Suicidal Mortality and Motives Among Middle-School, High-School, and University Students

Abstract

ImportanceThe suicide mortality rate per 100 000 population (SMRP) consistently decreased before the COVID-19 pandemic outbreak in Japan and then unexpectedly increased during the pandemic. However, the underlying mechanisms remain poorly understood.ObjectiveTo identify trends in and factors associated with suicidal mortality and motives among students in Japan from 2007 to 2022.Design, Setting, and ParticipantsIn this cross-sectional study, data on SMRPs among Japanese middle-school, high-school, and university students were obtained from the government suicide database Suicide Statistics of the National Police Agency.Main Outcomes and MeasuresAge-dependent and temporal fluctuations in annual SMRPs, disaggregated by suicidal motive (7 categories and 52 subcategories), sex, and school, were analyzed using linear mixed-effect and joinpoint regression models, respectively.ResultsTotal suicide numbers from 2007 to 2022 were as follows: 760 male middle-school students, 635 female middle-school students, 2376 male high-school students, 1566 female high-school students, 5179 male university students, and 1880 female university students. The mean (SD) student populations from 2007 to 2022 were as follows: 1 752 737 (81 334) male middle-school students, 1 675 572 (78 824) female middle-school students, 1 648 274 (67 520) male high-school students, 1 614 828 (60 032) female high-school students, 1 652 689 (32 724) male university students, and 1 229 142 (57 484) female university students. Among male students, the leading motives were school-related factors (underachievement and worrying about the future), followed by family-related and health-related motives. Among female students, school-related and family-related motives decreased, but health-related motives showed an age-dependent increase. The SMRPs of middle-school male students and female students were almost equal (mean [SD], 2.7 [1.0] vs 2.4 [1.4]), but the age-dependent increase in SMRPs among male students was pronounced (mean [SD], high-school vs university male students, 9.1 [2.4] vs 19.6 [3.0]; high-school vs university female students, 6.1 [2.4] vs 9.6 [1.8]). However, the incidence of suicide among high-school students associated with health-related motives was greater in female students. The majority of suicides associated with major impactable suicidal motives (school-related, health-related, and family-related motives) began increasing before the pandemic. Changes in SMRP associated with interpersonal relationships, such as conflict with classmates or parents, were not significant, but the rates increased greatly during the pandemic.Conclusions and RelevanceSchool-related, health-related, and family-related problems were major motives, whereas the impacts of health-related and family-related motives increased and decreased with age, respectively. Notably, most SMRPs associated with major impactable motives (underachievement, conflict with a parent or classmate, and mental illnesses) had already begun increasing in the late 2010s, indicating that recent increasing SMRPs among school-aged individuals were associated with pandemic-related factors and other factors affecting this generation before the pandemic. It may be inappropriate to uniformly apply research findings based on school-aged individuals to school-based suicide prevention programs for students in middle school, high school, and university.

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

“… 41 , 42 , 43 , 44 , 45 , 46 To overcome these issues, recent studies have analyzed the temporal fluctuation or excess mortality of SDR/CSMR using four main models: (1) comparison between previous averages and observed data using an analysis of variance (ANOVA) or linear mixed‐effect model (LMM), 23 , 28 , 47 (2) comparison between predicted values calculated from the seasonal autoregressive integrated moving average (sARIMA) and observed value using ANOVA/LMM, 24 , 27 (3) detection of impacts of intervention (changing trends and discontinuities) using interrupted time‐series analysis (ITSA), 13 , 20 , 25 , 47 and (4) detection of fluctuations of trends using joinpoint regression analysis (JPRA). 12 , 13 , 26 , 28 …”

“…The method uses model fitting to divide a long‐term trend line into several trend sections. 12 , 26 , 28 A comprehensive review of the statistics and underlying methodology applied in JPRA has been reported. 57 The connecting points of different trend segments are called joinpoints.…”

“…A number of Japanese studies have reported that males <30 years and females <70 years were at high risk for suicide during the pandemic. 12 , 13 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 Our previous studies using JPRA revealed that the temporal fluctuations in CSMRs were composed of various patterns (Figure 3 ): 12 , 13 , 14 , 25 , 26 , 28 (1) decreasing CSMR trends of males of 30–69 years of age were attenuated prior to the pandemic; (2) CSMR trends of males <20 years began to increase prior to the pandemic and continued increasing throughout the pandemic; (3) CSMR trends of females <30 years began increasing prior to the pandemic and sharply increased synchronously with the pandemic, followed by unchanging trends during the pandemic; (4) CSMR trends of males of 40–69 years of age increased throughout the pandemic; (5) decreasing CSMR trends of males of 70–79 years and females in their 70s and 80s were attenuated during the pandemic; (6) CSMRs of males of 20–29 years and females of 20–49 years sharply increased synchronously with the pandemic, followed by a decrease during the pandemic; and (7) CSMRs of males of 60–69 and >80 years increased in the late phase of the pandemic (Figure 3 ).…”

“…11 , 12 , 13 , 14 Given the timing of the COVID‐19 pandemic, most reports have concluded that the increase was impacted by psychosocial and/or socioeconomic deterioration associated with the pandemic. 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 However, on closer scrutiny of these reports, it was demonstrated that, with the exception of a few reports, 12 , 13 , 14 , 27 , 28 most findings regarding the CSMR or age‐standardized suicide death rate (SDR) were inferred based on the increase in comparison to before the pandemic or synchronized with the pandemic, without analyzing the underlying causes, therefore the reasons for the increased SDR/CSMR in 2020–2022 remain to be clarified.…”

“…29 Going forward, continuous fine‐grained observation of fluctuations of suicides is essential for public health because many hope for rapid improvement of increasing suicide in the postpandemic era. However, some studies have reported that suicides in some subgroups began increasing prior to the pandemic, which cannot be ignored, 12 , 13 , 14 , 25 , 26 , 28 therefore complicated interactions among various factors may underlie the increase in suicides in Japan since 2020. Accordingly, evidence‐based policymaking concept, logic and critical thinking, 30 and the identification of the underlying causes of decreasing CSMR/SDR during 2009–2019 and increasing from 2020 to 2022 could contribute to the improvement of suicide prevention program planning.…”