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Updated: Aug 18, 2026

Brain Morphology of Cannabis Users With or Without Psychosis: A Pilot MRI Study
Published on: August 18, 2020
Symptoms of schizotypy precede cannabis use
Jason Schiffman1, Brad Nakamura, Mitchell Earleywine
1Department of Psychology, University of Hawaii at Manoa, 2430 Campus Road, 110 Gartley Hall, Honolulu, HI 96822, USA. schiffma@hawaii.edu
Abstract:
The current investigation uses a large non-clinical sample of undergraduate college students (N=189) to investigate schizotypal traits among cannabis and non-cannabis users, as well as the temporal order of the onset of these traits and cannabis use. Findings suggest that regular cannabis users are significantly more prone to cognitive and perceptual distortions as well as disorganization, but not interpersonal deficits, than non-regular users and those who have never used. Additionally, the onset of schizotypal symptoms generally precedes the onset of cannabis use. The findings do not support a causal link between cannabis use and schizotypal traits.
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