Device-measured sleep onset and duration in the development of depressive symptoms in adolescence

Abstract

Depression is a serious public health concern, both socially and economically, and is increasing in prevalence (World Health Organization, 2017). In 2017, more than 322 million people suffered from depression globally, and depression is predicted to be the leading cause of the total disease burden by 2030 (GBD 2017 Disease and Injury Incidence and Prevalence Collaborators, 2018; Mathers et al., 2008). In order to address this growing problem, there is a need to better understand the features of our modern lifestyles which may be contributing to this disease. The incidence of depressive episodes rises sharply during adolescence (Malhi and Mann, 2018). This increase is thought to be the result of cognitive changes related to the development of brain circuitry, hormones, and accompanying social changes (Thapar et al., 2012). Defined as a cluster of specific symptoms and associated impairment, depression in adolescents may exhibit as irritability and mood reactivity, as well as anhedonia and low mood (Thapar et al., 2012). One factor which may contribute to risk for development of depression is sleep duration. Although the association between sleep duration and depression is well supported in adults, with those sleeping too little and too much at risk for subsequent depression (Zhai et al., 2015), much less is known about this association in adolescence. As sleep duration in childhood and adolescence appears to be decreasing in the population by an average of 0.75 mins per year (Matricciani et al., 2012), advancing knowledge on the causal relationship between sleep and subsequent depression is of urgent concern.