Temporal evolution of suicide by levels of rurality and deprivation among Japanese adults aged 20 years or over between 2009 and 2022

Purpose Previous studies have reported that levels of rurality and deprivation are factors associated with suicide risk. Reports on the association between rurality, deprivation and suicide incidence during the COVID-19 pandemic are scarce. The study aims to investigate how suicide rates evolved in areas with different levels of rurality and deprivation among Japanese adults aged 20 years or older between 2009 and 2022. Methods This study used population density in 2020 as an indicator of rurality and per capita prefectural income in 2019 as a proxy for deprivation in Japan’s 47 prefectures. Joinpoint regression analysis was performed to analyze secular trends in suicide rates by rurality and deprivation. Results Suicide rates for both men and women at different levels of rurality and deprivation remained roughly parallel during the research period. Suicide rates for men and women at all levels of rurality and deprivation were on a downward trend until around 2019, just before the onset of the pandemic. Following this, suicide rates in women showed a clear upward trend, while the trend in suicide rates for men also changed around 2019, with a slightly increasing or flat trend thereafter. Changes in suicide rates were greater among women and those aged 20–59 years. Conclusions In Japan, time trends in suicide rates for both men and women have changed before and after the pandemic, but levels of rurality and deprivation across the 47 prefectures do not appear to have contributed much to these changes.