Don't have a link but I'll describe it as best I can. The article cropped up in a copy of Scientific American about 6-8 months ago (yes, I'm that far behind). The article described how recent studies have seemed to indicate that a lot of the dementia related problems associated with things like Alzheimers and other neurodegenerative diseases could actually be made far worse by fucked up sleep rhythms. Apparently, they did a study that looked at the sleep patterns of such patients and found they were way out of whack compared to normal. The patients would be up in the wee hours of the morning and sound asleep in the afternoon, sometimes even randomly so. With a combination of light therapy (full spectrum lamps) and injections they managed to restore the people's sleep patterns and seemingly improve their mental health slightly. One of the more interesting things was that they visited a good number of old age homes and found that light levels were much lower than an average family's living room, even during the early evening hours. The article assumed that the motivation was cost of electricity which could very well be the case. With 40-50 residents and all that lighting you could certainly save a good bit by switching to lower lux value lighting.