Optogenetic control of mRNA condensation reveals an intimate link between condensate material properties and functions

Biomolecular condensates, often assembled through phase transition mechanisms, play key roles in organizing diverse cellular activities. The material properties of condensates, ranging from liquid droplets to solid-like glasses or gels, are key features impacting the way resident components associate with one another. However, it remains unclear whether and how different material properties would influence specific cellular functions of condensates. Here, we combine optogenetic control of phase separation with single-molecule mRNA imaging to study relations between phase behaviors and functional performance of condensates. Using light-activated condensation, we show that sequestering target mRNAs into condensates causes translation inhibition. Orthogonal mRNA imaging reveals highly transient nature of interactions between individual mRNAs and condensates. Tuning condensate composition and material property towards more solid-like states leads to stronger translational repression, concomitant with a decrease in molecular mobility. We further demonstrate that β-actin mRNA sequestration in neurons suppresses spine enlargement during chemically induced long-term potentiation. Our work highlights how the material properties of condensates can modulate functions, a mechanism that may play a role in fine-tuning the output of condensate-driven cellular activities.

Prevalence and Associated Factors of Depression and Anxiety Among Healthcare Workers During the Coronavirus Disease 2019 Pandemic: A Nationwide Study in Korea

BACKGROUND

A healthcare system's collapse due to a pandemic, such as the coronavirus disease 2019 (COVID-19), can expose healthcare workers (HCWs) to various mental health problems. This study aimed to investigate the impact of the COVID-19 pandemic on the depression and anxiety of HCWs.

METHODS

A nationwide questionnaire-based survey was conducted on HCWs who worked in healthcare facilities and public health centers in Korea in December 2020. Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7) were used to measure depression and anxiety. To investigate factors associated with depression and anxiety, stepwise multiple logistic regression analysis was performed.

RESULTS

A total of 1,425 participating HCWs were included. The mean depression score (PHQ-9) of HCWs before and after COVID-19 increased from 2.37 to 5.39, and the mean anxiety score (GAD-7) increased from 1.41 to 3.41. The proportion of HCWs with moderate to severe depression (PHQ-9 ≥ 10) increased from 3.8% before COVID-19 to 19.5% after COVID-19, whereas that of HCWs with moderate to severe anxiety (GAD-7 ≥ 10) increased from 2.0% to 10.1%. In our study, insomnia, chronic fatigue symptoms and physical symptoms after COVID-19, anxiety score (GAD-7) after COVID-19, living alone, and exhaustion were positively correlated with depression. Furthermore, post-traumatic stress symptoms, stress score (Global Assessment of Recent Stress), depression score (PHQ-9) after COVID-19, and exhaustion were positively correlated with anxiety.

CONCLUSION

In Korea, during the COVID-19 pandemic, HCWs commonly suffered from mental health problems, including depression and anxiety. Regularly checking the physical and mental health problems of HCWs during the COVID-19 pandemic is crucial, and social support and strategy are needed to reduce the heavy workload and psychological distress of HCWs.

Association of hair cortisol concentration with brain-derived neurotrophic factor gene methylation: The role of sex as a moderator

Hair cortisol concentration (HCC) reflects the long-term activity of the hypothalamus-pituitary-adrenal (HPA) axis in response to stress. Brain-derived neurotrophic factor DNA methylation (BDNF DNAM) may affect HCC, and sex and Val66Met may contribute to this association. Thus, the aim of this study was to investigate the associations between HCC and Brain-derived neurotrophic factor (BDNF) DNAM, and the moderating effects of Val66Met and sex. We recruited 191 healthy young participants (96 women, mean age 23.0 ± 2.6 years) and collected body samples to evaluate HCC, and to determine BDNF DNAM and Val66Met genotypes. We analyzed the effects of BDNF DNAM, sex, and Val66Met on HCC. We also evaluated the associations between BDNF DNAM and HCC in groups separated by sex and genotypes. We found a marked association of BDNF DNAM with HCC across men and women. After dividing the data by sex, a positive correlation of HCC with BDNF DNAM was found only in women. There was no substantial moderation effect of Val66Met genotypes on the association between BDNF DNAM and HCC. Therefore, BDNF DNAM was found to have positive association with HCC only in healthy young women, indicating that sex moderates the association of BDNF DNAM with long-term HPA axis activity.

New-onset mental illness and long-term survival in survivors of critical illness: population-based cohort study in South Korea

BACKGROUND

Critical care unit (CCU) survivors have a high risk of developing mental illness.

AIMS

We aimed to examine the incidence and associated factors of newly developed mental illness among CCU survivors of critical illness. Moreover, we examined the association between newly developed mental illness and 2-year all-cause mortality.

METHOD

All adult patients (≥20 years) who were admitted to the CCU during hospitalisation between 2010 and 2018 and survived for 1 year were defined as CCU survivors and were included in this nationwide population-based cohort study. CCU survivors with a history of mental illness before CCU admission were excluded from the study.

RESULTS

A total of 1 353 722 CCU survivors were included in the analysis; of these, 33 743 survivors (2.5%) had newly developed mental illness within 1 year of CCU admission. Old age, longer CCU stay, hospital admission through the emergency room, increased total cost of hospitalisation, mechanical ventilatory support, extracorporeal membrane oxygenation support and continuous renal replacement therapy were associated with an increased incidence of newly developed mental illness. Moreover, the newly developed mental illness group showed a 2.36-fold higher 2-year all-cause mortality rate than the no mental illness group (hazard ratio: 2.36; 95% CI: 2.30-2.42; P < 0.001).

CONCLUSIONS

In South Korea, 2.5% of CCU survivors had newly developed mental illness within 1 year of CCU admission. Moreover, newly developed mental illness was associated with an increased 2-year all-cause mortality.

Thermodynamic modulation of gephyrin condensation by inhibitory synapse components

Phase separation drives compartmentalization of intracellular contents into various biomolecular condensates. Individual condensate components are thought to differentially contribute to the organization and function of condensates. However, how intermolecular interactions among constituent biomolecules modulate the phase behaviors of multicomponent condensates remains unclear. Here, we used core components of the inhibitory postsynaptic density (iPSD) as a model system to quantitatively probe how the network of intra- and intermolecular interactions defines the composition and cellular distribution of biomolecular condensates. We found that oligomerization-driven phase separation of gephyrin, an iPSD-specific scaffold, is critically modulated by an intrinsically disordered linker region exhibiting minimal homotypic attractions. Other iPSD components, such as neurotransmitter receptors, differentially promote gephyrin condensation through distinct binding modes and affinities. We further demonstrated that the local accumulation of scaffold-binding proteins at the cell membrane promotes the nucleation of gephyrin condensates in neurons. These results suggest that in multicomponent systems, the extent of scaffold condensation can be fine-tuned by scaffold-binding factors, a potential regulatory mechanism for self-organized compartmentalization in cells.

Insomnia disorder and cancer mortality in South Korea: a secondary analysis of musculoskeletal disease cohort

PURPOSE

The association between insomnia disorder and cancer-related mortality risk remains controversial. Therefore, this study aimed to investigate the correlation between insomnia disorder and cancer-related mortality.

METHODS

Patients who were diagnosed with musculoskeletal disease (MSD) between 2010 and 2015 were included in this study as a secondary analysis of a patient cohort with MSD in South Korea. Cancer mortality was evaluated between January 1, 2016, and December 31, 2020, using multivariable Cox regression modeling. Patients with and without insomnia disorder constituted the ID and non-ID groups, respectively.

RESULTS

The final analysis incorporated a total of 1,298,314 patients diagnosed with MSDs, of whom 11,714 (0.9%) died due to cancer. In the multivariable Cox regression model, the risk of total cancer-related mortality was 14% (hazard ratio [HR], 1.14; 95% confidence interval [CI], 1.10-1.19; P < 0.001) higher in the ID group than in the non-ID group. Moreover, the ID group had a higher risk of mortality due to esophageal (HR, 1.46; 95% CI, 1.08-1.96; P = 0.015), colorectal (HR, 1.20; 95% CI, 1.05-1.36; P = 0.007), head and neck (HR, 1.39; 95% CI, 1.01-1.94; P = 0.049), lung (HR, 1.17; 95% CI, 1.08-1.27; P < 0.001), and female genital organ (HR: 1.39, 95% CI: 1.09, 1.77; P = 0.008) cancers; leukemia; and lymphoma (HR, 1.30; 95% CI, 1.12-1.49; P < 0.001).

