Methylphenidate in the treatment of children and adolescents with bipolar disorder and attention-deficit/hyperactivity disorder.

Objective: To examine the short-term efficacy of methylphenidate in the treatment of youths with bipolar disorder (BD) and comorbid attention deficit/hyperactivity disorder (ADHD).

Method: A 4-week double-blind, placebo-controlled trial in youths ages 5 to 17 years was conducted. Subjects met DSM-IV criteria for bipolar disorder and ADHD, were currently receiving a stable dose of at least one thymoleptic, and while euthymic continued to have clinically significant symptoms of ADHD. Patients received 1 week each of placebo, methylphenidate 5 mg twice daily, methylphenidate 10 mg twice daily, and methylphenidate 15 mg twice daily using a crossover design. Subjects were randomly assigned to receive one of six possible dosing orders. At study's end, and before the blind being broken, a "best dose week" for each subject was determined. The primary outcome measure was the total score on the parent-completed ADHD Rating Scale-IV.

Results: Sixteen patients, with a mean age of 10.43 (SD 3.14) years completed the trial. Lower scores during best dose treatment compared to the week of placebo treatment were found on the ADHD Rating Scale-IV (p < .05), suggesting a therapeutic benefit. A large effect size (Cohen's d = 0.90) was found for methylphenidate. Treatment was generally well tolerated.

Conclusions: Euthymic youths with bipolar disorder and ADHD may benefit from short-term concomitant treatment with methylphenidate.