Verbal fluency in anorexia nervosa.

Verbal fluency performance is commonly evaluated in clinical neuropsychology, in particular for assessment of executive functioning. Fluency is usually assessed by the person's ability to produce as many words as possible from a given cue within a specific timeframe. The cues are typically phonemic, e.g. words beginning with a specific letter, or semantic, e.g. words within a given category. Important components underlying fluency performance include clustering (the production of words within subcategories) and switching (the switch between clusters). Previous studies have demonstrated good performance on verbal fluency tasks in patients with anorexia nervosa (AN), but have not investigated the underlying components of this performance. The aim of the present study was to compare phonemic fluency performance in patients with AN to healthy controls (HC) and to investigate the use of clustering and switching in the two groups. Fifty-two patients with AN were compared with 37 HC on a phonemic fluency task. The patient group produced more words in total but the results were not significantly different compared to the HC sample. There were no differences between the two groups with regard to clustering, but patients with AN performed significantly more switches. In addition, switching was significantly more related to total output score in the patient sample. In contrast with previous studies of other areas of cognitive flexibility in AN, patients with AN appear to have good verbal set-shifting skills.