While DSM-IV Attention-deficit/hyperactivity disorder (ADHD) comorbid with antisocial behaviours
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 present
study investigated the associations of past ODD with past and recent psychopathology in adults with ADHD.
94 clinic-referred adults (73 male; 21 female) with DSM-IV ADHD, and their informants, completed questionnaires.
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 features
of ADHD. In males and females, ratings of past CD (but not of ODD) were correlated with features of personality
The results indicated that ODD ( and a history of ODD) is relevant in studies of the validity of ADHD subtypes
based on comorbid antisocial behaviour. Identification of valid subtypes is important for studies of clinical course
and response to treatment.