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Behavioural Disorders

What is it?

There are several types of behavioural disorders, including:

  • oppositional defiant disorder
  • conduct disorder
  • intermittent explosive disorder
  • kleptomania
  • pyromania and others

These disorders affect the way a child or youth acts or behaves. Some people think a child or youth with a behavioural disorder is “bad” and may even blame a parent for their child’s behaviour. But these disorders are real problems that affect many children and youth. Fortunately, there are many different treatments and things to try at home.

What is normal behaviour?

It’s normal for children and youth to act out from time to time. They may seem grumpy or angry when they’re tired, upset or feeling a lot of stress. It’s also normal for children and youth to act out more than usual during certain times in their life. Preschool-aged children and teens in particular may seem keen to disobey or talk back. This is a normal part of growing up.

How do I know?

Oppositional Defiant Disorder

The signs of oppositional defiant disorder include very angry and negative behaviours that:

  • last for many months (usually 6 months)
  • happen often
  • cause a lot of problems in the child or youth’s life

With this disorder, a child or youth may often:

  • be angry and irritable
  • argue with parents, teachers and other adults
  • be mean, hurtful, spiteful or vindictive

You can usually see signs of oppositional defiant disorder before a child is eight years old. It starts slowly and gradually. Parents may notice the signs at home first, but the disorder may start to affect other parts of the child or youth’s life, such as school. This disorder does not usually start after the early teenage years.

The length of time that symptoms last is different for everyone. Many children and youth recover, but some may go on to develop conduct disorder or another mental health disorder.

Before puberty, more boys than girls have the disorder. After puberty, it’s more equal between boys and girls.

Conduct Disorder

The signs of conduct disorder include behaviours that go against rules or other people’s rights and:

  • last for many months (usually 12 months)
  • happen often
  • cause a lot of problems in the child or youth’s life

With this disorder, a child or youth may often:

  • be aggressive towards other people or animals - bullying, starting fights, hurting others, using a weapon
  • harm someone’s property on purpose
  • tell major lies - to get something or avoid responsibilities
  • steal - break into a house or car, or steal something that’s important to someone
  • break serious rules - run away from home or skip school a lot

Conduct disorder usually happens between the ages of 6 and 15 and it is more common in boys than girls.

Most symptoms lessen or go away by the time the child or youth becomes an adult. But some may develop an adult form of the disorder called antisocial personality disorder. Conduct disorder can go along with substance use problems, and lead to problems with the law. It is important to watch for warning signs and find help early.

For severe conduct disorders, resources are offered by youth forensics psychiatric services.

What causes Oppositional Defiant Disorder and Conduct Disorder?

Risk factors include:

  • genes
  • differences in brain chemistry
  • abuse or neglect
  • seeing or experiencing violence
  • family problems

Children or youth may struggle with Impulse Disorders, some of which are outlined below.

Intermittent Explosive Disorder

This disorder is diagnosed in children who are at least six years old. These children and youth have repeated angry outbursts that are out of proportion to the situation and are not planned. These children and youth are aggressive in words and actions, damage things and property, and hurt animals and people.


Kleptomania is a disorder of stealing objects and may start at different ages. Children and youth with kleptomania struggle to resist impulses to steal things that they do not need.


Pyromania involves setting fire repeatedly and on purpose, without a reason such as gaining money.

What mental health challenges may be connected to Disruptive Behaviour Disorders?

About half of children living with attention deficit/hyperactivity disorder (ADHD) also have other challenges or disorders that occur with, or look like, an oppositional defiant disorder or conduct disorder. These include:

What can be done?

The main treatments for oppositional defiant disorder and conduct disorder are:

  • counselling
  • skills training
  • changes at home
  • changes at school if the behaviour affects schoolwork a lot
  • treatment for other mental health challenges or disorders (treating ADHD often ends problems with oppositional defiant disorder)


A type of talk therapy called cognitive behavioural therapy(CBT) may help boost healthy ways of thinking. Family counselling may help the entire family work together.

Skills training for children and youth

It often helps children and youth cope with strong feelings and get along with others if they learn how to:

  • manage anger
  • problem solve
  • be with other people

Skills training for parents or caregivers

This training helps parents or caregivers to learn skills and feel more confident to:

  • deal with anger
  • be consistent
  • discipline effectively
  • work with their child to solve problems that work for everyone

Changes at home

  • don’t set too many rules - focus on the most important ones, and work with your child to establish those rules
  • offer choices to give children a sense of control
  • keep a regular routine, and make sure to spend time with your child
  • take a time out when you start to get angry - this also teaches the child a more positive way to deal with frustration and anger
  • set reasonable limits and make sure the consequences are the same every time
  • congratulate good behaviours like flexibility and cooperation
  • try to limit the number of aggressive playmates around your child, and increase positive contacts with other children

Changes at school

The classroom teacher may suggest changes and bring in other staff members like a counsellor to help manage the child or youth’s behaviour problems. If the behaviour problems are extremely difficult, the parents and school may decide on an Individual Education Plan (IEP) or a positive behaviour support plan like this. These plans let the school make bigger changes to help a child. They also set goals for the child to reach. Their plan may be linked with other mental health services outside the school, like a social worker or mental health professional.

Healthy Living

  • being active regularly
  • good sleep habits
    • limit TV, video games and computer time before bedtime
    • try relaxing activities - quiet music, reading
    • same bedtime every night - even on weekends, holidays and vacations
    • a comfortable bedroom - dark, quiet and not too warm or cool
    • no caffeine later in the day - it’s in some soft drinks and snacks
  • eating well – Canada’s Food Guide has information on healthy eating in different languages
  • healthy thinking skills are an important part of cognitive behavioural therapy 
  • your doctor or mental health professional can also suggest self-help books or websites

Take care of yourself

  • talk to a counsellor or therapist to help work through your own thoughts and feelings
  • learn a few different ways to calm yourself
  • spend time doing something you enjoy, away from your child
  • think of each new day as a fresh start - try not to keep thinking about past behaviours
Where to from here?

Talk to your doctor and get help from a mental health professional by:

  • Meeting with your family doctor/primary care team and considering a referral to a pediatrician and/or a child and adolescent psychiatrist
  • Getting a mental health assessment and support through your local Child and Youth Mental Health team (through a walk-in intake clinic in your community). 
  • Connecting with the school team - counsellor or school psychologist
  • Contacting a private psychologist or counsellor, or your Employee Assistance Plan (EAP), if you have this option. 

Looking for more information on this topic? Connect with a family peer support worker at the Kelty Centre to discover additional resources, learn more about support and treatment options, or just to find a listening ear.   

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Through real stories, expertise, and practical tips, this podcast helps families promote their mental health and wellness, navigating important topics to meet you where you are in your journey.