Is childhood oppositional defiant disorder a precursor to adolescent conduct disorder? Findings from a four-year follow-up study of children with ADHD.

OBJECTIVE: To evaluate the overlap between attention-deficit hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD), addressing whether ODD is subsyndromal form of conduct disorder (CD) and, if so, whether it is a precursor or prodrome syndrome of CD.
METHOD: Assessments from multiple domains were used to examine 140 children with ADHD and 120 normal controls at baseline and 4 years later.
RESULTS: Of children who had ADHD at baseline, 65% had comorbid ODD and 22% had CD. Among those with ODD, 32% had comorbid CD. All but one child with CD also had ODD that preceded the onset of CD by several years. ODD+CD children had more severe symptoms of ODD, more comorbid psychiatric disorders, lower Global Assessment of Functioning Scale scores, more bipolar disorder, and more abnormal Child Behavior Checklist clinical scale scores compared with ADHD children with non-CD ODD and those without ODD or CD. In addition, ODD without CD at baseline assessment in childhood did not increase the risk for CD at the 4-year follow-up, by midadolescence.
CONCLUSIONS: Two subtypes of ODD associated with ADHD were identified: one that is prodromal to CD and another that is subsyndromal to CD but not likely to progress into CD in later years. These ODD subtypes have different correlates, course, and outcome.