The COVID-19 pandemic has adversely affected the mental health of the global population. This study aimed to assess the acute and persistent symptoms of depression, as well as factors related to their manifestation, through a longitudinal study design. A total of 1,492 community-dwelling adults from an online public panel across three regions were evaluated at baseline, with 908 adults (60.9%) followed up after six months. Depression symptoms were evaluated using Patient Health Questionnaire-9 (PHQ-9). Participants also completed self-administered questionnaires on sociodemographic information, psychosocial experiences related to COVID-19, the UCLA Loneliness Scale, and the Korean version of the Gratitude Questionnaire (K-GQ-6).The prevalence of acute and persistent depression symptoms was 8.4% and 12.0%, respectively. Multivariate logistic regression analysis identified changes in predictors of depression over time, with younger age and self-isolation experience found to be associated with acute depression. Factors such as underlying mental illness, eating and sleeping disturbances, loneliness, and COVID-19-related stress emerged as significant risk factors for persistent depression. A disposition toward gratitude was identified as a protective factor for persistent depressive symptoms. These findings suggest that during any long-term pandemic crisis such as COVID-19, timely support and attention are essential for vulnerable populations, including young people and individuals with mental health conditions, to prevent depression. Specifically, promoting daily routines such as regular eating and sleeping patterns, and managing COVID-19-related stress may be critical in preventing persistent depression. Additionally, psychological support that reduces loneliness and fosters gratitude may help mitigate depression risk.

Objectives: This study aimed to investigate the impact of behavioral and psychological symptoms (BPS), assessed by the neuropsychiatric inventory (NPI) total score, on instrumental activities of daily living (IADL) performance in patients with mild cognitive impairment. Methods: Ninety-two patients diagnosed with mild cognitive impairment who visited a university hospital dementia clinic were recruited. Assessments included the Korean version-Mini Mental State Examination, NPI, Korean-IADL (KIADL), and Short Form of Geriatric Depression Scale-Korean version. Correlation and hierarchical multiple regression analyses were performed to analyze the relationship between BPS and IADL. Results: The mean age of participants was 74.61±5.86 years. K-IADL scores significantly correlated with age (r=0.347, p<0.001) and NPI total score (r=0.265, p<0.05). Hierarchical regression analysis showed that the addition of the NPI total score significantly increased the explained variance of functional decline (R 2 =0.197, F=5.332, p<0.001), with age (β=0.354, p<0.001) and NPI total score (β=0.248, p<0.05) identified as independent predictors in patients with mild cognitive impairment. Conclusions The overall severity of BPS exerts a detrimental effect on IADL function in mild cognitive impairment patients, independent of age and cognitive status. These results underscore the clinical importance of evaluating the cumulative burden of BPS to predict functional prognosis and implement early interventions.

Purpose: Although gastric cancer (GC) exhibits significant genomic heterogeneity, the clinical implications of its immune microenvironment remain poorly understood. Materials and Methods: We retrospectively evaluated patients with GC who underwent gastrectomies between 2011 and 2014. The tumors were analyzed for Epstein–Barr virus (EBV), microsatellite instability-high (MSI-H), tumor-infiltrating lymphocytes (CD3), tumor-associated macrophages (CD68 and CD163), and programmed death-ligand 1 (PD-L1) expression. Tumors were classified using the modified The Cancer Genome Atlas scheme, and their clinical characteristics were compared. Results: A total of 567 patients were classified into EBV (6%), MSI-H (10%), chromosomal instability-like (36%), and genomically stable-like (48%) subtypes. EBV tumors exhibited the highest PD-L1 expression (85%) and immune infiltration by CD3+ T cells (86%), CD68+ macrophages (58%), and CD163+ macrophages (40%). High CD68+ macrophage tumors were associated with advanced stages and worse 5-year disease-free survival (83% vs. 95%; P<0.001);however, this association was not independently significant after adjusting for the tumor-nodemetastasis stage. PD-L1 expression did not significantly affect the survival outcomes. Conclusions GC subtypes have distinct immune microenvironments that influence prognosis. Our findings highlight the prognostic and therapeutic potential of immune profiling in GC.

