title: Symptom dimensions of the psychotic symptom rating scales in psychosis: a multisite study.
abstract: The Psychotic Symptom Rating Scales (PSYRATS) is an instrument designed to quantify the severity of delusions and hallucinations and is typically used in research studies and clinical settings focusing on people with psychosis and schizophrenia. It is comprised of the auditory hallucinations (AHS) and delusions subscales (DS), but these subscales do not necessarily reflect the psychological constructs causing intercorrelation between clusters of scale items. Identification of these constructs is important in some clinical and research contexts because item clustering may be caused by underlying etiological processes of interest. Previous attempts to identify these constructs have produced conflicting results. In this study, we compiled PSYRATS data from 12 sites in 7 countries, comprising 711 participants for AHS and 520 for DS. We compared previously proposed and novel models of underlying constructs using structural equation modeling. For the AHS, a novel 4-dimensional model provided the best fit, with latent variables labeled Distress (negative content, distress, and control), Frequency (frequency, duration, and disruption), Attribution (location and origin of voices), and Loudness (loudness item only). For the DS, a 2-dimensional solution was confirmed, with latent variables labeled Distress (amount/intensity) and Frequency (preoccupation, conviction, and disruption). The within-AHS and within-DS dimension intercorrelations were higher than those between subscales, with the exception of the AHS and DS Distress dimensions, which produced a correlation that approached the range of the within-scale correlations. Recommendations are provided for integrating these underlying constructs into research and clinical applications of the PSYRATS.
authors.affiliation: Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada; BC Mental Health and Addictions Research Institute, Vancouver, British Columbia, Canada; todd.woodward@ubc.ca.
authors.forename: Todd S
authors.initials: TS
authors.lastname: Woodward
authors.affiliation: Department of Pediatrics, University of Texas Health Science Center, Houston, TX;
authors.forename: Kwanghee
authors.initials: K
authors.lastname: Jung
authors.affiliation: Department of Psychology, McGill University, Montreal, Québec, Canada;
authors.forename: Heungsun
authors.initials: H
authors.lastname: Hwang
authors.affiliation: Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada; BC Mental Health and Addictions Research Institute, Vancouver, British Columbia, Canada;
authors.forename: John
authors.initials: J
authors.lastname: Yin
authors.affiliation: Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada; BC Mental Health and Addictions Research Institute, Vancouver, British Columbia, Canada;
authors.forename: Laura
authors.initials: L
authors.lastname: Taylor
authors.affiliation: Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada;
authors.forename: Mahesh
authors.initials: M
authors.lastname: Menon
authors.affiliation: Department of Psychology, and the BRC of the South London and Maudsley NHS Foundation Trust, Institute of Psychiatry, King's College London, London, UK;
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Peters
authors.affiliation: Department of Psychology, and the BRC of the South London and Maudsley NHS Foundation Trust, Institute of Psychiatry, King's College London, London, UK;
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Kuipers
authors.affiliation: North Metro Health Service Mental Health, and School of Psychiatry and Clinical Neuroscience, University of Western Australia, Perth, Australia;
authors.forename: Flavie
authors.initials: F
authors.lastname: Waters
authors.affiliation: Department of Psychology, University of Montreal, Montreal, Québec, Canada;
authors.forename: Tania
authors.initials: T
authors.lastname: Lecomte
authors.affiliation: Department of Psychiatry, Universitair Medisch Centrum, Utrecht, The Netherlands;
authors.forename: Iris E
authors.initials: IE
authors.lastname: Sommer
authors.affiliation: Department of Psychiatry, Universitair Medisch Centrum, Utrecht, The Netherlands;
authors.forename: Kirstin
authors.initials: K
authors.lastname: Daalman
authors.affiliation: Department of Psychiatry, Universitair Medisch Centrum, Utrecht, The Netherlands;
authors.forename: Remko
authors.initials: R
authors.lastname: van Lutterveld
authors.affiliation: Department of Psychiatric Neurophysiology, University Hospital of Psychiatry, University of Bern, Bern, Switzerland;
authors.forename: Daniela
authors.initials: D
authors.lastname: Hubl
authors.affiliation: Department of Psychiatric Neurophysiology, University Hospital of Psychiatry, University of Bern, Bern, Switzerland;
authors.forename: Jochen
authors.initials: J
authors.lastname: Kindler
authors.affiliation: Department of Psychiatric Neurophysiology, University Hospital of Psychiatry, University of Bern, Bern, Switzerland;
authors.forename: Philipp
authors.initials: P
authors.lastname: Homan
authors.affiliation: School of Psychology, University of Western Australia, Crawley, Western Australia, Australia;
authors.forename: Johanna C
authors.initials: JC
authors.lastname: Badcock
authors.affiliation: School of Psychology, University of Western Australia, Crawley, Western Australia, Australia;
authors.forename: Saruchi
authors.initials: S
authors.lastname: Chhabra
authors.affiliation: Department of Psychology, and the BRC of the South London and Maudsley NHS Foundation Trust, Institute of Psychiatry, King's College London, London, UK;
authors.forename: Matteo
authors.initials: M
authors.lastname: Cella
authors.affiliation: Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, IL;
authors.forename: Sarah
authors.initials: S
authors.lastname: Keedy
authors.affiliation: Department of Psychosis Studies, King's College London, London, UK;
authors.forename: Paul
authors.initials: P
authors.lastname: Allen
authors.affiliation: Department of Psychosis Studies, King's College London, London, UK;
authors.forename: Andrea
authors.initials: A
authors.lastname: Mechelli
authors.affiliation: Department of Education, Psychology, Philosophy, University of Cagliari, Cagliari, Italy;
authors.forename: Antonio
authors.initials: A
authors.lastname: Preti
authors.affiliation: Department of Education, Psychology, Philosophy, University of Cagliari, Cagliari, Italy;
authors.forename: Sara
authors.initials: S
authors.lastname: Siddi
authors.affiliation: Fraser North Early Psychosis Program, Royal Columbian Hospital, New Westminster, British Columbia, Canada.
authors.forename: David
authors.initials: D
authors.lastname: Erickson
mesh_terms: D000328:Adult; D003702:Delusions / Q000175:diagnosis / Q000523:psychology*; D005163:Factor Analysis, Statistical; D005260:Female; D006212:Hallucinations / Q000175:diagnosis / Q000523:psychology*; D006801:Humans; D008297:Male; D008960:Models, Psychological; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics / Q000295:instrumentation; D011618:Psychotic Disorders / Q000175:diagnosis / Q000523:psychology*; D012559:Schizophrenia / Q000175:diagnosis*; D012565:Schizophrenic Psychology; D055815:Young Adult
keywords: delusions; hallucinations; principal component analysis; psychosis; schizophrenia; structural equation modeling; symptom rating scales