CONCLUSION

Insomnia disorder was associated with elevated overall cancer mortality in patients with MSDs, which was more evident for cancer mortality due to esophageal, colorectal, head and neck, lung, and female genital organ cancers; leukemia; and lymphoma.

Predicting delirium and the effects of medications in hospitalized COVID-19 patients using machine learning: A retrospective study within the Korean Multidisciplinary Cohort for Delirium Prevention (KoMCoDe)

Objective

Delirium is commonly reported from the inpatients with Coronavirus disease 2019 (COVID-19) infection. As delirium is closely associated with adverse clinical outcomes, prediction and prevention of delirium is critical. We developed a machine learning (ML) model to predict delirium in hospitalized patients with COVID-19 and to identify modifiable factors to prevent delirium.

Methods

The data set (n = 878) from four medical centers was constructed. Total of 78 predictors were included such as demographic characteristics, vital signs, laboratory results and medication, and the primary outcome was delirium occurrence during hospitalization. For analysis, the extreme gradient boosting (XGBoost) algorithm was applied, and the most influential factors were selected by recursive feature elimination. Among the indicators of performance for ML model, the area under the curve of the receiver operating characteristic (AUROC) curve was selected as the evaluation metric.

Results

Regarding the performance of developed delirium prediction model, the accuracy, precision, recall, F1 score, and the AUROC were calculated (0.944, 0.581, 0.421, 0.485, 0.873, respectively). The influential factors of delirium in this model included were mechanical ventilation, medication (antipsychotics, sedatives, ambroxol, piperacillin/tazobactam, acetaminophen, ceftriaxone, and propacetamol), and sodium ion concentration (all p < 0.05).

Conclusions

We developed and internally validated an ML model to predict delirium in COVID-19 inpatients. The model identified modifiable factors associated with the development of delirium and could be clinically useful for the prediction and prevention of delirium in COVID-19 inpatients.

Statistical modeling of mRNP transport in dendrites: A comparative analysis of β-actin and Arc mRNP dynamics

Localization of messenger RNA (mRNA) in dendrites is crucial for regulating gene expression during long-term memory formation. mRNA binds to RNA-binding proteins (RBPs) to form messenger ribonucleoprotein (mRNP) complexes that are transported by motor proteins along microtubules to their target synapses. However, the dynamics by which mRNPs find their target locations in the dendrite have not been well understood. Here, we investigated the motion of endogenous β-actin and Arc mRNPs in dissociated mouse hippocampal neurons using the MS2 and PP7 stem-loop systems, respectively. By evaluating the statistical properties of mRNP movement, we found that the aging Lévy walk model effectively describes both β-actin and Arc mRNP transport in proximal dendrites. A critical difference between β-actin and Arc mRNPs was the aging time, the time lag between transport initiation and measurement initiation. The longer mean aging time of β-actin mRNP (~100 s) compared with that of Arc mRNP (~30 s) reflects the longer half-life of constitutively expressed β-actin mRNP. Furthermore, our model also permitted us to estimate the ratio of newly generated and pre-existing β-actin mRNPs in the dendrites. This study offers a robust theoretical framework for mRNP transport, which provides insight into how mRNPs locate their targets in neurons.

Suicidal Thinking Among Patients With Spinal Conditions in South Korea: A Population-Based Cross-Sectional Study

OBJECTIVE

Chronic pain increases the risk of suicide because it is often accompanied by depressive symptoms. However, the existing information regarding suicidal thinking in patients with chronic pain such as spinal conditions is insufficient. We aimed to examine the prevalence of suicidal thinking and the factors associated with it among patients with spinal conditions.

METHODS

Data from the National Health Insurance Service database in South Korea were used in this population-based, cross-sectional study, and 2.5% of adult patients diagnosed with spinal conditions (low back pain and/or neck pain) between 2018 and 2019 were selected using a stratified random sampling technique. Patient Health Questionnaire-9 was used to determine the presence of suicidal thoughts and depressive symptoms.

RESULTS

33,171 patients with spinal conditions were included in this study. Among them, 5.9% had suicidal thinking and 20.7% had depressive symptoms. In the multivariable logistic regression model, old age, male sex, and employment were associated with a decreased prevalence of suicidal thinking. Current smokers, previous smokers, medical aid program recipients, and patients with mild-to-moderate or severe disability showed increased suicidal thinking. Underlying depression, bipolar disorder, insomnia disorder, and substance abuse were also associated with increased suicidal thinking.

CONCLUSION

In South Korea, 5.9% and 20.7% of patients with spinal conditions had suicidal thoughts and depressive symptoms, respectively. Some factors were associated with an increased prevalence of suicidal thoughts among patients with spinal conditions. Our results suggest that screening for these factors can help prevent suicide in patients with spinal conditions.

Cortical astrocytes modulate dominance behavior in male mice by regulating synaptic excitatory and inhibitory balance

Social hierarchy is established as an outcome of individual social behaviors, such as dominance behavior during long-term interactions with others. Astrocytes are implicated in optimizing the balance between excitatory and inhibitory (E/I) neuronal activity, which may influence social behavior. However, the contribution of astrocytes in the prefrontal cortex to dominance behavior is unclear. Here we show that dorsomedial prefrontal cortical (dmPFC) astrocytes modulate E/I balance and dominance behavior in adult male mice using in vivo fiber photometry and two-photon microscopy. Optogenetic and chemogenetic activation or inhibition of dmPFC astrocytes show that astrocytes bidirectionally control male mouse dominance behavior, affecting social rank. Dominant and subordinate male mice present distinct prefrontal synaptic E/I balance, regulated by astrocyte activity. Mechanistically, we show that dmPFC astrocytes control cortical E/I balance by simultaneously enhancing presynaptic-excitatory and reducing postsynaptic-inhibitory transmission via astrocyte-derived glutamate and ATP release, respectively. Our findings show how dmPFC astrocyte-neuron communication can be involved in the establishment of social hierarchy in adult male mice.

How Can We Deal with Psychosocial Issues in an Emerging Infectious Disease Outbreak? Lessons from a Qualitative Study for the MERS Outbreak in Korea

BACKGROUND

The 2015 Middle East respiratory syndrome (MERS) coronavirus outbreak in Korea led to profound emotional and social burdens, especially in patients and health care professionals.

MATERIALS AND METHODS

Focus group interviews were conducted with 2 patients, 1 family member and 6 health care professionals about psychological distress related to MERS in 2017 and analyzed the interview data using the consensual qualitative research method.

RESULTS

Four domains and 17 core ideas were identified within three interview groups, including psychological distress during the outbreak, problems regarding the response to the outbreak, positive experiences, and future directions for enhancing intervention to improve mental health and prevent psychosocial problems during the outbreak. Psychological consequences were affected by the characteristics of the emerging infectious disease and the structure and process of institutional or governmental response to the MERS outbreak. Mental health services and psychosocial support reduced the negative impact on psychological distress.

CONCLUSION

The MERS outbreak in 2015 gave rise to emotional and social injuries to patients and health care professionals, some of which can be long-lasting constraints in their lives. Preparedness in a society's response to a pandemic considering mental health in related parties can minimize negative psychological consequences and enhance resilience at the individual and society levels.

Association between Depression and Mortality in Patients with Pain Conditions: A South Korean Nationwide Cohort Study

PURPOSE

Patients with pain conditions may experience depression that greatly complicates treatment. In this study, we examined risk factors for depression in patients with pain conditions and associations between depression and long-term mortality in such patients.

MATERIALS AND METHODS

Data from the National Health Insurance Service database in South Korea were used in this cohort study. A total of 2.5% of adult patients diagnosed with pain conditions in 2010 were selected using a stratified random sampling technique and included for analysis. We performed multivariate logistic regression modelling to identify risk factors associated with depression and multivariate Cox regression modelling to determine whether depression is associated with 10-year survival outcomes in patients with pain conditions.