Purpose: Endoscopic submucosal dissection (ESD) has become a standard minimally invasive treatment for selected patients with early gastric cancer (EGC). This study presents the first nationwide survey of patients with EGC treated with ESD in 2023, conducted by the Korean College of Helicobacter and Upper Gastrointestinal Research. Materials and Methods: Data were retrospectively collected from participating referral centers across Korea using a standardized case report form covering patient characteristics, tumor features, procedural details, histopathological findings, and clinical outcomes.Descriptive and comparative analyses were conducted to summarize nationwide ESD practice patterns and outcomes. Results: Data from 5,460 ESD cases from 5,250 patients across 27 institutions were analyzed. The mean age was 67.4 years, with 74.1% males. Multiple synchronous lesions were identified in 3.7%. Most lesions were located in the lower third of the stomach (64.0%), and differentiated-type adenocarcinomas accounted for 87.8%. The en bloc and complete resection rates were 99.2% and 91.4%, respectively. Curative resection was achieved in 80.5%, whereas local non-curative resection (L-NCR) and surgical non-curative resection (S-NCR) were identified in 2.8% and 16.7%, respectively. Additional surgery was performed more frequently in patients with S-NCR than in those with L-NCR (59.3% vs. 24.7%). The bleeding and perforation rates were 3.6% and 0.9%, respectively, and were mostly managed conservatively or endoscopically. The median length of hospitalization was 4.0 days. Conclusions This first nationwide survey provides a comprehensive overview of the current practice of EGC treatment using ESD in Korea, demonstrating high technical success and safety, and establishing a baseline dataset for future longitudinal research.

This study aimed to determine the prevalence of human epidermal growth factor receptor 2 (HER2)–ultralow breast cancer among cases initially classified as HER2 immunohistochemistry (IHC) 0 and assess interobserver variability in interpreting low-level HER2 expression. Methods: In this multicenter retrospective study, all invasive breast cancer cases diagnosed between January and December 2022 across 10 Korean institutions were retrieved. Institutional pathologists reexamined HER2 IHC slides originally reported as IHC 0 according to the 2018 American Society of Clinical Oncology/College of American Pathologists guidelines and reclassified them as HER2-null (0), HER2-ultralow (0+), or HER2-low (1+). Slides from 10% of HER2-null and HER2-ultralow cases were digitized for central review and independently assessed by two pathologists, with discrepancies resolved by consensus. Results: Among 8,026 cases, 2,836 cases (35.5%) were initially reported as IHC 0. Upon re-review, 1,673 (59.0%), 1,139 (40.2%), and 24 (0.8%) cases were reclassified as HER2-null, HER2-ultralow, and HER2-low, respectively. The prevalence of HER2-ultralow breast cancer varied considerably across institutions (23.7%–78.1%). Central review of 268 digitized cases showed concordance in 193 cases (72.0%). Among the 75 discordant cases, 54 tumors (72.0%) were upgraded from HER2-null to HER2-ultralow, and 18 (24.0%) tumors were upgraded from HER2-ultralow to HER2-low. Furthermore, two tumors (2.7%) were downgraded from HER2-ultralow to HER2-null. Conclusions: Approximately 40% of cases initially categorized as IHC 0 were reclassified as HER2-ultralow. The substantial inter-institutional variability observed in interpreting low-level HER2 expression highlights the need for standardized training and quality assurance to ensure accurate identification of patients eligible for HER2-targeted antibody–drug conjugates.

Objective: This study examined whether baseline levels of 14 serum biomarkers predicted antidepressant remission differently by sex at 12 weeks and 12 months. Methods: In a prospective cohort, 1,086 outpatients with depressive disorders received stepwise antidepressant treatment following a naturalistic protocol. Baseline serum samples were analyzed for biomarkers from six systems: immune (high-sensitivity C-reactive protein, tumor necrosis factor-alpha, interleukin-1 beta, interleukin-6, interleukin-4, interleukin-10), metabolic (leptin, ghrelin, total cholesterol), neurotrophic (brain-derived neurotrophic factor), neurotransmitter (serotonin), endocrine (cortisol), and nutritional (folate, homocysteine). Remission, defined as a Hamilton Depression Rating Scale scores ≤ 7, was assessed at 12 weeks and 12 months. Logistic regression models with biomarker-by-sex interaction and stratified analyses were used, adjusting for clinical covariates. Results: Higher baseline serotonin predicted 12-week remission in males but not in females. At 12 months, lower leptin and higher folate predicted remission only in males, while lower cortisol predicted remission only in females. These showed significant biomarker-sex interactions. No sex-specific interactions were found for immune markers. Conclusion Baseline serum biomarkers across biological systems showed sex-specific associations with treatment outcomes. Neurotransmitter, metabolic, endocrine, and nutritional markers may offer predictive value for sex-tailored, biomarker-informed treatment strategies in depression.

