The effect of personality disorder symptoms on response to treatment with methylphenidate transdermal system in adults with attention-deficit/hyperactivity disorder.

OBJECTIVE

This trial was designed to prospectively explore the relationship among personality disorder (PD) symptoms, attention-deficit/hyperactivity disorder (ADHD), and treatment response in a randomized, double-blind, crossover clinical trial of methylphenidate transdermal system (MTS) and to confirm results of a prior exploratory study.

METHOD: 67 adults who met the Utah and/or DSM-IV-TR criteria for ADHD were recruited with no attempt to include or exclude patients with PD. Responders were defined by a 50% improvement on the Wender-Reimherr Adult Attention Deficit Disorder Scale (WRAADDS), the primary outcome measure. Personality disorder was diagnosed by the clinicians using the Structured Clinical Interview for DSM-IV-TR Axis II Personality Disorders Questionnaire, several self-report scales, and clinical observations. Subjects were categorized as: no PD (PD-negative), 1 PD (PD-positive), and 2 or more PDs (PD-plus). The study was conducted from February 2007 to December 2009 at the Mood Disorders Clinic at the University of Utah School of Medicine, Salt Lake City.

RESULTS

37% (n = 25) were PD-positive, and another 27% (n = 18) were PD-plus. In those with a PD, 65% (n = 28) had a cluster C diagnosis, 44% (n = 19) cluster B, and 5% (n = 12) cluster A. PD-plus subjects had significantly higher levels of oppositional defiant disorder (ODD) symptoms (P = .007) and emotional dysregulation (P = .004). 71% (15/21) of the PD-positive and PD-negative subjects were responders in the MTS arm (P < .001) as opposed to 38% (6/16) of the PD-plus subjects (P = .24). Conversely, the interaction between treatment (placebo versus MTS) and the 3 PD groups was not statistically significant (P = .46) when the total WRAADDS was used as the outcome measure.

CONCLUSIONS

Personality disorder status was associated with more complex ADHD, especially high levels of emotional dysregulation and ODD symptoms. There was a significant treatment effect for PD-positive and PD-negative, but not PD-plus subjects.

TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT00506285.