I often get asked at workshops if the increase of media screen time by children causes ADD/ADHD.  I answer this question with a “No, but.”  I am not aware of any brain or media research linking media consumption with ADD or ADHD.  The study that is often cited in this regard is Dimitri Kristakis' study which appeared in the journal Pediatrics several years ago. Kristakis, a University of Washington researcher, found a link between media use before the age of three with "attention problems" when these children reached school age. The attention problems were based on parent and teacher ratings. The media translated these findings into "media causes ADD and ADHD."  The study never made that claim.
 
My own view is that Kristakis' study supports the connection between early childhood media use and distraction. There is a difference between distracted kids and the clinical syndrome of ADD/ADHD. I believe there is abundant evidence that heavy media use is linked to attention problems but not ADD/ADHD.  Interestingly Ed Hallowell, one of the leading experts on ADD/ADHD (author of the best-selling book Driven to Distraction) agrees with this. He and I have presented together and he agrees that we are raising a generation of distracted kids.

Why?  We know that experience drives the neural wiring of children’s brains.  “The neurons that fire together, wire together.”  A brain that is exposed to heavy media use reinforces and wires the reactive attention centers in the brain, the part of the brain that pays attention to movement and sound.  The type of attention kids need for school, however, is focused attention.  This type must be learned and kids cannot learn focused attention from media use.  If kids arrive at school with an over-developed reactive attention center and an underdeveloped focused attention center, the result is a distracted kid.  They just can’t seem to focus on the task at hand and have difficulty staying on task.  

That’s a powerful reason to limit your child’s media use: no media for children under two, one hour a day for preschoolers, and two hours a day for older children.  Make media a fun, but healthy part of your child’s life.

Dr. Dave