The impact of screen time and green time on mental health in children and adolescents during the COVID-19 pandemic.

The COVID-19 pandemic has affected the life of children and adolescents in an unprecedented way. In the present study, we focused on two activities that have been likely affected by mitigation measures: screen time and green time. We investigated how both influenced each other during the pandemic, how they affected children's and adolescents' mental health, and which role socio-demographic characteristics have in predicting screen time, green time, and mental health. We used data collected between autumn 2020 and spring 2021 from 844 participants aged 5 to 19 of a population-based, prospective cohort study in Canton Ticino, Italian-speaking Switzerland. We analyzed the data using an extended version of the Random Intercept Cross-Lagged Panel Model with time-invariant socio-demographic covariates and mental health as outcome. Results showed that, at the between-person level, screen time was a risk factor and green time a protective factor of mental health. However, within-person deviations of screen time and green time during the pandemic did not consistently predict mental health. Furthermore, they did not influence each other over time. Gender, age, perceived economic situation of the family, Body Mass Index and the availability of green space nearby all influenced stable measures of green time and screen time (i.e., random intercepts). Our results highlight the need for targeted actions to promote green time and raise awareness about the detrimental effect of screen time on children's and adolescents' mental health.