Loneliness and social isolation pose significant public health concerns globally, with adverse effects on mental health and well-being. Although the terms are often used interchangeably, loneliness refers to the subjective feeling of lacking social connections, whereas social isolation is the objective absence of social support or networks.

To investigate the prevalence of loneliness and social isolation and their associations with psychiatric disorders.

This study used data from the Republic of Korea National Mental Health Survey 2021, a nationally representative survey. A total of 5511 adults aged 18–79 residing in South Korea participated in the survey. Loneliness and social isolation were assessed using the Loneliness and Social Isolation Scale, whereas psychiatric disorders were evaluated using the Korean version of the Composite International Diagnostic Interview. Multivariate logistic regressions were performed after adjustment for sociodemographic variables.

Among the participants, 11.8% reported experiencing loneliness, 4.3% reported social isolation and 3.4% reported both. Co-occurrence of loneliness and social isolation was significantly associated with psychiatric disorders (adjusted odds ratio (AOR) 7.59, 95% CI: 5.48–10.52). Loneliness alone was associated with greater prevalence and higher probability of psychiatric disorders (AOR 3.12, 95% CI: 2.63–3.71), whereas social isolation did not show any significant association (AOR 0.88, 95% CI: 0.64–1.22).

The co-occurrence of loneliness and social isolation is particularly detrimental to mental health. This finding emphasises the need for targeted interventions to promote social connection and reduce feelings of isolation.

Women with schizophrenia frequently discontinue antipsychotic medications during pregnancy. However, evidence on the risk of postpartum relapse associated with antipsychotic use during pregnancy is lacking.

To investigate the within-individual association between antipsychotic continuation during pregnancy and postpartum relapse in women with schizophrenia.

This retrospective cohort study used data of women with schizophrenia who gave live birth between 2007 and 2018 identified from the National Health Information Database of South Korea. Women were classified according to antipsychotic use patterns during the 12 months before delivery as non-users, discontinuers and continuers. Relapse was defined as admission for psychosis (ICD-10, F20–29). The incidence rate ratio (IRR) for admission for psychosis in the 6-month postpartum period was estimated using conditional Poisson regression, with the reference period set between 2 and 1 years before delivery. Additionally, we calculated the relative risk ratios (RRRs) for the IRRs of different antipsychotic use patterns.

Among the 3026 women included in the analysis (median age 34 years, interquartile range 31–37), the within-individual risk of admission for psychosis in the 6-month postpartum period was 0.56 times (RRR, 95% CI 0.36–0.87) lower in continuers (IRR = 1.31, 95% CI 0.89–1.72) than in discontinuers (IRR = 2.34, 95% CI 1.87–2.91). Among discontinuers, the IRRs of admission for psychosis in the 6-month postpartum period did not change significantly with the timing of discontinuation (trend P = 0.946).

Antipsychotic continuation during pregnancy was associated with a reduced risk of postpartum relapse in women with schizophrenia. Continuing antipsychotics during pregnancy would be recommended after a risk–benefit assessment.

Breast cancer is a major global health issue, especially among women. Previous research has indicated a possible association between psychiatric conditions, particularly schizophrenia, and an increased risk of breast cancer. However, the specific risk of breast cancer in women with schizophrenia, compared with those with other psychiatric disorders and the general population, remains controversial and needs further clarification.

To estimate the risk of breast cancer among people with schizophrenia compared with people with other psychiatric disorders and people in the general population.

We utilised medical claims data of women aged 18 to 80 years in the Korean National Health Information Database from 2007 to 2018. Individuals with schizophrenia were defined as women with ICD-10 codes F20 or F25 (n = 224 612). The control groups were defined as women with other psychiatric disorders (n = 224 612) and women in the general Korean population (n = 449 224). Cases and controls were matched by index date and age, in a 1:1:2 ratio. We estimated the hazard of breast cancer using the Cox proportional hazards model, adjusting for insurance premiums and medical comorbidities. Among the people with schizophrenia, we used the landmark method to estimate the association between duration of antipsychotic medication use and the incidence of breast cancer.

In multivariable Cox regression models, the hazard rate of breast cancer was 1.26 times higher in the people with schizophrenia than in the general population (95% CI: 1.20–1.32). In comparison with the psychiatric patient group, the hazard ratio was 1.17 (95% CI: 1.11–1.28). Among women with schizophrenia, the hazard of breast cancer was greater among those who took antipsychotic medications for 1 year or more compared with those who took antipsychotics for less than 6 months.

Women with schizophrenia have an elevated risk of breast cancer, and long-term use of antipsychotics is associated with an increased risk of breast cancer.

