This is a multinational study with sites in the US, India, Singapore, South Korea, Mexico and Chile. There will be 210 subjects (male or female) enrolled that are residing in community or facilities with a reliable caregiver that have been clinically diagnosed with Down syndrome. The assessments performed during this study will be used to evaluate skills. The study duration will be 10 weeks of double blind treatment with a total of 6 visits; 4 in office visit and 2 phone visits.