title: Greater impairment of ability in the divided attention task is seen in Alzheimer's disease patients with depression than in those without depression.
abstract: BACKGROUND
  Recent studies have emphasized specific deficits of attention and executive functions, such as those of cognitive flexibility, divided attention, in geriatric patients with depression. In Alzheimer's disease (AD), depressive symptoms are known to occur even from an early stage of the disease. However, the nature of the impairment of executive functions in depression associated with AD remains unclear, because of the frequent occurrence of the apathy syndrome as a major confounding factor.
  
  
  METHODS
  In this study, we conducted a comprehensive comparative neuropsychological assessment in AD patients with (n=21) and without (n=21) depression. The diagnosis of depression was based on provisional criteria proposed by Olin's group.
  
  
  RESULTS
  In terms of apathy symptoms, both groups had a similar degree of deficits, which were mild as assessed according to Neuropsychiatric Inventory criteria. While no significant differences were observed in regard to the scores in general intellectual functioning, episodic memory and some attention and executive tasks between the two groups, AD patients with depression showed significantly lower scores in several attention and executive function tasks, such as the dual-task performance task administered to assess the capacity for divided attention, and the cognitive flexibility (Trail Making Test; Part B), than AD patients without depression.
  
  
  CONCLUSIONS
  Our results suggest that depressive symptoms in AD patients increase the deficits of cognitive flexibility and divided attention. This is the first study to report a correlation between depressions, diagnosed based on the provisional criteria for depression in AD by Olin's group, and an impaired capacity for divided attention in AD patients.
authors.affiliation: Department of Psychiatry and Cognitive-Behavioral Medicine, Nagoya City University Graduate School of Medical Sciences, and Yagoto Hospital, Nagoya, Japan. hzi05510@nifty.com
authors.forename: Shutaro
authors.initials: S
authors.lastname: Nakaaki
authors.forename: Yoshie
authors.initials: Y
authors.lastname: Murata
authors.forename: Junko
authors.initials: J
authors.lastname: Sato
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Shinagawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tatsumi
authors.forename: Nobutsugu
authors.initials: N
authors.lastname: Hirono
authors.forename: Toshiaki A
authors.initials: TA
authors.lastname: Furukawa
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000150:complications* / Q000503:physiopathology / Q000523:psychology; D000704:Analysis of Variance; D001288:Attention; D003072:Cognition Disorders / Q000150:complications* / Q000503:physiopathology / Q000523:psychology; D003863:Depression / Q000150:complications* / Q000503:physiopathology; D005260:Female; D005364:Field Dependence-Independence; D006801:Humans; D008297:Male; D016555:Matched-Pair Analysis; D009483:Neuropsychological Tests