Although young people spend increasing amounts of time online, many gaps remain in the literature regarding the effect of time spent online on young people's development of well-being. We focus on the influence of time spent online on feelings of self-reported (a) depression and (b) health of adolescents. We also consider the mediating role of digital skills and digital activities, each of which is broken down into five dimensions. We collected data through a two-wave longitudinal online survey among 3,942 adolescents aged 12-17 years in six European countries (first wave [W1] = 2021; second wave [W2] = 2022). We specifically want to understand how feelings of self-reported depression and health at W2 are affected by the time spent online at W1, and how digital skills and digital activities at W2 mediate these relationships. Findings indicate a significant increase in feelings of depression and a decrease in self-reported health between W1 and W2. Regarding digital skills, information navigation and communication and interaction were linked to greater well-being (lower depression and greater self-reported health). Regarding digital activities, the development of social relationships online was linked to lower self-reported depression and greater health, while frequently using the Internet to look up information on physical or mental health issues was strongly linked to greater depression and lower health. We discuss the implications of these findings for practice and policy on young people's well-being.
Keywords: Internet use; digital activities; digital skills; longitudinal; subjective well-being; young people.