Body temperature and diurnal type in women with seasonal affective disorder.

Body temperature rhythms and diurnal type were explored in female controls and women with seasonal affective disorder (SAD) before and after phototherapy. Women with SAD reported being more like evening types than did controls. Morning phototherapy advanced the body temperature rhythms of women with SAD, and shifted their morningness/eveningness scores toward the morning end of the continuum. The implications of these results for our understanding of both SAD and depression in women are discussed.