Plasma dopamine and norepinephrine correlations with psychomotor retardation, anxiety, and depression in non-psychotic depressed patients: a pilot study.

The relationship of plasma catecholamine levels to severity of depression and psychomotor retardation was examined in 12 male inpatients who met criteria for major depressive episode. Psychomotor retardation was measured with the Psychomotor Retardation Rating Scale (PRRS), and depression was assessed with the Hamilton Rating Scale for Depression (HRSD). Blood samples for biochemical measurements were obtained from drug-free patients at approximately 09:00 h. Plasma dopamine (DA) levels correlated significantly with the HRSD total score and the anxiety subscale score. Plasma norepinephrine (NE) levels demonstrated a trend toward a negative correlation with the HRSD total score. Neither plasma DA nor NE levels showed a significant correlation with either the global PRRS score or the cognitive or motor subscale score. HRSD scores failed to correlate with the PRRS scores.