title: Cannabis use, cognition and brain structure in first-episode psychosis.
abstract: Cannabis use is highly prevalent worldwide and it is associated with psychosis, but its effects on brain structure and cognition are still controversial. The aim of this paper is to investigate cognitive functioning and brain structure in patients with their first episode of psychosis who used Cannabis. We examined gray matter and lateral ventricle volumes in 28 patients with first-episode psychosis and a history of Cannabis use, 78 patients without a history of Cannabis use and 80 healthy controls who had not used Cannabis. Cognition was assessed using forward and backwards digit span tests, from the Wechsler Memory Scale-Third Edition (WMS-III) and the Controlled Oral Word Association Test (COWAT). Patients with a history of Cannabis use had less brain abnormalities, characterized by gray matter and lateral ventricle volume preservation, as well as less attentional and executive impairments compared to patients without a history of Cannabis use. Cannabis-using patients who develop psychosis have less neurodevelopmental impairment and better cognitive reserve than other psychotic patients; perhaps reflecting different etiological processes.
authors.affiliation: Laboratory of Psychiatric Neuroimaging (LIM-21), Department of Psychiatry, Faculty of Medicine, University of São Paulo, Rua Dr Ovídio Pires de Campos, s/n, 05403-010 São Paulo, SP, Brazil. pjcunha@usp.br
authors.forename: Paulo Jannuzzi
authors.initials: PJ
authors.lastname: Cunha
authors.forename: Pedro Gomes P
authors.initials: PG
authors.lastname: Rosa
authors.forename: Adriana de Mello
authors.initials: Ade M
authors.lastname: Ayres
authors.forename: Fábio L S
authors.initials: FL
authors.lastname: Duran
authors.forename: Luciana C
authors.initials: LC
authors.lastname: Santos
authors.forename: Marcia
authors.initials: M
authors.lastname: Scazufca
authors.forename: Paulo R
authors.initials: PR
authors.lastname: Menezes
authors.forename: Bernardo
authors.initials: B
authors.lastname: dos Santos
authors.forename: Robin M
authors.initials: RM
authors.lastname: Murray
authors.forename: José Alexandre S
authors.initials: JA
authors.lastname: Crippa
authors.forename: Geraldo F
authors.initials: GF
authors.lastname: Busatto
authors.forename: Maristela S
authors.initials: MS
authors.lastname: Schaufelberger
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001921:Brain / Q000473:pathology*; D001938:Brazil; D002391:Catchment Area, Health; D003072:Cognition Disorders / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D002189:Marijuana Abuse / Q000453:epidemiology*; D008875:Middle Aged; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000453:epidemiology* / Q000473:pathology* / Q000523:psychology; D055815:Young Adult