An exploratory study on spatiotemporal clustering of suicide in Korean adolescents.

BACKGROUND: Adolescent suicides are more likely to form clusters than those of other age groups. However, the definition of a cluster in the space-time dimension has not been established, neither are the factors contributing to it well known. Therefore, this study aimed to identify space-time clusters in adolescent suicides in Korea and to examine the differences between clustered and non-clustered cases using novel statistical methods. METHODS: From 2016 to 2020, the dates and locations, including specific addresses from which the latitude and longitude of all student suicides (aged 9-18 years) in Korea were obtained through student suicide reports. Sociodemographic characteristics of the adolescents who died by suicide were collected, and the individual characteristics of each student who died by suicide were reported by teachers using the Strengths and Difficulties Questionnaire (SDQ). Density-Based Spatial Clustering of Applications with Noise (DBSCAN) analysis was used to assess the clustering of suicides. RESULTS: We identified 23 clusters through the data analysis of 652 adolescent suicides using DBSCAN. By comparing the size of each cluster, we identified 63 (9.7%) spatiotemporally clustered suicides among adolescents, and the temporal range of these clusters was 7-59 days. The suicide cluster group had a lower economic status than the non-clustered group. There were no significant differences in other characteristics between the two groups. CONCLUSION: This study has defined the space-time cluster of suicides using a novel statistical method. Our findings suggest that when an adolescent suicide occurs, close monitoring and intervention for approximately 2 months are needed to prevent subsequent suicides. Future research using DBSCAN needs to involve a larger sample of adolescents from various countries to further corroborate these findings.

Suicide warning signs that are challenging to recognize: a psychological autopsy study of Korean adolescents.

BACKGROUND: In South Korea, the leading cause of youth death has been suicide for about 20 years. In this study, we conducted a multi-method psychological autopsy to identify the psychiatric diagnosis, developmental history, personality traits, family history, school life, warning signs of suicide, and risk factors related to suicide for the first time in Korea. METHODS: This was a postmortem, retrospective, and descriptive study of 36 adolescents who died by suicide between August 2015 and July 2021 in South Korea. We obtained qualitative and quantitative data from the Korean Psychological Autopsy of Adolescent, conducted by the Suicide and School Mental Health Institute, the official student mental health policy-focused research institute of the Korean Ministry of Education. RESULTS: The adolescents comprised equal percentage of girls and boys. Approximately half of the deaths (55.6%) occurred at home and most (72.2%) involved jumping from a height. Most of the adolescents (97.2%) had one major psychiatric disorder before death, with depressive disorder being the most prevalent (75%). They were at a high risk for internet addiction before death. The most common personality trait was avoidance (28.6%), followed by submissiveness (27.3%). Half of the parents reported that the adolescents were satisfied with their school life and the teachers observed that they had no behavioral problems. One year before death, seven (19.4%) adolescents injured themselves and five (13.9%) had attempted suicide. Most of the deceased (80.6%) had expressed suicide warning signs to their families within one year before death. Adolescents had a long experience of family-related adverse events. CONCLUSIONS: Most of the adolescents had mental health disorders and expressed suicidal intentions using verbal and nonverbal signs. However, it was challenging for families to recognize the risk signs because of adolescents' personality traits or a good school life. To prevent adolescent suicide, adolescents, parents, and teachers need to be educated to recognize signs of suicide warning signs and equipped to guide adolescents to appropriate care.

Latent Classes based on Clinical Symptoms of Military Recruits with Mental Health Issues and Their Distinctive Clinical Responses to Treatment over 6 Months.

Objective: : This study aimed (1) to identify distinct subgroups of psychiatric patients referred for a mental health certificate for military service suitability and (2) to determine whether there is a difference in clinical features such as treatment responsiveness and prognosis among certain subgroups. Methods: : We conducted latent profile analysis (LPA) using the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) clinical profiles of the participants. Linear mixed model analysis was performed to examine changes in the severity of clinical symptoms and functional level according to the treatment period of the latent classes derived from the LPA. Results: : The results indicated that the best-fitting model was a three-class model, comprising Class 1 (mild maladjustment), Class 2 (neurotic depression and anxiety), and Class 3 (highly vulnerable and hypervigilant). We demonstrated that the three subgroups displayed different characteristics in treatment responsiveness and clinical course based on their Clinical Global Impression-Severity and Global Assessment of Functioning scores over a treatment period of 6 months. While subjects in Classes 1 and 2 significantly improved over 6 months, those in Class 3 showed little or no improvement in our clinical parameters. Conclusion: : This study has yielded data with clinical implications for treatment planning and interventions for each subgroup classified that were based on MMPI-2 clinical profiles of military recruits who might be maladjusted to serve.

