Differential diagnosis of oppositional defiant and conduct disorder utilizing the Millon Adolescent Clinical Inventory

Studying disruptive behavior disorders in adolescents is critical; however, there is a paucity of literature on methods for differentially diagnosing the two main disruptive behavior disorders: Oppositional Defiant Disorder and Conduct Disorder. Conduct Disorder is defined as a persistent pattern of behavior where the basic rights of others or other major social norms are violated whereas Oppositional Defiant Disorder is usually diagnosed in childhood or adolescence, and is defined by a pattern of disobedient, hostile, or defiant behavior towards authority figures. Despite some similarities in presentation, the majority of research supports the notion that these two disorders are distinct. Finding accurate ways to differentiate these two disorders is important for discovering and implementing empirically validated treatments. The primary purpose of this study was to determine how the Millon Adolescent Clinical Inventory, a commonly used self-report scale, distinguished between adolescents presenting with either Oppositional Defiant or Conduct Disorder who had been admitted to a residential treatment facility. A secondary component of the current study examined gender differences in the two disorders.Multivariate Analysis of Variance was used to determine if the two diagnostic or gender groups were significantly different. If so, discriminant function analysis was employed to determine where the difference occurred. Although some scales approached significance, there were no statistical differences among adolescents with Conduct Disorder and Oppositional Defiant Disorder across any of the dependent variables. There were, however, gender and age differences found across several scales. Unfortunately, because there were no interactions with diagnosis on any scales, differences occurred equally among adolescents from either diagnostic group. This result raises questions as to whether the Millon Adolescent Clinical Inventory is a useful diagnostic instrument for disruptive behavior disorders. This instrument may be more useful to determine individual characteristics that would impact treatment than as an instrument for researchers studying empirically validated interventions for Conduct Disorder and Oppositional Defiant Disorder.Department of Educational PsychologyThesis (Ph. D.