Personality disorder in ADHD Part 1: Assessment of personality disorder in adult ADHD using data from a clinical trial of OROS methylphenidate.
BACKGROUND
Comorbidity of personality disorder (PD) and attention-deficit/hyperactivity disorder (ADHD) has been suggested in several reports. However, assessment of PD is problematic, and studies have over-relied on baseline evaluations.


METHODS
Forty-seven patients entered a double-blind trial of osmotic release oral system (OROS) methylphenidate (MPH). Patients were assessed at baseline with the Wisconsin Personality Inventory IV (WISPI-IV) and the Structured Clinical Interview for DSM-IV Axis II Personality Disorders (SCID-II). Following the study, all information-including tests, family reports, and extended clinical observations-produced a final PD diagnosis. Three post hoc categories were created: PD-negative (no PD), PD-positive (1 PD), and PD-plus (2 or more PDs).


RESULTS
Twenty-one (45%) patients had a PD on the final assessment vs 62% using SCID-II and 33% using WISPI-IV; final PD diagnosis revealed 9% cluster A, 17% cluster B, and 28% cluster C. Twenty-one percent of patients experienced multiple disorders. Using a weighted kappa, the number of PDs on the final assessment correlated with the WISPI-IV (kappa=.53; P > .001) and the SCID-II (kappa =.70; P < .001). However the SCID-II overidentified and the WISPI-IV underidentified PD.


CONCLUSIONS
Almost all PDs were represented in this sample, and past emphasis on cluster B appears unwarranted. Although the SCID-II and WISPI-IV had limited success in identifying specific PDs, they were more successful in identifying the number of PDs present in each patient. The small sample makes these findings preliminary.
Williams
Erika D
ED
Mood Disorders Clinic, Department of Psychiatry, University of Utah, Salt Lake City, UT 84132, USA.
Reimherr
Frederick W
FW
Marchant
Barrie K
BK
Strong
Robert E
RE
Halls
Corinne
C
Soni
Poonam
P
Gale
Phillip D
PD
Robison
Reid J
RJ
D000328:Adult; D001289:Attention Deficit Disorder with Hyperactivity / Q000175:diagnosis / Q000188:drug therapy* / Q000453:epidemiology*; D000697:Central Nervous System Stimulants / Q000627:therapeutic use*; D015897:Comorbidity; D039721:Diagnostic and Statistical Manual of Mental Disorders; D018765:Dopamine Uptake Inhibitors / Q000627:therapeutic use; D006801:Humans; D008774:Methylphenidate / Q000627:therapeutic use*; D010552:Personality Assessment; D010554:Personality Disorders / Q000145:classification / Q000175:diagnosis* / Q000453:epidemiology*; D011581:Psychological Tests; D016032:Randomized Controlled Trials as Topic
D000697:Central Nervous System Stimulants; D018765:Dopamine Uptake Inhibitors; D008774:Methylphenidate