Clinical Utility of the Minnesota Multiphasic Personality Inventory-Adolescent Restructured Form in the Assessment of Internalizing and Externalizing Disorders in Adolescents: A Preliminary Approach.

Objectives: This study investigated whether the Minnesota Multiphasic Personality Inventory-Adolescent Restructured Form (MMPI-ARF) can differentiate between two groups of adolescents, one diagnosed with internalizing disorders and another with externalizing disorders, and examined the clinical utility of the MMPI-A-RF by examining which subscales can significantly discriminate between these two groups. Methods: A total of 105 adolescents aged 13-18 years completed the MMPI-A-RF (53 internalizing disorder and 52 externalizing disorder groups). Independent t-test, chi-square test (χ2), and discriminant analysis were used to examine whether MMPI-A-RF can distinguish between the two groups. Results: Sixteen MMPI-A-RF scales best predicted differences between the groups with internalizing and externalizing disorders. Fourteen scales (Higher-Order Scale [Emotional/Internalizing Dysfunction], Restructured Clinical [RC] Scale [RC demoralization, Somatic Complaints (RC1), and Low Positive Emotions (RC2)], Personality Psychopathology Five Scale [Introversion/Low Positive Emotionality- Revised, Negative Emotionality/Neuroticism-Revised], Somatic/Cognitive Scale [Malaise, Head Pain Complaints, and Gastrointestinal Complaints], Internalizing Scale [Stress/Worry, Self-Doubt], Externalizing Scale [Negative School Attitudes], Interpersonal Scale [Social Avoidance, Shyness]) were associated with the internalizing disorder group, whereas two scales (Externalizing Scale [Conduct Problems, Negative Peer Influence]) were associated with the externalizing disorder group. Conclusion: The MMPI-A-RF can be an efficient assessment tool for a quick diagnosis as it can classify individuals with internalizing and externalizing disorders in clinical settings that lack a variety of assessment tools for children and adolescents.

Korean adolescent suicide and search volume for "self-injury" on internet search engines.

Introduction: Many adolescents with suicidal ideation receive support through the Internet. However, they also find ways to attempt suicide or strengthen their suicidal ideation through this medium. This study analyzed the association between the search volume of suicide-related terms and the number of suicides among Korean adolescents. We also analyzed the correlations between the search volumes of suicide-related terms. Methods: We selected seven words (suicide, self-injury, depression, academic score, school violence, outcasts, and family trouble) related to adolescent suicide. A dataset was constructed by combining data from the most commonly used search engine in Korea (Naver Datalab) and the daily number of adolescent suicides in school settings (n = 347) from January 1, 2016 to December 31, 2018, collected from the Ministry of Education. Poisson regression and Pearson correlation analyses were performed. Results: Significant associations were found between suicide attempts and search term volumes, which differed according to sex and time interval. Among the search terms, "self-injury" was most strongly associated with suicide, and this association was significant at all time intervals (daily, weekly, and monthly) in female adolescents and in the total population. Further, the association was strongest in the daily suicide data. More search term volumes were related to suicide in the daily and weekly data than in the monthly data. There were positive correlations between "suicide," "self-injury," and "depression" search volumes. Conclusion: Further studies with larger sample sizes, more search terms, and analysis of time intervals between suicide-related term search and suicide death are required. These studies can contribute to the establishment of an online suicide prevention system to detect suicide risk in adolescents and provide interventions.

Can We Notice the Suicidal Warning Signs of Adolescents With Different Psychometric Profiles Before Their Death?: Analysis of Teachers' Reports.

