Pre-pandemic suicidal ideation and preventive behavior during COVID-19: A prospective cohort study

Background: Cross-sectional studies have shown associations between suicide risk factors and COVID-19 preventive behaviors. Aims: We investigated the impact of suicidal ideation on COVID-19 preventive behaviors to augment literature focused on suicide risk factors and COVID-19 preventive health measures. Significant findings may reveal factors that explain dangerous behavior and inspire policy to mitigate negative health outcomes. Method: This study used a prospective observational longitudinal design (n = 6683). A baseline survey (January 24, 2020 = before COVID-19 pandemic, T1) and a follow-up survey (between April 27 and April 30, 2020 = during COVID-19 pandemic, T2) were conducted among the general adult population in Japan. Results: Adjusted for demographic and socioeconomic factors, high suicidal ideation at T1 was associated with significantly low levels of engagement in COVID-19 preventive behaviors at T2. Limitations: As this was an Internet survey and contained selection bias, the sample may not be representative of the general population in Japan. Pandemic severity may impact results in other geographies, reducing the applicability of study findings. Conclusion: Individuals with strong suicidal ideation before the pandemic were less likely to engage in COVID-19 preventive behaviors. These individuals are at risk not only for suicide but also for infectious disease.