RESULTS

In total, data from 1808043 patients with pain conditions in 2010 were analyzed. Among them, 70148 (3.9%) patients had depression. Multivariate logistic regression modelling identified older age, comorbidities, analgesics, female sex, living in an urban area, and other underlying psychiatric morbidities as potential risk factors for depression in patients with pain conditions. Multivariate Cox regression revealed that 10-year all-cause mortality in patients with depression was 1.13-fold (hazard ratio, 1.13; 95% confidence interval, 1.11-1.16; p<0.001) higher than that in patients without depression and pain conditions.

CONCLUSION

We identified a few potential risk factors for depression among South Korean patients with pain conditions. Depression was associated with elevated 10-year all-cause mortality in patients with pain conditions.

Ethical Issues Referred to Clinical Ethics Support at a University Hospital in Korea: Three-Year Experience After Enforcement of Life-Sustaining Treatment Decisions Act

BACKGROUND

Clinical ethics support is a form of preventive ethics aimed at mediating ethics-related conflicts and managing ethical issues arising in the healthcare setting. However, limited evidence exists regarding the specific ethical issues in clinical practice. This study aimed to explore the diverse ethical issues of cases referred to clinical ethics support after the new legislation on hospice palliative care and end-of-life decision-making was implemented in Korea in 2018.

METHODS

A retrospective study of cases referred to clinical ethics support at a university hospital in Korea from February 2018 to February 2021 was conducted. The ethical issues at the time of referral were analyzed via qualitative content analysis of the ethics consultation-related documents.

RESULTS

A total of 60 cases of 57 patients were included in the study, of whom 52.6% were men and 56.1% were older than 60 years of age. The majority of cases (80%) comprised patients from the intensive care unit. One-third of the patients were judged as being at the end-of-life stage. The most frequent ethical categories were identified as goals of care/treatment (78.3%), decision-making (75%), relationship (41.7%), and end-of-life issues (31.7%). More specifically, best interests (71.7%), benefits and burdens/harms (61.7%), refusal (53.3%), and surrogate decision-making (33.3%), followed by withholding or withdrawal (28.3%) were the most frequent ethical issues reported, which became diversified by year. In addition, the ethical issues appeared to differ by age group and judgment of the end-of-life stage.

CONCLUSION

The findings of this study expand the current understanding of the diverse ethical issues including decision-making and goals of care/treatment that have been referred to clinical ethics support since the enforcement of the new legislation in Korea. This study suggests a need for further research on the longitudinal exploration of ethical issues and implementation of clinical ethics support in multiple healthcare centers.

Moral Distress Regarding End-of-Life Care Among Healthcare Personnel in Korean University Hospitals: Features and Differences Between Physicians and Nurses

BACKGROUND

Healthcare professionals often experience moral distress while providing end-of-life care. This study explored how physicians and nurses experienced moral distress when they cared for critically and terminally ill patients in tertiary hospitals in South Korea.

METHODS

This study used semi-structured in-depth interviews. A total of 22 people in two tertiary hospitals were interviewed, nine (40.9%) of which were physicians and 13 (59.1%) were nurses. The recorded interview files and memos were analyzed using grounded theory.

RESULTS

Most physicians and nurses encountered similar feelings of anger, helplessness, and burden owing to a lack of appropriate resources for end-of-life care. However, the factors and contexts of their moral distress differed. Nurses mainly addressed poorly organized end-of-life care, intensive labor conditions without support for nurses, and providing care without participation in decision-making. Meanwhile, physicians addressed the prevailing misperceptions on end-of-life care, communication failure between physicians owing to hierarchy and fragmented disciplines, the burden of responsibility in making difficult decisions, and the burden of resource allocation.

CONCLUSION

Differences in moral distress between physicians and nurses leave them isolated and can affect communication regarding healthcare. Mutual understanding between job disciplines will enhance their communication and help resolve conflicts in end-of-life care.

Causing trouble and being transmissible: COVID-19 survivors’ experiences of stigma and discrimination in South Korea

Background

The stigma associated with coronavirus disease (COVID-19) is relatively neglected in policies for handling the disease. Stigmatization occurs only within specific social contexts in local societies.

Objective

This study aims to examine COVID-19 survivors’ experiences of social stigma and discrimination in South Korea in the first 2 years of the pandemic.

Methods

Semi-structured interviews were conducted.

Results

Of 52 participants, 45 reported that they had to cope with stigma and discrimination in their intimate social relationships, workplaces, and children’s schools, ranging from subtle actions to job loss. Sexual minorities who were involved in mass disease transmission in the early part of the pandemic experienced a higher level of stigmatization. The stigmatization dealt with in this study was related to two themes: survivors’ sense of causing trouble and possibility of transmission.

Conclusion

By intertwining this stigma with the experiences of public health measures through the voices of survivors, this study reveals the local context of East Asia in terms of culture-specific aspects of COVID-19-related stigma.

Association between insomnia disorder and mortality among patients who underwent craniotomy for brain tumor resection: a South Korean nationwide cohort study

PURPOSE

To assess the prevalence and related factors of a newly developed insomnia disorder following craniotomy for brain tumor resection. Furthermore, we examined the association of pre- and postoperative insomnia with the 2-year mortality rate.

METHODS

The South Korean national registration cohort database was used as the data source. This study includes all adult patients who underwent craniotomy for brain tumor resection from January 1, 2011, to December 31, 2017. G47.0 and F51.0 (International Statistical Classification of Diseases and Related Health Problems 10th Revision codes) were used to identify insomnia disorders.

RESULTS

In total, 4,851 patients were included. Among them, 913 (18.8%) and 447 (9.2%) patients were assigned to the preoperative and postoperative insomnia groups, respectively. After modeling using multivariable logistic regression, older age (odds ratio (OR) 1.02, 95% confidence interval (CI) 1.01-1.03; P < 0.001), reoperation within 1 year (OR 2.12, 95% CI 1.47-3.06; P < 0.001), and newly acquired brain disability (OR 1.32, 95% CI 1.01-1.71; P = 0.043) were associated with an increased prevalence of newly developed postoperative insomnia disorder. After modeling using multivariable Cox regression, the preoperative and postoperative insomnia disorder groups showed a 1.17-fold (hazard ratio (HR) 1.17, 95% CI 1.02-1.34; P = 0.021) and a 1.85-fold (HR 1.85, 95% CI 1.59-2.15, P < 0.001) increased 2-year all-cause mortality risk compared to the control group, respectively.

CONCLUSION

In South Korea, 9.2% of the patients with brain tumors were newly diagnosed with an insomnia disorder following craniotomy for brain tumor resection, which was associated with an increased risk of 2-year mortality.

Correlates of burnout among healthcare workers during the COVID-19 pandemic in South Korea

Burnout is a form of negative emotional and physical response to job stress. This study aimed to investigate the prevalence of burnout among healthcare workers responding to the coronavirus disease 2019 (COVID-19) outbreak in Korea and to explore correlates of burnout among healthcare workers. A nationwide questionnaire-based survey was conducted from December 1, 2020, to January 29, 2021 on 1425 healthcare workers who worked in one of the 16 healthcare facilities designated for COVID-19 care, in public health centers, or as paramedics in Korea. Burnout was assessed using 16 Korean-adapted items based on the Oldenburg Burnout Inventory (OLBI). Data were collected using a structured questionnaire and analyzed using the R version 4.1.1 software program. OLBI results indicate clinically exhaustion in 84.5% (1204/1425) and clinically disengagement in 91.1% (1298/1425), and 77.3% (1102/1425) met the score criteria for both the exhaustion and disengagement subscales for burnout. Burnout rate was significantly increased in the group with chronic fatigue symptoms (Fatigue Severity Scale ≥ 3.22) after the outbreak of COVID-19 (OR, 3.94; 95% CI 2.80-5.56), in the female group (OR, 2.05; 95% CI 1.46-2.86), in the group with physical symptoms (Patient Health Questionnaire-15 ≥ 10) after the outbreak of COVID-19 (OR, 2.03; 95% CI 1.14-3.60), in the group with a higher Global Assessment of Recent Stress scale (OR, 1.71; 95% CI 1.46-2.01), in the group with post-traumatic stress symptoms (Primary Care Post-Traumatic Stress Disorder-5 ≥ 2) (OR, 1.47; 95% CI 1.08-2.01), and in the younger age group(OR, 1.45; 95% CI 1.22-1.72). The chronic fatigue symptoms were correlated with cumulative days of care (OR, 1.18; 95% CI 1.02-1.37). The physical symptoms were correlated with average contact hours with COVID-19 patients per day (OR, 1.34; 95% CI 1.17-1.54), and cumulative days of care (OR, 1.21; 95% CI 1.06-1.38). Most Korean healthcare workers suffered from burnout related to excessive workload during the COVID-19 pandemic. During a widespread health crisis like COVID-19, it is necessary to regularly check the burnout status in healthcare workers and reduce their excessive workload by supplementing the workforce and providing appropriate working hours sufficient rest hours.

