Serotonergic responsivity in eating disorders

Evidence suggests that serotonin may play a role in the pathogenesis of eating disorders. In this ongoing study, serotonin-mediated physiological responses and whole-blood serotonin content are measured in young women with an eating disorder during the active phase of the illness and at the conclusion of inpatient treatment. The responsivity of central nervous system (CNS) serotonergic pathways is assessed by neuroendocrine challenge with a 60-mg oral dose of dl-fenfluramine, an indirect serotonin agonist, whereas the responsivity of the platelet serotonin2 (5-HT2) receptor complex is evaluated by measurement of the magnitude of serotonin-amplified platelet aggregation. Compared with normal controls, eating-disorder patients have exhibited a trend toward reduced prolactin responses to fenfluramine challenge at both the initial and followup assessments. Patients also have exhibited a substantially wider range of serotonin-amplified platelet aggregation responses than have controls; normal-weight bulimic patients have had significantly greater responses than both anorexic restrictors and normal subjects. These preliminary results suggest potential alterations in serotonin-mediated responses in eating-disorder patients that may vary with the diagnostic subgroup.