Hi slse174,
Thank you for your question! Adderall (regular Adderall, not the XR formulation) is approved for children over age 3. Dexedrine is approved for children over age 3.
Adderall XR, Concerta, Ritalin (all formulations - original, LA, and SR), Focalin (original and XR), and Strattera are not approved for children under the age of 6. Just because a medication is not approved for use in younger children doesn't mean it can't be used. Medications are only approved for age ranges in which they've been tested. Most likely, these medications have not been tested in children younger than 6 years old, so there's no data to say whether they're safe or harmful in young children.
This list is not all-inclusive. These are some of the more commonly prescribed medications for ADD/ADHD. You should discuss with your doctor your child's symptoms, and he or she will be able to decide what the best treatment is for your child at this time.
You can follow this link to get a list of articles and more information about ADHD in children.
Best of luck,
Casey