In answer to your thread, Metadate is from a family of stimulant medications called methylphenidate, the same thing that Ritalin is derived from. Whereas Vyvanse is Lisdexamfetamine, and is a "Pro-Drug", which is a drug that has no physiological activity of and in itself, but once metabolized by the body (after passing through the liver) it is transformed into an active drug. There is a protein attached to the medication that prevents it from taking effect until after it is processed through the liver, making the Drug non-habit forming. Finding the right medication for your child is always a trial and error process, as there are no set rules one can follow for EVERY child. Most of the time, your Dr. will try a drug from the methylphenidate family (like Ritalin or Focalin XR), and if there is no success, will then try a drug, like Adderall, from the amphetamine or dextroamphetamine family and compare the results. If one medication seemed to work better than the other, the Physician will most likely, then attempt to prescribe different medications in the same family of the medication that had a better effect. Vyvanse is becoming increasingly more popular because many parents see the effects of the medication immediately, and because it cannot be abused like many other medications for ADHD that are on the market. My daughter has Asperger's Syndrome and ADHD, and Vyvanse has worked amazingly for her, as well as my youngest son (who has only ADHD). My oldest son has been on Focalin XR for several years with excellent results, so we have not changed his medication because the Focalin XR DOES work very well for HIM. It was not easy to find the correct medication and dosage for each child, even though they are siblings. It took months of trial and error for each child to find the medication that worked well (and the correct dose of the medication) for their individual needs. I hope that this answers many questions, and that it better informs you of what to expect if you are just embarking on the journey of ADHD with your child. Good Luck!