ABSTRACT
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. CONCLUSION: 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.
Subject(s)
Attention Deficit Disorder with Hyperactivity/drug therapy , Attention Deficit Disorder with Hyperactivity/epidemiology , Central Nervous System Stimulants/therapeutic use , Methylphenidate/therapeutic use , Personality Disorders/diagnosis , Personality Disorders/epidemiology , Adult , Attention Deficit Disorder with Hyperactivity/diagnosis , Comorbidity , Diagnostic and Statistical Manual of Mental Disorders , Dopamine Uptake Inhibitors/therapeutic use , Humans , Personality Assessment , Personality Disorders/classification , Psychological Tests , Randomized Controlled Trials as TopicABSTRACT
BACKGROUND: This study explored the relationship between personality disorder (PD) and treatment response in a randomized, double-blind, clinical trial of osmotic release oral system (OROS) methylphenidate (MPH). METHODS: Forty-seven patients entered a crossover trial using the Wender-Reimherr Adult Attention Deficit Disorder Scale (WRAADDS) to assess outcome. A final personality diagnosis was made using staff consensus and information from the Wisconsin Personality Inventory IV (WISPI-IV) and the Structured Clinical Interview for DSM-IV Axis II Personality Disorders (SCID-II). Three post hoc categories were created: PD-negative (no PD; n = 26), PD-positive (patients with 1 PD; n = 11), and PD-plus (patients with 2 or more PDs; n = 10). Improvement in attention-deficit/hyperactivity disorder (ADHD) symptoms was assessed using a mixed-model analysis with treatment and personality categories as fixed variables. Average z scores on the WISPI-IV and items endorsed on SCID-II provided dimensional measures of PD severity. RESULTS: Different treatment effects were observed for the PD subgroups (P < .001). PD-negative patients improved 40% on OROS MPH vs 7% on placebo, and PD-positive patients improved 66% on OROS MPH vs 9% on placebo. In contrast, PD-plus patients improved 26% on OROS MPH vs 23% on placebo. CONCLUSION: Most patients experienced significantly reduced ADHD symptoms on OROS MPH; however, patients with 2 or more PDs did not. The 2 alternate measures of PD supported this observation in this small exploratory study.
