Attention deficit hyperactivity disorder (ADHD) is a clinical diagnosis, meaning that the doctor can only determine if someone has ADHD by taking a good history, asking about symptoms, and learning about the person's development, family background, and family psychiatric history. The doctor will then integrate all these pieces of information and, using accepted clinical guidelines, provide feedback as to whether or not this person has ADHD.
There is no test for ADHD. We know that there are anatomical differences in the brains of individuals who have ADHD, and these have been studied with sophisticated brain imaging techniques. However, brain imaging techniques are still only research tools and cannot be used to make a clinical diagnosis.
An assessment for ADHD may include psychological testing. These tests will provide information about intelligence (IQ), academic achievement, and whether there are problems with a learning disability. While these tests may be useful, and may indicate other possible causes of difficulty with attention, they are not diagnostic in themselves. The testing situation itself may mask the ADHD, since the testing is a very structured task with continuous supervision and requiring high motivation and high interest. An individual with ADHD might do well in such a test situation, but still be unable to force themselves to pay attention to boring material in a busy classroom.
Some, but not all, clinicians also use computerized tests of attention such as the Continuous Performance Test or the Gordon Diagnostic System as part of their assessment. These tests may help the doctor obtain a better sense of a person's attention skills and weaknesses, but they are never diagnostic in themselves. The tests cannot determine if the symptoms are caused by something else. Some individuals who clearly have ADHD still do well on these tests. Therefore, while these tests may be useful, they are not essential, and do not establish that the assessment is more "scientific" than a good clinical interview.
Rating scales are a very important part of the assessment process. Rating scales are checklists that allow the doctor to compare the individual's symptoms with those experienced by people in general. They also serve to give the doctor a sense of the individual's difficulty in different environments, and in different areas of functioning. The Diagnostic and Statistical Manual - 4th edition, Text Revision (DSM-IV-TR) is the best-known set of symptom criteria that doctors use to make a diagnosis of ADHD. These symptoms have been chosen because they are often more frequent and problematic in individuals who suffer from ADHD. These diagnostic criteria are also often used as a rating scale. Symptoms of oppositional defiant disorder (ODD) are also included for reference, since about half of all individuals with ADHD will also have ODD. Some children with ADHD have serious problems with getting into trouble such as fighting, lying, stealing, and hurting animals (conduct disorder), and these difficulties cause problems in their own right, over and above the difficulties associated with ADHD.
If you are concerned your child may have ADHD, complete the symptoms of ADHD checklist to discuss with your doctor.
Margaret Weiss MD, PhD