Hello! Please remember that my response is for information only, we are not establishing a therapeutic relationship.
If the current psychiatrist does not or will not clearly explain to your son what his diagnosis(es) are, then consulting another professional is a good idea. You might want to consider a Psychologist for more comprehensive testing (Psychologists in addition to a clinical interview will also give written psychological tests that could help rule in or rule out Bipolar).
If your son does have Bipolar, then medication is necessary, however, perhaps a Psychiatrist who can help address the "dopey" issue is in order.
Please follow up with me if you would like.
You are welcome --and you're right, it doesn't make sense to move forward with a treatment plan if you don't have a good diagnosis. I hope that you find someone that works well with your son so that you can move forward with confidence.
Thank you for your accept and take good care.