The long-term impact of violent video games on people has always been a matter of debate. A new research, conducted by the Max Planck Institute for Human Development and the University Clinic Hamburg-Eppendorf in Germany, revealed playing violent video games for prolonged periods does not make adults more aggressive.

The paper, which was published in the journal Molecular Psychiatry, is the first-ever study to examine the long-term effects of such video games. The paper acknowledges the growing concern in American society that such pastimes "may promote aggression or reduce empathy in its players is pervasive and given the popularity of these games their psychological impact is an urgent issue for society at large."

For the study, 77 participants were recruited and divided into three groups. The violent video game group of 25 played Grand Theft Auto V on a Playstation 3 console daily for two months, while the active control team of 24 took part in the non-violent simulation game Sims 3 on the same console for the same period of time. A passive control group of 28 did not play any video games for two months. The violent and non-violent training groups were instructed to play the games for at least 30 minutes a day.

Levels of anxiety, mood, aggression, empathy, interpersonal competencies, impulsivity, and executive control were measured in the participants before and after the two-month period with the help of questionnaires and computerized behavioral assessments.

Upon examination, the researchers were unable to find any relevant negative effect across the assessed variables. Only 3 tests from the 208 statistical tests performed showed a pattern but the figure was not considered important as at least "ten significant effects would be expected purely by chance."

"We did not find relevant negative effects in response to violent video game playing," said lead author Simone Kühn. "The fact that we assessed multiple domains, not finding an effect in any of them, makes the present study the most comprehensive in the field."

Two months after the participants stopped playing daily video games, there was still no difference in levels of aggression or any of the other variables.

It is suggested the contrast may be evident due to differences in how research has been conducted. The study argued other short-term experimental analyses were unable to replicate consistent results, also noting if video games do cause aggression, it is often short-lived and not representative of society at large.

"The American Psychological Association recently summarized the previous findings on violent video games as indicating that they pose a risk factor for adverse outcomes, including increased aggression and decreased empathy," added Kühn. "The present findings of this study clearly contradict this conclusion."

Kühn also said similar studies need to be conducted in the future using children as participants.