1.Comparison of Suicide Completion Rate in Korean Students Pre- and Post-COVID-19 Pandemics
Kyungjin LEE ; Boram NAM ; Kyoil SEO ; Eunkyung JO ; Seohyun KIM ; Deokyong SHIN ; Aeju KIM ; Youngil JEONG ; Yeni KIM
Psychiatry Investigation 2025;22(2):204-211
Objective:
This study compared the incidence of suicide cases among Korean students before and after the coronavirus disease-2019 (COVID-19) pandemic.
Methods:
Aggregated case reports of all known suicide victims attending elementary, middle, and high school in South Korea from 2017 to 2022 were analyzed. These reports, compiled by teachers under the directive of the South Korean Department of Education, surveyed the circumstances surrounding each suicide and identified associated risk factors posthumously.
Results:
The completed suicide rate was 2.37 per 100,000 students pre-COVID-19 (2017–2019), significantly increasing to 3.37 per 100,000 students post-COVID-19 (2020–2022; odds ratio [OR] 1.42, p<0.001). The rate began to rise approximately 6 months into the pandemic and continued to worsen throughout 2021 and 2022. Fair attendance significantly increased in 2020 (74.83%, p=0.003) during the initial stage of school closure measures compared to 2019 (58.27%) among students prior to suicide completion. However, as social distancing measures continued, “absence due to medical reasons” showed a significant increase in 2022 (23.56%) compared to 2019 (13.67%, p=0.025) and 2020 (9.52%, p<0.001) among these students. Among those who completed suicide, teachers reported increased signs of depression and anxiety posthumously compared to pre-COVID-19 periods.
Conclusion
The incidence of completed suicide among students was significantly higher in the post-COVID-19 years compared to pre-COVID-19. Attendance records and teachers’ reports indicated a deterioration in mental health among these students before suicide completion, highlighting the need to consider mental health impacts when implementing future quarantine policies.
2.Reliability and Validity of the Korean Version of the Quantitative Checklist for Autism in Toddlers: A Comparison Study Between the Clinical and Community Population
Youngeun HONG ; Kyungjin LEE ; Namhee YOO ; Jungwon CHOI ; Yeni KIM
Psychiatry Investigation 2025;22(3):231-242
Objective:
This study aimed to evaluate the utility of the Korean version of the Quantitative Checklist for Autism in Toddlers (Q-CHAT) in hospital settings and to identify items sensitive for detecting autism spectrum disorder (ASD) trait.
Methods:
The Q-CHAT was administered to a clinical sample of children presenting with developmental delays with a high probability of ASD in a hospital setting (n=37), as well as to typically developing community children (n=67), aged 12 to 54 months.
Results:
The mean Q-CHAT total score in the hospital sample (42.0±13.6) was significantly higher than in the community sample (29.9±7.8), with maximized sensitivity and adequate specificity at 32.5 (sensitivity=0.811, specificity=0.687). The internal consistency of Q-CHAT was 0.764 for the overall sample and 0.825 for the hospital sample. Q-CHAT total scores and item scores in the hospital sample remained stable across age groups, indicating age-invariant properties. The hospital sample showed higher endorsement of less favorable development in social interaction and reciprocity items compared to community sample. No difference in the Q-CHAT item scores was present among age groups in the hospital samples. In the community samples, item scores, such as comprehending a child’s speech, using the hand of others as a tool, adapting to a change in routine, repeating the same action, and making unusual finger movements, decreased with the advance of age.
Conclusion
The Korean version of the Q-CHAT demonstrates good validity and reliability and is effective in discriminating autistic traits even in children older than 24 months. The items endorsed for hospital samples varied from community samples, implying item-specific sensitivity for hospital samples.
3.Comparison of Suicide Completion Rate in Korean Students Pre- and Post-COVID-19 Pandemics
Kyungjin LEE ; Boram NAM ; Kyoil SEO ; Eunkyung JO ; Seohyun KIM ; Deokyong SHIN ; Aeju KIM ; Youngil JEONG ; Yeni KIM
Psychiatry Investigation 2025;22(2):204-211
Objective:
This study compared the incidence of suicide cases among Korean students before and after the coronavirus disease-2019 (COVID-19) pandemic.
Methods:
Aggregated case reports of all known suicide victims attending elementary, middle, and high school in South Korea from 2017 to 2022 were analyzed. These reports, compiled by teachers under the directive of the South Korean Department of Education, surveyed the circumstances surrounding each suicide and identified associated risk factors posthumously.
