Conduct Disorder

Clinical picture

• Aggression toward people and animals including bullying, fighting, weapon use, cruelty, robbery, and forced sexual activity.
• Deliberate property destruction through fire setting or vandalism intended to cause substantial damage or loss to others.
• Deceitfulness and theft, including breaking and entering, conning others for goods or favors, and shoplifting without confrontation.
• Serious rule violations such as staying out at night before age 13, running away overnight, and chronic truancy from school.
• The limited prosocial emotions phenotype shows shallow affect, absent remorse, callous use of others, and unconcern about performance.
• Presentation commonly includes early substance use, early sexual activity, school exclusion, and juvenile justice system contact.

Criteria snapshot

• Requires three or more of fifteen criteria within the past 12 months, with at least one criterion present in the past 6 months.
• Criteria span four clusters: aggression to people and animals, destruction of property, deceitfulness or theft, and serious rule violations.
• Specify childhood-onset type when a criterion is present before age 10, adolescent-onset type, or unspecified onset when timing is unknown.
• Specify with limited prosocial emotions when two or more callous-unemotional features persist across settings for at least 12 months.
• Severity is rated mild, moderate, or severe based on the number of symptoms and the degree of harm caused to other people.

Neurobiology

• Reduced amygdala reactivity to fearful faces and impaired fear conditioning characterize the callous-unemotional subtype.
• Reduced gray matter in ventromedial prefrontal cortex, orbitofrontal cortex, and anterior insula tracks antisocial behavior severity.
• Low resting heart rate is among the best-replicated biological correlates of antisocial and aggressive behavior in youth.
• A hypoactive HPA axis with blunted cortisol reactivity and altered serotonergic function is linked to impulsive aggression.
• Heritability is roughly 50% and higher for callous-unemotional traits, with strong gene-by-environment interplay throughout development.
• Childhood maltreatment, prenatal substance exposure, and lead exposure interact with genotype, including MAOA variants, to raise risk.

Psychology

• Social information processing biases include hostile attributions, limited response generation, and positive outcome expectancies for aggression.
• Coercive family process combined with deviant peer affiliation supplies both the training and the reinforcement for antisocial acts.
• Callous-unemotional youth show reward-dominant responding and poor punishment learning, which blunts standard consequence-based discipline.
• Reactive aggression follows perceived threat and provocation, whereas proactive aggression is planned, goal-directed, and instrumental.
• Group treatment that aggregates delinquent peers risks deviancy training and iatrogenic worsening of antisocial behavior.

Differential & comorbidity

• ODD lacks aggression, destruction, deceit, and serious rule violations, while intermittent explosive disorder lacks the nonaggressive criteria.
• Bipolar disorder, psychosis, PTSD, and substance intoxication can produce aggression without the chronic pervasive antisocial pattern.
• ADHD co-occurs in 30-50%, substance use disorders rise sharply in adolescence, and depression is common and raises suicide risk.
• Screen for trauma exposure, exploitation, gang involvement, firearm access, and fire setting at every assessment contact.
• Suicide attempts, homicide, serious injury, and premature mortality are all elevated well above general population rates.

Pharmacologic treatment

• No agent is approved for conduct disorder itself; medication targets comorbidity and severe aggression rather than the diagnosis.
• Risperidone 0.5-3 mg/day has the strongest evidence for severe aggression; monitor weight, lipids, glucose, and prolactin.
• Stimulants for comorbid ADHD reduce aggression with moderate to large effect and should be optimized before any antipsychotic.
• Lithium and valproate have limited support for impulsive aggression and require serum levels and hepatic or renal monitoring.
• Treat substance use disorders directly, since ongoing use undermines essentially every psychosocial intervention attempted.

Psychotherapy

• Multisystemic therapy, delivered in home over 3-5 months with low caseloads, reduces reoffending and out-of-home placement.
• Functional family therapy across 12-16 sessions targets family communication and reduces recidivism in justice-involved adolescents.
• Multidimensional Treatment Foster Care outperforms group residential care for severe, chronically offending adolescents.
• Parent management training and PCIT remain first line for childhood-onset cases in children under about age 12.
• Avoid aggregating antisocial youth in unsupervised groups, boot camps, and scared-straight programs, which can worsen outcomes.

Adjunct options

• Assess with the CBCL, callous-unemotional measures such as the ICU, and structured violence risk tools such as the SAVRY.
• Coordinate care across school, juvenile justice, and child welfare systems, since fragmented plans reliably predict treatment failure.
• Educational placement, vocational training, and sustained mentoring build alternatives to antisocial sources of reinforcement.
• Restrict firearm access, address neighborhood violence exposure, and structure unsupervised after-school and evening hours.
• Reserve residential care for imminent safety risk, prioritizing family-based and community-based alternatives whenever feasible.

Clinical pearls

• Childhood onset with callous-unemotional traits predicts the worst trajectory.
• Family- and community-based care beats group residential care for antisocial youth.
• Treat ADHD and substance use; both amplify aggression and undermine therapy.