title: Deconstructing negative symptoms of schizophrenia: avolition-apathy and diminished expression clusters predict clinical presentation and functional outcome.
abstract: BACKGROUND
  Previous studies indicate that negative symptoms reflect a separable domain of pathology from other symptoms of schizophrenia. However, it is currently unclear whether negative symptoms themselves are multi-faceted, and whether sub-groups of patients who display unique negative symptom profiles can be identified.
  
  
  METHODS
  A data-driven approach was used to examine the heterogeneity of negative symptom presentations in two samples: Study 1 included 199 individuals with schizophrenia assessed with a standard measure of negative symptoms and Study 2 included 169 individuals meeting criteria for deficit schizophrenia (i.e., primary and enduring negative symptoms) assessed with a specialized measure of deficit symptoms. Cluster analysis was used to determine whether different groups of patients with distinct negative symptoms profiles could be identified.
  
  
  RESULTS
  Across both studies, we found evidence for two distinctive negative symptom sub-groups: one group with predominantly Avolition-Apathy (AA) symptoms and another with a predominantly Diminished Expression (DE) profile. Follow-up discriminant function analyses confirmed the validity of these groups. AA and DE negative symptom sub-groups significantly differed on clinically relevant external validators, including measures of functional outcome, premorbid adjustment, clinical course, disorganized symptoms, social cognition, sex, and ethnicity.
  
  
  CONCLUSIONS
  These results suggest that distinct subgroups of patients with elevated AA or DE can be identified within the broader diagnosis of schizophrenia and that these subgroups show clinically meaningful differences in presentation. Additionally, AA tends to be associated with poorer outcomes than DE, suggesting that it may be a more severe aspect of psychopathology.
authors: Department of Psychiatry, University of Maryland School of Medicine, Maryland Psychiatric Research Center, P.O. Box 21247, Baltimore, MD 21228, USA. gstrauss@mprc.umaryland.edu
authors: Gregory P
authors: GP
authors: Strauss
authors: William P
authors: WP
authors: Horan
authors: Brian
authors: B
authors: Kirkpatrick
authors: Bernard A
authors: BA
authors: Fischer
authors: William R
authors: WR
authors: Keller
authors: Pinar
authors: P
authors: Miski
authors: Robert W
authors: RW
authors: Buchanan
authors: Michael F
authors: MF
authors: Green
authors: William T
authors: WT
authors: Carpenter
mesh_terms: D000328:Adult; D000339:Affect / Q000502:physiology*; D057565:Apathy / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D012559:Schizophrenia / Q000145:classification / Q000208:ethnology / Q000503:physiopathology*; D012565:Schizophrenic Psychology; D012737:Sex Factors; D014836:Volition / Q000502:physiology*