title: Comparison of language impairment in late-onset depression and Alzheimer's disease.
abstract: OBJECTIVE
  Depression and dementia are highly prevalent in the elderly. Language impairment is an inherent component of Alzheimer's disease (AD), which can also be encountered in depressed patients. The aim of this study wasto compare the profiles of language abilities in late-onset depression and mild AD groups.
  
  
  METHODS
  We studied 25 patients with late-onset depression (mean age 73.6 ± 6.6 years; schooling 9.1 ± 5.7 years) and 30 patients with mild AD (77.6 ± 5.4 years; 7.5 ± 7.1 years) using the Arizona Battery for Communication Disorders of Dementia (ABCD), compared to a group of 30 controls (73.8 ± 5.8 years; 9.1 ± 5.4 years). Cut-off scores to discriminate between Controls × Depression and Depression × AD were determined.
  
  
  RESULTS
  Depressed patients' scores were similar to AD in confrontation naming, concept definition, following commands, repetition and reading comprehension (sentence). Episodic memory and mental status subtests were useful in differentiating depressed patients from AD, a result that was reproduced when using analysis of covariance to control for the effect of age in the same subtests (p = 0.01 and 0.04, respectively).
  
  
  CONCLUSIONS
  Language impairment resembling AD was found in the aforementioned language subtests of the ABCD in elderly depressed patients; the mental status and episodic memory subtests were useful to discriminate between AD and depression. The ABCD has proven to be a suitable tool for language evaluation in this population and should aid in the differentiation of AD and pseudodementia (as that of depression).
authors.affiliation: Behavioral and Cognitive Neurology Unit, Department of Neurology, University of São Paulo School of Medicine, São Paulo, Brazil.
authors.forename: Tânia M
authors.initials: TM
authors.lastname: da Silva Novaretti
authors.affiliation: Behavioral and Cognitive Neurology Unit, Department of Neurology, University of São Paulo School of Medicine, São Paulo, Brazil.
authors.forename: Maria I
authors.initials: MI
authors.lastname: D'Ávila Freitas
authors.affiliation: Behavioral and Cognitive Neurology Unit, Department of Neurology, University of São Paulo School of Medicine, São Paulo, Brazil.
authors.forename: Letícia L
authors.initials: LL
authors.lastname: Mansur
authors.affiliation: Behavioral and Cognitive Neurology Unit, Department of Neurology, University of São Paulo School of Medicine, São Paulo, Brazil.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Nitrini
authors.affiliation: Behavioral and Cognitive Neurology Unit, Department of Neurology, University of São Paulo School of Medicine, São Paulo, Brazil.
authors.forename: Marcia
authors.initials: M
authors.lastname: Radanovic