> “Sleep deprivation really has opposite effects in healthy people and those with depression,” says Benedetti. If you’re healthy and you don’t sleep, you’ll feel in a bad mood. But if you’re depressed, it can prompt an immediate improvement in mood, and in cognitive abilities. But, Benedetti adds, there’s a catch: once you go to sleep and catch up on those missed hours of sleep, you’ll have a 95 per cent chance of relapse.

This is really counter intuitive to me. The article goes on explaining that using a combination of skipping sleep, lithium and light treatment the results are much better.