PhotoperiodEffect.com

19. If extra light makes me feel good, won't less artificial light make me feel awful? I'm grumpy enough as it is. Plus, I've heard staying up can be a treatment for depression.

Actually you'll feel better without the extra light soon enough. The key here is to distinguish between short term effects happening this moment and longer term effects – and in this case the long term may be as short as next day (although, granted, some of the worst long term effects of “light abuse” build up over years. In other words, you may indeed find that for a few days at least, if you plunge yourself into a completely natural night, you're antsy during the night, or the first part of the night. But even the very next morning, your mood will be improved, not worse. This is because, amongst other things, the feel-good neurotransmitter serotonin is made at night in darkness. It's effect is masked by melatonin during darkness, so you'll only feel it's good effects when your day begins, but you can wait that long. If you're afraid you'll be restless at night in the dark, you can be more gradual about adapting yourself for darkness. Say, making your nights truly dark and at consistent times first, and then slowly lengthening your period of darkness. It take three weeks to establish most habits; you'll be happy enough in the dark after that time. After three weeks of true, long dark nights your mood and energy will be very noticeably improved. “Sleep hygiene” is now the number-one recommendation for people who are suffering from depression or bipolar illness.

Moreover, it's proverbial that poor people in third world nations appear (and in studies report themselves as being) much happier than the far richer inhabitants of modern industrialized nations. It may also be that their melatonin levels do not drop as they age, as happens to those of us in industrial countries. So you've every reason to expect that more darkness will make you, and keep you, happier – not grumpier.