title: Confirmatory Factor Analysis and Differential Relationships of the Two Subdomains of Negative Symptoms in Chronically Ill Psychotic Patients.
abstract: Research suggests a two factor structure for negative symptoms in patients with psychotic disorders: social amotivation (SA) and expressive deficits (ED). Applying this two-factor structure in clinical settings may provide valuable information with regard to outcomes and to target treatments. We aimed to investigate 1) whether the factor structure is also supported in chronically ill patients with a psychotic disorder and 2) what the relationship is between these factors and functioning (overall functioning and living situation), depressive symptoms and quality of life. 1157 Patients with a psychotic disorder and a duration of illness of 5 years or more were included in the analysis (data selected from the Pharmacotherapy Monitoring Outcome Survey; PHAMOUS). A confirmatory factor analysis was performed using items of the Positive and Negative Syndrome Scale that were previously identified to reflect negative symptoms (N1-4, N6, G5, G7, G13, G16). Subsequently, regression analysis was performed on outcomes. The results confirmed the distinction between SA (N2, N4, G16) and ED (N1, N3, N6, G5, G7, G13) in chronically ill patients. Both factors were related to worse overall functioning as measured with the Health of the Nation Outcome Scales, ED was uniquely associated with residential living status. Higher scores for SA were associated with more depressive symptoms and worse quality of life. Thus, SA is most strongly related to level of social-emotional functioning, while ED are more related to living situation and thereby are indicative of level of everyday functioning. This subdivision may be useful for research purposes and be a valuable additional tool in clinical practice and treatment development.
authors.affiliation: Department of Rehabilitation, Lentis Center for Mental Health Care, Zuidlaren, the Netherlands.|Rob Giel Research Center, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
authors.forename: Annemarie P M
authors.initials: AP
authors.lastname: Stiekema
authors.affiliation: Rob Giel Research Center, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.|Department of Neuroscience, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.|Research Department, Lentis Center for Mental Health Care, Groningen, the Netherlands.
authors.forename: Edith J
authors.initials: EJ
authors.lastname: Liemburg
authors.affiliation: Department of Rehabilitation, Lentis Center for Mental Health Care, Zuidlaren, the Netherlands.|Rob Giel Research Center, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.|Department of Neuroscience, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
authors.forename: Lisette
authors.initials: L
authors.lastname: van der Meer
authors.affiliation: Rob Giel Research Center, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.|Research Department, Lentis Center for Mental Health Care, Groningen, the Netherlands.
authors.forename: Stynke
authors.initials: S
authors.lastname: Castelein
authors.affiliation: Department of Health Sciences, Community and Occupational Medicine, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
authors.forename: Roy
authors.initials: R
authors.lastname: Stewart
authors.affiliation: Parnassia Group, Dijk en Duin Mental Health Center, Castricum, the Netherlands.|Tilburg University, Tilburg School of Social and Behavioral Sciences, Tranzo Scientific center for Care and Welfare, Tilburg, the Netherlands.|Phrenos, Center of Expertise on severe mental illness, Utrecht, the Netherlands.
authors.forename: Jaap
authors.initials: J
authors.lastname: van Weeghel
authors.affiliation: Department of Neuroscience, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
authors.forename: André
authors.initials: A
authors.lastname: Aleman
authors.affiliation: Rob Giel Research Center, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.|University Center of Psychiatry, University of Groningen, University Medical Center Groningen, Groningen, the Netherlands.
authors.forename: Richard
authors.initials: R
authors.lastname: Bruggeman
mesh_terms: D000328:Adult; D000368:Aged; D002908:Chronic Disease; D003147:Communication Disorders / Q000523:psychology; D003863:Depression; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011618:Psychotic Disorders / Q000175:diagnosis / Q000523:psychology*; D011788:Quality of Life; D012044:Regression Analysis; D012918:Social Alienation / Q000523:psychology; D063189:Symptom Assessment; D055815:Young Adult