Causal effect of video gaming on mental well-being in Post-COVID Japan

<jats:p>IMPORTANCE With a growing global user base of 3.5 billion and users spending nearly as much time gaming as on social media, video gaming's effects on mental well-being have attracted scholarly and public interest. Despite the WHO's inclusion of gaming disorder in ICD-11 and government-mandated restrictions in multiple countries, the causal evidence supporting such policies remains limited. OBJECTIVE To investigate the causal effect of video gaming on mental well-being in the post-COVID period. DESIGN A natural experiment of game console lottery was used to identify the causal effect of video gaming on mental well-being. The intention-to-treat effect was estimated using multivariate regression and propensity score matching. Causal effects of game engagement were estimated using the instrumental variable method (two-stage least squares) and a causal machine learning algorithm, instrumental forest. SETTING Online surveys were conducted between September 2022 and March 2023, covering all 47 prefectures in Japan. PARTICIPANTS A total of 71,435 participants aged 10-69 answered the surveys. 6,911 individuals participated in the natural experiment. EXPOSURES Video game engagement, including video game console ownership, use of the console in the last 30 days, and video gaming duration. MAIN OUTCOMES AND MEASURES Psychological distress and life satisfaction. RESULTS The intention-to-treat effects of winning game console lotteries on mental well-being were positive (0.1 SD). Game console ownership improved mental well-being by 0.1-0.2 SD, and past-month play improved it by 0.2-0.3 SD. An extra hour of daily video game play led to 0.3-0.5 SD improvements in mental well-being. CONCLUSIONS AND RELEVANCE This study found that video gaming had a positive effect on mental well-being in the post-COVID period. The consistency of the effect size with that of a related COVID-period study adds robustness to our findings. Our findings add to the growing evidence that digital media screen time has diverse effects on well-being and support public health policies that recognize the potential mental well-being benefits of appropriate levels of video gaming.</jats:p>