Neurocognition as a stable endophenotype in bipolar disorder and schizophrenia

J Nerv Ment Dis. 2006 Apr;194(4):255-60. doi: 10.1097/01.nmd.0000207360.70337.7e.


Linkage and association studies have paid increasing attention to neurocognition as a putative endophenotype. However, there exists little documentation of its trait stability in schizophrenia or bipolar disorder. Our aim was to determine the longitudinal stability of neurocognitive performance in bipolar versus schizophrenia probands. We administered a neurocognitive battery at two time points, approximately 5 years apart, in 16 schizophrenia and 16 bipolar disorder age-matched subjects. There were no significant changes over time on variables including education, estimated IQ, depression, psychosis, global functioning, or medication status. Schizophrenia subjects showed significant deterioration in one measure of executive functioning but no significant changes in seven of eight other domains. Bipolar patients showed stability over time in attentional measures but greater variability in other domains. These preliminary findings suggest that neurocognitive domains appear longitudinally stable across broad domains in schizophrenia. In contrast, stable functioning may be more limited to attentional domains in bipolar disorder.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Ambulatory Care
  • Attention
  • Bipolar Disorder / diagnosis*
  • Bipolar Disorder / drug therapy
  • Bipolar Disorder / genetics*
  • Cognition Disorders / diagnosis*
  • Cognition Disorders / genetics*
  • Cognition Disorders / psychology
  • Follow-Up Studies
  • Humans
  • Longitudinal Studies
  • Neuropsychological Tests / statistics & numerical data*
  • Phenotype*
  • Psychiatric Status Rating Scales
  • Psychotropic Drugs / therapeutic use
  • Schizophrenia / diagnosis*
  • Schizophrenia / drug therapy
  • Schizophrenia / genetics*
  • Schizophrenic Psychology
  • Treatment Outcome


  • Psychotropic Drugs