Simultaneous monitoring of activity and heart rate variability in depressed patients: A pilot study using a wearable monitor for 3 consecutive days.

We obtained evidence for reduced activity, increased lying/resting time, and reduced HRV indices in male depressed patients. The simultaneous monitoring for activity and HRV suggested greater sympathetic load during sleep is associated with damped rest-activity rhythm (increased activity during sleep and decreased daytime activity), which might be a characteristic pathology of depression.