New-onset and exacerbated insomnia symptoms during the COVID-19 pandemic in US military veterans: A nationally representative, prospective cohort study.

The COVID-19 pandemic has had a negative impact on physical and mental health worldwide. While pandemic-related stress has also been linked to increased insomnia, scarce research has examined this association in nationally representative samples of high-risk populations, such as military veterans. We evaluated pre- and pandemic-related factors associated with new-onset and exacerbated insomnia symptoms in a nationally representative sample of 3,078 US military veterans who participated in the National Health and Resilience in Veterans Study. Veterans were surveyed in the USA in 11/2019 (pre-pandemic) and again in 11/2020 (peri-pandemic). The Insomnia Severity Index was used to assess severity of insomnia symptoms at the pre- and peri-pandemic assessments. Among veterans without clinical or subthreshold insomnia symptoms pre-pandemic (n = 2,548), 11.5% developed subthreshold (10.9%) or clinical insomnia symptoms (0.6%) during the pandemic; among those with subthreshold insomnia symptoms pre-pandemic (n = 1,058; 26.0%), 8.0% developed clinical insomnia symptoms. Pre-pandemic social support (21.9% relative variance explained), pandemic-related stress related to changes in family relationships (20.5% relative variance explained), pre-pandemic chest pain (18.5% relative variance explained) and weakness (11.1% relative variance explained), and posttraumatic stress disorder (8.2% relative variance explained) explained the majority of the variance in new-onset subthreshold or clinical insomnia symptoms during the pandemic. Among veterans with pre-pandemic subthreshold insomnia, pandemic-related home isolation restrictions (59.1% relative variance explained) and financial difficulties (25.1% relative variance explained) explained the majority of variance in incident clinical insomnia symptoms. Taken together, the results of this study suggest that nearly one in five US veterans developed new-onset or exacerbated insomnia symptoms during the pandemic, and identify potential targets for prevention and treatment efforts.