Are affective disorders associated with alterations of heart rate variability?

A standardized heart rate analysis was carried out in unmedicated patients with major depression, melancholic type (n = 16), panic disorder (n = 16), reactive depression with suicide attempts during the preceding 24 h (n = 16) and in 16 normal control subjects. The investigations included time- and frequency-derived measurements of heart rate variability. In the patients with reactive depression, no differences could be detected as compared with the control group. The patients with panic disorder showed a significantly increased low-frequency band of spectral analysis (P < 0.01) and a marginally significant increment of heart rate (P = 0.05), probably indicating predominance of sympathetic control of heart rate. In the patients with major depression, we found significantly lower values of heart's beat-to-beat intervals and of the high-frequency peak of spectral analysis than in the other groups (P < 0.025), indicating decreased parasympathetic activity.