I was told my son produces too much dopamine. is there a way to test this? what are the symptoms of that?

How was this figured: I think there may be a miscommunication between you and the doctor. Although there are diseases with too little dopamine, i.e. Parkinson disease, I have never heard of a condition where we say there is too much dopamine. Certainly this isn't something that could be measured. I suppose theoretically there could be hallucinations or impulsiveness.