I have been noticing that a lot of difficult child's with ADHD and ODD are taking Vyvanse. What is the difference between Vyvanse and Metadate CD? We tried a switch of daughter's medications back in April from Metadate CD to Concerta and her teacher reported that her impulstivity was in full swing and it was like she wasn't medicated. So went back to Metadate CD. Just wondering about the Vyvanse and how it has helped with issues.