Personality characteristics of ADHD adults assessed with the millon clinical multiaxial inventory-II: Evidence of four distinct subtypes

This study compared the personality characteristics of 104 adults diagnosed with attention deficit hyperactivity disorder (ADHD). Personality features were assessed with the MCMI-II(Millon, 1987). Participants were divided in to 4 groups based on the presence of persisting oppositional defiant disord er (ODD) or other comorbid diagnoses (ADHD only, ADHD-comorbid, ADHD-ODD, A DHD-ODD-comorbid). Significant differences between these groups were presen t for 9 of the 13 MCMI-Il personality scales, resulting in 4 modal personal ity styles. ADHD-only adults evidenced mild histrionic traits, whereas the ADHD-comorbid group was more often avoidant and dependent in personality st yle. ADHD-ODD adults showed histrionic, narcissistic, aggressive-sadistic, and negativistic traits whereas the ADHD-ODD-comorbid group had a combinati on of avoidant, narcissistic, antisocial, aggressive-sadistic, negativistic , and self-defeating personality features. Implications for treatment are d iscussed.