I will get one done soon. It has taken 5 months or more since it was prescribed. I don´t expect anything useful from the study bearing in mind the experiences of people, but my parents would get mad if I didn´t this stupid and useless test. I know perfectly that I have sleep problems because of melatonin defficiency, HPA/CNS dysregulation, intestinal inflammation and who knows more. My melatonin defficiency showed up in tests and not surprisingly melatonin sublingual is the only supp that has made a dent in my insomnia. I only expect to sleep horrible, if I sleep some, and to have an awful day after the "study". Even if I managed to sleep through, they would only see that I wake up 4-6 times per night or more, but would be clueless of the cause. Oh Medicine, often you are not very upstanding. Oh yeah re melatonin and depression. It is confirmed in some studies and empirically by people that it does enhance depression. It does so for me, BUT sleeping shittier makes me wayyyy more depressed so I can handle it.