Once the diagnosis of conduct disorder is established, the prognosis is usually considered to be poor, though the outcome varies. Antisocial personality disorder, which has a particularly poor prognosis, develops in slightly less than 50% of patients with conduct disorder; however, youth with conduct disorder in whom antisocial personality disorder does not develop typically have other long-term problems. Thus, persistent psychopathology is the rule, though its nature can vary.16 Considerable stability is seen in callous–unemotional traits, with stability coefficients of 0.5 to 0.7 among children followed over a period of 4 to 9 years.4 The outcome may be particularly poor if the behavioral problems begin before 10 years of age.17 Some research suggests that such an early onset predicts stronger biologic correlates and greater persistence into adulthood than the later-onset variant.17 However, research has not consistently shown such distinctions for biologic features18 or outcome.19
