Definition & core features

• Recurrent behavioural outbursts representing a failure to control aggressive impulses (verbal aggression or physical aggression) that are disproportionate to any provocation.
• Outbursts are not premeditated (they are impulsive) and are not committed to achieve some tangible objective (e.g., money, power).
• Episodes cause marked distress or impairment and may result in legal or interpersonal consequences.
• Diagnosis requires that the behaviours are not better explained by another mental disorder, medical condition, or substance intoxication/withdrawal.

Typical phenomenology

• Brief onset of anger with rapid escalation (minutes) followed by regret, remorse or indifference after the episode.
• Triggers may be minor and not proportional to the response (e.g., being bumped in a queue).
• May include throwing objects, punching walls, or brief assaults; frequency varies from episodic to multiple times per week.

Assessment checklist

1. History of episodes: frequency, severity, triggers, context, injury to self/others and legal outcomes.
2. Differentiate impulsive aggression from premeditated aggression (criminal intent), manic or psychotic aggression, and substance‑related aggression.
3. Screen for comorbidity: substance use, mood disorders, personality disorders (especially antisocial and borderline), traumatic brain injury, and neurodevelopmental disorders.
4. Risk assessment: current suicidality, homicidal intent, access to weapons, victim vulnerability, and presence of coercive behaviour in relationships.
5. Collateral information from family, employers, or legal records is often essential.

Investigations & when to consider medical causes

• Consider urine toxicology if substance use suspected.
• Investigate neurological causes (e.g., head injury, epilepsy) if atypical features, new onset in later life, or focal neurological signs — CT/MRI or neurology referral as indicated.
• Assess for endocrine/metabolic contributors (thyroid dysfunction, hypoglycaemia) when clinically suggested.

Treatment — psychological interventions

• Cognitive‑behavioural therapy (CBT) focusing on anger management, cognitive restructuring, and problem‑solving skills has the strongest support.
• Techniques: relaxation training, exposure to triggers with response prevention, emotion regulation skills and communication training.
• Group programmes for anger management can be helpful for some individuals when individualized therapy is not available.

Treatment — pharmacologic options

• SSRIs (fluoxetine, sertraline) have evidence for reducing aggressive outbursts in IED and are commonly used as first‑line medication when indicated.
• Mood stabilisers/anticonvulsants (e.g., valproate, carbamazepine) and atypical antipsychotics (e.g., risperidone) have shown benefit in some trials—use specialist guidance and monitor side effects.
• Short‑term benzodiazepines are generally avoided for impulsive aggression due to disinhibition and dependence risk, except for brief crisis management where necessary.
• Individualise pharmacotherapy based on comorbidity (e.g., treat comorbid depression or substance dependence concurrently).

Risk management & safety planning

• Address immediate safety: remove access to weapons, ensure victim safety, inform legal authorities if mandatory, and create a clear crisis plan.
• Use behavioural contracts, contingency planning and involve family in supervision and de‑escalation strategies.
• Consider structured follow‑up with community mental health, forensic services or probation when legal issues are present.

Key takeaways

• IED is an impulsive aggressive disorder — diagnosis depends on episodic, disproportionate outbursts not explained by other conditions.
• Prioritise safety, comprehensive assessment for comorbidity and targeted CBT; consider SSRIs or other agents when indicated.
• Coordinate with family, legal and community services for risk management and long‑term follow‑up.

Diagnostic criteria (high level)

CD involves behaviours such as aggression to people/animals, destruction of property, deceitfulness or theft, and serious violations of rules. Symptoms must persist for at least 12 months (with at least one criterion in the past 6 months) and cause significant impairment.

Specifiers & subtypes

• Child‑onset type: onset of at least one symptom before age 10 — associated with worse prognosis.
• Adolescent‑onset type: onset after age 10 — generally better prognosis than child‑onset.
• With limited prosocial emotions (callous‑unemotional traits): lack of remorse, shallow affect, unconcern about performance — predicts persistent antisocial behaviour.

Common presentations & red flags

• Physical fights, bullying, cruelty to animals, use of weapons.
• Deliberate property destruction (arson, vandalism), shoplifting, lying and truancy.
• Running away from home, staying out late, association with delinquent peers.
• Red flags: weapon access, sexual offending, serious violence, escalating criminal charges, substance dependence.

Assessment checklist

1. Obtain developmental and family history, review for conduct symptoms before age 10 (to identify child‑onset).
2. Gather collateral: school records, police/juvenile records, caregiver and teacher reports.
3. Screen for comorbid ADHD, learning difficulties, ASD, mood disorders, PTSD and substance use.
4. Assess for trauma, abuse or neglect which may underlie behaviours; evaluate safety and legal risks.
5. Use structured instruments where available (e.g., the Child Behavior Checklist, the Antisocial Process Screening Device, Structured diagnostic interviews).

