Serotonergic dysfunction across the eating disorders: relationship to eating behaviour, purging behaviour, nutritional status and general psychopathology

Background. Several recent studies have pointed to a dysfunction of seroton in transmission in patients with eating disorders. Notwithstanding, it is n ot known whether serotonergic abnormalities are related primarily to eating and/or purging behaviour, nutritional status or general psychopathological dimensions. Therefore, by using a validated neuroendocrine strategy, we in vestigated central serotonergic function in patients with anorexia nervosa, bulimia nervosa or binge-eating disorder who differ on the above parameter s. Methods. Plasma prolactin response to D-fenfluramine (30 mg p.o.) or placeb o was measured in 58 drug-free female volunteers, comprising 15 underweight anorexic women, 18 bulimic women, 10 women with binge-eating disorder and 15 female healthy controls. Behavioural assessment included ratings of eati ng disorder symptoms, depression, aggression and food-related obsessions an d compulsions. Results. A significantly decreased prolactin response to D-fenfluramine was found in underweight anorexic women and in bulimics with high frequency bi ngeing(greater than or equal to 2 binge episodes/day), but not in patients with binge-eating disorder or in bulimics with low frequency bingeing (less than or equal to 1 binge episode/day). In the whole bulimic group, a negat ive correlation emerged between frequency of bingeing and prolactin respons e. No significant correlation was found between physical or psychopathologi cal measures and the hormonal response in any group. Conclusions. These results confirm our previous findings of an impaired ser otonergic transmission in underweight anorexics and in bulimics with high f requency bingeing, but not in patients with less severe bulimia nervosa. Mo reover, they show, for the first time, that the hypothalamic serotonergic s ystem is not altered in women with binge-eating disorder.