title: Utility of the Neurobehavioral Cognitive Status Examination (COGNISTAT) in differentiating between depressive states in late-life depression and late-onset Alzheimer's disease: a preliminary study.
abstract: BACKGROUND
  It is often difficult to differentiate between the depressive states seen in late-life depression and late-onset Alzheimer' disease (AD) in the clinical setting.
  
  
  METHODS
  Thirty-four outpatients were recruited, all fulfilling the criteria of aged 65 years or above, scores of 14 or more on the Hamilton depression rating scale (HAM-D), and 26 or less on the Mini-Mental State Examination (MMSE). At the initial visit, they were administered the Neurobehavioral Cognitive Status Examination (COGNISTAT). At 1 month, a diagnosis of either senile depression (n = 24) or Alzheimer' disease (n = 10) was made.
  
  
  RESULTS
  The COGNISTAT revealed that the late-life depression group showed significantly higher scores in orientation and comprehension subtests compared with the AD group. At the study endpoint (6 months after treatment), MMSE detected significant improvements in the late-life depression group (n = 15), but no changes in the late-onset AD group (n = 7). Scores for memory, similarities, and judgment on the second COGNISTAT were significantly improved in the depressed group, whereas calculation scores deteriorated significantly in the AD group.
  
  
  CONCLUSIONS
  The COGNISTAT could prove useful in differentiating late-life depression from late-onset AD, despite similar scores on MMSE.
authors.affiliation: Department of Psychiatry, Teikyo University Chiba Medical Center, 3426-3 Anesaki, Ichihara, 299-0111 Japan ; Shirayurikai Otaki Hospital, 786 Uehara, Otaki, 298-0223 Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Tsuruoka
authors.affiliation: Department of Psychiatry, Teikyo University Chiba Medical Center, 3426-3 Anesaki, Ichihara, 299-0111 Japan.
authors.forename: Michio
authors.initials: M
authors.lastname: Takahashi
authors.affiliation: Department of Psychiatry, Teikyo University Chiba Medical Center, 3426-3 Anesaki, Ichihara, 299-0111 Japan.
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: Department of Psychiatry, Teikyo University Chiba Medical Center, 3426-3 Anesaki, Ichihara, 299-0111 Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Sato
authors.affiliation: Department of Psychiatry, Teikyo University Chiba Medical Center, 3426-3 Anesaki, Ichihara, 299-0111 Japan.
authors.forename: Yukihiko
authors.initials: Y
authors.lastname: Shirayama
keywords: Alzheimer’s disease; COGNISTAT; Cognition; HAM-D; Late-life depression; MMSE