Withdrawal symptoms - these things can/may happen when a person quits gaming.

Anger (if forced to leave by parents or someone else)
Feeling of emptiness
Depressed
Relief
Sleep pattern interrupted
Have fantasies and dream about the game
Urge to go back to gaming and try to control the time played
Think about the game for extended periods of  time
Feelings become uncontrolled
Rampant mood [...]

We are On-Line Gamers Anonymous, a twelve-step, self-help organization and web site dedicated to helping those addicted to computer/video/console/on-line games. We also welcome the gamer’s friends and family, by offering our support and sympathy. Regardless of involvement or severity of addiction, these web pages and message board forums are always open to those in need.
We [...]