My son, 8, seems distracted at home and school. His teacher reports he has difficulty following multi-part directions and completing work (though she was quick to note it was not a behavior/attitude problem). When I thought about it, I realized he has similar challenges at home and has for a while -- I always just thought he was slow to get things done. She suggested I consider consulting our pediatrician with our joint concerns. Now I'm wondering if my son may have ADD or ADHD. What is the difference between the two, and what are common red flags? Should I have noticed this earlier?

Many parents become concerned about their child's ability to concentrate or follow directions at some point in their lives. In fact, parents often reach out to pediatricians for concerns related to their child's developmental status or their child's behaviors.

An inability to concentrate or follow multipart directions may be cause to consult your child's pediatrician for more information. Often times, an outsider's perspective (such as the child's teacher) is helpful in identifying or noticing behaviors that might not be expected at various ages. As the parent, you may not see an issue right away, especially if you have no other children to which you can compare your child's performance.

It is important to understand that there is no longer a clinical difference between ADD and ADHD. The appropriate technical term is now ADHD, for anyone diagnosed. There are three categories of ADHD: inattentive, hyperactive, and a combination of the two, which is the most common.

There are different screening and diagnostic tools that can be used to test children for ADHD. For example, the Vanderbilt Rating Scale for ADHD is available in a version specifically for parents, as well as teachers. This could be a good place to start if you and/or your child's teacher has some concerns.

It's also good to know that you can request an evaluation from your child's school. A school-based evaluation is especially important if reasons other than a short attention span are the cause of the child's performance difficulties. If you are concerned, it is always best to reach out to your child's pediatrician and discuss any worries you may have.

Many children with ADHD will be diagnosed by the age of 5-6, as they are entering Kindergarten and first grade. It is at this age that we begin to demand more of them cognitively. Children at this age are expected to sit, pay attention to a specific learning task, or participate in a play or social activity for 15-20 minutes at a time.

Also, by this age, we start to expect children to be able to follow a routine -- and without much prompting. This means that children remember normal classroom routines, such as hanging up their coat and bag when they arrive at school; sitting still at circle time; raising their hands before speaking; and lining up before going outside. However, children can only participate in activities that last 15 to 20 minutes, and can only complete a routine that includes multiple steps, if their attention span has developed sufficiently. A short attention span is a barrier that can interfere with the child's success. There certainly can be other reasons why a child might not be capable of following classroom or home routines despite adequate instruction, but a short attention span is a common reason.

Dr. Erik von Hahn, MDCM, is a developmental-behavioral pediatrician at Floating Hospital for Children at Tufts Medical Center and an associate professor at Tufts University School of Medicine. He is interested in all developmental and behavioral disorders of childhood, and especially in creating collaborative relationships between hospital-based clinicians, school professionals, and families through communication and joint training.