Which kind of doctor should i see if i want my son 19 years to be tested for add?

Psychiatrist/neuro: I have great reluctance to accept the ADD label for anyone who did not have it as a kid. There are a great number of other issues of health/sleep/ nutrition that have some overlapping symptoms. If you want accurate testing/diagnosis find those with the most skill, rather than a doc who would just hand out the pill for the asking.