title: Disorganization and reality distortion in schizophrenia: a meta-analysis of the relationship between positive symptoms and neurocognitive deficits.
abstract: BACKGROUND
  Factor analytic studies have shown that in schizophrenia patients, disorganization (e.g., conceptual disorganization and bizarre behavior) is a separate dimension from other types of positive symptoms such as reality distortion (delusions and hallucinations). Although some studies have found that disorganization is more strongly linked to neurocognitive deficits and poor functional outcomes than reality distortion, the findings are not always consistent.
  
  
  METHODS
  A meta-analysis of 104 studies (combined n=8015) was conducted to determine the magnitude of the relationship between neurocognition and disorganization as compared to reality distortion. Additional analyses were conducted to determine whether the strength of these relationships differed depending on the neurocognitive domain under investigation.
  
  
  RESULTS
  The relationship between reality distortion and neurocognition was weak (r=-.04; p=.03) as compared to the moderate association between disorganization and neurocognition (r=-.23; p<.01). In each of the six neurocognitive domains that were examined, disorganization was more strongly related to neurocognition (r's range from -.20 to -.26) than to reality distortion (r's range from .01 to -.12).
  
  
  CONCLUSIONS
  The effect size of the relationship between neurocognition and disorganization was significantly larger than the effect size of the relationship between neurocognition and reality distortion. These results hold across several neurocognitive domains. These findings support a dimensional view of positive symptoms distinguishing disorganization from reality distortion.
authors.affiliation: UCLA Department of Psychiatry, 300 Medical Plaza, Room 2243, Los Angeles CA 90095-6968, United States. jventura@ucla.edu
authors.forename: Joseph
authors.initials: J
authors.lastname: Ventura
authors.forename: April D
authors.initials: AD
authors.lastname: Thames
authors.forename: Rachel C
authors.initials: RC
authors.lastname: Wood
authors.forename: Lisa H
authors.initials: LH
authors.lastname: Guzik
authors.forename: Gerhard S
authors.initials: GS
authors.lastname: Hellemann
mesh_terms: D003072:Cognition Disorders / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D010469:Perceptual Distortion / Q000502:physiology*; D011569:Psychiatric Status Rating Scales; D011936:Reality Testing; D012559:Schizophrenia / Q000150:complications*; D012565:Schizophrenic Psychology