Hippocampal engram networks for fear memory recruit new synapses and modify pre-existing synapses in vivo

As basic units of neural networks, ensembles of synapses underlie cognitive functions such as learning and memory. These synaptic engrams show elevated synaptic density among engram cells following contextual fear memory formation. Subsequent analysis of the CA3-CA1 engram synapse revealed larger spine sizes, as the synaptic connectivity correlated with the memory strength. Here, we elucidate the synapse dynamics between CA3 and CA1 by tracking identical synapses at multiple time points by adapting two-photon microscopy and dual-eGRASP technique in vivo. After memory formation, synaptic connections between engram populations are enhanced in conjunction with synaptogenesis within the hippocampal network. However, extinction learning specifically correlated with the disappearance of CA3 engram to CA1 engram (E-E) synapses. We observed "newly formed" synapses near pre-existing synapses, which clustered CA3-CA1 engram synapses after fear memory formation. Overall, we conclude that dynamics at CA3 to CA1 E-E synapses are key sites for modification during fear memory states.

Influence of Biogenetic Explanations of Mental Disorders on Stigma and Help-Seeking Behavior: A Systematic Review and Meta-Analysis

BACKGROUND

Biogenetic causal explanations of mental disorders are commonly used for public education and campaigns. However, the influence of biogenetic explanations on the ideas about and attitudes toward mental illness is unclear. We examined the influence of biogenetic explanations on attitudes toward mental disorders using a meta-analytic method accompanied by subgroup analyses.

METHODS

The protocol for this meta-analysis was registered in PROSPERO (CRD42020158656) in March 2020. Experimental and correlational studies were analyzed separately. Five outcome measures related to attitudes toward mental disorders were included: 'attitude toward help-seeking,' 'blame,' 'perceived dangerousness,' 'prognostic pessimism,' and 'social distance.' Subgroup analyses were performed for the type of mental disorder, population, and geographic region for which a biogenetic explanation was provided.

RESULTS

A total of 44 studies were included, of which 24 were experimental and 20 were correlational. A positive attitude toward help-seeking was associated with having a biogenetic concept (d = 0.43; 95% confidence interval [CI], 0.18 to 0.67; P < 0.001) in general population and in Eastern countries in particular. Although a biogenetic explanation was associated with a decreased level of blame (d = -0.20; 95% CI, -0.38 to -0.02; P = 0.029) in the general population, it was also associated with significantly higher levels of perceived dangerousness (d = 0.13; 95% CI, 0.03 to 0.23; P = 0.008). A tendency toward a higher level of prognostic pessimism and social distance was associated with a biogenetic concept of mental disorders although there was no statistical significance.

CONCLUSION

Having a biogenetic concept of the cause of mental disorders was related with a positive attitude toward help-seeking, particularly in the general population and individuals living in Eastern countries. Providing a biogenetic explanation decreased blame toward individuals with mental illness but was associated with increased perceived dangerousness and prognostic pessimism. Therefore, although a biogenetic explanation promotes public use of mental health services, it should be carefully applied to avoid an increase in negative thoughts, such as that mental illness is biologically irreversible and untreatable.

Resting-state heart rate variability, level of stress and resilience in internet gaming disorder and alcohol use disorder

Stress and resilience are involved in the pathophysiology of addictive disorders, and heart rate variability (HRV) is an index of an individual's global capability to regulate psychological responses. In this study, we aimed to identify transdiagnostic and disorder-specific markers in people with addictive disorders by analyzing resting-state HRV and associations with the levels of stress and resilience. We compared relevant data between patients with internet gaming disorder (IGD) and/or alcohol use disorder (AUD) and healthy controls (HCs). In all, 163 adults aged 18-35 years (53 with IGD, 49 with AUD, 61 HCs) participated. The levels of stress and resilience were measured using the Psychosocial Wellbeing Index and the Connor-Davidson Resilience Scale, respectively. The HRV was obtained from each participant during a 5 min resting-state. The IGD and AUD patients exhibited increased levels of stress and decreased resilience compared to the HCs. Patients with either addictive disorder exhibited a lower standard deviation of the normal-to-normal beat interval (SDNN) index [SDNNi] compared to HCs even after adjusting for clinical variables such as depression, anxiety, and impulsivity. In multiple comparison tests among the three groups, the AUD group had lower HRV than HCs, but no differences were observed among the groups after adjusting for the clinical variables. The HRV indices were correlated with the levels of stress, resilience, and disease severity. In conclusion, IGD and AUD patients exhibit lower HRV as indicated by the SDNNi compared to HCs, revealing their vulnerability to stress as well as a common transdiagnostic marker of addiction.

Hippocampal astrocytes modulate anxiety-like behavior

Astrocytes can affect animal behavior by regulating tripartite synaptic transmission, yet their influence on affective behavior remains largely unclear. Here we showed that hippocampal astrocyte calcium activity reflects mouse affective state during virtual elevated plus maze test using two-photon calcium imaging in vivo. Furthermore, optogenetic hippocampal astrocyte activation elevating intracellular calcium induced anxiolytic behaviors in astrocyte-specific channelrhodopsin 2 (ChR2) transgenic mice (hGFAP-ChR2 mice). As underlying mechanisms, we found ATP released from the activated hippocampal astrocytes increased excitatory synaptic transmission in dentate gyrus (DG) granule cells, which exerted anxiolytic effects. Our data uncover a role of hippocampal astrocytes in modulating mice anxiety-like behaviors by regulating ATP-mediated synaptic homeostasis in hippocampal DG granule cells. Thus, manipulating hippocampal astrocytes activity can be a therapeutic strategy to treat anxiety.

Effect of preoperative psychiatric morbidity on postoperative outcomes of lung cancer surgery: A nationwide cohort study in South Korea

OBJECTIVE

Lung cancer is the leading cause of cancer-related mortality worldwide, and cancer is associated with severe psychological distress. We aimed to investigate whether preoperative psychiatric morbidities affect clinical outcomes of lung cancer surgery in South Korea.

METHODS

Using the National Health Insurance Service database, all adult patients who were diagnosed with lung cancer and underwent lung cancer surgery from January 1, 2011, to December 31, 2018, were included in this retrospective, population-based cohort study. Depression, anxiety disorder, schizophrenia, alcohol abuse, non-alcohol substance abuse, and post-traumatic stress disorder were considered as preoperative psychiatric morbidities.

RESULTS

Overall, 60,031 adult patients who underwent lung cancer surgery were included in the final analysis. Of these, 17,255 (28.7%) patients had preoperative psychiatric morbidity before lung cancer surgery. Multivariable logistic regression modeling revealed patients with preoperative alcohol abuse (odds ratio [OR]: 2.51, 95% confidence interval [CI]: 1.24, 5.08; P = 0.011) and those with bipolar disorder (OR: 2.91, 95% CI: 1.94, 4.53; P &lt; 0.001) to be associated with increased in-hospital mortality. Moreover, patients with preoperative psychiatric morbidities were associated with longer length of hospitalization (LOS), higher cost of hospitalization, and increased 1-year all-cause mortality.

