Digital media takes an increasingly large part of children’s time, however, the long-term effect on brain development is unclear. In this project, we will investigate the individual effects of digital media use (watching television and videos, using social media, or playing video games, respectively) on brain development, while controlling for genetic predisposition and socioeconomic status. We will analyse brain metrics of ~6000 children who underwent brain MRI at three different time points. Digital media use was collected through questionnaires completed by children. For the purpose of the analysis, we will use Bayesian mixed effect modelling. All the analysis will be carried out in R studio.