title: P300 asymmetry and positive symptom severity: a study in the early stage of a first episode of psychosis.
abstract: The amplitude of the P300 event-related potential (ERP) has been reported to be reduced over left compared to right temporal sites in schizophrenia patients. This left temporal P300 reduction has been associated with positive symptom severity and gray matter reduction in the left superior temporal gyrus. We investigated a group of patients with a first episode of schizophrenia spectrum psychosis and a group of normal controls to verify if P300 amplitude asymmetry already exists around the time of presentation for treatment. Relative to normal control subjects, no P300 asymmetry was found in patients. Nevertheless, P300 asymmetry was correlated with the severity of positive symptoms and worse global functioning (GAF), a good predictor of poor outcome.
authors.affiliation: Department of Neurology and Neurosurgery, McGill University, Montréal, Québec, Canada.
authors.forename: Louis
authors.initials: L
authors.lastname: Renoult
authors.forename: Marie
authors.initials: M
authors.lastname: Prévost
authors.forename: Mathieu
authors.initials: M
authors.lastname: Brodeur
authors.forename: Claire
authors.initials: C
authors.lastname: Lionnet
authors.forename: Ridha
authors.initials: R
authors.lastname: Joober
authors.forename: Ashok
authors.initials: A
authors.lastname: Malla
authors.forename: J Bruno
authors.initials: JB
authors.lastname: Debruille
mesh_terms: D000293:Adolescent; D000328:Adult; D001288:Attention / Q000502:physiology; D002540:Cerebral Cortex / Q000503:physiopathology*; D003702:Delusions / Q000175:diagnosis / Q000503:physiopathology / Q000523:psychology; D004292:Dominance, Cerebral / Q000502:physiology*; D042241:Early Diagnosis; D018913:Event-Related Potentials, P300 / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010898:Pitch Perception / Q000502:physiology; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D012559:Schizophrenia / Q000175:diagnosis / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D012569:Schizotypal Personality Disorder / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology; D013223:Statistics as Topic; D013702:Temporal Lobe / Q000503:physiopathology