Atomoxetine as an Adjunct Therapy in the Treatment of Co-Morbid Attention-Deficit/Hyperactivity Disorder in Children and Adolescents with Bipolar I or II Disorder

Abstract

Atomoxetine has been proposed to be effective for treating co-morbid attention-deficit/hyperactivity disorder (ADHD) in children with bipolar disorder (BPD) without destabilizing mood. We conducted an 8-week, open label study to study the efficacy and tolerability of adjunct atomoxetine in euthymic children and adolescents with BPD and ADHD. We evaluated 12 youth aged 6-17 years (mean = 11.3 years; 7 males) with a diagnosis of BPD I or II and ADHD. Subjects were euthymic at baseline and taking at least one mood stabilizer or antipsychotic. Primary outcome measure was the ADHD Rating Scale-IV (ADHD-RS-IV) (response = 25% decrease; remission = 40% decrease). Secondary outcome measures were change in Young Mania Rating Scale (YMRS) and Children's Depression Rating Scale (CDRS). In primary outcome criteria, 8 (67%) were responders and 6 (50%) were remitters by ADHD-RS criteria. There was a significant decrease in ADHD-RS scores over the study (p < 0.0001; Cohen d = 2.18, effect size = 0.73). YMRS and CDRS scores did not change significantly from baseline to week 8. No subjects experienced a manic or mixed episode during the study, but 2 subjects were discontinued early due to worsening of mood symptoms. We found atomoxetine to be efficacious in treating symptoms of ADHD in children and adolescents with BPD taking mood stabilizers or antipsychotics. It is unclear whether symptomatic worsening of 2 subjects was due to atomoxetine or the natural course of illness. Placebo-controlled studies are needed to clarify the role of atomoxetine in this population.