Working from home due to the COVID-19 pandemic abolished the sleep disturbance vulnerability of late chronotypes relieving their predisposition to depression
Authors: Salfi Federico , D’Atri Aurora , Amicucci Giulia , Viselli Lorenzo , Gorgoni Maurizio , Scarpelli Serena , Alfonsi Valentina , Ferrara Michele 
Published: February 2022

AbstractBackground and aimsEveningness is distinctively associated with sleep disturbances and depression symptoms due to the misalignment between biological and social clock. The widespread imposition of remote working due to the COVID-19 pandemic allowed a more flexible sleep schedule. This scenario could promote sleep and mental health of evening-type subjects. We investigated the effect of working from home on sleep quality/quantity and insomnia symptoms within the morningness-eveningness continuum, and its indirect repercussions on depressive symptomatology.Methods610 Italian office workers (mean age ± standard deviation, 35.47 ± 10.17 yrs) and 265 remote workers (40.31 ± 10.69 yrs) participated in a web-based survey during the second contagion wave of COVID-19 (28 November–11 December 2020). We evaluated chronotype, sleep quality/duration, insomnia, and depression symptoms through validated questionnaires. Three moderated mediation models were performed, testing the mediation effect of sleep variables on the association between morningness-eveningness continuum and depression symptoms, with working modality (office vs. remote working) as moderator of the relationship between chronotype and sleep variables.ResultsRemote working led to delayed bedtime and get-up time. Working modality moderated the chronotype effect on sleep variables, as eveningness was related to worse sleep disturbances and shorter sleep duration only among the office workers. Working modality moderated the mediation of sleep variables between chronotype and depression. The above mediation vanished among remote workers.ConclusionsRemote working strikingly abolished the vulnerability to sleep problems of evening-type subjects, relieving their predisposition to depressive symptomatology. A working environment complying with individual circadian preferences might ensure an adequate sleep quantity/quality to late chronotypes, promoting their mental health.Statement of SignificanceThe present study is the first to evaluate the different effect of pandemic-related remote working on sleep health/habits depending on the chronotype. We found longer sleep duration and improved sleep disturbances among evening-type subjects when working from home. This outcome could be ascribable to a better alignment between the endogenous circadian phase and the working schedule, as remote workers reported later bedtimes and get-up times. Moreover, we showed how improved sleep weakened the susceptibility to depressive symptomatology of evening-type people, highlighting an intriguing implication of working remotely on mental health in this category. Morningness-eveningness predisposition should be considered when designing remote working policies, in order to promote sleep and mental health of late chronotypes during the pandemic emergency, as well as in the post-covid era.