Prolonged psychological stress suppresses cortisol secretion

Response to acute psychological stress is characterized by activation of the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic nervous system. However, response to the prolonged psychological stress is less well known.

This study was designed as a prospective assessment of cortisol secretion during prolonged psychological stress induced by continuous air raids and after elimination of the stress-inducing factor.

The study group consisted of five healthy subjects (34-39 years).

Psychological and endocrine (morning cortisol and 1 microg ACTH test) testing was done 2 months after the war had begun and 18 months after the end of it. Psychiatric assessment was done at the same periods, and 30 months after the start of the study.

After 2.5 years of follow-up, there were no signs of endocrine or psychiatric disorders in any of the subjects. After the war, Beck Inventory of Depression and Hamilton Anxiety Rating Scale scores were significantly reduced. Suppression of the HPA axis was present during the war but not after.

Prolonged psychological stress is associated with a transient suppression of the HPA axis, manifested by low morning cortisol and reduced cortisol response to ACTH. The reduction of cortisol response is sufficient to cause false diagnosis of HPA insufficiency.