Effect of Vyvanse on Sleep in Children Aged 6-12 Years With Attention Deficit Hyperactivity Disorder (ADHD)

Inclusion Criteria: 1. Male or female subject 6 to 12 years of age, inclusive 2. Subject meets DSM-IV-TR criteria for a primary diagnosis of ADHD 3. Female subjects of childbearing potential (FOCP) must have a negative urine pregnancy test 4. Subject must be in general good health 5. Subject's parent or legally authorized guardian provides signature of informed consent, and there is documentation of assent by the subject. 6. Subject and parent/caregiver are willing and able to comply with all the testing and requirements defined in the protocol. 7. Subject is generally functioning academically at age-appropriate levels 8. Subject is able to swallow a capsule. 9. Subject and parent/guardian are willing to comply with entire visit schedule for the study and Sleep Hygiene Instructions Exclusion Criteria: 1. Subject has a comorbid psychiatric diagnosis that contraindicates VyvanseTM treatment or would confound efficacy or safety assessments. 2. Subject has any comorbid illness that could interfere with participation in the study. 3. Subject is a known non-responder to an adequate trial of stimulant medication for ADHD. 4. Subject has history of symptoms or has an identified sleep disorder 5. Subject has a history of seizure during the last 2 years 6. Subject is significantly overweight or obese 7. Subject has any clinically significant ECG or laboratory abnormalities at screening or baseline. 8. Subject has any specific cardiac condition or family history of cardiac disease 9. Subject is taking medications that affect blood pressure or heart rate (except current ADHD therapy, if any). 10. Subject has a positive urine drug result at screening (except current ADHD therapy, if any). 11. Subject is hypertensive. 12. Subject has any documented adverse reactions, allergy, or intolerance to amphetamines or dextroamphetamines. 13. Subject is taking exclusionary medications 14. Subject currently has (or had a history in the previous 12 months) a drug dependence or substance abuse disorder 15. Subject has taken another investigational product or taken part in a clinical trial within the 30 days prior to Screening (Visit 1).