If you mean is there a blood test for brain chemicals, there isn't...
Your reg Bloods from the GP show a lot, for instance thyroid and Vit D levels. Things that they can treat. Also some people take Lithium, which requires a certain blood level to be effective, depends on how your body uses it.
GPs will prescribe anti-anxiety, anti-depressant meds, but then if they think you need further evaluation will refer you to a psychiatrist.
Then the trial and error begin, but have hope. Sometimes you hit a winner first time out.
Be patient.
Good luck,
Post Edited (Trying to Understand) : 10/30/2010 11:30:35 AM (GMT-6)