Violent video games might be harmful to brains, study says

A study out of the University of Montreal found that violence played out during a video game can have negative impact on the brain.

Scientists compared brain scans of frequent video game players, and found that video games like "Call of Duty" reduce the amount of gray matter in brains. The result can increase the risk of brain illnesses, like depression and schizophrenia. 

The study also found that  games -- such as those from the Super Mario series -- can increase gray matter in brains because they allow for constructional thinking.