Differential working memory impairment in bipolar disorder and schizophrenia: Effects of lifetime history of psychosis

David C. Glahn, Carrie E. Bearden, Sibel Cakir, Jennifer A. Barrett, Pablo Najt, E. Serap Monkul, Natalie Maples, Dawn I. Velligan, Jair C. Soares

Research output: Contribution to journalArticle

140 Scopus citations

Abstract

Background: Although bipolar disorder and schizophrenia have long been viewed as distinct illnesses, there is growing evidence that these two complex diseases share some common genes, which may manifest as overlapping neuropsychological impairments. Although working memory dysfunction has been proposed to be central to the pathophysiology of schizophrenia, it has received less attention in studies of bipolar disorder. Method: We applied measures of working memory to patients with schizophrenia (n = 15), patients with schizoaffective disorder (n = 15), patients with psychotic (n = 11) and non-psychotic (n = 15) bipolar disorder, and demographically matched healthy subjects (n = 32), in order to determine the extent to which these groups show common or unique impairments. Results: While patients with bipolar disorder (with and without psychotic features) and those with schizophrenia/schizoaffective disorder were impaired on backward digit span, only patients with a lifetime history of psychotic features, regardless of diagnosis, were impaired on spatial delayed response task. Conclusions: Backward digit span performance is comparable in bipolar disorder and schizophrenia, and may be an appropriate endophenotypic marker that cuts across diagnostic categories. In contrast, spatial working memory performance clearly distinguishes non-psychotic bipolar disorder patients from patients with functional psychosis.

Original languageEnglish (US)
Pages (from-to)117-123
Number of pages7
JournalBipolar disorders
Volume8
Issue number2
DOIs
StatePublished - Apr 2006

Keywords

  • Bipolar disorder
  • Delayed response task
  • Digit span
  • Psychotic features
  • Schizoaffective disorder
  • Schizophrenia
  • Working memory

ASJC Scopus subject areas

  • Psychiatry and Mental health
  • Biological Psychiatry

Fingerprint Dive into the research topics of 'Differential working memory impairment in bipolar disorder and schizophrenia: Effects of lifetime history of psychosis'. Together they form a unique fingerprint.

  • Cite this