Results:
The completed suicide rate was 2.37 per 100,000 students pre-COVID-19 (2017–2019), significantly increasing to 3.37 per 100,000 students post-COVID-19 (2020–2022; odds ratio [OR] 1.42, p<0.001). The rate began to rise approximately 6 months into the pandemic and continued to worsen throughout 2021 and 2022. Fair attendance significantly increased in 2020 (74.83%, p=0.003) during the initial stage of school closure measures compared to 2019 (58.27%) among students prior to suicide completion. However, as social distancing measures continued, “absence due to medical reasons” showed a significant increase in 2022 (23.56%) compared to 2019 (13.67%, p=0.025) and 2020 (9.52%, p<0.001) among these students. Among those who completed suicide, teachers reported increased signs of depression and anxiety posthumously compared to pre-COVID-19 periods.
Conclusion
The incidence of completed suicide among students was significantly higher in the post-COVID-19 years compared to pre-COVID-19. Attendance records and teachers’ reports indicated a deterioration in mental health among these students before suicide completion, highlighting the need to consider mental health impacts when implementing future quarantine policies.
4.Reliability and Validity of the Korean Version of the Quantitative Checklist for Autism in Toddlers: A Comparison Study Between the Clinical and Community Population
Youngeun HONG ; Kyungjin LEE ; Namhee YOO ; Jungwon CHOI ; Yeni KIM
Psychiatry Investigation 2025;22(3):231-242
Objective:
This study aimed to evaluate the utility of the Korean version of the Quantitative Checklist for Autism in Toddlers (Q-CHAT) in hospital settings and to identify items sensitive for detecting autism spectrum disorder (ASD) trait.
Methods:
The Q-CHAT was administered to a clinical sample of children presenting with developmental delays with a high probability of ASD in a hospital setting (n=37), as well as to typically developing community children (n=67), aged 12 to 54 months.
Results:
The mean Q-CHAT total score in the hospital sample (42.0±13.6) was significantly higher than in the community sample (29.9±7.8), with maximized sensitivity and adequate specificity at 32.5 (sensitivity=0.811, specificity=0.687). The internal consistency of Q-CHAT was 0.764 for the overall sample and 0.825 for the hospital sample. Q-CHAT total scores and item scores in the hospital sample remained stable across age groups, indicating age-invariant properties. The hospital sample showed higher endorsement of less favorable development in social interaction and reciprocity items compared to community sample. No difference in the Q-CHAT item scores was present among age groups in the hospital samples. In the community samples, item scores, such as comprehending a child’s speech, using the hand of others as a tool, adapting to a change in routine, repeating the same action, and making unusual finger movements, decreased with the advance of age.
Conclusion
The Korean version of the Q-CHAT demonstrates good validity and reliability and is effective in discriminating autistic traits even in children older than 24 months. The items endorsed for hospital samples varied from community samples, implying item-specific sensitivity for hospital samples.
5.Comparison of Suicide Completion Rate in Korean Students Pre- and Post-COVID-19 Pandemics
Kyungjin LEE ; Boram NAM ; Kyoil SEO ; Eunkyung JO ; Seohyun KIM ; Deokyong SHIN ; Aeju KIM ; Youngil JEONG ; Yeni KIM
Psychiatry Investigation 2025;22(2):204-211
Objective:
This study compared the incidence of suicide cases among Korean students before and after the coronavirus disease-2019 (COVID-19) pandemic.
Methods:
Aggregated case reports of all known suicide victims attending elementary, middle, and high school in South Korea from 2017 to 2022 were analyzed. These reports, compiled by teachers under the directive of the South Korean Department of Education, surveyed the circumstances surrounding each suicide and identified associated risk factors posthumously.
Results:
The completed suicide rate was 2.37 per 100,000 students pre-COVID-19 (2017–2019), significantly increasing to 3.37 per 100,000 students post-COVID-19 (2020–2022; odds ratio [OR] 1.42, p<0.001). The rate began to rise approximately 6 months into the pandemic and continued to worsen throughout 2021 and 2022. Fair attendance significantly increased in 2020 (74.83%, p=0.003) during the initial stage of school closure measures compared to 2019 (58.27%) among students prior to suicide completion. However, as social distancing measures continued, “absence due to medical reasons” showed a significant increase in 2022 (23.56%) compared to 2019 (13.67%, p=0.025) and 2020 (9.52%, p<0.001) among these students. Among those who completed suicide, teachers reported increased signs of depression and anxiety posthumously compared to pre-COVID-19 periods.
Conclusion
The incidence of completed suicide among students was significantly higher in the post-COVID-19 years compared to pre-COVID-19. Attendance records and teachers’ reports indicated a deterioration in mental health among these students before suicide completion, highlighting the need to consider mental health impacts when implementing future quarantine policies.
