Using verbal fluency to detect very mild dementia of the Alzheimer type

The study sample included 76 healthy older adults and 77 individuals with very mild dementia of the Alzheimer type (DAT). Semantic (animal) and letter (S and P) fluency tasks were used to examine quantitative (word generation) and qualitative (category clustering and switching) aspects of verbal fluency. The goal of the study was to evaluate the utility of fluency tasks in discriminating between healthy aging and very mild DAT. Our results indicated better performance for the healthy group than the DAT group in terms of number of words, number of clusters, number of switches, and size of clusters generated (an exception was clustering on letter S fluency). Clustering and switching variables were significantly correlated with number of words generated and therefore were not included in discriminant analysis. Discriminant analysis revealed that the combination of semantic fluency and narrative recall may be particularly useful in differentiating healthy aging from very mild DAT.