Parents are usually urged to contact a physician if their child is having trouble concentrating, remaining still or behaving properly. Despite the fact that symptoms of ADHD appear before age seven, many experts agree that ADHD should not be diagnosed in a child prior to age seven. This is because many of the symptoms associated with ADHD are often present in a milder form in younger children who do not have the condition. For example, children and adolescents are often noted for having higher energy levels and shorter attention spans than adults. 

Diagnosing ADHD may involve multiple medical professionals. Parents may begin with their child’s pediatrician, and from there the diagnostic process may proceed with other health professionals including psychiatrists, developmental and behavioral pediatricians, behavioral neurologists or clinical social workers. Parents are urged to seek out the care of health professionals who have experience in diagnosing children with ADHD.

Diagnosing ADHD is not easy.  No single test reveals the presence of the disorder. A physician begins with a complete physical examination and a thorough medical history, concentrating on differentiating ADHD from other medical conditions. The physician may use questionnaires or interviews with parents, teachers, babysitters, coaches and others who may describe behaviors typically associated with ADHD. Teachers in particular may be asked to record their observations on standard evaluation forms called behavior rating scales. These forms take advantage of a teacher’s experience working with various children by asking the teacher to compare the child’s behavior to others of the same age group. The physician will look for behaviors that have a long history, and will note when they occur.

Questions that may be asked by the physician include:

• At what age did the child first begin displaying these symptoms?
  
  
• Do problems tend to appear periodically or are they chronic?
  
  
• Does the child struggle academically?
  
  
• Does the child have trouble maintaining relationships?
  
  
• Are there other problems or symptoms that may be apparent?

Standardized testing also may be used to evaluate a child’s mental health status, intelligence level, learning abilities and social adjustment.

Before diagnosing ADHD, the physician will rule out other potential causes of symptoms. Sleep disorders such as sleep apnea (temporary cessation of breathing during sleep) are frequently the cause of inattention in children. Other disorders that cause symptoms similar to ADHD include hyperthyroidism (excessive production of thyroid hormone), seizure disorders, and vision or hearing problems. Sudden life changes (such as the death of a loved one) can also cause emotional disruption in children that may appear similar to ADHD.

A diagnosis of ADHD is made according to certain criteria established by the American Psychiatric Association. Patients should exhibit six or more symptoms in at least one of two categories that persist for at least six months and that are maladaptive and inconsistent with developmental level.

Regarding inattention, the symptoms include:

• Fails to pay close attention to details or makes careless errors in schoolwork, work or other activities.
  
  
• Has difficulty staying focused on tasks or play activities.
  
  
• Does not appear to listen when spoken to directly.
  
  
• Fails to carry out instructions or to finish schoolwork, chores or workplace duties. This cannot be the result of oppositional behavior or a failure to understand directions.
  
  
• Has difficulty with organization of tasks or activities.
  
  
• Avoids or dislikes tasks that involve concentrated mental effort.
  
  
• Loses items necessary to complete tasks or activities, such as books and pencils or toys.
  
  
• Becomes easily distracted by extraneous stimuli.
  
  
• Is forgetful in daily activities.

Regarding hyperactivity and impulsivity, the symptoms include:

• Fidgets with hands or feet or squirms in seat.
  
  
• Leaves seat in classroom when expectation is to remain seated.
  
  
• Runs about or climbs excessively in inappropriate situations.
  
  
• Has difficulty playing or engaging in leisure activities quietly.
  
  
• Is often “on the go” or acts as if “driven by a motor.”
  
  
• Talks excessively.
  
  
• Blurts out answers before question is finished.
  
  
• Has difficulty awaiting turn.
  
  
• Interrupts or intrudes on others.

These symptoms should be present before the age of seven, and the impairment should be present in two or more settings.

In addition, the patient must have clinically significant impairment in social, academic or occupational functioning, and symptoms cannot be due to an autistic spectrum disorder, schizophrenia, or another psychotic disorder and cannot be better accounted for by another mental disorder. 

Patients are diagnosed with predominantly inattentive ADHD if they have symptoms that fit this category but not the hyperactive-impulsive type over a period of six months. They are diagnosed with hyperactive-impulsive ADHD if the opposite is true. Finally, the patient will be diagnosed with combined ADHD if the criteria from both of the two major categories are met over a period of six months.