Objectives: Endoscopic submucosal dissection (ESD) has become a standard minimally invasive treatment for selected patients with early gastric cancer (EGC). This study presents the first nationwide survey of patients with EGC treated with ESD in 2023, conducted by the Korean College of Helicobacter and Upper Gastrointestinal Research. Methods: Data were retrospectively collected from participating referral centers across Korea using a standardized case report form covering patient characteristics, tumor features, procedural details, histopathological findings, and clinical outcomes. Descriptive and comparative analyses were conducted to summarize nationwide ESD practice patterns and outcomes. Results: Data from 5460 ESD cases from 5250 patients across 27 institutions were analyzed. The mean age was 67.4 years, with 74.1% males. Multiple synchronous lesions were identified in 3.7%. Most lesions were located in the lower third of the stomach (64.0%), and differentiated-type adenocarcinomas accounted for 87.8%. The en bloc and complete resection rates were 99.2% and 91.4%, respectively. Curative resection was achieved in 80.5%, whereas local non-curative resection (L-NCR) and surgical non-curative resection (S-NCR) were identified in 2.8% and 16.7%, respectively. Additional surgery was performed more frequently in patients with S-NCR than in those with L-NCR (59.3% vs. 24.7%). The bleeding and perforation rates were 3.6% and 0.9%, respectively, and were mostly managed conservatively or endoscopically. The median length of hospitalization was 4.0 days. Conclusions This first nationwide survey provides a comprehensive overview of the current practice of EGC treatment using ESD in Korea, demonstrating high technical success and safety, and establishing a baseline dataset for future longitudinal research.

Echinococcosis, caused by the tapeworm Echinococcus, is rare in Korea and is primarily imported from endemic areas. We report a case of a 37-year-old Korean man with multiple large hepatic cysts, initially diagnosed as simple cysts at a local clinic in 2018. The patient had lived in Oman, an endemic area, for several months in 2016. Upon referral to a tertiary hospital in 2023, due to progressive cyst enlargement, liver magnetic resonance imaging revealed three large cysts with a water lily sign. Serum IgG against Echinococcus was positive by enzyme-linked immunosorbent assay. After diagnosis of echinococcosis, treatment with albendazole and puncture-aspiration-injection-reaspiration (PAIR) was performed.Microscopic and molecular analysis of cyst aspirates confirmed Echinococcus granulosus infection. Follow-up computed tomography demonstrated a reduction in cyst size, yet the emergence of a new right pleural effusion and consolidation in the left lower lobe of the lung necessitated the continuation of albendazole therapy. This case highlights the importance of thorough travel history, imaging findings, and the effectiveness of PAIR combined with albendazole in treating imported echinococcosis.

Background: This study evaluated the practicability of the suicide rate reduction target set by the current national suicide prevention policy in Korea, the fifth Master Plan for Suicide Prevention (2023–2027). This policy aims to lower the suicide rate from 26/100,000 in 2021 to 18.2/100,000 by 2027. Methods: We utilized monthly suicide statistics data from 2011 onwards. Using Bayesian regression and Autoregressive Integrated Moving Average (ARIMA) models, we conducted interrupted time series analyses to estimate the effect of the previous policy, the National Action Plan for Suicide Prevention (2018–2022), on suicide rates. We assumed this as the additional suicide reduction expected from the current policy. We generated point predictions and simulations for suicide rates from 2023 to 2027 using Bayesian regression and ARIMA models. Results: The interrupted time series analyses did not reveal a significant reduction in suicides attributable to the previous policy. Point predictions from the two models indicated that the suicide rate would remain approximately 24/100,000 in 2027. Almost all of the simulations of the 2027 suicide rate did not meet the policy target of 18.2/100,000. Conclusion The findings suggest that the Korean government’s suicide rate reduction target for 2027 is likely unattainable based on current trends and the limited effectiveness of previous policies. The objectives of suicide prevention policies should be evidence-based, attainable, and accountable.