Attention-Deficit/Hyperactivity Disorder (ADHD) Brain Activity Changes to Psychostimulants

The purpose of this study is to examine the neural basis of response inhibition, working memory, and sustained attention in adolescents and adults with Attention-Deficit/Hyperactivity Disorder (ADHD), with particular emphasis on quantifying the effects of methylphenidate (i.e., treatment with psychostimulants) on neural function. Participants will undergo electrophysiological measurement of brain function during laboratory cognitive tasks. This research is aimed to develop a better understanding of how ADHD neural dysfunction relates to clinical presentation and medication response during the transition from adolescence to adulthood. The specific aims and hypotheses are: Specific Aim: To characterize the effect of Ritalin (methylphenidate) on neural activity underlying performance on the response inhibition task in ADHD adolescents and adults. Hypothesis 1) Methylphendiate will increase N2 and P3 amplitude in ADHD persons during medicated EEG sessions; Hypothesis 2) There will be a significant age × medication interaction such that ADHD teens will show increased amplitude of N2 while medicated, particularly at frontal sites, whereas ADHD adults will show differentially greater effect of medication on P3 amplitude and latency at central sites. Hypothesis 3) Brain activity assessed by fMRI will differ between unmedicated and medicated states.