conduct disorder

**Definition (DSM-5-TR):** Repetitive and persistent pattern of behavior violating the rights of others or age-appropriate norms, with ≥3 of 15 criteria in the past 12 months and ≥1 in the past 6 months. The behavior must cause clinically significant impairment in social, academic, or occupational functioning.

**Four criterion categories:** 1. Aggression to people and animals (bullying, fights, weapon use, physical cruelty to people/animals, mugging, forced sex) 2. Destruction of property (fire-setting, vandalism) 3. Deceitfulness or theft (breaking and entering, lying to obtain goods, shoplifting) 4. Serious violations of rules (truancy before age 13, running away overnight, staying out at night despite parental prohibition before age 13)

**Subtypes/specifiers:** - Childhood-onset (≥1 symptom before age 10), which has a worse prognosis, is more often male, and has more ADHD comorbidity - Adolescent-onset - Unspecified onset - "With limited prosocial emotions" (callous-unemotional traits): lack of remorse/guilt, lack of empathy, unconcern about performance, shallow affect. This specifier predicts a more severe, stable course and is the closest childhood analog of psychopathy.

**Epidemiology and risk factors:** - More common in males - Genetic and temperamental factors (difficult temperament, low IQ, low autonomic reactivity) - Environmental factors: child abuse/neglect, harsh or inconsistent parenting, parental criminality or substance use, family conflict, poverty, peer rejection or deviant peers - Neurobiology: reduced amygdala and prefrontal (ventromedial) function, low resting heart rate and low cortisol reactivity

**Comorbidities:** ADHD (very common), oppositional defiant disorder (ODD), substance use disorders, depression/anxiety, learning disorders, and PTSD.

**Differential diagnosis:** - **ODD:** Defiant, angry, vindictive behavior toward authority figures, but without violating others' basic rights. ODD is less severe and often precedes conduct disorder. - **ADHD:** Impulsivity without a pattern of rights violations (though the two often co-occur). - **Antisocial personality disorder:** Age ≥18 with a pattern of disregard for others' rights and a history of conduct disorder before age 15. - **Mood disorders, intermittent explosive disorder, adjustment disorder:** Consider these if the behaviors do not fit the pattern above.

**Management:** - First line is psychosocial: parent management training (PMT) and multisystemic therapy (MST) for adolescents. Cognitive-behavioral and problem-solving skills training are also used. - No medication is FDA-approved for conduct disorder. Treat comorbid conditions (e.g., stimulants for ADHD). Atypical antipsychotics (e.g., risperidone) or mood stabilizers may be used for severe aggression, but only as adjuncts.

**Prognosis/High-yield points:** - A substantial proportion of those with childhood-onset conduct disorder (especially with callous-unemotional traits) progress to ASPD. - Other adult outcomes include substance use disorders, incarceration, and mood disorders. - Boards classic: a child or adolescent with truancy, cruelty to animals, fire-setting, and fighting. If the patient is under 18, the diagnosis is conduct disorder; if 18 or older with a conduct disorder history, it is ASPD. - The triad of enuresis, fire-setting, and cruelty to animals (the "Macdonald triad") is historically linked to later violence, but it has poor predictive validity.