personality changes that appear to be modulated by 5-HT2A receptors. These changes seem to induce therapeutic effects that should be further explored in randomized controlled studies.

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Research Summary of 'Serotonergic psychedelics and personality: A systematic review of contemporary research'

Introduction

Psychedelics have long been associated with claims—both positive and negative—about their capacity to produce enduring changes in personality. Early clinical and observational reports suggested acute alterations on personality measures but provided mixed evidence on whether such changes persisted. Debate has also concerned directionality: whether particular personality profiles predispose people to use psychedelics, or whether drug exposure itself produces personality change. Methodological shortcomings in older research and a renewed scientific interest in psychedelics' neurobiology and therapeutic potential motivated contemporary, more rigorous investigations. Bouso and colleagues set out to systematically review contemporary clinical and observational studies (from 01 January 1985 to 14 December 2016) that examined personality in relation to serotonergic psychedelics (5-HT2A receptor agonists). The review aimed to summarise evidence on acute and longer-term personality effects, compare findings across study types (experimental administration, recreational users, ritual/ceremonial users), and consider possible neurobiological mechanisms underlying reported changes. The authors limited the search to serotonergic hallucinogens and to the post-1985 period to increase comparability across modern psychometric instruments.

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Study Details

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