print article
For optimal print results, please use Internet Explorer, Chrome or Safari.

What is attention deficit hyperactivity disorder?

By Patrick J. McGrath, OC, PhD, FRSC


My 10-year-old son was diagnosed by his teacher as having attention deficit disorder. What is that?

Dr. Pat responds:

Teachers are not qualified to diagnose attention deficit disorder. A health professional such as a paediatrician, psychologist, or psychiatrist should diagnose.

Obviously, your child's teacher is frustrated with him. Pay attention to this concern. You can ask for a meeting to find out more.

Talk to your family doctor about the problems your son is having. He or she may have some specific suggestions or may refer your child. You can also contact your local hospital for referrals.

You could see a private psychologist (look in the phone book) but you will have to pay for this service.

Attention-deficit/hyperactivity disorder, or ADHD as it is often called, is diagnosed because of:

  • problems in paying attention (distractibility)
  • problems in doing things without thinking (impulsivity)
  • almost constant activity (hyperactivity)

ADHD is common. ADHD is diagnosed by reports of behaviour in different settings. There is no blood test or X-ray for ADHD.

For more information, please see the ADHD Resource Centre.

Patrick J. McGrath OC, PhD, FRSC is a clinical psychologist and a researcher. He is Professor of Psychology, Pediatrics, and Psychiatry at Dalhousie University and Vice President - Research at IWK Health Centre in Halifax. He is also the CEO of the Strongest Families Institute, which provides mental health care to families across Canada.

Read more "Ask Dr. Pat" columns

If you would like to send Dr. Pat a question, please email us at  

Dr. Pat will respond to as many letters as possible with evidence-based answers. We hope that the column will be interesting and helpful for readers; however, Dr. Pat cannot provide health care through the column. Please contact a physician or other registered health care professional to provide health care guidance or advice.