The purpose of this research study is to evaluate whether Vyvanse, a psychostimulant, can help children ages 6-16 with attention deficits due to traumatic brain injury (TBI). Vyvanse is currently approved for the treatment of Attention-Deficit/Hyperactivity (ADHD). The exact effects this drug may have on adults with attention deficits caused by TBI have been investigated prior. The exact effects this drug may have on children with attention deficits caused by TBI are not known, but the investigators expect that Vyvanse will be of some help in treating this population as well.