Figure 7. Percent change in SIGH-SAD score as a function of net change in absolute deviation toward and away from PAD 6 in PM melatonin treated advanced and delayed subjects. Pretreatment vs posttreatment shifts with respect to PAD 6 account for 35% of the variance. SAD, seasonal affective disorder; PAD, phase angle difference Adapted from ref 20: Lewy AJ, Lefler BJ, Emens JS, Bauer VK. The circadian basis of winter depression. Proc Natl Acad Sci U S A. 2006:103:74147419. Copyright © National Academy of Sciences 2006.
