Psychotic and nonpsychotic depressions: I. Comparison of plasma catecholamines and cortisol measures.

Unconjugated plasma catecholamines and cortisol were measured before and after a 1 mg dose of dexamethasone in 22 medication-free depressed patients and 6 healthy, medication-free control subjects. Plasma dopamine (DA) levels in the psychotically depressed subgroup (n = 4) were significantly higher both before and after dexamethasone than those in the nonpsychotic depressed group and higher before dexamethasone than in the control group. Similarly, the psychotically depressed group exhibited significantly higher cortisol levels both before and after dexamethasone than the nonpsychotic depressed group or the control group. In contrast, the psychotically depressed group had significantly lower postdexamethasone plasma norepinephrine levels compared to the nonpsychotic depressed group. In both patients and controls, plasma DA was significantly higher after dexamethasone administration than before, but the magnitude of the increase was 10 times greater in controls than in patients.