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Diagnosis of ADHD

Mother and daughter at doctorsMother and daughter at doctors

A child's teacher may be the first person to suspect that a child has ADHD, especially if he is hyperactive and often disrupts class. However, parents may notice signs of ADHD before the child begins school, such as problems with social skills and disruptive behaviour. Alternatively, parents may realize that their child is having problems if she does poorly at school. If you or your child’s teacher suspect your child might have ADHD, your child should be assessed by a doctor or psychologist.

ADHD is very common; it is estimated that between 5% and 12% of children have ADHD. For this reason, a doctor or psychologist will consider ADHD when they see a child who:

  • is doing poorly or failing at school
  • disrupts class
  • cannot sit still or is hyperactive
  • acts without thinking
  • does not pay attention or does not seem to listen
  • cannot concentrate
  • daydreams
  • has problems with friendships and other social relationships
  • has low self-esteem

If your child has signs or symptoms that make your child's doctor suspect your child has ADHD, she will do a thorough assessment.

ADHD is not always easy to diagnose, for several reasons:

  • The symptoms of ADHD are inattention and/or hyperactivity and impulsivity, but it is normal for all children to be restless, impulsive, or inattentive sometimes.
  • There is no one specific test for ADHD.
  • Children behave differently in different settings and with different people.
  • The symptoms of ADHD look different in different children, in boys and girls, and at different ages.
  • Children with only symptoms of inattention are often overlooked.

For these reasons, the doctor will need as much information as possible from you, your child, your child's teacher, and other caregivers.

It may take some time to figure out whether your child really has ADHD. Once the doctor knows what is happening with your child, she will sit down with you and explain the diagnosis and treatment plan.

This section discusses:

  • how ADHD is diagnosed
  • the symptoms of ADHD
  • the subtypes of ADHD
  • ADHD in girls and boys
  • ADHD at different ages and stages of development
  • other conditions that often affect children with ADHD (comorbidity)
  • conditions that may look like ADHD, but are not

Click the links on the left to learn more.

Peter Chaban, MA, MEd

Rosemary Tannock, PhD