title: Empirical evidence for discrete neurocognitive subgroups in bipolar disorder: clinical implications.
abstract: BACKGROUND
  Recent data suggest trait-like neurocognitive impairments in bipolar disorder (BPD), with deficits about 1 s.d. below average, less severe than deficits noted in schizophrenia. The frequency of significant impairment in BPD is approximately 60%, with 40% of patients characterized as cognitively spared. This contrasts with a more homogeneous presentation in schizophrenia. It is not understood why some BPD patients develop deficits while others do not.
  
  
  METHODS
  A total of 136 patients with BPD completed the MATRICS Consensus Cognitive Battery and data were entered into hierarchical cluster analyses to: (1) determine the optimal number of clusters (subgroups) that fit the sample; and (2) assign subjects to a specific cluster based on individual profiles. We then compared subgroups on several clinical factors and real-world community functioning.
  
  
  RESULTS
  Three distinct neurocognitive subgroups were found: (1) an intact group with performance comparable with healthy controls on all domains but with superior social cognition; (2) a selective impairment group with moderate deficits on processing speed, attention, verbal learning and social cognition and normal functioning in other domains; and (3) a global impairment group with severe deficits across all cognitive domains comparable with deficits in schizophrenia.
  
  
  CONCLUSIONS
  These results suggest the presence of multiple cognitive subgroups in BPD with unique profiles and begin to address the relationships between these subgroups, several clinical factors and functional outcome. Next steps will include using these data to help guide future efforts to target these disabling symptoms with treatment.
authors: Departments of Psychiatry,Icahn School of Medicine at Mount Sinai,New York, NY,USA.
authors: K E
authors: KE
authors: Burdick
authors: Departments of Psychiatry,Icahn School of Medicine at Mount Sinai,New York, NY,USA.
authors: M
authors: M
authors: Russo
authors: Departments of Psychiatry,Icahn School of Medicine at Mount Sinai,New York, NY,USA.
authors: S
authors: S
authors: Frangou
authors: Departments of Psychiatry,Icahn School of Medicine at Mount Sinai,New York, NY,USA.
authors: K
authors: K
authors: Mahon
authors: Zucker Hillside Hospital - North Shore Long Island Jewish Health System,Glen Oaks, NY,USA.
authors: R J
authors: RJ
authors: Braga
authors: Departments of Psychiatry,Icahn School of Medicine at Mount Sinai,New York, NY,USA.
authors: M
authors: M
authors: Shanahan
authors: Zucker Hillside Hospital - North Shore Long Island Jewish Health System,Glen Oaks, NY,USA.
authors: A K
authors: AK
authors: Malhotra
mesh_terms: D000328:Adult; D001714:Bipolar Disorder / Q000145:classification / Q000150:complications / Q000503:physiopathology*; D016000:Cluster Analysis; D003072:Cognition Disorders / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012938:Social Perception