PSYCH 239: When Behaviour Becomes Disruptive (ODD, IED, & Conduct Disorder)

A comprehensive vocabulary review of disruptive, impulse-control, and conduct disorders covering diagnostic features, developmental patterns, and clinical differentiation.

Disruptive, Impulse-Control, and Conduct Disorders

A diagnostic family characterized by a persistent difficulty regulating behaviour, emotion, impulses, or conduct in ways that impact others, rules, or societal rights.

Oppositional Defiant Disorder (ODD)

A persistent, developmentally atypical interpersonal pattern characterized by angry or irritable mood, argumentative or defiant behaviour, and vindictiveness that causes significant impairment or conflict.

Intermittent Explosive Disorder (IED)

A disorder characterized by recurrent, impulsive, or reactive aggressive outbursts (verbal, property, or physical) that are grossly disproportionate to the minor provocation or frustration triggering them.

Conduct Disorder (CD)

A disorder involving a persistent pattern of behaviour in which the basic rights of others or major age-appropriate societal norms and rules are violated.

Angry / Irritable Dimension

An ODD symptom cluster characterized by frequently losing one's temper, being touchy or easily annoyed, and acting angry or resentful.

Argumentative / Defiant Dimension

An ODD symptom cluster characterized by arguing with authority figures, actively refusing requests or rules, deliberately provoking others, and blaming others for mistakes or misbehaviour.

Vindictiveness

An ODD symptom dimension characterized by spiteful or vindictive behaviour, evaluated by frequency, duration, relationships, and developmental context.

Coercive Cycles

An interactional pattern where an adult issues a demand, the child refuses, both escalate, and the demand is ultimately withdrawn—unintentionally reinforcing the child's escalatory behaviour.

Reactive / Impulsive Aggression

An aggressive response marked by rapid escalation, high emotional arousal, and poor inhibition that is not primarily aimed at obtaining an external reward ('I exploded').

Instrumental / Goal-Directed Aggression

Deliberate aggressive behaviour that serves a specific functional goal, such as obtaining tangible gain, intimidation, status, escape, or control ('I did it to get ___').

Childhood-Onset Pattern (Conduct Disorder)

A developmental subtype where characteristic conduct problems emerge prior to adolescence; often linked to greater persistence, comorbidity, and developmental adversity.

Adolescent-Onset Pattern (Conduct Disorder)

A developmental subtype where conduct problems emerge later in development, typically reflecting stronger influences from peer context, developmental risk-taking, and the social environment.

Limited Prosocial Emotions Specifier

A Conduct Disorder specifier designating a persistent, multi-setting pattern of limited guilt, lack of empathy, and shallow or unconcerned affect.

Four Core Behavioural Categories of Conduct Disorder

1) Aggression to people or animals, 2) destruction of property (e.g., fire-setting), 3) deceitfulness or theft, and 4) serious violations of rules (e.g., truancy, running away).

Diagnostic Reasoning Ladder

A structured six-step clinical assessment process: 1) Observe (actions), 2) Development (age expectations), 3) Pattern (frequency/pervasiveness), 4) Function (antecedents/outcomes), 5) Differential (alternative causes), and 6) Fit (diagnostic alignment).