Actigraphy has been used to measure the effects of various depressive disorders on sleep3, circadian patterns2 and daytime activity patterns4, 5, 7. Although the association of circadian disorders with bipolar disorder has been well documented2, more recent literature has discussed the use of sophisticated signal processing tools to show alterations in motion patterns with depression. For example, Zeitzer used functional principal component analysis of 24-hr activity patterns to differentiate among patients with Azheimer’s disease who were apathetic versus those who were not7 .
Ding used similar techniques to discriminate among subjects who were healthy, mildly depressed and severely depressed1. Krane-Gartiser used signal processing endpoints on 65 min activity samples to show that actigraphy can be used to quantify depressive moods5.
A recent review article concludes that new analytical methods for analyzing motion data will aid in application to neurological or psychopathic disorders6.