I've seen studies where college students were shown a series of images. The sleep deprived students were more likely to recall the negative images. Focusing on

I've seen studies where college students were shown a series of images. The sleep deprived students were more likely to recall the negative images. Focusing on the negative appears to be a hallmark of depression. However, a depressed person can't seem to get enough sleep. Is it a snowball effect? Maybe the balance isn't about sleep deprivation, but finding the correct amount of sleep, waking to bright light, and keeping a consistent schedule.