The Effects of Dextroamphetamine on Brain Function

The purpose of this study is to determine the effects of the drug dextroamphetamine on the brain function and mood of healthy volunteers. Monoaminergic drugs are substances that affect the nervous system; these drugs can raise, hamper, or have no effect on brain function when given to healthy individuals. Different responses to a drug may be the result of genetic variations. This study will examine the effects of the monoaminergic drug dextroamphetamine on thought and sensorimotor processes while participants perform a variety of tasks. Participants in this study will undergo a medical history, physical examination, blood tests, and an electrocardiogram (EKG). Women of reproductive potential will undergo a pregnancy test. Participants will be given either dextroamphetamine or placebo (an inactive solution) on two occasions separated by at least 3 to 7 days. Participants will then perform neuropsychological tests that will measure attention, problem solving, memory, and ability to complete simple motor tasks.