MAKING THE RIGHT DIAGNOSIS I: DEALING WITH UNCERTAINITY

Obviously starting with the correct diagnosis is critical for our medical-problem solving system to work. If I think you have a strep throat but you really have diabetes, we are both in a lot of trouble. Doctors understand here is always some degree of uncertainty in every patient. The only physician who knows the diagnosis without a doubt is the pathologist at the autopsy—absolutely sure about everything but way too late to help. In real life we need to come up with a way to reduce the uncertainty of the diagnosis of ADHD and school problems right now.

Physicians use evidence from the history, physical and lab test to build a case for the most likely diagnosis. If you say that your throat hurts, your tonsils are big and red, and your throat culture is positive, the probability that you have a strep throat is high. You will be given a prescription for penicillin with instructions to call back tomorrow to check for improvement or side effects. Our working diagnosis is like a three-legged stool that securely rests on history, physical and lab results. The problem with behavioral diagnoses such as ADHD is that there are no positive physical findings or test. There should be because we know that ADHD is more strongly inherited even than height. Research evidence is accumulating towards specific ADHD genetic patterns, MRI findings and neurotransmitter brain levels that someday will help us nail the diagnosis—but not yet.

Before we give up and throw away our shaky one-legged diagnosis stool, we need to consider how we might strength it. If we could expand the history to form a rock-solid post, it might be able to hold a circus elephant. The diagnosis of ADHD requires a complete history from the child or adolescent, the parent as well as the teacher. Specific behavior patterns need to be looked for and then compared to same-age children using standardized questionnaires.

It is possible to make the diagnosis of ADHD and start safe, effective educational, behavioral, and medical treatment. Parents can do this. Next up, dealing with complexity.