Although people who attempted suicide tend to repeat suicide attempts, there is a lack of evidence on the association between psychiatric service factors and suicide reattempt among them.

We used a nationwide, population-based medical record database of South Korea to investigate the use of psychiatric services before and after the index suicide attempt and the association between psychiatric service factors after the index suicide attempt with the risk of suicide reattempt.

Among 5,874 people who had attempted suicide, the all-cause mortality within 3 months after the suicide attempt was 11.6%. Among all subjects who attempted suicide, 30.6% of them had used psychiatric services within 6 months before the suicide attempt; 43.7% of them had used psychiatric services within 3 months after the suicide attempt. Among individuals who had visited clinics following attempted suicide, the cumulative incidence of suicide reattempt over a mean follow-up period of 5.1 years was 3.4%. About half of suicide reattempts occurred within 1 year after the index suicide attempt. Referral to psychiatric services within 7 days was associated with a decreased risk of suicide reattempt (adjusted hazard ratio, 0.51; 95% confidence intervals, 0.29-0.89).

An early psychiatric referral within 1 week after a suicide attempt was associated with a decreased risk of suicide reattempt.

Mood disorders require consistent management of symptoms to prevent recurrences of mood episodes. Circadian rhythm (CR) disruption is a key symptom of mood disorders to be proactively managed to prevent mood episode recurrences. This study aims to predict impending mood episodes recurrences using digital phenotypes related to CR obtained from wearable devices and smartphones.

The study is a multicenter, nationwide, prospective, observational study with major depressive disorder, bipolar disorder I, and bipolar II disorder. A total of 495 patients were recruited from eight hospitals in South Korea. Patients were followed up for an average of 279.7 days (a total sample of 75 506 days) with wearable devices and smartphones and with clinical interviews conducted every 3 months. Algorithms predicting impending mood episodes were developed with machine learning. Algorithm-predicted mood episodes were then compared to those identified through face-to-face clinical interviews incorporating ecological momentary assessments of daily mood and energy.

Two hundred seventy mood episodes recurred in 135 subjects during the follow-up period. The prediction accuracies for impending major depressive episodes, manic episodes, and hypomanic episodes for the next 3 days were 90.1, 92.6, and 93.0%, with the area under the curve values of 0.937, 0.957, and 0.963, respectively.

We predicted the onset of mood episode recurrences exclusively using digital phenotypes. Specifically, phenotypes indicating CR misalignment contributed the most to the prediction of episodes recurrences. Our findings suggest that monitoring of CR using digital devices can be useful in preventing and treating mood disorders.

The two key mechanisms affected by internet gaming disorder (IGD) are cognitive and reward processing. Despite their significance, little is known about neurophysiological features as determined using resting-state electroencephalography (EEG) source functional connectivity (FC).

We compared resting-state EEG source FC within the default mode network (DMN) and reward/salience network (RSN) between patients with IGD and healthy controls (HCs) to identify neurophysiological markers associated with cognitive and reward processing. A total of 158 young male adults (79 patients with IGD and 79 HCs) were included, and the source FC of the DMN and RSN in five spectral bands (delta, theta, alpha, beta, and gamma) were assessed.

Patients with IGD showed increased theta, alpha, and beta connectivity within the DMN between the orbitofrontal cortex and parietal regions compared with HCs. In terms of RSN, patients with IGD exhibited elevated alpha and beta connectivity between the anterior cingulate gyrus and temporal regions compared with HCs. Furthermore, patients with IGD showed negative correlations between the severity of IGD symptoms and/or weekly gaming time and theta and alpha connectivity within the DMN and theta, alpha, and beta connectivity within the RSN. However, the duration of IGD was not associated with EEG source FC.

Hyper-connectivities within the DMN and RSN may be considered potential state markers associated with symptom severity and gaming time in IGD.

There are growing concerns about the impact of the COVID-19 pandemic on the mental health of older adults. We examined the effect of the pandemic on the risk of depression in older adults.

We analyzed data from the prospective cohort study of Korean older adults, which has been followed every 2 years. Among the 2308 participants who completed both the third and the fourth follow-up assessments, 58.4% completed their fourth follow-up before the outbreak of COVID-19 and the rest completed it during the pandemic. We conducted face-to-face diagnostic interviews using Mini International Neuropsychiatric Interview and used Geriatric Depression Scale. We performed generalized estimating equations and logistic regression analyses.

