• To assess the effect of Vyvanse on brain hemodynamics during attention & reading tasks in children with ADHD. [ Time Frame: 6-8 weeks ] [ Designated as safety issue: No ]
  

Drug: Vyvanse
Subject's will participate in an open-label dose optimization period and successful titration to an optimal dose of Vyvanse™, subjects will take their optimized dose of Vyvanse™ (30, 50 or 70 mg/day) during the week leading up to their final visit. During the study subject's will take their prescribed dose once a day in the morning with breakfast.

Inclusion Criteria:

1. Females of child-bearing potential must have a negative pregnancy test.
2. Subjects must meet DSM-IV-TR™ criteria for a primary diagnosis of ADHD.
3. Subjects must have an ADHDRS-IV-Parent: Inv total score at least 1.5 standard deviations above the age and gender norms.
4. The subject is functioning at an age appropriate level intellectually as determined by an IQ score of ≥ 80 on the Kaufman Brief Intelligence Test.
5. The subject and subject's parent or legal guardian must be willing and able to comply with all the testing and dosing requirements in this study.
6. Subject has blood pressure measurements within the 95th percentile for age, gender, and height.
7. All subjects and their parents must be able to communicate effectively in English with the doctor and his/her staff without the aid of an interpreter.

Exclusion Criteria:

1. Subject has any documented, current, controlled psychiatric illness [except Oppositional Defiant Disorder (ODD)]. The child may continue participating in a behavior modification program during this study as long as he/she has been participating in the program for at least one month at the time of the baseline visit.
2. Subject has Conduct Disorder (CD).
3. Subject has a documented allergy, hypersensitivity or intolerance to amphetamines, which is the class of drug to which Vyvanse™ belongs.
4. Subject has failed to respond to one or more adequate courses (dose and duration) of amphetamine therapy.
5. Subject has a recent history (within the past 6 months) of suspected substance abuse or dependence disorder (excluding nicotine).
6. Subject had a history of seizures during the last two years (exclusive of febrile seizures), a tic disorder, or a current diagnosis and/or family history of Tourette's Disorder.
7. Subject has a history of heart abnormalities that the study doctor feels would exclude him/her from the study.
8. Subject has a positive urine drug result at the screening visit.
9. Subject weighs less than 50 pounds (22.7 kg).
10. Subject has taken another investigational drug within the last 30 days prior to the screening visit.
11. Subject has any reported history of abnormal thyroid function.
12. Subject has any clinically significant electrocardiogram reading (an electrical recording of the heart - ECG) or laboratory abnormalities at the screening and/or baseline visits.
13. The study doctor feels that the subject's safety would be jeopardized if entered in this study due to a current illness or medical condition. Mild, stable asthma is not exclusionary.
14. Subject is taking any medication that is excluded.