A study by a team of researchers at Seoul National University in Korea used magnetic resonance imaging of the brains of 15 adolescents who were addicted to internet gaming, to see if there were brain changes that would be typical of individuals with addictions to drugs or other addictive behaviors. The determination as to what level of internet gaming constituted an actual addiction was made by looking at such measures of addiction generally as: "tolerance, withdrawal, preoccupation with playing it, repeated unsuccessful attempts to reduce or stop it, negatively influenced mood when attempting to reduce it, and neglecting important relationships or activities because of it."
The teens were screened to exclude those with psychiatric disorders. The researchers were looking at the region of the brain known as the orbitofrontal cortex (OFC), which is known to be thinner in individuals with addictions. The results of the brain scans evidenced a clear thinning of the OFC in the internet addicted group as compared to control subjects. While the researchers stress that this was a small study and that more investigation is needed, they note that their findings were consistent with prior research and that there is a " shared neurobiological mechanism between internet addiction and other addictive disorders." They also note that the connection between brain changes and addiction -- and which comes first -- needs to be examined further.