6.Reliability and Validity of the Korean Version of the Quantitative Checklist for Autism in Toddlers: A Comparison Study Between the Clinical and Community Population
Youngeun HONG ; Kyungjin LEE ; Namhee YOO ; Jungwon CHOI ; Yeni KIM
Psychiatry Investigation 2025;22(3):231-242
Objective:
This study aimed to evaluate the utility of the Korean version of the Quantitative Checklist for Autism in Toddlers (Q-CHAT) in hospital settings and to identify items sensitive for detecting autism spectrum disorder (ASD) trait.
Methods:
The Q-CHAT was administered to a clinical sample of children presenting with developmental delays with a high probability of ASD in a hospital setting (n=37), as well as to typically developing community children (n=67), aged 12 to 54 months.
Results:
The mean Q-CHAT total score in the hospital sample (42.0±13.6) was significantly higher than in the community sample (29.9±7.8), with maximized sensitivity and adequate specificity at 32.5 (sensitivity=0.811, specificity=0.687). The internal consistency of Q-CHAT was 0.764 for the overall sample and 0.825 for the hospital sample. Q-CHAT total scores and item scores in the hospital sample remained stable across age groups, indicating age-invariant properties. The hospital sample showed higher endorsement of less favorable development in social interaction and reciprocity items compared to community sample. No difference in the Q-CHAT item scores was present among age groups in the hospital samples. In the community samples, item scores, such as comprehending a child’s speech, using the hand of others as a tool, adapting to a change in routine, repeating the same action, and making unusual finger movements, decreased with the advance of age.
Conclusion
The Korean version of the Q-CHAT demonstrates good validity and reliability and is effective in discriminating autistic traits even in children older than 24 months. The items endorsed for hospital samples varied from community samples, implying item-specific sensitivity for hospital samples.
7.Comparison of Suicide Completion Rate in Korean Students Pre- and Post-COVID-19 Pandemics
Kyungjin LEE ; Boram NAM ; Kyoil SEO ; Eunkyung JO ; Seohyun KIM ; Deokyong SHIN ; Aeju KIM ; Youngil JEONG ; Yeni KIM
Psychiatry Investigation 2025;22(2):204-211
Objective:
This study compared the incidence of suicide cases among Korean students before and after the coronavirus disease-2019 (COVID-19) pandemic.
Methods:
Aggregated case reports of all known suicide victims attending elementary, middle, and high school in South Korea from 2017 to 2022 were analyzed. These reports, compiled by teachers under the directive of the South Korean Department of Education, surveyed the circumstances surrounding each suicide and identified associated risk factors posthumously.
Results:
The completed suicide rate was 2.37 per 100,000 students pre-COVID-19 (2017–2019), significantly increasing to 3.37 per 100,000 students post-COVID-19 (2020–2022; odds ratio [OR] 1.42, p<0.001). The rate began to rise approximately 6 months into the pandemic and continued to worsen throughout 2021 and 2022. Fair attendance significantly increased in 2020 (74.83%, p=0.003) during the initial stage of school closure measures compared to 2019 (58.27%) among students prior to suicide completion. However, as social distancing measures continued, “absence due to medical reasons” showed a significant increase in 2022 (23.56%) compared to 2019 (13.67%, p=0.025) and 2020 (9.52%, p<0.001) among these students. Among those who completed suicide, teachers reported increased signs of depression and anxiety posthumously compared to pre-COVID-19 periods.
Conclusion
The incidence of completed suicide among students was significantly higher in the post-COVID-19 years compared to pre-COVID-19. Attendance records and teachers’ reports indicated a deterioration in mental health among these students before suicide completion, highlighting the need to consider mental health impacts when implementing future quarantine policies.
8.Reliability and Validity of the Korean Version of the Quantitative Checklist for Autism in Toddlers: A Comparison Study Between the Clinical and Community Population
Youngeun HONG ; Kyungjin LEE ; Namhee YOO ; Jungwon CHOI ; Yeni KIM
Psychiatry Investigation 2025;22(3):231-242
Objective:
This study aimed to evaluate the utility of the Korean version of the Quantitative Checklist for Autism in Toddlers (Q-CHAT) in hospital settings and to identify items sensitive for detecting autism spectrum disorder (ASD) trait.
Methods:
The Q-CHAT was administered to a clinical sample of children presenting with developmental delays with a high probability of ASD in a hospital setting (n=37), as well as to typically developing community children (n=67), aged 12 to 54 months.