CONCLUSION

In South Korea, patients with preoperative alcohol abuse and bipolar disorder were associated with increased in-hospital mortality after lung cancer surgery. Moreover, they were associated with increased 1-year all-cause mortality, longer LOS, and higher total costs for lung cancer surgery.

Dynamics of axonal β-actin mRNA in live hippocampal neurons

Localization of mRNA facilitates spatiotemporally controlled protein expression in neurons. In axons, mRNA transport followed by local protein synthesis plays a critical role in axonal growth and guidance. However, it is not yet clearly understood how mRNA is transported to axonal subcellular sites and what regulates axonal mRNA localization. Using a transgenic mouse model in which endogenous β-actin mRNA is fluorescently labeled, we investigated β-actin mRNA movement in axons of hippocampal neurons. We cultured neurons in microfluidic devices to separate axons from dendrites and performed single-particle tracking of axonal β-actin mRNA. Compared with dendritic β-actin mRNA, axonal β-actin mRNA showed less directed motion and exhibited mostly subdiffusive motion, especially near filopodia and boutons in mature dissociated hippocampal neurons. We found that axonal β-actin mRNA was likely to colocalize with actin patches (APs), regions that have a high density of filamentous actin (F-actin) and are known to have a role in branch initiation. Moreover, simultaneous imaging of F-actin and axonal β-actin mRNA in live neurons revealed that moving β-actin mRNA tended to be docked in the APs. Our findings reveal that axonal β-actin mRNA localization is facilitated by actin networks and suggest that localized β-actin mRNA plays a potential role in axon branch formation.

Relationship of neurocognitive ability, perspective taking, and psychoticism with hostile attribution bias in non-clinical participants: Theory of mind as a mediator

Objectives

Hostile attribution bias is reportedly common from non-clinical population to those with serious mental illness, such as schizophrenia, and is known to be closely related to theory of mind (ToM). This study aimed to investigate whether ToM skills mediate the relationship among neurocognitive ability, personality traits, and attribution bias.

Methods

A total of 198 (101 females) non-clinical youths were recruited. To assess their neurocognitive ability and ToM skills, the participants were asked to complete Raven’s Standard Progressive Matrices (SPM) and the Korean version of the Reading the Mind in Eyes Test (K-RMET). To determine their personality traits, the Eysenck Personality Questionnaire (psychoticism) and interpersonal reactivity index (perspective taking) were used. To evaluate hostile attribution bias, the Ambiguous Intentions Hostility Questionnaire was administered. Path analysis and bias-corrected percentile bootstrap methods were used to estimate model fit and the parameters of the mediating effects.

Results

Based on model comparison, the best model characterized (1) two direct pathways from psychoticism and the K-RMET to hostility attribution bias and (2) three indirect pathways, wherein SPM, perspective taking, and psychoticism influenced hostile attribution bias through K-RMET. The final model fit indices were good [x²/df = 1.126; comparative fit index = 0.996; root mean square error of approximation = 0.026; standard root mean square residual = 0.026 and Akaike information criterion = 28.251] and the K-RMET fully mediated the association between SPM, perspective taking, psychoticism, and hostile attribution bias.

Conclusion

The main findings suggested that ToM skills, such as the RMET, play an important role in explaining the relationship among neurocognitive ability, personality traits, and hostile attribution bias. ToM skills and a remediation strategy may need to be developed to balance the enhanced hostility bias that underlies the paranoia.

Psychiatric morbidity among survivors of in-hospital cardiopulmonary resuscitation: A nationwide cohort study in South Korea

BACKGROUND

We aimed to examine the prevalence and associated factors of newly developed psychiatric morbidity among survivors of in-hospital cardiopulmonary resuscitation (ICPR). Additionally, we investigated whether pre-existing and newly developed psychiatric morbidities affect long-term mortality.

METHODS

We extracted data from the National Health Insurance Service database in South Korea. Adult ICPR survivors who underwent ICPR from January 1, 2010, to December 31, 2018, and who were alive for more than 1 year after ICPR were enrolled. Depression, anxiety, substance abuse, and post-traumatic stress disorder (PTSD) were evaluated as psychiatric morbidity.

RESULTS

A total of 22,611 survivors of ICPR from 615 hospitals in South Korea were included in the final analysis. Among them, 7825 (34.6%) had pre-existing psychiatric morbidity before ICPR, while 2524 (11.2%) had newly developed psychiatric morbidity after ICPR. In multivariable Cox regression analysis, compared to the no psychiatric morbidity group, the pre-existing psychiatric morbidity group (adjusted hazard ratio, 1.02; 95% confidence interval, 0.94, 1.11; P = 0.629) and the newly developed psychiatric morbidity group (adjusted hazard ratio, 1.02; 95% confidence interval, 0.90, 1.15; P = 0.798) were not associated with 1-year all-cause mortality among 1-year survivors of ICPR.

LIMITATION

Retrospective cohort design.

CONCLUSIONS

In South Korea, 11.2% of ICPR survivors had newly developed psychiatric morbidity such as depression, anxiety disorder, substance abuse, and PTSD within 1 year after ICPR. However, both pre-existing and newly developed psychiatric morbidities were not associated with 1-year all-cause mortality among 1-year survivors of ICPR.

Suicide Risk in Survivors of Acute Respiratory Distress Syndrome: A Nationwide Cohort Study in South Korea

OBJECTIVE

We aimed to examine the prevalence and risk factors of suicide among patients with acute respiratory distress syndrome (ARDS).

METHODS

Data were extracted from the National Health Insurance Service database in South Korea. This study included all adults admitted to intensive care units with a diagnosis of ARDS from January 1, 2010 to December 31, 2019, who survived ≥365. The primary endpoint in this study was suicide within 1 year of an ARDS diagnosis, which was determined as death by a suicide attempt or self-harm.

RESULTS

Analysis included 9,928 patients identified as ARDS survivors. One-year all-cause mortality occurred in 5,021 patients, 186 (1.9%) of which died by suicide. In multivariable Cox regression, older age, continuous renal replacement therapy, cardiopulmonary resuscitation incidence, history of self-harm or attempted suicide and concurrent substance abuse were associated with a higher risk of death by suicide among ARDS survivors.

CONCLUSION

During the 1-year follow-up period, 1.9% of ARDS survivors died by suicide in South Korea, and some factors were identified as potential risk factors for death by suicide. Knowledge of the factors associated with suicide might allow for earlier intervention to potentially reduce the death by suicide among ARDS survivors.

Identifying Terpenoid Biosynthesis Genes in Euphorbia maculata via Full-Length cDNA Sequencing

The annual herb Euphorbia maculata L. produces anti-inflammatory and biologically active substances such as triterpenoids, tannins, and polyphenols, and it is used in traditional Chinese medicine. Of these bioactive compounds, terpenoids, also called isoprenoids, are major secondary metabolites in E. maculata. Full-length cDNA sequencing was carried out to characterize the transcripts of terpenoid biosynthesis reference genes and determine the copy numbers of their isoforms using PacBio SMRT sequencing technology. The Illumina short-read sequencing platform was also employed to identify differentially expressed genes (DEGs) in the secondary metabolite pathways from leaves, roots, and stems. PacBio generated 62 million polymerase reads, resulting in 81,433 high-quality reads. From these high-quality reads, we reconstructed a genome of 20,722 genes, in which 20,246 genes (97.8%) did not have paralogs. About 33% of the identified genes had two or more isoforms. DEG analysis revealed that the expression level differed among gene paralogs in the leaf, stem, and root. Whole sets of paralogs and isoforms were identified in the mevalonic acid (MVA), methylerythritol phosphate (MEP), and terpenoid biosynthesis pathways in the E. maculata L. The nucleotide information will be useful for identifying orthologous genes in other terpenoid-producing medicinal plants.

