Noradrenergic function and the cortisol response to dexamethasone in depression.

Abnormalities of the hypothalamic-pituitary-adrenal (HPA) axis and the noradrenergic system have been reported in depression. To study possible interrelations between these two systems, plasma free 3-methoxy-4-hydroxyphenylglycol (MHPG) was compared with the cortisol response to dexamethasone in 64 depressed patients. Postdexamethasone cortisol nonsuppressors had higher baseline plasma free MHPG values than did cortisol suppressors. Increased severity of some depressive symptoms was associated with increased post-dexamethasone cortisol levels. These results indicate that depressed patients with dexamethasone nonsuppression have increased noradrenergic turnover.