Objective: Auditory cognitive evoked potential (P300) topography was reported to predict robust response to the stimulants pemoline and extended-release methylphenidate in patients with attention-deficit/hyperactivity disorder (ADHD). Patients with a right fronto-central to parietal auditory P300 amplitude ratio >0.5 respond robustly to stimulants, others do not. This exploratory study was performed to demonstrate whether the P300 predicts treatment response to the selective norepinephrine re-uptake inhibitor, atomoxetine.
Methods: Patients aged 6-17 with DSM-IV diagnosis of ADHD were administered P300 testing. They then underwent open-label treatment with atomoxetine. Robust response was defined as a 60% decrease from baseline in the ADHD rating scale (parent version, investigator rated).
Results: Ten of 17 subjects responded robustly. They did not differ from the non-robust responders in age, baseline attention or hyperactivity ratings, or any P300 parameter except 31-electrode mean auditory P300 amplitude (mean AA). Mean AA >6.8 microV predicted robust response with positive predictive value of 0.88 and negative predictive value of 0.67.
Conclusions: Mean AA seems to predict response to atomoxetine in patients with ADHD.
Significance: As non-stimulant treatments are approved for the treatment of ADHD, tests such as this may help pinpoint whether to use a stimulant or a medicine with some other mechanism of action.