Changes in sleep quality and sleep disturbances in the general population from before to during the COVID-19 lockdown: A systematic review and meta-analysis

Introduction

Alarmed by its severity, transmissibility, rising levels of contagion, and the strain on healthcare systems, on March 11, 2020, the World Health Organization (WHO) declared the Coronavirus disease 2019 (COVID-19) outbreak, a global pandemic (1). In the absence of vaccines or pharmaceutical treatment, non-pharmaceutical interventions (NPIs) were implemented in most countries of the world to limit the diffusion of the virus and to mitigate the burden on health systems. The NPIs included strict hand hygiene and the use of face masks and more restrictive measures such as isolation, quarantine, social distancing, curfews, travel bans, remote working, school closures, and full or partial lockdowns (2). A growing body of evidence has, however, shown that these restrictive measures have adversely affected people’s mental health and well-being. For instance, in several studies more stringent NPIs have been associated with higher anxiety and depressive symptoms (3), a decrease in mental well-being (4, 5) as well as to an increase in psychological distress (6).