title: The trajectory of neuropsychological dysfunctions in bipolar disorders: a critical examination of a hypothesis.
abstract: OBJECTIVE
  The hypothesis of a progressive nature of neuropsychological deficits in bipolar disorders is often accepted as an axiom by many clinicians and researchers in the field. However, contradictory pieces of data and a number of methodological concerns put it under debate.
  
  
  METHODS
  We reviewed findings from three different approaches to the study of the trajectory of cognitive features in bipolar disorders: longitudinal evaluation of cognition in affected subjects, cross-sectional neuropsychological assessment of patients belonging to different age groups, and exploration of the risk of dementia in bipolar subjects.
  
  
  RESULTS
  An increased risk of developing dementia was found in bipolar subjects. However, evidence from cross-sectional studies did not show more severe cognitive deficits in patients with longer illness duration. Furthermore, longitudinal studies revealed that bipolar subjects׳ cognitive performance did not change between different points in time.
  
  
  CONCLUSIONS
  After a thorough discussion of these findings and the limitations of the different approaches, we argue that, at present, there is no consistent evidence supporting that bipolar disorders, as a group, have a progressively deteriorating course of cognitive functions. Furthermore, we highlight the possible influence of psychotropic agents and metabolic factors on neuropsychological outcomes. Finally, we discuss the clinical implications of these findings and propose targets for forthcoming research.
authors: Bipolar Disorders Program, Institute of Neurosciences, Favaloro University, Buenos Aires, Argentina; Institute of Cognitive Neurology (INECO), Buenos Aires, Argentina. Electronic address: sstrejilevich@ffavaloro.org.
authors: Sergio A
authors: SA
authors: Strejilevich
authors: Bipolar Disorders Program, Institute of Neurosciences, Favaloro University, Buenos Aires, Argentina; National Scientific and Technical Research Council (CONICET), Buenos Aires, Argentina.
authors: Cecilia
authors: C
authors: Samamé
authors: Bipolar Disorders Program, Institute of Neurosciences, Favaloro University, Buenos Aires, Argentina; National Scientific and Technical Research Council (CONICET), Buenos Aires, Argentina.
authors: Diego J
authors: DJ
authors: Martino
mesh_terms: D000368:Aged; D001714:Bipolar Disorder / Q000503:physiopathology* / Q000523:psychology*; D003071:Cognition; D060825:Cognitive Dysfunction / Q000523:psychology*; D003430:Cross-Sectional Studies; D003704:Dementia / Q000453:epidemiology / Q000523:psychology; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D012307:Risk Factors
keywords: Bipolar disorder; Cognition; Neuroprogression; Staging; Temporal evolution