Treatment — evidence‑based approaches

Family‑based interventions

• Parent Management Training (PMT) / Parent–Child Interaction Therapy (PCIT): teach caregivers consistent, positive behaviour management and contingency strategies.
• Multisystemic Therapy (MST): intensive home‑ and community‑based programme for severe or chronic cases with strong evidence for reducing reoffending.

School & community interventions

• School‑based behaviour plans, mentoring, vocational support and structured after‑school programmes to reduce peer influences and increase prosocial engagement.

Individual therapies

• Cognitive‑behavioural strategies for anger management, problem‑solving and social skills training.
• Trauma‑focused therapies where PTSD or abuse history present.

Pharmacotherapy

• No medication treats CD per se; medications target comorbid conditions (stimulants for ADHD, SSRIs for mood/anxiety) or severe aggression (atypical antipsychotics) short‑term under specialist guidance.

Risk management & legal liaison

• Safety planning for victims, restrict weapon access, and coordinate with child protection and juvenile justice systems when required.
• Document risks, interventions, and engage multidisciplinary teams (social work, education, probation) to create coordinated plans.
• Consider secure or residential interventions for those with persistent dangerous behaviours despite community care.

Key takeaways

• Early identification and family‑based interventions (PMT, PCIT, MST) are central to improving outcomes in CD.
• Assess for comorbidity and trauma; coordinate care across health, education and justice sectors.
• Prioritise safety, legal liaison and long‑term psychosocial supports to reduce harm and promote rehabilitation.

Definition & core features

• Recurrent behavioural outbursts representing a failure to control aggressive impulses (verbal aggression or physical aggression) that are disproportionate to any provocation.
• Outbursts are not premeditated (they are impulsive) and are not committed to achieve some tangible objective (e.g., money, power).
• Episodes cause marked distress or impairment and may result in legal or interpersonal consequences.
• Diagnosis requires that the behaviours are not better explained by another mental disorder, medical condition, or substance intoxication/withdrawal.

Typical phenomenology

• Brief onset of anger with rapid escalation (minutes) followed by regret, remorse or indifference after the episode.
• Triggers may be minor and not proportional to the response (e.g., being bumped in a queue).
• May include throwing objects, punching walls, or brief assaults; frequency varies from episodic to multiple times per week.

Assessment checklist

1. History of episodes: frequency, severity, triggers, context, injury to self/others and legal outcomes.
2. Differentiate impulsive aggression from premeditated aggression (criminal intent), manic or psychotic aggression, and substance‑related aggression.
3. Screen for comorbidity: substance use, mood disorders, personality disorders (especially antisocial and borderline), traumatic brain injury, and neurodevelopmental disorders.
4. Risk assessment: current suicidality, homicidal intent, access to weapons, victim vulnerability, and presence of coercive behaviour in relationships.
5. Collateral information from family, employers, or legal records is often essential.

Investigations & when to consider medical causes

• Consider urine toxicology if substance use suspected.
• Investigate neurological causes (e.g., head injury, epilepsy) if atypical features, new onset in later life, or focal neurological signs — CT/MRI or neurology referral as indicated.
• Assess for endocrine/metabolic contributors (thyroid dysfunction, hypoglycaemia) when clinically suggested.

Treatment — psychological interventions

• Cognitive‑behavioural therapy (CBT) focusing on anger management, cognitive restructuring, and problem‑solving skills has the strongest support.
• Techniques: relaxation training, exposure to triggers with response prevention, emotion regulation skills and communication training.
• Group programmes for anger management can be helpful for some individuals when individualized therapy is not available.

Treatment — pharmacologic options

• SSRIs (fluoxetine, sertraline) have evidence for reducing aggressive outbursts in IED and are commonly used as first‑line medication when indicated.
• Mood stabilisers/anticonvulsants (e.g., valproate, carbamazepine) and atypical antipsychotics (e.g., risperidone) have shown benefit in some trials—use specialist guidance and monitor side effects.
• Short‑term benzodiazepines are generally avoided for impulsive aggression due to disinhibition and dependence risk, except for brief crisis management where necessary.
• Individualise pharmacotherapy based on comorbidity (e.g., treat comorbid depression or substance dependence concurrently).

Risk management & safety planning

• Address immediate safety: remove access to weapons, ensure victim safety, inform legal authorities if mandatory, and create a clear crisis plan.
• Use behavioural contracts, contingency planning and involve family in supervision and de‑escalation strategies.
• Consider structured follow‑up with community mental health, forensic services or probation when legal issues are present.

Key takeaways

• IED is an impulsive aggressive disorder — diagnosis depends on episodic, disproportionate outbursts not explained by other conditions.
• Prioritise safety, comprehensive assessment for comorbidity and targeted CBT; consider SSRIs or other agents when indicated.
• Coordinate with family, legal and community services for risk management and long‑term follow‑up.