Difficulties of healthcare workers encountered under cohort isolation in a psychiatric hospital during the COVID-19 pandemic: A qualitative study

This study examined the experiences of healthcare workers who were quarantined within the psychiatric wards due to COVID-19 and analyzed those experiences with a consensual qualitative research method. Participants experienced (a) difficulties due to the specificity of a mental hospital, including a lack of protocols, noncompliance with quarantine guidelines among patients with severe mental illness, and a shortage of institutions capable of containing confirmed COVID-19 patients with severe mental illness. Furthermore, (b) difficulties related to isolation of the cohort itself included a workforce shortage, physical problems, fear of infection, limited facilities, guilt toward newly confirmed cases, exhaustion, and distress caused by separation from family. The participants also described (c) difficulties related to external factors, including administrative orders and the perceived stigma, and (d) positive experiences. Appropriate support is needed during the COVID-19 pandemic to reduce the difficulties among healthcare workers in psychiatric hospitals. This includes preparation for future scenarios, facilities, and workers in response to outbreaks of infection in psychiatric hospitals that cause unique risks and challenges among those workers.

Associations of health-related quality of life with depression and stigma in MERS-CoV survivors during the recovery period

We explored factors related to health-related quality of life (HRQOL), including psychiatric symptoms and stigma related to Middle East respiratory syndrome coronavirus (MERS-CoV) infection, among MERS-CoV survivors during the recovery period.Sixty-three MERS-COV survivors were recruited from five hospitals for a cohort study, one year after their infection in 2015. The subjects' demographic information and medical conditions associated with MERS-CoV were recorded. HRQOL was evaluated using the Short Form-8 Health Survey (SF-8). Depression, post-traumatic stress symptoms, chronic fatigue, and perceived stigma were assessed using several questionnairesThe mean physical component summary (PCS) and mean mental component summary (MCS) of the SF-8 score were below 50 T (43.47 ± 9.60, 45.74 ± 10.18). Depression, chronic fatigue, posttraumatic stress symptoms and stigma were negatively correlated with the SF-8 PCS and MCS. Multivariate logistic regression analysis showed that the PCS was associated with stigma (OR 8.66, 95% CI 1.96-38.23), whereas MCS was associated with depression (OR 26.62, 95% CI 3.56-198.85).The estimated HRQOL of MERS-CoV survivors during recovery was poor and appeared to be associated with depression and MERS-related stigma.

Perceived barriers to psychiatric help-seeking in South Korea by age groups: text mining analyses of social media big data

BACKGROUND

The psychiatric treatment gap is substantial in Korea, implying barriers in seeking help.

OBJECTIVES

This study aims to explore barriers of seeing psychiatrists, expressed on the internet by age groups.

METHODS

A corpus of data was garnered extensively from internet communities, blogs and social network services from 1 January 2016 to 31 July 2019. Among the texts collected, texts containing words linked to psychiatry were selected. Then the corpus was dismantled into words by using natural language processing. Words linked to barriers to seeking help were identified and classified. Then the words from web communities that we were able to identify the age groups were additionally organized by age groups.

RESULTS

97,730,360 articles were identified and 6,097,369 were included in the analysis. Words implying the barriers were selected and classified into four groups of structural discrimination, public prejudice, low accessibility, and adverse drug effects. Structural discrimination was the greatest barrier occupying 34%, followed by public prejudice (27.8%), adverse drug effects (18.6%), and cost/low accessibility (16.1%). In the analysis by age groups, structural discrimination caused teenagers (51%), job seekers (64%) and mothers with children (43%) the most concern. In contrast, the public prejudice (49%) was the greatest barriers in the senior group.

CONCLUSIONS

Although structural discrimination may most contribute to barriers to visiting psychiatrists in Korea, variation by generations may exist. Along with the general attempt to tackle the discrimination, customized approach might be needed.

Linear Six-Carbon Sugar Alcohols Induce Lysis of Microcystis aeruginosa NIES-298 Cells

Cyanobacterial blooms are a global concern due to their adverse effects on water quality and human health. Therefore, we examined the effects of various compounds on Microcystis aeruginosa growth. We found that Microcystis aeruginosa NIES-298 cells were lysed rapidly by linear six-carbon sugar alcohols including mannitol, galactitol, iditol, fucitol, and sorbitol, but not by other sugar alcohols. Microscopic observations revealed that mannitol treatment induced crumpled inner membrane, an increase in periplasmic space, uneven cell surface with outer membrane vesicles, disruption of membrane structures, release of intracellular matter including chlorophylls, and eventual cell lysis in strain NIES-298, which differed from the previously proposed cell death modes. Mannitol metabolism, antioxidant-mediated protection of mannitol-induced cell lysis by, and caspase-3 induction in strain NIES-298 were not observed, suggesting that mannitol may not cause organic matter accumulation, oxidative stress, and programmed cell death in M. aeruginosa. No significant transcriptional expression was induced in strain NIES-298 by mannitol treatment, indicating that cell lysis is not induced through transcriptional responses. Mannitol-induced cell lysis may be specific to strain NIES-298 and target a specific component of strain NIES-298. This study will provide a basis for controlling M. aeruginosa growth specifically by non-toxic substances.

Enhanced Extraction Efficiency of Flavonoids from Pyrus ussuriensis Leaves with Deep Eutectic Solvents

In this study, deep eutectic solvents (DESs) were synthesized using different ratios of choline chloride (CC) and dicarboxylic acids, and their eutectic temperatures were determined. The DES synthesized using CC and glutaric acid (GA), which showed a higher extraction efficiency than conventional solvents, was used for the extraction of flavonoid components from Pyrus ussuriensis leaves (PUL), and the extraction efficiency was evaluated using the response surface methodology. The flavonoid components rutin, hyperoside, and isoquercitrin were identified through high-performance liquid chromatography (HPLC), equipped with a Waters 2996 PDA detector, and HPLC mass spectrometry (LC-MS/MS) analyses. The optimum extraction was achieved at a temperature of 30 °C using DES in a concentration of 30.85 wt.% at a stirring speed of 1113 rpm and an extraction time of 1 h. The corresponding flavonoid content was 217.56 μg/mL. The results were verified by performing three reproducibility experiments, and a high significance, with a confidence range of 95%, was achieved. In addition, the PUL extracts exhibited appreciable antioxidant activity. The results showed that the extraction process using the DES based on CC and GA in a 1:1 molar ratio could effectively improve the yield of flavonoids from PUL.

Prevalence and risk factors for suicide in patients with sepsis: nationwide cohort study in South Korea

BACKGROUND

Although a recent study reported that survivors of critical illness have an increased risk of suicide, the suicide rate and factors associated with suicide in patients with sepsis have not yet been investigated.

AIMS

We aimed to examine the prevalence and risk factors of suicide among patients with sepsis in South Korea.

METHOD

All adult patients who were admitted to all hospitals in South Korea with a main diagnosis of sepsis, from 1 January 2010 to 31 December 2018, were included in the study. The primary outcome was suicide within 1 year after sepsis diagnosis.

RESULTS

A total of 251 837 adult patients with sepsis were included, of which 132 691 patients (52.7%) died within 1 year after the diagnosis of sepsis, and death by suicide was the cause in 3903 patients (1.5%). Older age, male gender, living in a rural area, higher Charlson Comorbidity Index and Elixhauser Comorbidity Index scores, invasive treatment (continuous renal replacement therapy and mechanical ventilator support) and admission to a hospital with low annual case volumes were associated with a higher risk of suicide. In addition, concurrent substance misuse, post-traumatic stress disorder, bipolar disorder, dementia and previous attempt of suicide or self-harm were associated with a higher risk of suicide.

CONCLUSIONS

During the 1-year follow-up period, 1.5% of patients died by suicide after the diagnosis of sepsis in South Korea. Knowledge of the factors associated with suicide might allow for earlier intervention to potentially reduce the number of suicide attempts in patients with sepsis.

