A recent study conducted by the renowned University of Oxford has found "a small positive relation" between time spent playing video games and the player's mental health.
The study, which can be found here, was based off surveys from 6500 players along with telemetry from over 3000 of them covering when they played. The games involved in the study were Plants vs. Zombies: Battle For Neighborville and Animal Crossing: New Horizons. The data was collected over two week periods in August and September, with the bulk of it coming from Animal Crossing players. The telemetry itself was obtained from Nintendo and Electronic Arts directly (presumably after asking the players if they wanted to share that data with Oxford), and was anonymized without any personally identifying information before being matched up to survey responses.
The results of the study indicated that players who played longer were more likely to express positive feelings in their results. However, there are a number of caveats and cautionary statements in the study. For one, some respondents overestimated their play times (by as much as two hours in some cases), which created mismatches in telemetry to survey responses. Another problem arises in the extremely limited number of games involved. Finally, as Professor Andrew Przybylski observed when speaking to the BBC about the study, there may be a self-selection element involved. "If you play Animal Crossing for four hours a day, every single day, you're likely to say you feel significantly happier than someone who doesn't," he said, "That doesn't mean Animal Crossing by itself makes you happy."
Food For Thought
Like a lot of behavioral science, this is only a starting point, which Przybylski and his colleagues cautioned, pointing out that more studies were needed, and that this particular study was more on the order of a "snapshot" rather than a sweeping longitudinal study. If future studies can be conducted with similarly high standards of transparency and cooperation with game publishers and developers, along with informed cooperation from players, the games industry may ultimately be in a better position to defend itself from spurious regulation with hard science to back them up.