HPA axis activation determined by the CRH challenge test in patients with few versus multiple episodes of treatment-refractory depression

Objective in clinical guidelines, risk factors for a malignant illness course include 3 or more lifetime episodes of depression. Our aim was to investigate the activation of the hypothalamic-pituitary-adrenal hormonal axis in treatment-refractory affective disorder in pauciepisodic (one or two episodes) versus multi-episodic (three or more episodes) patients. Methods We evaluated the HPA axis in 37 patients with treatment-refractory affective disorder and in 27 healthy volunteers by measuring adrenocorticotropin hormone (ACTH) and cortisol responses following administration of corticotropin-releasing hormone (CRH). In retrospective life charts was recorded every previous illness episode for each patient. Results Seven of the patients were pauciepisodic and 30 were multiepisodic. The pauciepisodic patients had significantly larger peak and total ACTH responses to CRH compared to the multiepisodic patients as well as to the control group. Multiepisodic patients showed no difference compared to controls in ACTH secretion pre- and post-CRH. Cortisol secretion was the same in all three groups. Conclusions The pituitary adrenocortical responses were stronger in pauciepisodic patients than in multiepisodic patients and in volunteers. This cross-sectional study suggests that the HPA axis, in refractory multiepisodic affective disorders, might weaken its original activity as the illness recurs with more episodes.