Conduct disorder is a disorder characterized by behaviors that violate social rules or cause harm to others. These behaviors often incur a high cost to families involved and to broader social spheres and legal bodies. The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), classifies problems of conduct in the category of disruptive, impulse-control, and conduct disorders, which all share a general difficulty with self-control of emotions and behaviors. Other disorders under this classification include oppositional defiant disorder (ODD), intermittent explosive disorder, antisocial personality disorder (ASPD), pyromania, and kleptomania. This entry examines the nature of conduct disorder, its prevalence and comorbidity, assessment, course, and risk factors.