Olfactory performance of patients with anorexia nervosa and healthy subjects in hunger and satiety.

The aim of this study was to compare the olfactory performance of anorectic patients and healthy controls with regard to the state of satiety. Using the Sniffin' Sticks, sensitivity to a non-food odor (n-butanol) and to a food-related odor (isoamyl acetate) was assessed in 12 anorectic females and compared with 24 healthy controls. Threshold tests were performed in a hungry as well as in a satiated state, odor discrimination and odor identification only when satiated. Pleasantness of the odors was recorded. In terms of the non-food odor n-butanol, the olfactory sensitivity of anorectic patients and controls did not differ. Patients with anorexia nervosa had a significantly lower detection threshold for the food-related odor, but only in the hungry condition. Anorectic patients showed significant deficits in odor discrimination and identification, and under-evaluated the pleasantness of isoamyl acetate. Our results suggest an impaired projection from secondary to tertiary olfactory structures in anorexia nervosa, based upon the dichotomy of performance between detection threshold and odor discrimination/identification. The reduced pleasantness of isoamyl acetate indicates a decreased olfactory responsiveness to food stimuli in anorexia nervosa.