Long-Term Cannabis Users Show No Cognitive Deficits When Abstinent — But Distinct Personality Traits
Chronic cannabis users showed no neuropsychological deficits after 10-30 days of abstinence but were distinguished by higher novelty seeking and impulsive nonconformity compared to non-users.
Quick Facts
What This Study Found
No significant group differences in neuropsychological performance between chronic cannabis users (n=56), ayahuasca users (n=69), and non-users (n=94) matched for age, education, and IQ; personality traits (novelty seeking, impulsive nonconformity) best distinguished cannabis users.
Key Numbers
56 cannabis users, 69 ayahuasca users, 94 non-users; matched by age, education, IQ; 10-30 days abstinence required; cannabis users: higher novelty seeking and impulsive nonconformity, lower introvertive anhedonia.
How They Did This
Cross-sectional study comparing matched groups of regular cannabis users, ayahuasca users, and non-users on neuropsychological battery and personality questionnaires after 10-30 days of abstinence.
Why This Research Matters
This challenges the persistent narrative that cannabis causes lasting brain damage — when users are matched for intelligence and education and given time to clear acute effects, cognitive deficits disappear.
The Bigger Picture
The finding that personality, not cognition, distinguishes users suggests that some 'cannabis-related' cognitive issues found in other studies may reflect pre-existing traits rather than drug effects.
What This Study Doesn't Tell Us
Cross-sectional design cannot determine if personality traits preceded or followed cannabis use; self-selected non-treatment-seeking sample; 10-30 day abstinence may not capture very long-term residual effects.
Questions This Raises
- ?Do personality traits predispose to cannabis use, or does long-term use shape personality?
- ?Would results differ in treatment-seeking or problematic users?
Trust & Context
- Key Stat:
- Evidence Grade:
- Well-matched cross-sectional design with comprehensive neuropsychological battery and validated personality measures, but cannot establish causation or generalize to all users.
- Study Age:
- Published in 2026 in European Neuropsychopharmacology, contributing to the ongoing debate about cannabis and cognition.
- Original Title:
- Personality, not cognition, distinguishes chronic ayahuasca and cannabis users from non-users.
- Published In:
- European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology, 106, 112782 (2026)
- Authors:
- Bouso, José Carlos(4), Andión, Oscar, Estévez, Sabela Fondevila, González, Débora, Alcázar-Córcoles, Miguel Ángel, Kohek, Maja, Santos, Rafael Guimaraes Dos, Hallak, Jaime, Riba, Jordi
- Database ID:
- RTHC-08133
Evidence Hierarchy
A snapshot of a population at one point in time.
What do these levels mean? →Frequently Asked Questions
Does long-term cannabis use cause permanent brain damage?
This study found no neuropsychological deficits in chronic cannabis users after 10-30 days of abstinence when matched for intelligence and education, suggesting acute effects may be reversible.
How are cannabis users different from non-users?
Personality, not cognition, was the distinguishing factor — cannabis users scored higher on novelty seeking and impulsive nonconformity, which may have preceded rather than resulted from use.
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Cite This Study
https://rethinkthc.com/research/RTHC-08133APA
Bouso, José Carlos; Andión, Oscar; Estévez, Sabela Fondevila; González, Débora; Alcázar-Córcoles, Miguel Ángel; Kohek, Maja; Santos, Rafael Guimaraes Dos; Hallak, Jaime; Riba, Jordi. (2026). Personality, not cognition, distinguishes chronic ayahuasca and cannabis users from non-users.. European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology, 106, 112782. https://doi.org/10.1016/j.euroneuro.2026.112782
MLA
Bouso, José Carlos, et al. "Personality, not cognition, distinguishes chronic ayahuasca and cannabis users from non-users.." European neuropsychopharmacology : the journal of the European College of Neuropsychopharmacology, 2026. https://doi.org/10.1016/j.euroneuro.2026.112782
RethinkTHC
RethinkTHC Research Database. "Personality, not cognition, distinguishes chronic ayahuasca ..." RTHC-08133. Retrieved from https://rethinkthc.com/research/bouso-2026-personality-not-cognition-distinguishes
Access the Original Study
Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.
This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.