these kinds of tests are not done by a pdoc (psychiatrist), they are medical tests which medical doctors (physicians or as some people call them Primary Care Physician (PCP) order.

my suggestion is next time you go to your physician ask to see their paper containing all the different blood tests and labs that they can order and have them explain what each one is. each grouping (Panel) on the paper tests for different things like how much sugar is in the body, iron is in the body zinc, lead, electroliytes, carbon, nitrogen, carbon dioxide, bun, chloride, creatine, sodium, dopamine, bilirubin, phosphates, amino acids, seratonin, all kinds of vitamin and minerals tests and more. they can also explain which tests on the panels are spit tests, urine tests, blood, they can even tell you what your number of red and white blood cells in your body are and what these cells chemical make up are, shape and so on. its amazing the strides america has made in the medical field and technology machines can now do thanks to the digital era. by the way on the panels you will find seratonin listed as 5-hydroxytryptamine level (5-HT)

my own dopamine level thanks to my medications is 185.6pmol/l and my seratonin level is 120 ng/ml