Texas A&M International University recently conducted a study in which volunteers were subjected to stress, with some subjects being allowed to play video games afterward. According to the results, the game-playing group reported less stress and depression afterward.
In a conclusion contrary to many recent studies, the research conducted by Texas A&M Associate Professor Christopher Ferguson concluded that violent video games could actually combat anger and depression.
The method of measurement came by subjecting four groups of predominantly Hispanic students to a scientifically-proven stress-inducer called the Paced Auditory Serial Addition Task. Afterward, two groups were given a violent game to play (Hitman: Blood Money or Call of Duty 2), one was given a non-violent game (Madden 2007) and a final group was told they wouldn't be able to play any games due to a malfunction.
While Ferguson concluded that the game-playing groups exhibited less hostility and depression, the professor presented a caveat regarding the conclusion -- that the uniqueness of the control groups could reveal different results with a larger and more diverse pool of subjects. To learn more about the study, check out the source links below. The full study will be found in volume 15 of the "European Psychologist" journal.