At the latest in 2004 video game addiction became popular by the online-role-playing-game World of Warcraft (Blizzard Entertainment). Since 2013 Internet Gaming Disorder is accepted as a diagnosis in the appendix of the DSM-5. The American Psychiatric Association invited scientists worldwide to research this phenomenon in more depth. In a three year longitudinal study, conducted in a research group of the Criminological Research Institute of Lower Saxony, we followed this call. One chapter reviews the present state of research (May 2014) in the field of video game addiction. 70 young adults were interviewed three times. This study showed that video game addiction can be a persistent phenomenon. However, only a few of the excessive video game players suffered from a video game addiction. Problematic video game players showed lower levels of conscientiousness, higher levels of impulsiveness and neuroticism. They suffered more frequently from psychiatric disorders.