The DSM does not list any tests that can be run to test for ADD, you cannot draw blood or look at someone's brain under a MRI and say, yep, there it is.
And it doesn't for Bi-Polar either...but yet this is a common concern for ones that have it and is quite known and recognized.
http://www.webmd.com/bipolar-disorder/tc/bipolar-disorder-exams-and-tests
There are no lab tests for bipolar disorder. Instead, your doctor will ask detailed questions about your symptoms, including how long they last and how often you have them. He or she will discuss your family history and may do a mental health assessment.
A mental health assessment tests your emotional functioning and your ability to think, reason, and remember. It includes an interview with a health professional, a physical exam, and written or verbal tests. During the interview, the health professional assesses your appearance, mood, behavior, thinking, reasoning, memory, ability to express yourself, and ability to maintain personal relationships.