Electronic screen use and trajectories of depression: an accelerated longitudinal study of Australian adolescents

BACKGROUND: Adolescents’ screen use has been linked to adverse mental health, yet longitudinal studies are rare. The objectives were to (i) identify the optimum number of latent trajectories of depressive symptoms among adolescents; and (ii) establish associations between depressive trajectories and time spent using screens (and across different screen activities). METHODS: An accelerated longitudinal cohort sequential design to assess and represent change spanning 10-18 years of age was implemented. Three cohorts randomly recruited at 10, 12/13, and 15/16 years of age (N = 2,620) were assessed on screen use and depressive symptoms (Children’s Depression Inventory: CDI 2) over three school years (i.e., 3 months, 12 months and 24 months after initial recruitment). A latent growth curve model using MPlus, was fitted to the trajectories of the depression measure (CDI 2 T-scores). FINDINGS: Three latent groups (“Normal”, “Depression at Time 1” and “Developing depression”) were identified. Substantial associations were observed between time spent using screens and depression, especially in the “developing depression” trajectory. The strongest association between the developing depression trajectory and changes in screen use over time were seen in those 12/13 years old at the start of the study. Associations between developing depression and screen use varied according to sex and type of screen activity. DISCUSSION: Approximately 8% of adolescents are on a developing depression trajectory and this is associated with increasing screen use in specific screen activities. This research provides health psychologists with empirical evidence to educate young people, their families and health services about appropriate screen use.