Internet searches for “insomnia” and “suicide” mediated by stay-at-home behaviors in 45 countries during the first 12 months of the COVID-19 pandemic

This study aimed to investigate (1) the mental health impacts (i.e., insomnia and suicide ideas) of the COVID-19 pandemic and (2) the mediation effects of stay-at-home levels on those impacts. This study investigated monthly national COVID-19 deaths, stay-at-home levels, and internet searches for words for “insomnia” and “suicide” across 45 countries during the first year of the COVID-19 pandemic (March 1, 2020, to February 28, 2021). We used the changes of internet search volumes for “insomnia” and “suicide” (from the Google Trends database) to represent the mental health impacts, and the time of cell phone activity at the residence (from Google Location History) to estimate the stay-at-home effects. We computed the proportion mediated (PM) caused by stay-at-home levels in the COVID-19 impacts on insomnia and suicide ideas, respectively. Throughout the first year of the COVID-19 pandemic, national COVID-19 deaths significantly correlated to increased internet searches for “insomnia” but decreased searches for “suicide”. In addition, the mediation effect was significant in the first six-month of COVID-19-related increases in insomnia (PM = 42.6 %, p = 0.016), but this effect was not significant (PM = 13.1 %, p = 0.270) in the second six-month. By contrast, the mediation effect was not significant in the first six-month of COVID-19-related decrease in suicide ideation (PM = 8.1 %, p = 0.180), but this effect was significant (PM = 39.6 %, p = 0.014) in the second six-month. Stay-at-home levels significantly mediated both increased insomnia and decreased suicide ideas, but within different time frames. •The speed of national COVID-19 spread increased insomnia but decreased suicide ideas.•The mental health impacts of COVID-19 significantly mediated by stay-at-home effects.•The stay-at-home mediated increased insomnia in the first half year of pandemic.•The stay-at-home mediated decreased suicide ideas in the second half year of pandemic.•The stay-at-home mediated insomnia and suicide in the first and the second half year respectively.