Associations of Past Oppositional Defiant Disorder in Adults with Attention- Deficit/Hyperactivity Disorder

Objective: While DSM-IV Attention-deficit/hyperactivity disorder (ADHD) comorbid with antisocial behav- iours identified by DSM-IV conduct disorder (CD) has been claimed as a 'distinct subtype', there is less information about the validity of a subtype based on the more prevalent comorbidity of oppositional defiant disorder (ODD). The pre- sent study investigated the associations of past ODD with past and recent psychopathology in adults with ADHD. Methods: 94 clinic-referred adults (73 male; 21 female) with DSM-IV ADHD, and their informants, completed question- naires. Results: 59% of males had past ODD (with or without past CD), 42% had past CD (with or without past ODD) and 36% had past ODD and past CD; for females, 57%, 33% and 29% respectively. In males with the DSM-IV ADHD 'combined' type (i.e. the most common presentation of ADHD), ratings of past ODD, when compared with those of past CD, were more strongly correlated with past and recent ADHD-related hyperactivity/impulsivity and with past and recent functional impairment. In females, ratings of past ODD, compared with those of past CD, also yielded stronger correlations with fea- tures of ADHD. In males and females, ratings of past CD (but not of ODD) were correlated with features of personality disorders. Conclusions: The results indicated that ODD ( and a history of ODD) is relevant in studies of the validity of ADHD sub- types based on comorbid antisocial behaviour. Identification of valid subtypes is important for studies of clinical course and response to treatment.