LAUSR

Disturbances in social circadian rhythms (e.g. regularity of meals and social interactions) and poor sleep are two potential factors that may contribute to the development of mood disorders. To date, no studies have investigated sleep behaviors (e.g. sleep health) and sleep thoughts (e.g. sleep self-efficacy) as potential links between social rhythmicity and mental health outcomes. The current study explored whether (1) higher social rhythmicity predicted fewer symptoms of depression and whether (2) sleep health and sleep self-efficacy act as mechanisms underlying this association. An archival analysis was performed using data from an online study, Investigating Sleep Across Normal Development (ISLAND Study). The sample consisted of 4,261 adults aged 18+. Measures of social rhythmicity (SRM-10), sleep self-efficacy (SES), sleep health (RU SATED), and depressive symptoms (PHQ-2) were utilized. Age and gender were included as covariates in mediation analyses. The overall model was significant, p < .0001 and 26.4% of the total variance was accounted for by social rhythmicity. Controlling for covariates, higher social rhythmicity was directly associated with fewer depressive symptoms (95% CI [.0326, .0420]). Additionally, both sleep health 95% CI [.0034, .0078] and sleep self-efficacy [.0119, .0169] significantly mediated the association between social rhythmicity and depressive symptoms. Individuals who have higher levels of daily routine regularity experienced less depressive symptoms than those who are more irregular in their daily routines. Furthermore, individuals who had more regular lifestyle habits were more likely to engage in healthy sleep behaviors and thoughts. Thoughts and behaviors are common factors that may have an impact on mental health given their daily reoccurrence. Also, as these factors are modifiable they could be targeted to potentially reduce depressive symptoms. Future research should continue to examine the link between social rhythmicity and sleep behaviors and thoughts on various health outcomes. This work was supported by the National Institute on Aging (K23AG049955, PI: Dzierzewski).