Working memory impairment in probands with schizoaffective disorder and first degree relatives of schizophrenia probands extend beyond deficits predicted by generalized neuropsychological impairment

Schizophr Res. 2015 Aug;166(1-3):310-5. doi: 10.1016/j.schres.2015.05.018. Epub 2015 May 23.

Abstract

Objective: Working memory impairment is well established in psychotic disorders. However, the relative magnitude, diagnostic specificity, familiality pattern, and degree of independence from generalized cognitive deficits across psychotic disorders remain unclear.

Method: Participants from the Bipolar and Schizophrenia Network on Intermediate Phenotypes (B-SNIP) study included probands with schizophrenia (N=289), psychotic bipolar disorder (N=227), schizoaffective disorder (N=165), their first-degree relatives (N=315, N=259, N=193, respectively), and healthy controls (N=289). All were administered the WMS-III Spatial Span working memory test and the Brief Assessment of Cognition in Schizophrenia (BACS) battery.

Results: All proband groups displayed significant deficits for both forward and backward span compared to controls. However, after covarying for generalized cognitive impairments (BACS composite), all proband groups showed a 74% or greater effect size reduction with only schizoaffective probands showing residual backward span deficits compared to controls. Significant familiality was seen in schizophrenia and bipolar pedigrees. In relatives, both forward and backward span deficits were again attenuated after covarying BACS scores and residual backward span deficits were seen in relatives of schizophrenia patients.

Conclusions: Overall, both probands and relatives showed a similar pattern of robust working memory deficits that were largely attenuated when controlling for generalized cognitive deficits.

Keywords: B-SNIP; Bipolar disorder; Familiality; Generalized cognitive deficit; Schizoaffective disorder; Schizophrenia; Working memory.

Publication types

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

MeSH terms

  • Adult
  • Bipolar Disorder / complications
  • Bipolar Disorder / genetics
  • Bipolar Disorder / psychology*
  • Family / psychology*
  • Female
  • Genetic Predisposition to Disease
  • Humans
  • Male
  • Memory Disorders* / complications
  • Memory Disorders* / genetics
  • Memory, Short-Term*
  • Neuropsychological Tests
  • Phenotype
  • Psychotic Disorders / complications
  • Psychotic Disorders / genetics
  • Psychotic Disorders / psychology*
  • Schizophrenia / complications
  • Schizophrenia / genetics
  • Schizophrenic Psychology*
  • United States