Suicide mortality rates in Japan before and beyond the COVID‐19 pandemic era

Abstract

Statistical analyses from Japan reported increasing suicides in 2020, first in the world, proving the severity of the public health crisis during the COVID‐19 pandemic; however, so far, international suicides have not been shown to be objectively increasing at population level. Followed studies reported the existence of a substantial heterogeneity of suicides among subgroups and time‐lag impacts. Against public health crisis in Japan, policymakers, psychiatrists and public health personnel should prioritize improving suicide prevention programs following evidence‐based policymaking. Understanding how/what factors relate to the COVID‐19 pandemic and what other factors have shaped the increasing suicide numbers since 2020 through objectively well‐controlled/fine‐grained analyses of high‐quality longitudinal/cross‐sectional data at the individual, regional, and national levels is important for identifying the reasons for the recent trend. For this purpose, this study examined suicide statistics, statistical analysis methods, and their interpretations. Recent analyses suggest an increased suicide risk among females <50 years and males <30 years in 2020–2022. Notably, time‐series analyses revealed that adolescent suicides began increasing before the pandemic, while working‐age female suicides sharply increased synchronously with the pandemic outbreak. Causality analyses suggest that social issues facing Japan and recent global psychosocial and socioeconomic transformations are risk factors for suicide in high‐risk groups. Finally, this report demonstrates the importance of providing appropriate support based on an objective understanding of individuals who are at risk for suicide, without being bound by traditional established knowledges.

Temporal Fluctuations of Suicide Mortality in Japan from 2009 to 2023 Using Government Databases

“…Contrary to our expectations, we did not detect any decreasing SMRs with the end of the pandemic. Therefore, the temporal fluctuation patterns of the SMRs of males younger than 30 and all females were similar to the results of previous reports that analyzed fluctuations from 2009 to 2022 using joinpoint regression analysis [14,15,39]; however, the non-significantly but sharply (transiently) increasing SMRs of working-age males in early 2022 possibly contributed to the tendency of previous reports to underestimate the decrease in SMRs in late 2022 [14,15,39].…”

“…Interrupted time series analysis can incorporate various options, including parametric/non-parametric regressions, seasonal variation and panel data analyses [15,[54][55][56], but it cannot detect unknown joinpoints (changing trends periods) during observation periods. Indeed, previous reports have suggested, when the intervention is set at the COVID-19 pandemic outbreak alone, interrupted time series analysis tends to overestimate the positive impacts of the pandemic outbreak on SMRs due to the attenuation of decreasing trends of male SMRs before the pandemic (in the late 2010s) [15,23,39,41]. In contrast, joinpoint regression analysis has been evaluated to be an appropriate statistical method, which can detect unknown joinpoints, where trends change via fitting the simplest joinpoint model that the trend data allow [57,58].…”

“…Although suicide rates among adolescents have globally been increasing over time, most studies from other OECD countries have reported that adolescent SMRs decreased or remained unchanged during the pandemic [61][62][63][64][65], whereas in Japan, it has been reported that the SMRs of both males and females under 20 years old increased during the pandemic [39][40][41]66,67]. These reports attributed the increase in adolescent SMRs to major lifestyle changes during the pandemic, particularly pertaining to the impaired ability to engage in recreational and educational opportunities and being forced to spend much of their time at home due to social restriction measures [39][40][41]66,67]. In contrast, several reports have suggested that the adolescent SMRs of both males and females in Japan had already begun to increase before the pandemic outbreak [16,17,23,40,41].…”

“…Adolescence is a period of psychosocial and biological development that involves various social stages (e.g., middle school, high school, university, special vocational school and work) [68]. A recent study, focusing on evidence-based policy making, suggested that recently increasing adolescent SMRs in Japan may be the result of national suicide prevention programs for young populations in the "General Principles of Suicide Prevention Policy", which place too much emphasis on making improvements in schools and relatively less on improving home environments, which play a key role in child rearing [39,41]. The primary causes of student SMRs were found to be worrying about the future and underachievement (in school-related problems) and mental illness (depression and anxiety disorders) [40,41].…”

“…It has been reported that the impacts of the COVID-19 pandemic were not uniform, with specific vulnerable groups being uniquely affected [14,15,[36][37][38][39]. In particular, lifestyle changes, including opportunities for education, coping with stress and the lack of recreation opportunities caused by social restriction measures and the rise in unemployment induced by economic deterioration could have contributed to increasing suicidal risks for some vulnerable individuals, such as the elderly/younger generation, psychiatric patients, unemployed individuals and healthcare workers [36][37][38].…”