Conduct Disorder

Conduct disorder involves a repetitive, persistent pattern of behaviour in which the basic rights of others or major age-appropriate societal norms or rules are violated, spanning categories such as aggression to people or animals, destruction of property, deceitfulness or theft, and serious rule violations. It is more serious than oppositional defiant disorder, with which it is sometimes confused, and requires prompt, structured assessment and treatment given both the impact on others and the significant long-term risks — including school failure, legal involvement, and substance use — associated with an untreated pattern, particularly when onset is in childhood rather than adolescence. Family involvement, early intervention, and identifying and treating co-occurring conditions such as ADHD or trauma give the best chance of changing the trajectory.

Conduct disorder is defined as a repetitive and persistent pattern of behaviour violating the basic rights of others or major age-appropriate societal norms, evidenced by at least three of fifteen specified criteria across four categories — aggression to people and animals, destruction of property, deceitfulness or theft, and serious rule violations — occurring in the past 12 months, with at least one criterion present in the past 6 months, and causing clinically significant impairment in social, academic or occupational functioning.

Conduct disorder arises from a combination of individual factors — including difficult temperament, impulsivity, and in some cases reduced sensitivity to punishment or others' distress — and environmental factors, including harsh, inconsistent or abusive parenting, exposure to violence, chronic family conflict, poverty-related stress, and association with antisocial peers. Childhood-onset conduct disorder (before age 10) is associated with a stronger biological/temperamental contribution and a higher risk of persisting into adulthood, while adolescent-onset conduct disorder is more strongly associated with peer influence and tends to have a better long-term prognosis. Undiagnosed ADHD, learning difficulties, trauma, and untreated depression can all present with or worsen conduct problems and should always be assessed for.

• Harsh, inconsistent, or abusive parenting, and exposure to family violence
• Family history of antisocial behaviour, substance use, or conduct disorder
• Co-occurring ADHD, especially when untreated
• Childhood trauma or significant early adversity
• Association with antisocial or delinquent peers, particularly for adolescent-onset presentations
• Poverty-related chronic stress and community violence exposure
• Low frustration tolerance and reduced sensitivity to punishment or others' distress

Conduct disorder, particularly presentations with limited prosocial emotions (reduced empathy, guilt or remorse), is associated with reduced amygdala responsiveness to others' distress and altered function in prefrontal regions involved in impulse control and moral reasoning, which together are thought to reduce the normal emotional brakes on harmful behaviour. Chronic early exposure to violence or severe stress can additionally alter stress-response systems in ways that lower the threshold for aggressive reactions. These are understood as risk-modifying brain differences that interact with environment and treatment, not a fixed or unchangeable trait, which is an important message for families given how often conduct disorder is met with hopelessness.

• Bullies, threatens or intimidates others
• Initiates physical fights
• Has used a weapon that can cause serious physical harm
• Has been physically cruel to people or animals
• Has stolen while confronting a victim, or engaged in forced sexual activity
• Has deliberately engaged in fire-setting with intent to cause damage
• Has deliberately destroyed others' property
• Has broken into someone else's house, building, or car
• Often lies to obtain goods or favours, or to avoid obligations
• Has stolen items of nontrivial value without confronting a victim
• Often stays out at night despite parental prohibition, beginning before age 13
• Has run away from home overnight at least twice, or once for a lengthy period
• Is often truant from school, beginning before age 13

• A repetitive and persistent pattern of behaviour violating the basic rights of others or major age-appropriate societal norms
• At least 3 of 15 specified criteria present in the past 12 months, with at least 1 present in the past 6 months
• The disturbance causes clinically significant impairment in social, academic or occupational functioning
• If the individual is 18 or older, criteria for antisocial personality disorder are not met
• Specified as childhood-onset (before age 10) or adolescent-onset, and with or without limited prosocial emotions (reduced empathy, guilt or remorse)

Conditions a psychiatrist will consider and rule out before confirming this diagnosis:

Oppositional defiant disorder (ODD)

ODD involves argumentative, defiant and irritable behaviour but not the serious rights violations — aggression to people/animals, property destruction, theft, serious rule-breaking — that define conduct disorder.

ADHD

Impulsivity in ADHD can lead to rule-breaking or conflict, but is not driven by the same pattern of intentional rights violation; the two conditions frequently co-occur and both should be assessed and treated.

Adjustment disorder

Behavioural problems that arise clearly in response to an identifiable stressor and are proportionate to it may better fit adjustment disorder than the more persistent, pervasive pattern of conduct disorder.

