title: Negative symptoms in individuals at clinical high risk of psychosis.
abstract: Negative symptoms are present in the psychosis prodrome. However, the extent to which these symptoms are present prior to the onset of the first episode of psychosis remains under-researched. The goal of this study is to examine negative symptoms in a sample of individuals at clinical high risk (CHR) for psychosis and to determine if they are predictive of conversion to psychosis. Participants (n=138) were all participants in the North American Prodrome Longitudinal Study (NAPLS 1) project. Negative symptoms were assessed longitudinally using the Scale of Prodromal Symptoms. The mean total negative symptom score at baseline was 11.0, with 82.0% of the sample scoring at moderate severity or above on at least one negative symptom. Over the course of 12 months, the symptoms remained in the above moderate severity range for 54.0% of participants. Associations between individual symptoms were moderate, and a factor analysis confirmed that all negative symptoms loaded heavily on one factor. Negative symptoms were more severe and persistent overtime in those who converted to psychosis, significantly predicting the likelihood of conversion. Thus, early and persistent negative symptoms may represent a vulnerability for risk of developing psychosis.
authors.affiliation: Department of Psychiatry, University of Calgary, Calgary, Alberta, Canada. dpiskuli@ucalgary.ca
authors.forename: Danijela
authors.initials: D
authors.lastname: Piskulic
authors.forename: Jean
authors.initials: J
authors.lastname: Addington
authors.forename: Kristin S
authors.initials: KS
authors.lastname: Cadenhead
authors.forename: Tyrone D
authors.initials: TD
authors.lastname: Cannon
authors.forename: Barbara A
authors.initials: BA
authors.lastname: Cornblatt
authors.forename: Robert
authors.initials: R
authors.lastname: Heinssen
authors.forename: Diana O
authors.initials: DO
authors.lastname: Perkins
authors.forename: Larry J
authors.initials: LJ
authors.lastname: Seidman
authors.forename: Ming T
authors.initials: MT
authors.lastname: Tsuang
authors.forename: Elaine F
authors.initials: EF
authors.lastname: Walker
authors.forename: Scott W
authors.initials: SW
authors.lastname: Woods
authors.forename: Thomas H
authors.initials: TH
authors.lastname: McGlashan
mesh_terms: D018450:Disease Progression; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000150:complications* / Q000175:diagnosis*; D012307:Risk Factors; D013997:Time Factors