The association of smartphone use and depression in Japanese adolescents.

The aim of this study is to assess the association between smartphone usage and depression in each gender of senior high school students. A cross-sectional study with self-administered questionnaires for 295 high school students, aged 15-19 was conducted in Japan. Depression was assessed using the Center for Epidemiologic Studies Depression Scale (CES-D). Female adolescents used smartphones more hours a day than males. Students who used the smartphones for three hours a day accounted for 44.3% of female students and 22.5% of male students. Female students spent longer hours on online chat, social networking sites (SNS), and Internet browsing. The longer hours they spent for online chat (Odds ratio (OR): 1.74; 95% confidence interval (CI): 1.18-2.56), and SNS (OR: 1.41, 95% CI: 1.04-1.92) were associated with depression. On the other hand, male students spent more hours playing games than female students, and their smartphone use was not correlated with depression. There were gender differences in smartphone usage: female students spent more time on social contacts, whereas males were more likely to use them for entertainment. Therefore, if female students overuse online communication, they may be at a higher risk for depression.