17. How Is Attention-Deficit Hyperactivity Disorder Diagnosed?

Parents usually seek professional help after repeated problems with the child's classmates and teachers. A diagnosis of ADHD is often the first step in treatment; identifying the behavioral problems as a treatable medical problem can relieve much of the stress and guilt. Diagnosis of attention-deficit hyperactivity disorder is difficult. Some children can display marked inattention and impulsivity without hyperactivity. Other children are inappropriately inattentive but are not hyperactive or impulsive. Physicians can fail to diagnose children with attention-deficit hyperactivity disorder because they often behave normally in the quiet physician's office where there are no distractions to trigger symptoms. A study showed that a mother's description of her child's behavior was a very accurate and reliable guide for diagnosing ADHD. Parents should not be shy about insisting on further evaluation if their experience does not match a doctor's single observation of their child. This is particularly important now, because under managed care the cost of pursuing a diagnosis is not always covered.

The physician will first require a detailed history of the child's behavior. They will match this against a standardized checklist used to define the disorder. [ See Table, Diagnostic Criteria for Attention-Deficit Disorder. ] The parents should describe specific problems they have encountered during the child's development, beginning as early as possible. School reports are very helpful. The health professional will want to know how the parents handle different situations and may want to observe them interacting with the child. The physician should also ask about any other factors that might affect the child's behavior, such as sibling relationships, recent life changes, a family history of ADHD, eating habits, sleep patterns, and speech and language development. A medical history will then be taken, not only of the child, but also of the mother's pregnancy and delivery. The child should also be given a general physical examination to determine if any medical causes are present. A series of screening tests are available to test neurologic, intellectual, and emotional development problems. Most involve learning and problem solving tasks and help define the particular areas that are most disabling. Laboratory tests are rarely recommended unless the physician suspects lead toxicity or other medical problems.

It is fairly common to use a trial of a psychostimulant (usually Ritalin) to achieve a diagnosis. An improvement in symptoms is considered an indication of ADHD . In non-ADHD children, however, the stimulant often increases agitation and hyperactivity. Experts, however, strongly recommend against this method of diagnosis, since it is not always accurate. Many children and adults without the disorder have a similar response, and such a diagnostic trial may lead to unnecessary prescriptions of this drug.

Brain scans using imaging techniques, including magnetic resonance imagine (MRI) or single photon emission computed tomography (SPECT) may eventually help confirm a diagnosis. At this time, however, abnormalities detected in ADHD patients do not provide enough evidence for widespread use.