Response to methylphenidate treatment among adults with ADHD according to comorbidity status.

Introduction and objective: The evaluation of methylphenidate (MPH) response in patients with ADHD has rarely evaluated the effect of comorbidities [1]. The aim of this study is to evaluate response to MPH in patients with ADHD and comorbid disorders. Methods: Sociodemographic variables, comorbidity status and response to MPH were evaluated in 164 patients with ADHD. The analyses were restricted to subjects whose comorbidities did not demand specific treatment before the use of MPH. Results: The diagnosis of current oppositional defiant disorder (ODD) was associated to a larger decrease in inattention (p = 0.05), hyperactivity (p = 0.006) and ODD SNAP scores (p\0.001) following MPH. After adjustment for basal scores, the only dimension that remained significant was SNAP ODD (p = 0.05). Other comorbidities did not present significant effects. Discussion: Overall, the presence of comorbidities does not have a major influence in response to MPH. However, patients with current ODD have a larger decrease in SNAP scores, especially in ODD scores. This effect is mainly explained by pre-treatment severity. Conclusions: These results reinforce the evidence suggesting that MPH may be effective in ODD treatment. [ABSTRACT FROM AUTHOR]