The factorial structure of the schedule for the deficit syndrome in schizophrenia

Schizophr Bull. 2006 Apr;32(2):274-8. doi: 10.1093/schbul/sbi064. Epub 2005 Sep 21.

Abstract

Deficit schizophrenia (DS) is considered a distinct subtype within the diagnosis of schizophrenia. While the common assumption is that DS represents a single, cohesive domain of psychopathology, the factorial structure of DS has not been investigated. We assessed 52 individuals with DSM-IV diagnoses of schizophrenia with DS. A principal component analysis (PCA) was conducted on the symptoms of the Schedule for the Deficit Syndrome. The PCA resulted in 2 distinct factors explaining 73.8% of the variance. Factor 1 (avolition) is made up of symptoms of curbing of interests, diminished sense of purpose, and diminished social drive. Factor 2 (emotional expression) is made up of symptoms of restricted affect, diminished emotional range, and poverty of speech. The results indicate that DS is best characterized by these 2 factors. The great majority of participants (86%) displayed DS symptoms from both factors. On average, participants had 4.19 (S.D. = 1.39) symptoms that were primary, enduring, and at least moderate in severity. The mean severity of symptoms was 2.25 (S.D. = 1.06). We discuss possible links between the obtained factors and putative neurobiological mechanisms, as well as directions for future research.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adolescent
  • Adult
  • Diagnostic and Statistical Manual of Mental Disorders
  • Expressed Emotion*
  • Factor Analysis, Statistical
  • Female
  • Humans
  • Interview, Psychological
  • Male
  • Middle Aged
  • Parietal Lobe / physiopathology
  • Prefrontal Cortex / physiopathology
  • Schizophrenia / diagnosis*
  • Schizophrenia / physiopathology
  • Schizophrenic Psychology*
  • Severity of Illness Index
  • Social Behavior*
  • Verbal Behavior*