BACKGROUND: This study explored the relationship between the dimensions of adult attention-deficit/hyperactivity disorder (ADHD), personality disorder (PD), and adverse social adjustment.

METHODS: In a controlled trial of osmotic release oral system methylphenidate, PD was assessed using the Wisconsin Personality Disorders Inventory IV (WISPI-IV), the Structured Clinical Interview for DSM-IV Axis II Personality Disorders (SCID-II), and a final consensus diagnosis. Participants were categorized 2 ways: (1) ADHD alone, ADHD with emotional dysregulation (ADHD + ED), and ADHD plus emotional dysregulation plus oppositional symptoms (ADHD + ED + ODD); and (2) those with no PD (PD-negative), 1 (PD-positive), and 2 or more (PD-plus) PDs.

RESULTS: None of the ADHD-alone patients had a PD compared with 33% of ADHD + ED patients and 68% of ADHD + ED + ODD patients. The level of ADHD-related emotional and oppositional symptoms correlated significantly with the severity of PD dimensions as assessed by WISPI-IV z scores and the number of items endorsed on the SCID-II screening questionnaire. Complex presentations (define by both ADHD and personality categories) were associated with high childhood ADHD ratings and problems in work, extended family, and economic functioning.

CONCLUSION: The ADHD symptoms of emotional dysregulation and oppositional symptoms were associated with increased Axis II disorders. Adverse outcomes were concentrated in patients with ADHD combined with emotional and oppositional symptoms, and in those with comorbid PDs.