question: Dear Doctor, I have a problem of sleeping at a scheduled time. I always sleep in a different time and it is getting delayed every day, like a cycle. For example: If today I sleep at 9:00 pm, in few days I will be sleeping at 10:00 pm. And in a few weeks, I would sleep at 4:00 AM. I also have depression and different forms of anxieties.I did a blood test for sertonin in blood. The result was 65.0 ng/mL. Normal range is 151-186. Does this test have anything to do with my anxiety and sleeping problem? What should I do about it? Age:29 years, Gender: male, Height:178cm, Weight:60kg, Medications: I take only 1 multivitamin every day.