Do you have references to read re: sleep deprivation decreasing serotonin?
RP mentioned it in a newsletter "Thought and Energy, Mood and Metabolism", he said oversleeping raises serotonin and undersleeping raises adrenaline. He also says oversleeping causes blood sugar to fall and undersleeping raises it. So sleep deprivation is an effective way to get out of depression/learned helplessness in the short-term until you can figure out what to do to get your thyroid working.