The COVID-19 pandemic was associated with increased depressive symptoms in older adults [b (standard error) = 0.42 (0.20), p = 0.040] and a doubling of the risk for incident depressive disorder even in euthymic older adults without a history of depression (odds ratio = 2.44, 95% confidence interval 1.18–5.02, p = 0.016). Less social activities, which was associated with the risk of depressive disorder before the pandemic, was not associated with the risk of depressive disorder during the pandemic. However, less family gatherings, which was not associated with the risk of depressive disorder before the pandemic, was associated with the doubled risk of depressive disorder during the pandemic.

The COVID-19 pandemic significantly influences the risk of late-life depression in the community. Older adults with a lack of family gatherings may be particularly vulnerable.

Accurate prognostication is important for patients and their families to prepare for the end of life. Objective Prognostic Score (OPS) is an easy-to-use tool that does not require the clinicians’ prediction of survival (CPS), whereas Palliative Prognostic Score (PaP) needs CPS. Thus, inexperienced clinicians may hesitate to use PaP. We aimed to evaluate the accuracy of OPS compared with PaP in inpatients in palliative care units (PCUs) in three East Asian countries.

This study was a secondary analysis of a cross-cultural, multicenter cohort study. We enrolled inpatients with far-advanced cancer in PCUs in Japan, Korea, and Taiwan from 2017 to 2018. We calculated the area under the receiver operating characteristics (AUROC) curve to compare the accuracy of OPS and PaP.

A total of 1,628 inpatients in 33 PCUs in Japan and Korea were analyzed. OPS and PaP were calculated in 71.7% of the Japanese patients and 80.0% of the Korean patients. In Taiwan, PaP was calculated for 81.6% of the patients. The AUROC for 3-week survival was 0.74 for OPS in Japan, 0.68 for OPS in Korea, 0.80 for PaP in Japan, and 0.73 for PaP in Korea. The AUROC for 30-day survival was 0.70 for OPS in Japan, 0.71 for OPS in Korea, 0.79 for PaP in Japan, and 0.74 for PaP in Korea.

Both OPS and PaP showed good performance in Japan and Korea. Compared with PaP, OPS could be more useful for inexperienced physicians who hesitate to estimate CPS.

To date, there have been few studies on dietary supplement (DS) use in Korean children and adolescents, using nationally representative data. This study aimed to investigate the current status of DS use and its related factors, among Korean children and adolescents from the Korean National Health and Nutrition Examination Survey (KNHANES) data.

A cross-sectional study.

Data from the KNHANES 2015–2017. Participants completed 24-h dietary recall interviews, including DS products that the subjects consumed.

The study population was 4380 children and adolescents aged 1–18 years.

Approximately 2013 % of children and adolescents were using DS; the highest use was among children aged 1–3 years old, and the lowest use was among adolescents aged 16–18 years. The most frequently used DS was prebiotics/probiotics, followed by multivitamin/mineral supplements. Factors that were associated with DS use were lower birth weight in children aged <4 years; younger age, higher household income, regular breakfast intake and lower BMI in children aged 4–9 years; and regular breakfast intake and use of nutrition facts label in adolescents aged 10–18 years. Feeding patterns in infancy and having chronic diseases were not associated with DS use.

We report that over 20 % of children and adolescents use DS. Nutritional education for parents and children about proper DS consumption is needed.

Although neurocognitive dysfunction and physical performance are known to be impaired in patients with schizophrenia, evidence regarding the relationship between these two domains remains insufficient. Thus, we aimed to investigate the relationship between various physical performance domains and cognitive domains in individuals with schizophrenia, while considering other disorder-related clinical symptoms.

Sixty patients with schizophrenia participated in the study. Cardiorespiratory fitness and functional mobility were evaluated using the step test and supine-to-standing (STS) test, respectively. Executive function and working memory were assessed using the Stroop task and Sternberg working memory (SWM) task, respectively. Clinical symptoms were evaluated using the Brief Psychiatric Rating Scale, Beck Depression Inventory, and State-Trait Anxiety Inventory. Multivariate analyses were performed to adjust for relevant covariates and identify predictive factors associated with neurocognition.

Multiple regression analysis revealed that the step test index was most strongly associated with reaction time in the Stroop task (β = 0.434, p = 0.001) and SWM task (β = 0.331, p = 0.026), while STS test time was most strongly associated with accuracy on the Stoop task (β=−0.418, p = 0.001) and SWM task (β=−0.383, p = 0.007). Total cholesterol levels were positively associated with Stroop task accuracy (β=−0.307, p = 0.018) after controlling for other clinical correlates. However, clinical symptoms were not associated with any variables in Stroop or SWM task.

The present findings demonstrate the relationship between physical performance and neurocognition in patients with schizophrenia. Considering that these factors are modifiable, exercise intervention may help to improve cognitive symptoms in patients with schizophrenia, thereby leading to improvements in function and prognosis.