Systematic review · 2026
Review of 48 studies: psychedelics linked to more Openness and less Neuroticism
- Original title
- Classic psychedelics and personality: An updated systematic review.
- Authors
- Vicentini AB, de Paula CC, Silva Reis JA, et al.
- Journal
- Journal of psychopharmacology (Oxford, England), 2026
- Molecules
- Psilocybin, LSD, DMT, Ayahuasca, Mescaline
- Conditions
- Healthy volunteers, Other
- Evidence grade
- Low
- Source
- Read the original paper
The question
Do classic psychedelics change personality traits, and if so which ones? The authors set out to update an earlier review with studies published between 2016 and 2024.
What they did
The researchers searched four research databases (PubMed, LILACS, PsycINFO and SciELO) for human studies of LSD, psilocybin, ayahuasca/DMT or mescaline that measured personality with a formal questionnaire. Randomized controlled trials, open-label trials and observational studies were all eligible. They followed standard reporting guidelines for systematic reviews and registered the protocol in advance.
What they found
From 6,043 records screened, 48 studies were included: 14 experimental and 34 observational. The most consistent results were increases in Openness (curiosity and receptiveness to new experience) and decreases in Neuroticism (a tendency toward negative emotion), particularly in studies of psilocybin and ayahuasca. Findings for Extraversion, Agreeableness and Conscientiousness were mixed. Microdosing was linked to modest reductions in Neuroticism and higher Absorption (a tendency to become deeply immersed in experience). Most studies used questionnaires based on the Five-Factor Model of personality.
The fine print
The review did not pool results statistically, and the abstract gives no total number of participants, no effect sizes and no follow-up lengths. Most included studies were observational, so people who chose to use psychedelics may differ from those who did not, and self-reported personality scores can shift for many reasons. Contradictory results across the literature were the reason for the review in the first place. This summary is based on the abstract only.
What it means
Across several decades of research, the most repeatable personality findings after classic psychedelic use are higher Openness and lower Neuroticism, but the evidence rests largely on observational studies and the size and durability of these shifts remain unclear.
Evidence grade: Low. A systematic review without pooled statistics, in which most included studies (34 of 48) were observational rather than controlled trials.
This summary is based on the study’s published abstract.