BACKGROUND: This study aimed to analyze the suicidal warning signs of Korean students with different psychometric profiles based on teacher reports. METHODS: This was a retrospective cohort study based on Korean school teachers' responses to the Student Suicide Report Form. In total, 546 consecutive cases of student suicide were reported from 2017 to 2020. After missing data were excluded, 528 cases were included. The report consisted of demographic factors, the Korean version of the Strengths and Difficulties Questionnaire (SDQ) for teacher reporting, and warning signs of suicide. Frequency analysis, multiple response analysis, the χ² test, and Latent Class Analysis (LCA) were performed. RESULTS: Based on the scores of the Korean version of the teacher-reported SDQ, the group was divided into nonsymptomatic (n = 411) and symptomatic (n = 117) groups. Based on the LCA results, four latent hierarchical models were selected. The four classes of deceased students showed significant differences in school type (χ² = 20.410, P < 0.01), physical illness (χ² = 7.928, P < 0.05), mental illness (χ² = 94.332, P < 0.001), trigger events (χ² = 14.817, P < 0.01), self-harm experience (χ² = 30.618, P < 0.001), suicide attempts (χ² = 24.072, P < 0.001), depressive symptoms (χ² = 59.561, P < 0.001), anxiety (χ² = 58.165, P < 0.001), impulsivity (χ² = 62.241, P < 0.001), and social problems (χ² = 64.952, P < 0.001). CONCLUSION: Notably, many students who committed suicide did not have any psychiatric pathology. The proportion of the group with a prosocial appearance was also high. Therefore, the actual suicide warning signals were similar regardless of students' difficulties and prosocial behaviors, so it is necessary to include this information in gatekeeper education.

Association Between Internet Searches Related to Suicide/Self-harm and Adolescent Suicide Death in South Korea in 2016-2020: Secondary Data Analysis.

BACKGROUND: Previous studies have investigated the association between suicide and internet search volumes of terms related to suicide or self-harm. However, the results varied by people's age, period, and country, and no study has exclusively investigated suicide or self-harm rates among adolescents. OBJECTIVE: This study aims to determine the association between the internet search volumes of terms related to suicide/self-harm and the number of suicides among South Korean adolescents. We investigated gender differences in this association and the time lag between the internet search volumes of the terms and the connected suicide deaths. METHODS: We selected 26 search terms related to suicide and self-harm among South Korean adolescents, and the search volumes of these terms for adolescents aged 13-18 years were obtained from the leading internet search engine in South Korea (Naver Datalab). A data set was constructed by combining data from Naver Datalab and the number of suicide deaths of adolescents on a daily basis from January 1, 2016, to December 31, 2020. Spearman rank correlation and multivariate Poisson regression analyses were performed to identify the association between the search volumes of the terms and the suicide deaths during that period. The time lag between suicide death and the increasing trend in the search volumes of the related terms was estimated from the cross-correlation coefficients. RESULTS: Significant correlations were observed within the search volumes of the 26 terms related to suicide/self-harm. The internet search volumes of several terms were associated with the number of suicide deaths among South Korean adolescents, and this association differed by gender. The search volume for "dropout" showed a statistically significant correlation with the number of suicides in all adolescent population groups. The correlation between the internet search volume for "dropout" and the connected suicide deaths was the strongest for a time lag of 0 days. In females, self-harm and academic score showed significant associations with suicide deaths, but academic score showed a negative correlation, and the time lags with the strongest correlations were 0 and -11 days, respectively. In the total population, self-harm and suicide method were associated with the number of suicides, and the time lags with the strongest correlations were +7 and 0 days, respectively. CONCLUSIONS: This study identifies a correlation between suicides and internet search volumes related to suicide/self-harm among South Korean adolescents, but the relatively weak correlation (incidence rate ratio 0.990-1.068) should be interpreted with caution.

A Latent Class Analysis of Suicidal Behaviors in Adolescents.

