We next examined whether pure cases of irritable and headstrong ODD could be identified within the DSM-IV diagnostic framework. The factor analysis identified 3 symptoms loading onto the irritability factor, and 5 symptoms loading onto the headstrong factor. Because DSM-IV criteria for ODD require 4 symptoms to be present, at least one headstrong symptom must be endorsed in all cases to reach the diagnostic threshold. Across the full 9-16 age-range, almost all cases that met ODD criteria also showed at least some level of irritability: only 3.3% had no irritability symptoms, 18.8% had one, 52.9% had two and 25.0% had three. These figures suggest few cases of ‘pure’ headstrong ODD exist within the DSM framework; most youth reaching the diagnostic threshold showed a mixed symptom pattern.
