An open trial of adjunctive donepezil in attention-deficit/hyperactivity disorder

Objective: Despite available pharmacotherapeutics, a number of youths with attention-deficit/hyperactivity disorder (ADHD) continue to experience residual symptoms and prominent executive function (EF) deficits resulting in impairment in multiple domains. We sought to determine if donepezil, used adjunctively to stimulant medication, would improve residual symptoms of ADHD and EF deficits. Methods: In a 12-week open trial, we treated 7 children and 6 adults who had ADHD and evidence of further EF deficits with adjunctive donepezil. All subjects were stabilized on stimulants, at which time donepezil was initiated at 2.5 mg daily and increased to a maximum of 10 mg over the 12-week trial. Results: Of 13 subjects receiving medication, 7 completed the trial. There was no clinically or statistically significant improvement in the ADHD Rating Scale and the Executive Function Checklist, our primary outcome measures. A majority of individuals experienced nonserious adverse events. Conclusions: Results of this small open study suggest that donepezil augmentation of stimulants is not well tolerated and does not appear useful for the treatment of residual ADHD and/or EF deficits.