OBJECTIVE: The purpose of the present study was to identify adolescents' suicide subgroups using five indicators (depression, anxiety, suicide ideation, and planned and attempted suicide), and explore the distinctive features of each subgroup. METHODS: This study included 2,258 teenagers from four schools. Both adolescents and their parents, who voluntarily agreed to participate in the study, completed a series of self-reported questionnaires on depression, anxiety, suicide, self-harm, self-esteem, impulsivity, childhood maltreatment, and deviant behaviors. The data were analyzed using latent class analysis, a person-centered method. RESULTS: Four classes were detected: "high risk for suicide without distress," "high risk for suicide with distress," "low risk for suicide with distress," and "healthy." The "high risk for suicide with distress" class was the most severe on all evaluated psychosocial risk factors, namely, impulsivity, low self-esteem, self-harming behaviours, deviant behaviour problems, and childhood maltreatment, followed by "high risk for suicide without distress." CONCLUSION: This study identified two high risk subgroups for adolescent' suicidality, "high risk for suicide with or without distress." Both high risk subgroups for suicide showed higher scores for all psychosocial risk factors than low risk subgroups for suicide. Our findings suggest that special attention needs to be paid to the latent class "high risk for suicide without distress," as this group's "cry for help" might be relatively difficult to detect. Specific interventions for each group (e.g., distress safety plans for "suicidal potential with or without emotional distress") need to be developed and implemented.

Suicidal Ideation, Depression, and Insomnia in Parent Survivors of Suicide: Based on Korean Psychological Autopsy of Adolescent Suicides.

BACKGROUND: This study aims to evaluate suicidal ideation, depression, and insomnia among parent survivors of adolescents who died by suicide and their relevant risk factors using psychological autopsy results from South Korea. METHODS: The participants were 42 parent survivors (10 fathers and 32 mothers) of 35 adolescents who died by suicide. We used the Patient Health Questionnaire-9 and the Korean version of the Insomnia Severity Index to evaluate the mental health of the bereaved parents. We used the Korean Psychological Autopsy Checklist for Adolescents, the Korean Beck Depression Inventory, the Korean Version of the Barratt Impulsiveness Scale-II, and the Kiddie-Schedule for Affective Disorders and Schizophrenia-Present and Lifetime-Korean versions to evaluate the mental health of deceased adolescents before their deaths. RESULTS: The results showed that many parent survivors of suicide had developed clinically significant suicidal ideation, depression, and insomnia (75.6%, 73.2%, and 42.9%, respectively). Furthermore, the higher the incidence of traumatic events experienced by the deceased adolescents, the higher the severity of depression and insomnia experienced by surviving parents. CONCLUSION: We should pay attention that parent survivors of suicide can suffer mental disorders after their offspring's death. In future studies, long-term follow-up studies with larger samples need to generalize our findings and clarify the causal relationship.

Characteristics of Korean students advised to seek psychiatric treatment before death by suicide.

Introduction: Suicide is the leading cause of death among adolescents in Korea. Psychiatric disorders are well-known risk factors for suicide, but the proportion of children and adolescents who died by suicide and who had received psychiatric treatment is low. This study aims to examine how many school students who died by suicide were advised by their school to seek psychiatric treatment before their death and to characterize their clinical characteristics. Methods: We analyzed data collected by the Ministry of Education of Korea for all students who died by suicide between 2016 and 2020. Students were grouped according to whether or not they were advised to seek psychiatric treatment by their school-based on mental health screening and teachers' judgments. Sociodemographic characteristics (sex, educational stage, family structure, and socioeconomic status), suicide-related characteristics (place of suicide, suicide method, suicide note, previous self-harm, and previous suicide attempt), emotional and behavioral status, school life and personal, and family problems were compared between the two groups. Results: Analysis was conducted for 544 students, 110 (20.2%) of whom were advised to seek psychiatric treatment by their school before their death. This group had a higher proportion of girls; poorer attendance; higher frequency of depression, anxiety, impulsivity, and social problems; personal problems (appearance, friend-related, and mental and physical health problems); family problems (mental health problems of family, bad relationship with parents, and conflict of parents); and higher incidence of self-harm or suicide attempts (P < 0.001) than the other group. Conclusion: Teachers seem to advise psychiatric treatment when mental health problems are revealed at school. It showed distinctive clinical characteristics between the two groups. Preventing suicide among students requires the attention and effort not only of schools, but also of families, communities, and mental health professionals.

Characteristics of Korean Children and Adolescents Who Die by Suicide Based on Teachers' Reports.

