Mirtazapine inhibits salivary cortisol concentrations in anorexia nervosa

The antidepressant mirtazapine has been demonstrated to acutely inhibit cortisol concentrations in healthy subjects and depressed patients. Since both depressed and anorectic patients are characterized by hyperactivity of the hypothalamo-pituitary-adrenocortical (HPA) system, the clinical usefulness and the endocrinological effects of mirtazapine were investigated in anorexia nervosa (AN). Five female patients suffering from AN restricting subtype (DSM-IV criteria) were admitted to a closed ward and treated with mirtazapine for three weeks receiving 15 mg mirtazapine on day 0; 30 mg mirtazapine on day 1; and 45 mg mirtazapine per day from day 2 up to the end of the study (day 21). Besides weekly determination of clinical parameters (Body Mass Index [BMI], Hamilton Depression Rating Scale [21-HAMD]), salivary cortisol concentrations were measured before treatment (day - 1), at the beginning of treatment (day 0), after 1 week (day 7), and after 3 weeks (day 21) of treatment with mirtazapine. Saliva samples were collected hourly from 0800 up to 1,400 h. Repeated-measures ANOVA revealed a significant inhibition of salivary cortisol levels during 3-week treatment with mirtazapine (p<0.05) which became obvious already after the first mirtazapine administration (day 0). Moreover, a trend for an increase in BMI was seen (p=0.063), whereas no significant changes in 21-HAMD sum scores could be demonstrated. Double-blind, placebo-controlled studies are needed to clarify the question whether the observed changes in BMI are related to the mirtazapine-induced attenuation of HPA axis activity or whether they are due to monitoring of food intake and purgative behaviour on the closed ward.