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

Key Points Question What factors are associated with the increasing number of suicides among individuals younger than 30 years in Japan during the COVID-19 pandemic? Findings In this cross-sectional study of 12 396 middle-school, high-school, and university students, from 2007 to 2022, suicide mortality rates have consistently increased since the late 2010s, with major associated factors including school-related, health-related, and family-related problems; however, the factors associated with suicide among students change according to their life stage (ie, life cycle). Meaning These findings suggest that designing and implementing school-based suicide prevention programs that are effective for the specific vulnerabilities in psychological and social developmental stages of middle-school, high-school, and university students can contribute to suicide prevention for students.


Introduction
From 2009 to 2019, Japan's governmental comprehensive regional suicide prevention programs [1][2][3][4][5][6][7][8][9] were associated with an approximately 30% decrease in the suicide mortality rate per 100 000 population (SMRP).1][12][13][14] The SMRP was 2.5 times greater among male individuals vs female individuals during 2009 to 2019, 4,6 but the differential decreased to 2.0 in 2021, 10,12,13 indicating that the increase in SMRP during the pandemic was more pronounced among female individuals.1][12][13][14][15] With the SMRPs of the young generation increasing, both the Ministry of Education, Culture, Sports, Science and Technology and Ministry of Health, Labor and Welfare enhanced school mental health supporting systems and developed crisis line resources using the internet 16,17 ; however, the increasing trends in SMRPs in the young generation remain unsuppressed. 10Thus, governmental suicide prevention programs could not decrease SMRPs in the young generation. 4,5,18In addition, the mechanisms underlying the increased SMRPs and reasons why suicide prevention programs could not decrease SMRPs in the young generation should be elucidated.
[19][20][21] Schools have been considered to be the most effective organizations for modifying environmental and psychological factors associated with suicides via standardized suicide prevention programs. 19,22,23The underlying mechanisms in adolescent suicides are complicated owing to their complex contexts, including specific physical, psychological, social, and educational developmental statuses. 24Therefore, it might be inappropriate to uniformly apply findings obtained from research on adolescents to suicide prevention programs for middle-school, high-school, and university students.We investigated temporal fluctuations in SMRPs disaggregated by suicidal motive, sex, and school, as published in the government suicide database, Suicide Statistics of the National Police Agency (SSNPA). 25

Methods
This cross-sectional study adhered to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline.The medical ethics review committee of Mie University waived requirements for informed consent and ethical approval because these are publicly available governmental data.were obtained from the SSNPA. 25,266][27][28][29] The detailed methods of the investigation of suicidal motives are explained in the eAppendix in Supplement 1. Annual student populations in middle school, high school, and university from 2007 to 2022 (denominator for SMRP derivation) were obtained from the School Basic Survey, a government database of the Ministry of Education, Culture, Sports, Science and Technology. 30SMRP was calculated by dividing the annual suicide numbers of the target group by the annual populations of the same target group in the same year (eg, the annual suicide number among male university students in 2020 was divided by the total number of male university students in 2020).SSNPA released annual suicide numbers for which motives were determined.

Statistical Analysis
In this study, the trends, discontinuity, and their effect size of SMRPs of male and female middleschool, high-school, and university students from 2007 to 2022 were analyzed by joinpoint regression analysis (JPRA) using the Joinpoint Regression Program version 5.0.2 (National Cancer Institute). 10,12,31,32The differences in SMRPs among sexes (male and female students) and schools (middle school, high school, and university) from 2007 to 2022 were compared using linear mixedeffect models with the Scheffe post hoc test using SPSS statistical software for Windows version 27 (IBM). 11,13The detailed statistical methods are described in the eAppendix in Supplement 1.
Two-tailed P < .05 was considered statistically significant.
Considering that each student accounted for approximately 2% to 3% of the Japanese population (eTables 1, 2, and 3 in Supplement 1), the student SMRPs were smaller than the national-level SMRP.
Student SMRPs of both sexes showed an age-dependent increase (Figure 1).