Predictors of the Development of Mental Disorders in Hospitalized COVID-19 Patients without Previous Psychiatric History: A Single-Center Retrospective Study in South Korea

The objective of this study was to investigate the predictors for new-onset mental disorders among patients with mild to moderate COVID-19 illness during hospitalization. A retrospective cohort study was performed in patients with confirmed COVID-19 admitted to a nationally designated hospital between 1 February and 30 June 2020. Demographic, clinical, psychological assessments, and psychiatric outcomes were obtained from electronic medical record review. Multivariate logistic regression analysis was used to identify predictors of new-onset mental disorders. Among 185 patients, 130 had no history of mental disorders or cognitive impairment at the time of admission. Of 130 patients, 29 (22.3%) were newly diagnosed with mental disorders during hospitalization. The following factors were significantly associated with an increased risk of a psychiatric diagnosis: Charlson comorbidity index core ≥1 (adjusted odds ratio (aOR) = 5.115, 95% confidence interval (CI): 1.737–15.058), length of stay (aOR per 1-day increase = 1.067, 95% CI: 1.035–1.100), and self-reported depressive symptoms at the time of admission (aOR = 5.357, 95% CI: 1.745–16.444). The predictive accuracy of combining these risk factors was relatively high (area under curve = 0.851, 95% CI: 0.778–0.923). These potential risk factors could help to predict the new-onset mental disorder among hospitalized patients with COVID-19.

De novo generation of a bright blue fluorophore from 2-oxoglutarate in biological samples

We discovered the generation of a new bright blue fluorophore from a particular type of amine and 2-oxoglutarate (2-OG) under mild conditions without any chemical additives. Two β-aminoethylamine molecules and three 2-OG molecules form an unprecedented 2-pyridone structure with a fused γ-lactam ring (DTPP) via complex reactions including double decarboxylation and quintuple dehydration. The DTPP fluorophore shows a high quantum yield (80%) and photostability. The great potential of the present DTPP generation in the quantitative analysis of 2-OG in biosamples is demonstrated.

A prospective study of remote delirium screening using the modified K-4AT for COVID-19 inpatients

BACKGROUND

Delirium is a neuropsychiatric condition strongly associated with poor clinical outcomes such as high mortality and long hospitalization. In the patients with Coronavirus disease 2019 (COVID-19), delirium is common and it is considered as one of the risk factors for mortality. For those admitted to negative-pressure isolation units, a reliable, validated and contact-free delirium screening tool is required.

MATERIALS AND METHODS

We prospectively recruited eligible patients from multiple medical centers in South Korea. Delirium was evaluated using the Confusion Assessment Method (CAM) and 4'A's Test (4AT). The attentional component of the 4AT was modified such that respondents are required to count days, rather than months, backward in Korean. Blinded medical staff evaluated all patients and determined whether their symptoms met the delirium criteria of the Diagnostic and Statistical Manual of Mental Disorders 5 (DSM-5). An independent population of COVID-19 patients was used to validate the 4AT as a remote delirium screening tool. We calculated the area under the receiver operating characteristic curve (AUC).

RESULTS

Out of 286 general inpatients, 28 (9.8%) inpatients had delirium. In this population, the patients with delirium were significantly older (p = 0.018) than the patients without delirium, and higher proportion of males were included in the delirium group (p < 0.001). The AUC of the 4AT was 0.992 [95% confidence interval (CI) 0.983-1.000] and the optimal cutoff was at 3. Of the independent COVID-19 patients, 13 of 108 (12.0%) had delirium. Demographically, the COVID-19 patients who had delirium only differed in employment status (p = 0.047) from the COVID-19 patients who did not have delirium. The AUC for remote screening using the 4AT was 0.996 (0.989-1.000). The optimal cutoff of this population was also at 3.

CONCLUSION

The modified K-4AT had acceptable reliability and validity when used to screen inpatients for delirium. More importantly, the 4AT efficiently screened for delirium during remote evaluations of COVID-19 patients, and the optimal cutoff was 3. The protocol presented herein can be used for remote screening of delirium using the 4AT.

Theory of mind and hair cortisol in healthy young adults: the moderating effects of childhood trauma

Background: Experiences of negative social interactions and childhood trauma (CT) can lead to aberrant hypothalamic-pituitary-adrenal functions. Poor theory of mind (ToM) ability is related to increased social stress levels; however, studies on the relationship between ToM and cortisol remain scarce. Objective: This study aimed to evaluate the relationship between ToM and the hair cortisol concentration (HCC) in healthy young adults considering the moderating role of CT. Method: A total of 206 healthy young adults were divided into two groups based on an experience of moderate-to-severe childhood trauma (CT+ and CT-). To determine whether CT moderated the relationship between ToM and HCC, moderation analysis was conducted controlling for age, sex, years of education, and scores of perceived stress, depression, and anxiety. Results: CT+ individuals reported higher subjective stress perception and depressive symptoms than CT- individuals, whereas anxiety-related symptoms, ToM, and HCC were not different between the groups. The experience of CT significantly moderated the relationship between ToM and HCC. The association between poorer ToM ability and higher HCC was significant only in CT+ group. Conclusion: CT is a moderator of the association between ToM and HCC, indicating the importance of CT in social cognition and the stress response.

Psychological Effects of COVID-19 Patient Management Experience among Paramedics and Emergency Medical Technicians: A Nationwide Survey in Korea

Background

Materials and Methods

Results

Conclusion

Incidence of Depression after Traumatic Brain Injury: A Nationwide Longitudinal Study of 2.2 Million Adults

Although improvements in acute care for traumatic brain injury (TBI) have increased the patient survival rate, many survivors often suffer from neuropsychiatric sequelae such as depression. This study investigated the influence of TBI on the risk of depression using South Korean nationwide data. Data were extracted from the National Health Insurance Service database for patients who experienced TBI from 2010 to 2017 (n = 1,141,593) and for 1:1 matched controls without TBI (n = 1,141,593). Patients under 18 years old or with a history of depression were excluded. TBI was used as a time-varying exposure and a time-dependent Cox regression model was adopted. Age, sex, insurance premium and type, region of residence, past psychiatric diseases, and Charlson Comorbidity Index were adjusted. The incidence of depression in the patients with TBI and matched controls was 34.60 and 21.42 per 1000 person-years, respectively. The risk of depression was higher in the patients with TBI (hazard ratio [HR] 1.19, 95% confidence interval [CI] = 1.18-1.20) than in the matched control group. After stratification by sex and age, the risk was higher in men and the younger age group. In subgroup analyses, patients with skull fracture showed the highest risk of depression. Notably, during the first year after TBI, the depression risk was almost 11 times higher than that in the matched control group (HR 11.71, 95% CI = 11.54-11.87). Our findings highlight a significant association of TBI with an increased risk of subsequent depression. Therefore, continuous awareness with regard to patients' mental health is needed.

Care for critically and terminally ill patients and moral distress of physicians and nurses in tertiary hospitals in South Korea: A qualitative study

Physicians and nurses working in acute care settings, such as tertiary hospitals, are involved in various stages of critical and terminal care, ranging from diagnosis of life-threatening diseases to care for the dying. It is well known that critical and terminal care causes moral distress to healthcare professionals. This study aimed to explore moral distress in critical and terminal care in acute hospital settings by analyzing the experiences of physicians and nurses from various departments. Semi-structured in-depth interviews were conducted in two tertiary hospitals in South Korea. The collected data were analyzed using grounded theory. A total of 22 physicians and nurses who had experienced moral difficulties regarding critical and terminal care were recruited via purposive maximum variation sampling, and 21 reported moral distress. The following points were what participants believed to be right for the patients: minimizing meaningless interventions during the terminal stage, letting patients know of their poor prognosis, saving lives, offering palliative care, and providing care with compassion. However, family dominance, hierarchy, the clinical culture of avoiding the discussion of death, lack of support for the surviving patients, and intensive workload challenged what the participants were pursuing and frustrated them. As a result, the participants experienced stress, lack of enthusiasm, guilt, depression, and skepticism. This study revealed that healthcare professionals working in tertiary hospitals in South Korea experienced moral distress when taking care of critically and terminally ill patients, in similar ways to the medical staff working in other settings. On the other hand, the present study uniquely identified that the aspects of saving lives and the necessity of palliative care were reported as those valued by healthcare professionals. This study contributes to the literature by adding data collected from two tertiary hospitals in South Korea.

