Impaired verb fluency: a sign of mild cognitive impairment.

We assessed verb fluency vs. noun and letter-based fluency in 199 subjects referred for cognitive complaints including Subjective Cognitive Impairment, Mild Cognitive Impairment, and Alzheimer's disease. ANCOVAs and factor analyses identified verb, noun, and letter-based fluency as distinct tasks. Verb fluency performance in Mild Cognitive Impairment differed significantly from Subjective Cognitive Impairment and Alzheimer's disease. Reduced verb fluency thus appears to be a linguistic marker for incipient dementia. One possibility is that the verb fluency deficit in Mild Cognitive Impairment results from degenerative processes known to occur in the parahippocampal region.