Corticotropin-releasing factor and adrenal function in major depression

Area of Science:

• Neuroendocrinology
• Psychiatry
• Hormone research

Background:

• Major depression is associated with dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis.
• Previous studies suggest altered responses to corticotropin-releasing hormone (CRH) in depression.

Purpose of the Study:

• To investigate the ACTH and cortisol responses to ovine CRF (oCRF) in patients with major depression.
• To compare these responses with those of healthy controls.

Main Methods:

• Administered a single bolus of 1 microgram/kg ovine CRF to 11 drug-free major depression patients and controls.
• Measured adrenocorticotropic hormone (ACTH) and cortisol levels before and after oCRF injection.
• Compared basal and stimulated hormone levels between depressed patients and controls.

Main Results:

• Depressed patients had significantly higher basal ACTH and cortisol levels compared to controls.
• ACTH response to oCRF was blunted in depressed patients (p < 0.23).
• Cortisol response to oCRF was significantly higher in depressed patients (p < 0.001).

Conclusions:

• The pituitary feedback mechanism appears intact in major depression.
• Evidence suggests adrenal cortex hyperresponsiveness to stimuli in depressed individuals.
• Hypersecretion of endogenous CRF is likely in patients with major depression.