What is Conduct Disorder?
Conduct disorder (CD) is a psychiatric syndrome occurring in childhood and adolescence, characterized by a repetitive and persistent pattern of behavior that violates the basic rights of others and major age-appropriate social norms—specifically including aggression toward people or animals, destruction of property, deceitfulness or theft, and serious violations of rules 1.
Diagnostic Criteria
To diagnose conduct disorder, at least three symptoms must have been present in the past 12 months, with at least one present in the past six months 1. The disorder encompasses both:
- Aggressive symptoms: Physical aggression toward people or animals
- Nonaggressive symptoms: Rule violations, truancy, deceitfulness, property destruction 2
Epidemiology and Demographics
The prevalence varies significantly:
- Approximately 1 in 30 preschoolers meets criteria for CD 3
- 1 in 14 meets criteria for oppositional defiant disorder (ODD), a related but distinct condition 3
- Male-to-female ratio ranges from 2.0-2.5:1 4
- Administrative prevalence varies dramatically by country (0.1% to 3.1%), though worldwide community prevalence is estimated at 2-4% 4
Clinical Presentation and Heterogeneity
Despite diagnostic criteria suggesting homogeneity, individuals with CD constitute a highly heterogeneous group 5. The disorder includes an important specifier:
Callous-Unemotional (CU) Traits
DSM-5 added a specifier for "limited prosocial emotions" (callous-unemotional traits), which represents the most relevant diagnostic change 2. These traits include:
- Lack of empathy
- Absence of guilt
- Shallow emotions
- Association with more severe antisocial and aggressive behaviors 6
Risk Factors
Key risk factors include 1:
- Male sex
- Maternal smoking during pregnancy
- Childhood poverty
- Exposure to physical or sexual abuse
- Exposure to domestic violence
- Parental substance use disorders or criminal behavior
Strong genetic liability interacts with parenting and environmental factors to produce elevated CD symptoms 6.
Course and Prognosis
CD exhibits considerable stability, particularly when symptoms start at an early age 5. The disorder:
- Can be detected in early childhood
- May remain stable through adolescence
- Confers risk for later psychopathology, family dysfunction, and criminality 3
- Often precedes a range of adult-onset mental disorders, not just antisocial personality disorder 7
Comorbidity
CD frequently co-occurs with other psychiatric conditions, with comorbidity rates ranging from 69.7% to 86.1% 4. The most common comorbidity is attention-deficit/hyperactivity disorder (ADHD) 4. The high comorbidity reflects shared genetic liability across multiple mental disorders 7.
Common Pitfalls
A critical caveat: Clinicians should not view CD solely as a precursor to antisocial personality disorder. Recent evidence demonstrates that CD is associated with polygenic risk for several child- and adult-onset mental disorders, reflecting the heterogeneous nature of this condition 7. This broader conceptualization should inform diagnostic assessments and clinical follow-up 7.