What is Conduct Disorder (CD)?

The co-morbid condition of Conduct Disorder (DC) occurs in some children with ADHD. 

A child or teenager who repetitively and persistently displays patterns of behavior whereby the basic rights of others or major societal norms are violated may be at risk of having Conduct Disorder.

The typical behaviors fall into four main areas:

  1. Aggressive conduct causing or threatening physical harm to other people
  2. Aggressive conduct causing or threatening physical harm to animals;
  3. Non-aggressive conduct causing property loss or damage, deceitfulness or theft;
  4. Repetitive serious violations of rules.

Specific Symptoms of Conduct Disorder

Aggression to people and animals

  • Frequent bullying, threatening or intimidating others
  • Frequent initiation of physical fights
  • Use of a weapon able to cause serious physical harm to others (e.g., a bat, brick, broken bottle, knife, gun)
  • Physical cruelty to people and/or animals
  • Stealing while confronting a victim (e.g., mugging, purse snatching, extortion, armed robbery)
  • Forcing someone into sexual activity 

Destruction of property

  • Deliberately engaging in fire setting with the intention of causing serious damage
  • Deliberately destroying others’ property (other than by fire setting) 

Deceitfulness or theft

  • Breaking into someone else’s house, building or car
  • Frequently lying to obtain goods or favors or to avoid obligations
  • Stealing items of non-trivial value without confronting a victim (e.g., shoplifting, but without breaking and entering; forgery) 

Serious violations of rules

  • Frequently stays out at night despite parental prohibitions, beginning before age 13;
  • has run away from home overnight at least twice while living in parental or parental surrogate home (or once without returning for a lengthy period);
  • Frequent truanting from school, beginning before age 13.

If the presence of 3 (or more) of the following criteria have occurred in the past 12 months, with at least one present in the past 6 months, Conduct Disorder could be a possibility and professional help should be sought.

The disturbance in behavior causes clinically significant impairment in social, academic, or occupational functioning.

There are 2 sub-types of Conduct Disorder:

Childhood-Onset Type

This sub-type is characterised by the onset of at least one criterion characteristic of Conduct Disorder prior to age 10 years.

Individuals with Childhood-Onset Type are most often male, frequently display physical aggression toward others, have disturbed peer relationships, may have had Oppositional Defiant Disorder during early childhood, and usually have symptoms that meet full criteria for Conduct Disorder prior to puberty.

Adolescent-Onset Type

This sub-type is defined by the absence of any criteria characteristic of Conduct Disorder prior to age 10 years.

Compared with those with the Childhood-Onset Type, these individuals are less likely to display aggressive behaviors and tend to have more normative peer relationships (although they often display conduct problems in the company of others).

The ratio of males to females with Conduct Disorder is lower for the Adolescent-Onset Type than for the Childhood-Onset Type.

If the individual is age 18 years or older, criteria are met for Antisocial Personality Disorder.

Conduct Disorder is one of a group of behavioural disorders known collectively as disruptive behaviour disorders, which include oppositional defiant disorder (ODD) and Attention Deficit Hyperactivity Disorder (ADHD).  Early intervention and treatment is important, since children with untreated CD are at increased risk of developing a range of problems during their adult years including substance use, personality disorders and mental illnesses.


PANDAS is an acronym for a condition called Paediatric Autoimmune Neuropsychiatric Disorder Associated with Streptococcus (PANDAS). Current research suggests that symptoms of Tourette’s and OCD have been associated with PANDAS at least in some cases. PANDAS results from the effect of the body's own immune system's antibodies attacking parts of the brain. The onset usually occurs following an ear, nose or throat (ENT) infection from Group A Beta Haemolytic Streptococcus (GABHS). GABHS antibodies in some cases can damage parts of the brain resulting in a range of behavioural disorders. OCD, Oppositional Defiant Disorder, Tourette’s, ADHD and even psychosis.

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