Results:
The mean Q-CHAT total score in the hospital sample (42.0±13.6) was significantly higher than in the community sample (29.9±7.8), with maximized sensitivity and adequate specificity at 32.5 (sensitivity=0.811, specificity=0.687). The internal consistency of Q-CHAT was 0.764 for the overall sample and 0.825 for the hospital sample. Q-CHAT total scores and item scores in the hospital sample remained stable across age groups, indicating age-invariant properties. The hospital sample showed higher endorsement of less favorable development in social interaction and reciprocity items compared to community sample. No difference in the Q-CHAT item scores was present among age groups in the hospital samples. In the community samples, item scores, such as comprehending a child’s speech, using the hand of others as a tool, adapting to a change in routine, repeating the same action, and making unusual finger movements, decreased with the advance of age.
Conclusion
The Korean version of the Q-CHAT demonstrates good validity and reliability and is effective in discriminating autistic traits even in children older than 24 months. The items endorsed for hospital samples varied from community samples, implying item-specific sensitivity for hospital samples.
9.Comparison of Suicide Completion Rate in Korean Students Pre- and Post-COVID-19 Pandemics
Kyungjin LEE ; Boram NAM ; Kyoil SEO ; Eunkyung JO ; Seohyun KIM ; Deokyong SHIN ; Aeju KIM ; Youngil JEONG ; Yeni KIM
Psychiatry Investigation 2025;22(2):204-211
Objective:
This study compared the incidence of suicide cases among Korean students before and after the coronavirus disease-2019 (COVID-19) pandemic.
Methods:
Aggregated case reports of all known suicide victims attending elementary, middle, and high school in South Korea from 2017 to 2022 were analyzed. These reports, compiled by teachers under the directive of the South Korean Department of Education, surveyed the circumstances surrounding each suicide and identified associated risk factors posthumously.
Results:
The completed suicide rate was 2.37 per 100,000 students pre-COVID-19 (2017–2019), significantly increasing to 3.37 per 100,000 students post-COVID-19 (2020–2022; odds ratio [OR] 1.42, p<0.001). The rate began to rise approximately 6 months into the pandemic and continued to worsen throughout 2021 and 2022. Fair attendance significantly increased in 2020 (74.83%, p=0.003) during the initial stage of school closure measures compared to 2019 (58.27%) among students prior to suicide completion. However, as social distancing measures continued, “absence due to medical reasons” showed a significant increase in 2022 (23.56%) compared to 2019 (13.67%, p=0.025) and 2020 (9.52%, p<0.001) among these students. Among those who completed suicide, teachers reported increased signs of depression and anxiety posthumously compared to pre-COVID-19 periods.
Conclusion
The incidence of completed suicide among students was significantly higher in the post-COVID-19 years compared to pre-COVID-19. Attendance records and teachers’ reports indicated a deterioration in mental health among these students before suicide completion, highlighting the need to consider mental health impacts when implementing future quarantine policies.
10.Reliability and Validity of the Korean Version of the Quantitative Checklist for Autism in Toddlers: A Comparison Study Between the Clinical and Community Population
Youngeun HONG ; Kyungjin LEE ; Namhee YOO ; Jungwon CHOI ; Yeni KIM
Psychiatry Investigation 2025;22(3):231-242
Objective:
This study aimed to evaluate the utility of the Korean version of the Quantitative Checklist for Autism in Toddlers (Q-CHAT) in hospital settings and to identify items sensitive for detecting autism spectrum disorder (ASD) trait.
Methods:
The Q-CHAT was administered to a clinical sample of children presenting with developmental delays with a high probability of ASD in a hospital setting (n=37), as well as to typically developing community children (n=67), aged 12 to 54 months.
Results:
The mean Q-CHAT total score in the hospital sample (42.0±13.6) was significantly higher than in the community sample (29.9±7.8), with maximized sensitivity and adequate specificity at 32.5 (sensitivity=0.811, specificity=0.687). The internal consistency of Q-CHAT was 0.764 for the overall sample and 0.825 for the hospital sample. Q-CHAT total scores and item scores in the hospital sample remained stable across age groups, indicating age-invariant properties. The hospital sample showed higher endorsement of less favorable development in social interaction and reciprocity items compared to community sample. No difference in the Q-CHAT item scores was present among age groups in the hospital samples. In the community samples, item scores, such as comprehending a child’s speech, using the hand of others as a tool, adapting to a change in routine, repeating the same action, and making unusual finger movements, decreased with the advance of age.
Conclusion
The Korean version of the Q-CHAT demonstrates good validity and reliability and is effective in discriminating autistic traits even in children older than 24 months. The items endorsed for hospital samples varied from community samples, implying item-specific sensitivity for hospital samples.

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