We analyzed the clinical characteristics and suicide-related factors of students who died by suicide in Korea in 2016-2020, based on teachers' reports. Using data on total suicide deaths (N = 654, mean age = 16.0, 52.6% boys) collected by the Ministry of Education of Korea, we investigated the demographic and clinical characteristics and suicide-related factors of suicide deaths in students aged 9-18 years. Considering gender, more boys (52.6%, N = 344) died by suicide than girls (47.4%, N = 310). About 425 (65.0%) of the suicides were among high school students. The most common suicide method was jumping from a high place (70.6%, N = 454), followed by hanging (25.7%, N = 165). Additionally, 9.4% (N = 48) of the students who died by suicide had a history of attempted suicide, 13.4% (N = 73) had attempted self-harm, and 12.8% (N = 48) were acquainted with someone who had died by suicide. Teachers observed 20.6% (N = 120) of the suicide warning signs at school. Girls tended to have higher rates of attempted suicide, emotional problems, and psychiatric disorders than boys. This study was conducted with the largest sample of Korean suicide students observed at school. Effective suicide-related mental health training for teachers could contribute to suicide prevention in students.

Comparison of Suicide Attempts and Suicide Deaths by Jumping from a High Place in Korean Children and Adolescents.

Jumping from a high place is the most common method of suicide among Korean children and adolescents. The aim of this study was to examine the personal, family, and school life of Korean children and adolescents who chose jumping from a high place, among suicide attempts and suicide deaths, based on teachers' reports. Data on suicide attempts and suicide deaths by jumping from a high place in children and adolescents were collected through the Ministry of Education in South Korea from 2016 to 2018. We compared sociodemographic variables, suicide-related variables, emotional and behavioral status, school life related variables, and variables related to family problems among suicide deaths (n = 262), actual suicide attempts (n = 50), and interrupted or aborted suicide attempts (n = 210). There were differences in educational stage (p < 0.001), place of suicide (p < 0.001), presence of suicide note (p < 0.05) and previous suicide attempt (p < 0.001) among the three groups. The total difficulty score on the Strength Difficulty Questionnaire of interrupted or aborted suicide attempts was higher than that of the other two groups. Our study suggests that the suicide death group tend to present fewer personal and family pathologies and better school adjustment than the suicide attempt group.

Investigation of gene-environment interactions in relation to tic severity.

Tourette syndrome (TS) is a neuropsychiatric disorder with involvement of genetic and environmental factors. We investigated genetic loci previously implicated in Tourette syndrome and associated disorders in interaction with pre- and perinatal adversity in relation to tic severity using a case-only (N = 518) design. We assessed 98 single-nucleotide polymorphisms (SNPs) selected from (I) top SNPs from genome-wide association studies (GWASs) of TS; (II) top SNPs from GWASs of obsessive-compulsive disorder (OCD), attention-deficit/hyperactivity disorder (ADHD), and autism spectrum disorder (ASD); (III) SNPs previously implicated in candidate-gene studies of TS; (IV) SNPs previously implicated in OCD or ASD; and (V) tagging SNPs in neurotransmitter-related candidate genes. Linear regression models were used to examine the main effects of the SNPs on tic severity, and the interaction effect of these SNPs with a cumulative pre- and perinatal adversity score. Replication was sought for SNPs that met the threshold of significance (after correcting for multiple testing) in a replication sample (N = 678). One SNP (rs7123010), previously implicated in a TS meta-analysis, was significantly related to higher tic severity. We found a gene-environment interaction for rs6539267, another top TS GWAS SNP. These findings were not independently replicated. Our study highlights the future potential of TS GWAS top hits in gene-environment studies.

Classification of Adolescent Suicide Based on Student Suicide Reports.

Exploring the risk factors of adolescent suicide is important for effective suicide prevention. This study explored the clustering of adolescent suicides based on six risk factors: mental disorder, broken family, depression, anxiety, previous suicide attempts, and deviant behaviors. Using 173 student suicide reports obtained from the Ministry of Education, we evaluated the associations between suicide and variables related to mental disorders; dysfunctional family life; depression and anxiety; previous suicide attempts; deviant behaviors such as drinking and smoking; and school life characteristics, including attendance and discipline, problems within the past year, and incidents prior to suicide. In addition, reports of warning signs just before suicide were included in the analysis. The two-stage cluster analysis classified the students into three clusters: the silent type (cluster 1; 48.55%), in which no risk factors were observed; environmental-risk type (cluster 2: 24.28%), which featured a high frequency of broken households, deviant behaviors such as smoking/drinking and running away from home; and depressive type (cluster 3: 27.17%), which featured a high frequency of mental health problems such as depression, anxiety, and suicide attempts. Identifying the sub-types of adolescent suicide may help to inform tailored suicide prevention and intervention strategies in school.

