The augmented platelet intracellular calcium response to serotonin in anorexia nervosa but not bulimia may be due to subsyndromal depression

OBJECTIVE: Serotonergic dysregulation is associated with both bulimia and anorexia nervosa. This study attempted to measure the levels of basal and serotonin-stimulated intracellular calcium in patients with bulimia and anorexia Nervosa. METHOD: In this study, basal levels of platelet intracellular calcium as well as the effects of serotonin on intracellular calcium were studied using the Fura-2 method in subjects with bulimia (N = 11), anorexia nervosa (N = 12), and in matched normal controls (N = 17). Depressed patients, defined as meeting DSM-IV criteria for major depression or having a Hamilton Depression Scale score over 16 were excluded from the study. RESULTS: An enhanced serotonin-mediated mobilization of intracellular calcium was found in anorexia compared to both bulimics and controls at serotonin concentrations of 100 nM (p < .002), 500 nM (p < .001), and 1 microM (p < .001, ANOVA), respectively. However, when the anorexic group was subdivided into high and low Hamilton Depression scale groups, only the high Hamilton group demonstrated an augmented intracellular response to serotonin, with the low Hamilton group not differing from controls. DISCUSSION: These results suggest that the augmented intracellular calcium response to serotonin in anorexia may be due to subsyndromal depression in that group rather than to a primary eating disorder.