You can test blood level of serotonin. Unfortunately it has absolutely NO relationship to serotonin in brain, which is what you need to know. Levels of seotonin in brain and only be tested on autopsy.
Well i dont want to know my levels THAT bad..........ive read that doctors can make an educated guess on levels in brain, is this true?
Sorry for delay. Computer crashed.
The educated guess is usually based on depressive or anxiety symptoms. A PET scan can measure sugar metabolism (activity) in certain parts of brain, but it is not at point it can narrow it down that much. Used more for severe impaiments, really severe. I wouldn't mind having one of thse multimillion dollar machines to play with, but my computer barely works.