Depression and mortality among survivors of acute respiratory distress syndrome in South Korea: A nationwide cohort study conducted from 2010 to 2018

It has been reported that survivors of acute respiratory distress syndrome (ARDS) experience depression. However, the relationship between newly developed depression and mortality among survivors of ARDS has not been elucidated. Thus, the aim of this study was to investigate the prevalence and associated factors of depression among survivors of ARDS and determine whether newly developed depression is associated with long-term mortality among them. The data used for this study were extracted from the national health insurance database of South Korea. All adult patients who were admitted into intensive care units for ARDS between January 1, 2010, and December 31, 2018, and survived for ≥1 year after treatment were defined as ARDS survivors and included in this study. A total of 4,452 ARDS survivors were included in the final analysis. Of these, 581 (13.4%) were newly diagnosed with depression within 1 year after ARDS diagnosis. Multivariable logistic regression showed that underlying anxiety disorder (odds ratio [OR], 2.35; 95% confidence interval [CI], 1.93-2.86; P < 0.001), substance abuse (OR, 2.18; 95% CI, 1.48-3.20; P < 0.001), and post-traumatic stress disorder (OR, 15.52; 95% CI, 2.57-93.51; P = 0.003) were associated with a higher prevalence of post-ARDS depression among survivors. Multivariable Cox regression analysis showed that post-ARDS depression was associated with a 1.49-fold increased risk of 2-year all-cause mortality (hazard ratio, 1.49; 95% CI, 1.18-1.88; P = 0.001). Underlying psychiatric illness is a potential risk factor for the development of depression among ARDS survivors. Post-ARDS depression is associated with an increased risk of 2-year all-cause mortality.

Effect of Childhood Trauma on the Association Between Stress-Related Psychological Factors and Hair Cortisol Level in Young Adults

OBJECTIVE

Relationship between hair cortisol concentration (HCC) and stress-related psychological measures are inconclusive, possibly due to overlooked heterogeneity regarding childhood trauma and a lack of comprehensive research on stress-related psychological factors. This study aims to compare young adults without history of childhood trauma to young adults who experienced childhood trauma using HCC and various stress-related psychological factors, as well as investigate the impacts of childhood trauma on the association between HCC and stress-related psychological measures.

METHODS

A total of 206 young, healthy adults were recruited. We divided participants into two groups depending on whether or not they had suffered moderate-to-severe childhood trauma (CT+ and CT-) and compared HCC and various stress-related psychological measures between groups. Using multiple linear regression analyses, we assessed the associations between HCC and stress-related psychological measures for each group.

RESULTS

We found no difference between the groups in HCC or the reported number of stressful life events in the past year; however, CT+ individuals reported higher stress perception, more depressive and anxiety-related symptoms, and more difficulties in emotion regulation than CT- individuals. HCC was associated with emotion dysregulation among the CT- individuals, but not among the CT+ individuals.

CONCLUSION

These findings suggest that history of childhood trauma should be considered in studies using HCC as a biomarker for stress in young adults. Furthermore, HCC might be a useful biomarker of stress and stress-related emotion dysregulation in individuals without moderate-to-severe childhood trauma.

Prevalence of mental illness among COVID-19 survivors in South Korea: nationwide cohort

BACKGROUND

Mental illness among survivors of coronavirus disease 2019 (COVID-2019) during the post-illness period is an emerging and important health issue.

AIMS

We aimed to investigate the prevalence of mental illness and the associated factors for its development among COVID-2019 survivors.

METHOD

From 1 January to 4 June 2020, data were extracted from the National Health Insurance Service COVID-19 database in South Korea. Patients with COVID-19 were defined as those whose test results indicated that they had contracted the infection, regardless of disease severity. COVID-19 survivors were defined as those who recovered from the infection. The primary end-point was the development of mental illness, which was evaluated between 1 January and 1 December 2020.

RESULTS

A total 260 883 individuals were included in this study, and 2.36% (6148) were COVID-19 survivors. The COVID-19 survivors showed higher prevalence of mental illness than the control group (12.0% in the COVID-19 survivors v. 7.7% in the control group; odds ratio (OR) = 2.40, 95% CI 2.21-2.61, P < 0.001). Additionally, compared with the control group, the no specific treatment for COVID-19 group (OR = 2.23, 95% CI 2.03-2.45, P < 0.001) and specific treatment for COVID-19 group (OR = 3.27, 95% CI 2.77-3.87, P < 0.001) showed higher prevalence of mental illness among survivors.

CONCLUSIONS

In South Korea, COVID-19 survivors had a higher risk of developing mental illness compared with the rest of the populations. Moreover, this trend was more evident in COVID-19 survivors who experienced specific treatment in the hospital.

Empathy and Theory of Mind in Ultra-High Risk for Psychosis: Relations With Schizotypy and Executive Function

OBJECTIVE

While recent studies have found deficits in theory of mind (ToM) skills in individuals at ultra-high risk (UHR) for psychosis, empathic tendencies in these subjects remain unclear. The presence of high schizotypy and compromised executive functions, which are found in UHR individuals, would affect ToM skills and empathic tendencies. We investigated the ToM skills and empathic tendencies of UHR individuals and examined their relationship with schizotypy and executive function.

METHODS

This study included 28 UHR individuals and 28 age- and sex-matched healthy controls. All participants completed a self-reported empathic scale (Interpersonal Reactivity Index) and the Wisconsin Schizotypy Scales. Additionally, the ToM Picture Stories Task and Wisconsin Card Sorting Test were conducted.

RESULTS

UHR individuals showed a trend toward lower self-reported empathic tendencies; however, there were no differences in ToM skills between the two groups. Of the four subscales of the IRI, only empathic concern showed a significant difference between the two groups. Empathic concern was inversely associated with negative schizotypy.

CONCLUSION

Our findings suggest that UHR individuals show relatively preserved cognitive empathy but compromised emotional empathy. Furthermore, in UHR individuals, the empathic concern subscale of the IRI was associated with negative schizotypy, while ToM skills were related to positive schizotypy and executive function.

Insomnia Disorder Among Coronavirus Disease Survivors: A South Korean Nationwide Cohort Study

OBJECTIVE

We investigated the prevalence and associated factors of insomnia disorder among survivors of coronavirus disease of 2019 (COVID-19).

METHODS

This population-based cohort study used data from the National Health Insurance Service COVID-19 cohort database from January 1 to June 4, 2020. COVID-19 patients were defined as individuals whose test confirmed that they were infected, regardless of the severity, and survivors were defined as individuals who recovered from the infection.

RESULTS

A total of 299,968 individuals were included in the final analysis, and 6,934 were considered as COVID-19 survivors, while the control group comprised 292,764 individuals. In the multivariable model after covariate adjustment, COVID-19 survivors had a 3.33-fold higher prevalence of insomnia disorder than the control group (odds ratio [OR]: 3.33, 95% confidence interval [CI]: 2.98-3.73; p<0.001). In the sensitivity analysis, the COVID-19 survivors with no specific treatment and the survivors with specific treatment were associated with a 3.16-fold (OR: 3.16, 95% CI: 2.77-3.59; p<0.001) and 3.89-fold (OR: 3.89, 95% CI: 3.17-4.78; p<0.001) higher prevalence of insomnia disorder than the control group.

CONCLUSION

In South Korea, 5.4% of COVID-19 survivors were diagnosed with insomnia disorder at 6 months follow-up. Thus, insomnia disorder is a public health issue for COVID-19 survivors.

Sex-specific association of hair cortisol concentration with stress-related psychological factors in healthy young adults

BACKGROUND

Hair cortisol concentration (HCC) has received attention as a useful marker of stress, but evidence on associations between psychological factors and cortisol concentration is inconsistent. The purpose of this study was to investigate the sex differences in the relationship between cortisol concentration and psychological factors in healthy young adults.

METHODS

A total of 205 (103 females, 102 males) healthy young adults participated. HCC and various stress-related psychological measures were compared between sexes. Multiple linear regression analyses were performed to assess associations between HCC and stress-related psychological measures for all participants and for each sex.

RESULTS

The difference in HCC according to sex was not significant. The reported number of stressful life events in the past year, stress perception, depressive and anxiety-related symptoms, and emotion dysregulation were not different between sexes, either. The association between HCC and emotion dysregulation was significant in females but not males.

CONCLUSION

We observed a sex-specific association between HCC and psychological factors. Our findings may imply that HCC could be a useful biomarker of stress and stress-related emotion dysregulation in healthy young women.