Conduct disorder is a complex mental health diagnosis characterized by a repetitive and persistent pattern of behavior that violates societal norms, the rights of others, or age-appropriate rules. The diagnostic criteria for conduct disorder require the presence of at least three problematic behaviors within the past 12 months, with at least one occurring in the past six months. These behaviors are grouped into four categories: aggression toward people and animals; destruction of property; deceitfulness or theft; and serious violations of rules. The severity of symptoms, age of onset, and associated features all play crucial roles in understanding the disorder's impact and prognosis.

Diagnostic Features and Severity

The behaviors defining conduct disorder range from bullying, physical cruelty, and theft, to truancy and property destruction. Severity is categorized as mild, moderate, or severe, based on the number of symptoms and their impact on others. Childhood-onset conduct disorder, marked by symptoms before age 10, is associated with a poorer prognosis compared to adolescent-onset conduct disorder. Those with the specifier "limited prosocial emotions" — such as lack of remorse, callousness, or shallow affect — exhibit a more severe and persistent course.

Associated Factors and Risks

A combination of genetic, environmental, and temperamental factors influences conduct disorder. Risk factors include parental neglect, inconsistent discipline, exposure to violence, and association with delinquent peers. Neurobiological findings, such as reduced autonomic fear responses, and structural differences in brain regions associated with emotional regulation, have been observed but are not diagnostic. Co-occurring conditions, including ADHD, substance use disorders, and mood disorders, are common and can exacerbate the symptoms of conduct disorder.

Developmental Trajectory

Conduct disorder typically emerges during middle childhood or adolescence, often following oppositional defiant disorder. Symptoms evolve with age, beginning with less severe behaviors such as lying and escalating to more severe actions like theft and aggression. While the majority of cases remit by adulthood, childhood-onset conduct disorder is strongly predictive of antisocial personality disorder and other psychosocial difficulties later in life.

Sociocultural and Gender Considerations

The expression of conduct disorder behaviors differs by gender, with boys more likely to exhibit physical aggression and girls more often engaging in relational aggression or truancy. Cultural and environmental contexts, such as systemic oppression or high-crime areas, may influence the prevalence and manifestation of conduct disorder, necessitating careful diagnostic evaluation to avoid bias.

Conduct disorder presents significant challenges for affected individuals, families, and communities. Its association with academic failure, legal issues, and health risks underscores the importance of early intervention and comprehensive treatment approaches tailored to the individual's developmental and social context.