My experience started years ago when I didn't sleep for 4 days in a row during a very depressive episode and body becomes dependent, no longer functions in sleep mode, plus I believe it affects memory and depression. I do not get tired and trying to taper off with 3 mg of Melatonin along with Indica a form of medical marijuana. Please be aware that high doses of Melatonin caused me to have vivid nightmares. Good luck.