The light therapy discussed in an article linked below is for anyone who needs additional help with sleep when the cause is applicable, but is especially good for any who have bipolar disorder. Avoiding blue light in the evening is important, and wearing amber glasses, after 8 PM, that you can get inexpensively from welding supply stores can solve that problem. They are highly stylish.
The appropriate amounts of light and darkness in our lives cause chemical reactions in our brain that allow normal sleep and waking. A central chemical naturally in this reaction chain is lithium. Making some changes that allow light and darkness to do the job naturally can affect the need for lithium in some- perhaps needing none at all.
I'm not trying to change your whole life or anything; I don't know your circumstances. I'm just writing this for anyone who cares.
Getting light in your eyes in the morning causes you to make melatonin on your own. Also, light at night causes melatonin to decrease in your body.
Modern life with lightbulbs and tv and computers that keep us up later also put light into our eyes and brains when we need quality darkness. If we must be typing at the computer at night, the amber glasses help us to filter out the blue light, from it and other sources, that is supposed to go away with sundown.
BTW; I edited my first post on this thread, if you are interested in reading it over.