Fluctuations in SMRPs Associated With School-Related Motives
Among school-related factors, underachievement was consistently the leading motive for suicide among male students, followed by worrying about the future and conflict with classmates (eFigure 1B in Supplement 1).Among female students, the rank-order of impacts of school-related motives transformed with age, shifting from conflict with classmates (77 students [26%]), underachievement

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Suicidal Mortality and Motives Among Middle-School, High-School, and University Students SMRPs associated with school-related motives among female middle-school and university students began increasing in 2012 and 2016, respectively.Those of male students changed from decreasing to increasing in 2020 (Figure 2 and eTable 4 in Supplement 1).Those of male and female high-school students increased in 2016 and 2019, respectively.
Of note, SMRPs associated with conflict with classmate of female middle-school and highschool students were greater compared with male student in the late 2010s.Suicides among male and female university students associated with conflict with classmates increased greatly in 2022 (Figure 2).

Fluctuations in SMRPs Associated With Health-Related Motives
Among health-related motives, depression and other mental illnesses were leading factors associated with student SMRPs.Their impacts increased in an age-dependent manner (eFigure 1C in Supplement 1).SMRPs of female high-school students associated with health-related motives, including depression and other mental illness, were markedly higher than in male students (Figure 3 and eFigure 1C and eFigure 2 in Supplement 1).
SMRPs associated with health-related factors among male and female middle-school students began increasing in 2020 and 2012, respectively (Figure 3; eTable 4 in Supplement 1).SMRPs associated with health-related factors among male and female high-school students turned from decreasing to increasing in 2017, whereas those of male and female university students turned from decreasing to increasing in 2018 and 2015, respectively (Figure 3).SMRPs associated with healthrelated factors, including depression and other mental illnesses, among female middle-school and high-school students were already larger than in male students in the late 2010s.SMRPs associated with depression and other mental illness among high-school female students displayed positive discontinuation synchronized with the COVID-19 outbreak (Figure 3).

Fluctuations in SMRPs Associated With Family-Related Factors
Among family-related factors, except for male middle-school students, conflict with parents was the leading factor associated with student SMRPs (153 male high-school students SMRPs associated with family-related motives of middle-school and high-school students increased in the early 2010s, but those of university students did not significantly change (Figure 4 and eTable 4 in Supplement 1).SMRPs associated with conflict with parents in groups other than middle-school and university male students increased from the late 2010s, whereas those in middleschool and university male students showed large increases that were not statistically significant  after the pandemic outbreak (Figure 4).SMRPs associated with severe verbal reprimand of middleschool students of both sexes consistently increased from 2007 to 2022.SMRPs of high-school and university students showed no significant change, but a sharp increase was observed in male highschool students in 2022 (Figure 4).

