The L.A. Times  has reported on a study done by Ghent University in Belgium, on the effects of video games on teens. They took a group of kids, divided them up by how much time they spent gaming and looked at how much their brain size grew by and where it grew in the brain.

They recruited 154 fourteen year olds, and divided them into groups of girls and boys who play more then nine hours of games a week and less then nine hours a week. They then took MRI images of their brains and the results showed that those teens who gamed nine hours or more, had more grey matter in the left ventral striatum, which affects the interplay of emotions and behavior. It also showed greater activity in their brains when the feedback told them they were loosing. This is similar to people with addictions to gambling, where dopamine levels increase when they loose money.

The long and short is, the authors feel this study helps them to understand the science behind addiction and could better help people that are addicted to drugs or gambling or some other addictive behavior. SO if you grabbed Modern Warefare 3 and started playing when you got home and that next thing you remember is waking up Monday morning looking like you were in a war zone, there is hope.