Attention-deficit/hyperactivity disorder affects attention span and concentration and can also affect how impulsive and active the person is.


Attention-deficit/hyperactivity disorder (ADHD) is one of the most common disorders among young people. It affects attention span and concentration and can also affect how impulsive and active the person is.

Most young people are, at times, inattentive, distractible, impulsive or highly active. They may have ADHD if such behaviours occur more frequently and are more severe than is considered average among young people of the same age or developmental level. A diagnosis of ADHD might also result if the behaviours persist over time and negatively affect the person’s family and his or her social and school life.

Studies have shown different rates of ADHD among young people, ranging from one per cent to 13 per cent. ADHD is three to four times more common in boys than girls.

Although aggression is not specifically a symptom of ADHD, the disorder is often diagnosed in young people who behave aggressively. Studies have not shown exactly how ADHD and aggression in young people are linked. Some behaviours that are not clearly defined symptoms of ADHD, but have been shown to be associated with it, may lead to aggression.

They include:

  • low tolerance for frustration
  • temper outbursts
  • emotional instability
  • stubbornness
  • conflicts with parents
  • problems with social skills
  • low self-esteem.

Signs & Symptoms

The symptoms of ADHD fall into two main groups: inattentive behaviours and hyperactive and impulsive behaviours. Young people may be diagnosed with ADHD if, for the past six months or more, they have displayed six or more symptoms of either inattentive behaviours or hyperactive or impulsive behaviours.

Inattentive Behaviours

  • often doesn’t pay attention to details or makes what appear to be careless mistakes in schoolwork or other activities
  • usually has problems staying focused on work or activities
  • often doesn’t seem to listen when spoken to
  • frequently doesn’t follow through on instructions and doesn’t finish tasks
  • often has difficulty organizing tasks
  • usually doesn’t like to do tasks that call for ongoing thinking
  • often loses things
  • is often easily distracted
  • often forgets things

Hyperactive Behaviours

  • often fidgets and squirms in chair
  • often leaves seat when required to sit still
  • frequently runs or climbs excessively (or, for adolescents, feels restless)
  • often talks excessively
  • usually has difficulty playing quietly
  • is constantly in motion

Impulsive Behaviours

  • usually has problems waiting for a turn
  • regularly blurts out answers before questions have been completed
  • often interrupts or intrudes on others’ conversations or games

Causes & Risk Factors

While there is no consensus about precisely what causes ADHD, it is believed that the most likely cause is genetics. Children born into families where there is a history of ADHD are more likely to be diagnosed with ADHD than children where there is no family history of ADHD. While there have been attempts to link parenting style, exposure to television at a young age and exposure to environmental hazards as a cause of ADHD, there has yet to be any conclusive evidence that they cause the disorder.

Diagnosis & Treatment

A number of treatment interventions are effective in helping young people with ADHD. Cognitive-behavioural therapy (CBT) can help build self-esteem, reduce negative thoughts and improve problem-solving skills. CBT can also help people learn self-control and improve their social skills.

Parents can learn how to better manage their children’s behaviour by taking parent management skills training. Educators can design programs for young people with ADHD to encourage success rather than failure and to address any co-existing learning disabilities that students might have, such as difficulty with reading. A child who is diagnosed with ADHD and treated appropriately can have a productive and successful life.

If you work or volunteer with young people who have (or who you think might have) ADHD, these tips might be helpful:

  • Provide the person with as structured an environment and as predictable a routine as possible.
  • Clearly warn the person of any changes in routine in advance.
  • Provide a calm, quiet atmosphere without too many visual distractions.
  • Begin conversations by addressing the person directly, using eye contact; wait until he or she is paying attention before speaking.
  • Give instructions one step at a time, rather than issuing multiple requests at once. Have the person repeat the instructions back to you.
  • Provide clear and simple rules. Consider posting the rules somewhere visible.
  • Find out what the person is good at and incorporate this into activities.
  • Ask the person what he or she thinks will help.

In a classroom setting:

  • Provide short work periods.
  • Break down assignments into small, manageable units.
  • Seat the student at the front of the class and away from distractions.
  • Give extra time for tests, and hand out one sheet of a multi-page test at a time.
  • Communicate each homework assignment a number of times, both verbally and in writing.
  • Have the student use a daily planner to keep a record of what he or she has done and still needs to do.
  • Encourage the student to use aids to deal with symptoms, such as earplugs to avoid distractions or a stress ball to play with instead of fidgeting.
  • For a younger child, assign simple errands, so that he or she can move around and feel useful.

Related Programs and Services

Original source:  Attention Deficit Hyperactivity Disorder (ADHD) | CAMH, 2023.