Factors associated with atomoxetine efficacy for treatment of attention-deficit/hyperactivity disorder in children and adolescents

The aims of this study were to determine if relationships exist between the efficacy of atomoxetine for treatment of attention-deficit/hyperactivity disorder (ADHD) and demographic characteristics, specific co-morbid diagnoses, subtype of ADHD, and/or additional use of a stimulant medication. A retrospective chart review was performed using data from an institutional electronic medical record system. Children aged 5-17 years who were diagnosed with ADHD and prescribed atomoxetine were included; 432 study subjects were categorized as treatment success (TS), treatment failure (TF), or undetermined. Co-morbid diagnoses, demographic factors, subtype of ADHD, and additional use of stimulant medications were examined for association with TS. A total of 88 children were categorized as TS, 197 as TF, and 147 as undetermined. More subjects in the TS group were receiving stimulant medication in addition to the atomoxetine than in the TF group (p = 0.0319; 95% Wald confidence interval [CI], 1.064-3.972). There was no significant difference between groups for any demographic characteristic, the presence of any co-morbid diagnosis, or type of ADHD. In particular, the presence of anxiety or depression was not associated with a response to atomoxetine. Children who were prescribed a stimulant medication in addition to atomoxetine had better outcomes in treating ADHD than those receiving only atomoxetine.