Discussion
This cross-sectional study elucidated the sex-dependent and school-dependent specific features of SMRPs among students in Japan from 2007 to 2022.First, SMRPs increased with age from middle school to high school to university.SMRPs of male and female middle-school students were almost equal, but the age-dependent increase in SMRPs among male students was more pronounced than that among female students.Second, from 2007 to 2022, SMRPs among middle-school and highschool students of both sexes increased, but the majority of joinpoints of enhanced increasing trends (school-related, health-related, and family-related motives) were detected before the pandemic.
SMRPs among female university students turned from decreasing to increasing in 2016; however, that of male students consistently decreased from 2009 to 2021, but then increased sharply in 2022.
Similar increasing patterns (sharp increase) of SMRPs associated with subcategorized motives were predominantly observed among male students.1][12][13] Third, generally, SMRPs for male students were larger than those for female students; however, the SMRPs associated with health-related factors, including depression and other mental illness, for middle-school and highschool female students were greater than those for male students.Furthermore, the SMRP associated with conflict with parent among middle-school female students was larger than that among male students.Accordingly, mental health impairment of female middle-school and highschool students plays an important role in their increased SMRPs.Regarding the increased SMRPs around the pandemic in Japan, it should be emphasized that they are exceptional in the global context.[35][36][37] In the late 2010s, SMRPs associated with health-related factors, including depression and other mental illness, increased among female middle-school and high-school students compared with male students.Therefore, increasing internalization symptoms or disorders of female students may be an underlying factor associated with increasing SMRPs among female students.In the relevant literature, 38 the age of onset of internalization disorders was approximately 15 years; there was no sex difference in their prevalence during elementary school.During high school, the prevalence of internalization disorders was significantly higher in female than in male students. 39,40Temporal fluctuation patterns between the prevalence of internalization disorders and increasing SMRPs associated with health-related factors are remarkably consistent.Furthermore, the Patient Survey of the Ministry of Health, Labor and Welfare reported that the prevalence of psychiatric disorders in female students aged 10 to 24 years in 2020 increased compared with that in 2017 (eFigure 2 in Supplement 1). 413][44] Anxiety plays important roles in the transition from suicidal ideation to suicidal behaviors 43 and is a factor associated with lifetime risk of suicidal ideation and behaviors. 44Retrospective studies in which families were interviewed reported the presence of psychiatric disorders in 90% of individuals who died by suicide. 45Students perceive increasing their internalization symptoms at the transition from middle school to high school, with larger impacts on female than male students, who are focusing on future academic and career options with age. 46,47erefore, the peculiar mentality of high-school students probably contributes to increasing SMRPs associated with health-related and school-related factors and the pronounced increase in SMRPs in female students in the late 2010s.In addition, the stress factors associated with the pandemic, 48 including the psychological burden of the pandemic itself and poor adaptation to school closures or changing educational opportunities, might adversely affect the mental health and resilience of highschool female students, resulting in increases in their SMRPs associated with depression, other mental health issues, and worrying about the future.
However, suicides, including suicidal ideation and behavior, are rarely explained by a single factor, and most contemporary theories of suicide emphasize interactions among several biological, environmental, social, and/or psychological factors. 19,49Accordingly, adding the increasing SMRP associated with internalization symptoms and disorders to increasing SMRPs associated with schoolrelated (underachievement and worrying about the future) and family-related (conflict with parent and severe verbal reprimand) motives can reveal a part of the complicated interactions behind increasing SMRPs among students.
Recently, perfectionism, whereby parents, educators, and students themselves highly expect to perform well in school, has become widespread in Western and East Asian countries, since good educational achievement is thought to lead to good life outcomes, including well-being, physical and mental health, and occupational status. 50To achieve good educational performance, parents tend to adopt attitudes with low levels of emotion and high levels of parental control or overprotection, called affectionless control. 502][53][54] In Europe, male and female students perceive increased schoolwork pressure with age; however, this pressure increases more for female students. 47During elementary school, female students report experiencing less pressure than male students, but the reverse is true during middle school and high school. 471][52][53][54]  high-school students associated with conflict with parent, underachievement, and worrying about the future, suggest the possibility that both affectionless control and excessive schoolwork pressure might also contribute to the increasing SMRPs among these male students.Therefore, the longterm increasing trends in the SMRPs of male and female students in Japan are consistent with worldwide trends. 20,21vernmental comprehensive suicide prevention programs via schools and communities have implemented enhanced support for students and children who have been bullied and abused.
Considering the 8-fold increase in the incidence of bullying and abuse in Japan from 2007 to 2021, 55 governmental comprehensive suicide prevention programs may have contributed to preventing SMRPs associated with bullying and abuse, since SMRPs associated with abuse and bullying did not increase from 2007 to 2022.However, governmental comprehensive suicide prevention programs have not listed addressing internalization symptoms or disorders, affectionless control, or excessive schoolwork pressure as priorities. 16Suppressive control of excessive schoolwork pressure and affectionless control may help to prevent suicides associated with family-related, school-related, and health-related factors among students.However, controlling internalization disorders and symptoms through interventions to prevent affectionless control or excessive schoolwork pressure may potentially violate the basic dignity of individuals and lead to unanticipated adverse reactions to the individual's psychosocial development. 56Therefore, even if an effective prevention method is established, its implementation requires sufficient discussion.
Interpersonal relationships at school and in one's family play important roles in the mental state of individuals as both risk and protective factors for suicide, 19,22 and the impacts of these relationships transform both quantitatively and qualitatively with age. 19,22,57In this study, the impactable suicidal motives associated with interpersonal relationships were conflict with parents or classmates and severe verbal reprimands.Impacts of conflict with parents and severe verbal reprimands on the SMRP decreased at the transition from high school to university, whereas those of conflict with classmate increased from middle school to high school.During adolescence, individuals ordinarily decrease their time with parents and establish complicated relationships with peers by increasing their time with peers. 58Therefore, long-term or frequent school closures may disrupt the psychosocial development of students via interpersonal relationships. 59Indeed, in a recent study, 60 43% of students said their lives were worse, 30% said they were unchanged, and 28% said they were better during school closures; however, 15% said they were worried, 22% said they were indifferent, and 64% said they were looking forward to seeing classmates and peers again after lockdown lifted.
These findings suggest that social restriction, including school closures during the pandemic, had not affected all students in the same way.Increasing time spent with parents because of school closures can easily be understood as a factor associated with increased risk of suicide among students with poor-quality relationships with their parents.Conversely, the absence of face-to-face interaction during school closure could actually be protective (at least in the short term) for students with poor-quality peer relationships or internalization symptoms.Therefore, the increasing SMRPs associated with conflict with classmate among male high-school students and university students of both sexes in 2022 indicates the possibility that the establishment of interpersonal relationships owing to resuming school attendance or normalization of the class format may be more burdensome for some students with internalization or poor-quality relationships.Further studies to explore this hypothesis may provide useful information for improving suicide prevention programs in schools.

