Risk of insomnia during COVID-19: effects of depression and brain functional connectivity.

Normal sleepers may be at risk for insomnia during COVID-19. Identifying psychological factors and neural markers that predict their insomnia risk, as well as investigating possible courses of insomnia development, could lead to more precise targeted interventions for insomnia during similar public health emergencies. Insomnia severity index of 306 participants before and during COVID-19 were employed to determine the development of insomnia, while pre-COVID-19 psychometric and resting-state fMRI data were used to explore corresponding psychological and neural markers of insomnia development. Normal sleepers as a group reported a significant increase in insomnia symptoms after COVID-19 outbreak (F = 4.618, P = 0.0102, df = 2, 609.9). Depression was found to significantly contribute to worse insomnia (ß = 0.066, P = 0.024). Subsequent analysis found that functional connectivity between the precentral gyrus and middle/inferior temporal gyrus mediated the association between pre-COVID-19 depression and insomnia symptoms during COVID-19. Cluster analysis identified that postoutbreak insomnia symptoms followed 3 courses (lessened, slightly worsened, and developed into mild insomnia), and pre-COVID-19 depression symptoms and functional connectivities predicted these courses. Timely identification and treatment of at-risk individuals may help avoid the development of insomnia in the face of future health-care emergencies, such as those arising from COVID-19 variants.

Effects of physical activity and sleep quality on well-being: A wrist actigraphy study during the pandemic.

Previous studies identified the effects of daytime activity, sleep quality and ambient light exposure on individual well-being. These factors have been greatly changed as people are required to stay home during the COVID-19 pandemic; thus, it is necessary to verify whether these factors effect well-being during the pandemic. We recruited 70 adults (females: 46; age range: 31-60) during a high incidence of COVID-19 in China (17-27 February 2020). Both subjective measurements based on self-report scales and objective measurements collected using wrist actigraphy were employed to investigate the effects of night-time sleep and daytime activity on subjective well-being. The actigraphy data show that participants' total sleep time (>8 hr) is sufficient. Self-reported sleep quality was significantly worse than pre-pandemic, and self-reported daytime activity levels significantly decreased during the pandemic. Physical activity was positively related to well-being, both for self-reported daytime activity (r = .346, p = .003) and for objective measurements (r = .234, p = .051). Our study found that sleep and daytime activity levels were negatively affected by the pandemic. However, increased daytime physical activity could potentially reduce these negative effects.