Antisocial personality disorder

Only diagnosed from age 18, and requires evidence of conduct disorder before age 15; conduct disorder is the childhood/adolescent precursor category, not used once ASPD criteria are met in an adult.

• Comprehensive developmental, family, and behavioural history from multiple informants (parents, school, where appropriate the young person themselves)
• Standardised behaviour rating scales and structured clinical interview
• Assessment for co-occurring ADHD, learning difficulties, depression, anxiety and trauma history
• Screening for substance use, particularly in adolescents
• Assessment of family functioning, discipline patterns, and any history of abuse or exposure to violence
• Risk assessment regarding safety to self and others

Multimodal, family-involved treatment is most effective, combining structured parent-management and family therapy approaches, individual skills-based therapy for the young person (problem-solving, anger management, social skills), school-based support, and treatment of any co-occurring condition such as ADHD, depression or trauma. Multisystemic therapy and similar intensive, family- and community-based models have strong evidence for more severe presentations. Medication is not a treatment for conduct disorder itself but can meaningfully help when a co-occurring condition, particularly ADHD, is identified and treated. Earlier intervention, before entrenched patterns and legal involvement develop, is associated with meaningfully better outcomes.

No medication is specifically approved for conduct disorder itself

Treatment of a genuinely co-occurring condition — most often ADHD, but also depression, anxiety or trauma-related symptoms — is pursued individually, since this can meaningfully reduce associated behavioural difficulties.

Stimulant or non-stimulant ADHD medication (where ADHD co-occurs)

Can reduce impulsivity that contributes to conduct problems, considered after careful individual psychiatric assessment.

Short-term, targeted use of other medication for severe aggression (specialist use)

Occasionally considered in severe, high-risk cases under close specialist supervision, always alongside, never instead of, structured behavioural and family treatment.

Parent management training and family therapy

Builds consistent structure, monitoring and communication at home; among the most evidence-supported approaches, particularly for younger children.

Multisystemic therapy (MST) or similar intensive models

Addresses the young person's behaviour across family, school, peer and community systems simultaneously; strong evidence for more severe or entrenched presentations, particularly in adolescents.

Individual skills-based therapy (problem-solving, anger management, social skills training)

Builds the young person's own capacity to manage frustration, resolve conflict and consider consequences, usually most effective combined with family-based work rather than alone.

• Maintain consistent, structured routines and clear, enforceable expectations at home
• Increase positive parental monitoring and involvement, including knowing the young person's friends and activities
• Reduce exposure to antisocial peer influence where possible, and support positive peer and community activities
• Coordinate closely and consistently between home and school
• Address any substance use directly and promptly
• Build in regular, low-conflict positive time between parent and young person, not solely disciplinary interaction

Outcomes vary considerably: adolescent-onset conduct disorder, particularly without limited prosocial emotions, often improves significantly by adulthood, especially with treatment, while childhood-onset conduct disorder carries a higher risk of persisting difficulties, including risk of antisocial personality disorder in adulthood if untreated. Early, sustained, family-involved intervention meaningfully improves outcomes at every level of severity, and identifying and treating co-occurring ADHD, trauma or mood difficulties is an important, sometimes decisive, part of changing the trajectory.

• Support consistent, warm but structured parenting from early childhood
• Identify and treat ADHD, learning difficulties, or trauma-related symptoms early
• Reduce children's exposure to family violence and chronic conflict where possible
• Support positive school engagement and prosocial peer relationships
• Seek assessment and intervention at the first signs of a persistent pattern, rather than waiting for legal or school-disciplinary involvement

A conduct disorder diagnosis is understandably frightening for families, but it is important to know that structured, sustained, family-involved treatment meaningfully changes outcomes, particularly the earlier it starts. Families benefit from consistent expectations and consequences applied calmly rather than punitively, active monitoring and involvement in the young person's life, and close coordination with school. It is also important for families to look after their own wellbeing and, where relevant, address their own mental health or relationship difficulties, since a calmer, more consistent home environment is one of the most powerful supports for a young person's recovery. Avoiding shame and hopelessness — while still taking the behaviour and its impact on others seriously — supports both engagement in treatment and the young person's own motivation to change.

1. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, 5th Edition, Text Revision (DSM-5-TR).
2. National Institute for Health and Care Excellence (NICE). Antisocial behaviour and conduct disorders in children and young people.
3. American Academy of Child and Adolescent Psychiatry (AACAP) practice parameters on conduct disorder.