BOSTON – Children and adolescents being treated for bipolar disorder and comorbid attention-deficit/hyperactivity disorder may benefit from the short-term use of adjunctive methylphenidate, a study has shown.
The findings add to the growing body of evidence supporting the concomitant treatment of both conditions. Using methylphenidate to treat patients with bipolar disorder has been the subject of controversy in light of concerns that the use of stimulant drugs in bipolar patients could exacerbate or trigger manic symptoms.
In fact, according to lead author Dr. Robert L. Findling of University Hospitals Case Medical Center, Cleveland, the addition of methylphenidate to monotherapy with either lithium or divalproex sodium (DVPX) or to combination therapy with both drugs “did not cause a destabilization of improved mood symptoms” in the 4-week, double-blind, placebo-controlled trial.
To examine the short-term efficacy of adjunctive methylphenidate in this patient population, Dr. Findling and his colleagues enrolled 20 young people aged 5–17 years who met DSM-IV criteria for bipolar disorder and ADHD. At the time of the investigation, all of the study participants were receiving a stable dose of at least one thymoleptic agent, and continued to have clinically significant symptoms of ADHD while euthymic.
As per study protocol, all of the patients received 1 week each of placebo, 5 mg of methylphenidate twice daily, 10 mg of methylphenidate twice daily, and 15 mg of methylphenidate twice daily using a crossover design, and were randomly assigned to receive one of six possible dosing orders.
The primary outcome measure for the study was the total score on the ADHD Rating Scale-IV (ARS-IV), which was completed by the parents. At the end of the study, before breaking the blind, the investigators determined a “best dose” week for each subject based on this measure.
A total of 16 patients, mean age 10.43 years, completed the trial. Of the 16, 12 were receiving combination therapy with DVPX and lithium, 3 were receiving DVPX monotherapy, and 1 was receiving lithium monotherapy.
To assess efficacy, the investigators compared psychometric ratings for the placebo week with those of the best dose week for each patient and observed significant differences for the ARS-IV Inattentive Subscale, the ARS-IV Impulsivity/Hyperactivity Subscale, and the ARS-IV total scores, indicating a therapeutic benefit, Dr. Findling reported in a poster presentation at the annual meeting of the American Academy of Child and Adolescent Psychiatry.
The investigators also used the Clinical Global Impression (CGI) severity scale to evaluate patient response to the therapy relative to the placebo week. The mean CGI-severity score was significantly lower at the best dose week, compared with the placebo week, “suggesting less psychiatric symptomatology,” said Dr. Findling, also of Case Western Reserve University.
The study was supported primarily by the Stanley Medical Research Institute. Study medications were provided, in part, by Abbott Laboratories, Dr. Findling disclosed.