Limitations
This study has several limitations.Because it is impossible to collect suicide motives directly from the decedents, the suicide numbers disaggregated by suicidal motives in the SSNPA may be incorrectly estimated owing to a potential bias.However, to eliminate subjectivity as much as possible, the police investigate suicide motives based on evidence, suicide notes, official documentation (eg, medical certificates and clinical recordings), and testimony from the decedent's family.

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Suicidal Mortality and Motives Among Middle-School, High-School, and University Students Although motive-unidentified suicides were homogeneous among schools and between sexes, motive-unidentified suicides might be biased toward overestimating or underestimating the results of the analysis.Despite these limitations, the SSNPA is evaluated as the most reliable governmental suicide database in Japan, since data were collected by the National Police Agency using consistent investigational methods from 2007 to 2022.

Conclusions
The findings of this cross-sectional study suggest the importance of interaction among affectionless control, excessive schoolwork pressure, and increasing prevalence of internalization symptoms for understanding the basis for increasing student SMRPs during the late 2010s and the pandemic in Japan.The suicidal motives of students transform with advancing psychosocial developmental stages (eg, family-related motives decrease, and school-related and health-related motives increase with age).These complicated interactions among suicidal motives probably play important roles in the recent fluctuation of SMRPs in 2 increasing phases, a long-lasting increase from the late 2010s and synchronization with the pandemic outbreak.Therefore, rather than uniformly applying

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university students, followed by school-related factors (eFigure 1A in Supplement 1).Impacts of other suicidal subcategories in school-related, health-related, and family-related motives on SMRPs are indicated in eFigure 1 in Supplement 1.

com/ on 11/04/2023 students
Furthermore, the consistently increasing SMRPs among middle-school male associated with severe verbal reprimands and underachievement, as well as that among Downloaded From: https://jamanetwork.
adolescent-based research results to school-based suicide prevention programs for middle-school, high-school, and university students, it can contribute to effective suicide prevention of students to design and implement programs that are tailored vulnerabilities of each developmental stage.SMRPs of Middle-School Students Disaggregated by Motives and Sex During 2007-2022 eTable 2. SMRPs of High-School Students Disaggregated by Motives and Sex During 2007-2022 eTable 3. SMRPs of University Students Disaggregated by Motives and Sex During 2007-2022 eFigure 1.Average of SMRPs Caused by Major 7 Categorized Motive and Impactable Subcategorized Motives of Students From 2007-2022 eTable 4. Summary of Joinpoint of SMRP Caused by Suicidal Motives, Sex and School From 2007-2022 Analyzed by Joinpoint Regression Analysis eFigure 2. Age-Dependent Ratio of Prevalence of Mental Disorders Between 2017 and 2020 eReferences