Long-term use of psychedelic drugs is associated with differences in brain structure and personality in humans
José Carlos Bouso, Fernanda Palhano-Fontes, Antoni Rodrı́guez-fornells, Sidarta Ribeiro, Rafael Faria Sanches, José Alexandre S. Crippa, Jaime E. C. Hallak, Dráulio Barros de Araújo, Jordi Riba
European Neuropsychopharmacology January 16, 2015 DOI: 10.1016/j.euroneuro.2015.01.008 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Observational cohort Peer reviewed |
|---|---|
| Sample size | 44 |
| Population | Regular ayahuasca users and matched controls |
| Intervention | Ayahuasca |
| Topics | Default mode network |
| Keywords | Posterior cingulate Hallucinogen Dissociative Personality Cognition Clinical psychology |
| Citations | 221 |
| Key findings | Regular ayahuasca users show cortical thinning in the posterior cingulate cortex, correlated with duration and intensity of use and with self-transcendence scores. |
Abstract
Psychedelic agents have a long history of use by humans for their capacity to induce profound modifications in perception, emotion and cognitive processes. Despite increasing knowledge of the neural mechanisms involved in the acute effects of these drugs, the impact of sustained psychedelic use on the human brain remains largely unknown. Molecular pharmacology studies have shown that psychedelic 5-hydroxytryptamine (5HT)2A agonists stimulate neurotrophic and transcription factors associated with synaptic plasticity. These data suggest that psychedelics could potentially induce structural changes in brain tissue. Here we looked for differences in cortical thickness (CT) in regular users of psychedelics. We obtained magnetic resonance imaging (MRI) images of the brains of 22 regular users of ayahuasca (a preparation whose active principle is the psychedelic 5HT2A agonist N,N-dimethyltryptamine (DMT)) and 22 controls matched for age, sex, years of education, verbal IQ and fluid IQ. Ayahuasca users showed significant CT differences in midline structures of the brain, with thinning in the posterior cingulate cortex (PCC), a key node of the default mode network. CT values in the PCC were inversely correlated with the intensity and duration of prior use of ayahuasca and with scores on self-transcendence, a personality trait measuring religiousness, transpersonal feelings and spirituality. Although direct causation cannot be established, these data suggest that regular use of psychedelic drugs could potentially lead to structural changes in brain areas supporting attentional processes, self-referential thought, and internal mentation. These changes could underlie the previously reported personality changes in long-term users and highlight the involvement of the PCC in the effects of psychedelics.
Comparable studies
Other observational and cohort studies on default mode network, most cited first.
| Study | Year | Design | Participants |
|---|---|---|---|
| A default mode of brain function Normal adult human brain | 2001 | Observational study | |
| Resting-State Functional Connectivity Reflects Structural Connectivity in the Default Mode Network Healthy subjects | 2008 | Observational cohort | |
| Meditation experience is associated with increased cortical thickness Participants with extensive Insight meditation experience and matched controls | 2005 | Observational cohort | n = 20 |
| Meditation experience is associated with differences in default mode network activity and connectivity Experienced meditators and matched meditation-naive controls | 2011 | Observational cohort | |
| The precuneus/posterior cingulate cortex plays a pivotal role in the default mode network: Evidence from a partial correlation network analysis Healthy subjects | 2008 | Observational study |
Citations in the library
Cited by 185
- REBUS and the Anarchic Brain: Toward a Unified Model of the Brain Action of Psychedelics Pharmacological Reviews June 20, 2019
- Psilocybin for treatment-resistant depression: fMRI-measured brain mechanisms. Scientific Reports October 13, 2017
- Antidepressive, anxiolytic, and antiaddictive effects of ayahuasca, psilocybin and lysergic acid diethylamide (LSD): a systematic review of clinical trials published in the last 25 years Therapeutic Advances in Psychopharmacology March 18, 2016
- The paradoxical psychological effects of lysergic acid diethylamide (LSD) Psychological Medicine February 5, 2016
- The Computational Boundary of a “Self”: Developmental Bioelectricity Drives Multicellularity and Scale-Free Cognition Frontiers in Psychology December 13, 2019
and 180 more in the library
Cites 23
- A default mode of brain function Proceedings of the National Academy of Sciences January 16, 2001
- Pilot Study of Psilocybin Treatment for Anxiety in Patients With Advanced-Stage Cancer Archives of General Psychiatry September 7, 2010
- Neural correlates of the psychedelic state as determined by fMRI studies with psilocybin Proceedings of the National Academy of Sciences January 23, 2012
- Psilocybin occasioned mystical-type experiences: immediate and persisting dose-related effects. Psychopharmacology December 1, 2011
- Mystical experiences occasioned by the hallucinogen psilocybin lead to increases in the personality domain of openness Journal of Psychopharmacology September 28, 2011
and 18 more in the library