Smartphone use in a large US adult population: Temporal associations between objective measures of usage and mental well-being

Smartphones are a vital tool for most people. They facilitate many everyday tasks and as a result they have become ubiquitous and indispensable. There are concerns about how the use of these devices may impact mental health and wellbeing. Yet, there are few studies that have reported objective data about phone usage from large and diverse cohorts and studies have found low correlations between subjective and objective smartphone use. In order to better elucidate these complex interactions, it is important to understand and characterize what resembles “normative” smartphone use behavior. In this paper, we present normative patterns of objectively measured phone usage from a large prospective observational study. We analyze a quarter of a million days of phone usage data from 10,099 adult subjects that provides objective longitudinal data over a four week period in the US general population. Contrary to popular belief, our model shows little support for the conclusion that smartphone use predicts mood the following week or that mood predicts smartphone use the following week, with some results differing depending on whether the effects are within-person or between-person. Lastly, while some findings are statistically significant, the effect sizes of these results are minimal, suggesting little to no impact in real-world settings and therefore a lack of clinical significance.