As the use of video games (VG) is rapidly increasing, many studies have tries to understand the effects of VG on the children and adolescents playing them.

Most of the research was directed towards negative effects (especially violence, attention and school performance), producing mixed results.

Recently, more studies had focused their attention on the opposite angle: The influence of the player's mental and behavioral parameters, influencing his VG playing patterns. The focus of most of these researches was time of playing, addictive patterns and exposure to violence.

The current study will try to characterize the variance of VG playing pattern among adolescents diagnosed with psychiatric disorders, in order to better under the rich interaction between a player and his VG, and to understand whether VG playing patterns holds diagnostical clues for the child's diagnosis and his inner world.

The participants will be asked to attend 2 session, 2 hours each, at 3-14 days interval.

At the first session, after signing consent form, will asked to fill out questionaires regarding demographic data, personality, empathy trait, aggression state and trait and computer games usage.

also, they will be asked to complete HTP and TAT psycho-diagnostic tests. Then, using heart rate variability (HRV) and Galvanic skin response (GSR), monitor of sympathetic tonus will be measured while playing a shooting and race game.

At the end of the first session, they will be asked to fill additional aggression state questionaire.

On the second session, monitored by HRV and GSR, they will be asked to play a role playing game (RPG) and real-time strategy game (RTS). At the end of session, they will be asked to fill additional aggression state questionaire.

Parameters of playing patterns collected from the VG will be recorded and analyzed.

Inclusion Criteria:

• Age 13-18
• Diagnosis matching one of the defined research arms, made by a childhood and adolescents psychiatry specialist
• Playing various computer games regularly, for at least 2 years
• Informed consent has been given by the minor and his parents

Exclusion Criteria:

• Organic sensory depravation (blindness, deafness)
• Motor dysfunction, relevant of using keyboard, mouse or remote
• Additional psychiatric diagnosis, apart the one matching the arm to which he was allocated
• Using illicit drugs during the previous 48 hours