Double-blind, placebo-controlled, crossover study of osmotic release oral system methylphenidate in adults with ADHD with assessment of oppositional and emotional dimensions of the disorder

Background: The realization that attention-deficit/hyperactivity disorder (ADHD) often persists into adulthood has led to increased frequency of diagnosis and treatment in adults. Osmotic release oral system (OROS) methylphenidate is a long-acting stimulant demonstrated to be effective in the treatment of children and adolescents with ADHD. Method: Forty-seven adults entered and 41 completed this double-blind, placebo-controlled, crossover trial of OROS methylphenidate. Each double-blind arm lasted 4 weeks; data were collected from August 2004 through December 2005. Subjects met both DSM-IV-TR and Utah Criteria for ADHD in adults. Outcome measures included the Wender-Reimherr Adult Attention Deficit Disorder Scale (WRAADDS), the adult ADHD-Rating Scale (ADHD-RS), and the Clinical Global Impressions-Improvement scale (CGI-I). At baseline, subjects were categorized as having significant emotional symptoms with the WRAADDS and/or significant oppositional-defiant symptoms using a self-report scale assessing the DSM-IV criteria for oppositional defiant disorder. Results: 17% of the sample (N=8) had ADHD alone, 38% (N=18) had ADHD plus significant emotional symptoms, and 40% (N=19) had ADHD with both significant emotional and oppositional symptoms. At a mean +/- SD dose of 64.0 +/- 23.3 (0.75 mg/kg), OROS methylphenidate proved superior to placebo for all clinical measures: total WRAADDS score decrease of 42% versus 13%, respectively, p<.001 and total ADHD-RS score decrease of 41% versus 14%, respectively, p=.003, plus the subscales addressing inattention, hyperactivity/impulsivity, and emotional dysregulation. Conclusions: OROS methylphenidate proved effective in treating adult ADHD. ADHD alone was relatively uncommon. Over 80% of our patients had ADHD with a combination of emotional and/or oppositional symptoms.