The Impact of Referral to Mental Health Services on Suicide Death Risk in Adolescent Suicide Survivors.

OBJECTIVES: This study aims to examine the effect of adolescent suicide survivors' experience on suicide death risk, and the effect of referral to mental health services (hereafter referral) in this regard. METHODS: This study used the data of 878 suicide-deceased and suicide-attempted adolescents aged 8-19 years, managed by the Suicide and School Mental Health Institute from 2016 to 2018. RESULTS: Regression analysis for main effects showed that although suicide experience had no direct effect on suicide death, non-referral status was associated with a greater risk of death by suicide. While the "non-suicide survivor with non-referral" and "suicide survivor with non-referral" groups showed 1.87 [adjusted odds ratio=1.87, 95% confidence interval (CI)=1.21-2.89] and 4.59 (adjusted odds ratio= 4.59, 95% CI=2.02-10.42) times higher odds of suicide death, respectively, the "suicide survivor with referral" group showed no difference compared to the "non-suicide survivor with referral" group. CONCLUSION: From these findings, there is a need to strengthen referral to mental health services and apply complicated grief treatment to improve the mental health of adolescent suicide survivors.

Characteristics of First Visit Pediatric Patients with Suicidal Ideation and Behavior: An 8-Year Retrospective Chart Review.

OBJECTIVES: Our study aimed to analyze the demographic and clinical characteristics of children and adolescents during their first visit to psychiatric outpatient departments for the management of suicidal ideation and behavior, and to compare the changes before and in 2012 or later. METHODS: This multicenter study was conducted at five university hospitals in a metropolitan area in South Korea. Medical records of patients aged 6-18 years were retrospectively reviewed from January 2009 to December 2016. Patients were analyzed by classifying them into suicidal and non-suicidal groups based on their visit to the hospital for management of suicidal ideation or suicide attempt and other mental problems, respectively. RESULTS: There were differences in the year of visit, diagnosis, education level, and referral sources between patients in the suicidal and non-suicidal groups. Multiple regression analysis was conducted based on the sex, education level, referral by school, and diagnosis of depression in patients in the suicidal group, which revealed significant association. CONCLUSION: Suicide-related problems were significantly associated with the sex, education level, referral by school, and a diagnosis of depression in the patients. A well-connected referral system would be necessary for professional mental health management of high-risk children and adolescents.

Gender-based Multilevel Analysis of Influential Factors for Suicide Attempts among At-risk Non-referred Adolescents in Korea.

OBJECTIVE: Effective suicide prevention for at-risk adolescents requires increased access to medical treatment. Investigating the unique characteristics of suicide in this vulnerable at-risk non-referred sample can contribute to establishing effective suicide prevention policies. This study aimed to (a) examine at-risk non-referred adolescents' suicide attempt rate, (b) investigate influential multilevel factors in predicting these adolescents' suicide attempts, and (c) compare the results of (a) and (b) by gender. METHODS: A total of 401 samples (216 boys and 185 girls) were recruited through a school-based mental health project for at-risk adolescents. Multivariate hierarchical logistic regression analyses were performed at the individual-, contextual-, and protective levels to evaluate three multilevel models as well as to investigate predictabilities for the overall group and by gender. RESULTS: The suicide attempt rate of the overall sample was 29.4% (boys: 18.1%, girls: 42.7%), which was significantly higher than that of community samples. For boys, individual-level predictors (depression and conduct problems) had the most significant contribution in predicting suicide attempts. In contrast, for girls, protective-level predictors (family satisfaction) contributed the most to the prediction of suicide attempts, followed by contextual-level predictors (academic grades). CONCLUSION: This study is an important step in understanding the unique characteristics of at-risk non-referred adolescents who have not yet been considered in mental health policies. Improving medical accessibility will be the first step in establishing effective suicide prevention policies for these vulnerable samples.

