--in the New York Times Tuesday Science Times section today, there is a nice little summary article about Seasonal Affective Disorder, once thought to be a "made-up" illness and now thought to affect a substantial percentage of people, especially at higher latitudes:

http://www.nytimes.com/2007/12/18/he...ce&oref=slogin

BTW--this was a particularly good Science Times week; in addition to that article there's one on ancient tuberculosis infections in hominids linking them to lower Vitamin D level/absorption at higher latitudes among people with darker skin (evolutionarily, light skin pigment as an adaptation to living at higher latitudes happened pretty late in the game), an article about a health insurance advocate for the elderly, and some good stuff on smart machines and cosmology. Take a look at them all from:

http://www.nytimes.com/pages/science/index.html