Severe effects of the COVID-19 confinement on young children's sleep: A longitudinal study identifying risk and protective factors

Abstract

The COVID-19 confinement has dramatically altered daily routines, causing decreased sleep quality in adults. This necessitates careful observation, as sleep plays a crucial role in brain maturation and poor sleep increases the risk of psychopathology, particularly in the young population. Through an online survey with one baseline (April 2020) and two follow-up assessments (May and June 2020), we examined the effect of confinement on sleep quality in 452 babies (0-35 months) and 412 preschool children (36-71 months) from several, mainly European, countries. An acute decrease in sleep quality was found in both groups of children. However, at follow-up assessments, this effect rebounded to the level reported for the period before the confinement. Importantly, caregiver's stress level was identified as a substantial risk factor determining lower sleep quality in both groups of children across assessments. Protective factors conserving children's sleep quality included caregiver's engagement in mindfulness techniques or childcare, and the presence of siblings and pets. In the near future, we may repeatedly experience the circumstances of abruptly enforced confinement. Our findings reveal promising pathways of action to protect young children's sleep, with which to essentially mitigate the long-term consequences of the pandemic on brain development and mental health.

Keywords: bedtime; circadian rhythm; lockdown; sensitive period; sleep regulation; stay-at-home.

FIGURE 1

Acute decrease in sleep quality in babies (0–35 months) and preschool children (36–71 months) as a consequence of the COVID‐19 confinement in April 2020. Raincloud plots indicate the distribution of core sleep quality measures (bedtimes, latency of sleep, duration of sleep and sleep fragmentation) before and during the confinement (452 babies and 412 preschool children). Dots represent individual subjects and box plots indicate the first and third quartiles (whisker length 1.5 * interquartile range; vertical lines represent the median). Statistics (z, p) are based on Wilcoxon signed‐rank tests (before versus during the confinement). Data were collected with age‐specific assessments: Brief Infant Sleep Questionnaire (BISQ) for babies and Children's Sleep Habits Questionnaire for preschool children. Consequently, we note the quantification of absolute values for babies and reports of frequency of occurrence for preschool children. The significance levels are indicated as *p < 0.05, **p < 0.01 and ***p < 0.001 after correcting for multiple testing by means of the false discovery rate. This figure was based on Blume et al. (2020) for the purpose of comparability

FIGURE 2

Evolution of sleep variables across the COVID‐19 confinement period from April to June 2020 in babies (0–35 months) and preschool children (36–71 months). Box plots, indicating the first and third quartiles as well as the mean (whisker length 1.5 * interquartile range), and scattered dots display core sleep measures (bedtimes, latency of sleep, duration of sleep and sleep fragmentation) for baseline assessment (April 2020; in orange; 452 babies and 412 preschool children), first follow‐up (May 2020; in blue; 96 babies and 100 preschool children) and second follow‐up (June 2020; in green; 90 babies and 95 preschool children). t‐ and p‐values depict significant time effects from our linear mixed model after correcting for multiple comparisons by means of the false discovery rate. Due to age‐specific assessment tools, absolute values are presented for babies and reports of frequency of occurrence for preschool children