Text mining analysis of teachers' reports on student suicide in South Korea.

A teacher as a suicide prevention gatekeeper has an important role in identifying suicide risks and warning signs in students. After a student's suicide, teachers in Korea have to write a student suicide case report based on their direct and indirect observations. In particular, the section 'characteristic of student suicide' of this report contains valuable information about the suicide; however, it is unstructured, and thus cannot be analyzed using conventional statistical methods. We aimed to identify the characteristics of observed Korean students, who have committed suicide, using text mining techniques as well as to improve our understanding of suicidal behaviors in the school contexts. Therefore, a series of text mining techniques: topic analysis, word correlation, and word frequency analysis, in three problem categories: health, school, and family problems, were used to analyze the characteristics of student suicides. Topic analysis showed that only 30% of the student suicide case reports identified problematic student characteristics related to suicide. Correlations between words showed that words in one problem category were often correlated with words in other problem categories. Frequency word analysis showed that the three problem categories varied across gender and school levels. These results provide interesting insights into the characteristics of suicides among Korean students and important implications for suicide intervention in the education field.

Youth Suicide in Korea Across the Educational Stages.

Background: Youth suicides have diverse characteristics according to the young people's developmental stages. Warning signs and communication of suicidal intent can be vague among early adolescents, while mental health problems may be more evidently related to suicidal ideation in older adolescents. Understanding the developmental characteristics of youth suicide is necessary for effective suicide prevention. Aims: We explored the differences between children and adolescents who died by suicide and the characteristics of these young people as observed by their school teachers. Method: We analyzed teachers' mandatory postmortem reports of suicides among 308 Korean students. We compared: suicide-related information including personal, familial, and school factors; stressful life events; and participation in interventions among elementary, middle, and high school students who died by suicide. We also assessed the distribution of student suicides per month. Results: Suicide among elementary school students increased during school vacations, and suicide among middle and high school students increased during the school semester. According to the teachers' reports, elementary school students who died by suicide were more extroverted and had better academic achievements than their high school peers, and had significantly lower levels of substance/tobacco use. Elementary school students who died by suicide showed significantly less academic stress and use of external professional help than did other groups. Limitations: Because this research is based on mandatory teacher reports, the subjective opinions of teachers may have affected the reliability of the data. Suicide by out-of-school youth was not included. Conclusion: School-based suicide prevention should be implemented in accordance with young people's developmental characteristics.

Four-year trajectory of Korean youth mental health and impacts of school environment and school counselling: a observational study using national schools database.

OBJECTIVES: This study aimed to investigate changes in the mental health status of South Korean adolescents at a school level and identify school-related factors affecting these changes. DESIGN: A retrospective data analysis, population study. SETTING: South Korean high schools from 2013 to 2016. PARTICIPANTS: Randomly sampled 827 schools (316 834 boys and 299 304 girls) PRIMARY OUTCOME MEASURES: Mean scores of the Adolescent Mental Health and Problem Behavior Questionnaire-II (AMPQ-II), a school-based mental health screening test, were used to explore changes in youth mental health. Data regarding the school environment and school counselling were gathered from the 'School info' website. A multilevel growth model was used to determine relationships between students' mental health and school-related factors. RESULTS: Students' mental health statuses in South Korea gradually improved over time (coefficient=-1.46 to -1.70, p<0.001). School mobility rates (coefficient=0.93 to 1.00, p<0.05), school dropout rates (coefficient=0.38 to 0.40, p<0.001), school budgets per student (coefficient=-0.05 to -0.06, p<0.01) and number of school counselling sessions (coefficient=0.14, p<0.01) were significantly associated with baseline AMPQ-II scores. The rate of change in AMPQ-II score increased when the number of school counselling sessions was higher (coefficient=-0.03, p<0.05) or the school budget was lower (coefficient=0.02, p<0.001). School environment explained 21.6% of the AMPQ-II baseline score variance and 9.3% of the rate of change variance. School counselling further explained 2.0% of the variance in baseline AMPQ-II scores and 2.3% of the rate of change variance. CONCLUSIONS: This study suggests that school environment stability and active provision of school-based mental health services have a positive impact on youth mental health.