Diagnostic utility of autonomic measures for major depressive disorders.

The diagnostic utility (sensitivity, specificity, and overall efficiency) of autonomic nervous system measures in distinguishing hospitalized patients with unipolar depression from age-matched normal controls is reported. Tonic resting skin conductance level (SCL), tonic resting heart rate level (HRL), and the phasic skin conductance and heart rate responses (SCRs and HRRs) to task-related stimuli were used. The overall efficiency of SCL of 70% was generally consistent with previous research. The other measures yielded greater efficiency: 80% for SCR, 90% for HRL, and 83% for HRR. The possible role of autonomic measures in the diagnosis of major depressive episodes is discussed.