Serum cortisol concentration in patients with major depression after treatment with clomipramine

Hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis and elevated cortisol (CORT) levels are characteristics of the pathophysiology of major depressive disorder. The aim of this study was to determine whether increased plasma CORT levels appear in patients with major depression and if effective antidepressant treatment by clomipramine (CLO) leads to regulation of CORT level. Plasma CORT levels were measured using high performance liquid chromatography (HPLC) methods in patients with major depression at time zero (before therapy) and after 3 h, 24 h, 4, 6 and 8 weeks of CLO administration. The study included 17 patients (12 women, 5 men; mean age 54.5 years, SD=12.3) and 21 healthy comparison subjects. The patients had a mean score on the 21-item Hamilton Depression Rating Scale (HDRS) of 26.8 (range 22-35). Eight of the patients with major depression recruited for the study showed a 46% increase in CORT concentration compared to the established standard. In 13 patients treated with CLO, serum CLO levels reached a therapeutic range. In recovered depressed patients, antidepressant treatment significantly reduced HDRS scores from the 6th week of treatment. A drop in plasma CORT levels in recovered depressed subjects occurred 0 to 6 weeks after CLO treatment (n = 5, p < 0.046). However, neither subject group exhibited any definitive markers of CORT secretion. In the population studied, patients had distinct profiles of HPA axis dysregulation. Finding a linear correlation between lower CORT secretion and therapeutic plasma CLO levels is the first aim of monitored therapy and may be important for understanding the pathophysiology of major depressive disorder.