Estrogen could control photoperiodic adjustment in seasonal affective disorder

Women are affected by winter seasonal affective disorder (SAD) more often than men. The female/male ratio is reported to range from 2:1 to 40:1 in samples of patients with winter SAD. It is suggested that this preponderance of women is based on the action of the ovarian steroid hormones estrogen and progesterone. However, the detailed mechanisms of action are not well understood to date. A new hypothesis claims that, in women with winter SAD, decreased levels of estradiol in the ventromedial hypothalamus are associated with the occurrence of atypical symptoms of depression, including increased daytime sleepiness and hypersomnia during the winter.