Children with ADHD are diagnosed more often in the early school years.  Children with ADD (without hyperactivity) are sometimes not diagnosed until later in childhood or in their teen years.  Many times, children with ADD do not have the behavioral problems associated with ADHD.  Their inattention may be harder to notice and harder to diagnose.  They may have gotten good grades through elementary school, where parent and teacher support are highest.  They may be very shy, withdrawn and...