Two Cases of Posttraumatic Stress Disorder Caused by a Motor Vehicle Accident Treated with Virtual Reality Exposure Therapy.

Exposure-response prevention is an effective approach to treat anxiety disorders. Virtual reality exposure therapy (VRET) is a promising treatment for patients with posttraumatic stress disorder (PTSD). New research has helped refine and update VRET. In this study, we introduce a form of VRET developed for patients suffering from PTSD after a traffic accident, and present two cases treated using this protocol. After 6 weeks of VRET treatment, the two participants not only improved their PTSD symptoms, but also improved their depressed mood, anxiety, and insomnia symptoms. Future studies of VRET for car accident-related PTSD should utilize a controlled design with randomization in order to account for numerous possible confounds.

The moderating role of circadian gene polymorphisms in the relationship between sleep disturbance and circulating lymphocyte subsets in colorectal cancer patients.

AIM: We investigated the impact of sleep disturbance on immune status in colorectal cancer (CRC) patients with consideration of the moderating role of circadian clock gene polymorphisms. METHODS: A prospective longitudinal study design was used to collect information regarding sleep disturbance. Blood samples for immunologic assays were obtained the day before the first (baseline) and last cycles of 5-fluorouracil, leucovorin, and oxaliplatin (FOLFOX) chemotherapy. Clinical sleep disturbance was compared between the two-time points using the Pittsburgh Sleep Quality Index (PSQI) global score. We analysed single-nucleotide polymorphisms in rs2278749, rs3749474, rs2291738, rs17031614, and rs2287161. The dependent variables included changes in the percentages of CD4+, CD8+, CD19+, and CD16/56+ lymphocytes between the two-time points. The results were analysed using moderated regression analysis; the p-values were adjusted using the false discovery rate. RESULTS: Among the 104 patients, no significant dyadic associations were observed between changes in lymphocyte percentages and the PSQI global score. However, the moderated regression analysis revealed five significant associations (rs2287161 with CD8+, rs2278749 and rs2291738 with CD19+, and rs17031614 with CD4+ and CD16/56+ lymphocytes). The inclusion of each interaction resulted in a significant increase (5.7-10.7%) in the variance explained by changes in lymphocyte percentage. CONCLUSION: Patients with specific circadian gene allele types may be more susceptible to immune dysregulation when experiencing sleep disturbances. Considering that sleep disturbance is a modifiable factor that can impact immune regulation, it is essential to prioritise the management of sleep disturbances in CRC patients receiving FOLFOX chemotherapy.

The relationship between depressive mood and subjective health in centenarians and near-centenarians: a cross-sectional study from Korean centenarian cohort.

BACKGROUND: With the rapid increase in population longevity, more clinical attention is being paid to the overall health of long-lived people, especially centenarians. Subjective health, which is the perception of one's health status, predicts both mortality and declining physical function in older adults. The purpose of this study was to investigate the factors related to subjective health among centenarians and near-centenarians (ages ≥95) living in a rural area of South Korea. METHODS: A total of 101 participants were enrolled from four different regions (Gurye, Gokseong, Sunchang, and Damyang), known as the Longevity Belt in Korea. Variables assessing physical and mental health, including the results of blood tests, were examined. Factors associated with good subjective health were identified with logistic regression analysis. RESULTS: Fifty-six participants (59.6%) were subjectively healthy among the centenarians and near-centenarians. Logistic regression analysis revealed that depressive mood was the only factor associated with subjective health and was negatively correlated. The regression model explained 39% of the variance in subjective health. CONCLUSIONS: These findings emphasize the importance of mental health at very advanced ages. Because depressive mood negatively correlates with subjective health, more attention is needed to prevent and manage mood symptoms of people of advanced ages, including centenarians.

Suicide and Non-Suicidal Self-Injury From Internet Addiction Among Korean Adolescents.

Objectives: This study examined the associations between Internet addiction and suicide and non-suicidal self-injury (NSSI) among South Korean adolescents. Methods: We conducted a cross-sectional study of 1694 Korean adolescents. The suicidal Ideation Questionnaire and Deliberate Self- Harm Inventories were used to identify high-risk suicide and NSSI groups, respectively. Internet addiction was assessed using the Internet Addiction Scale. Other questionnaires included sociodemographic data, perceived academic stress, and daily life-related factors. We also performed a logistic regression analysis using the high suicide risk and NSSI groups as dependent variables. Results: The high suicide risk and NSSI prevalence rates among participants were 11.8% and 28.3%, respectively. A multivariable logistic regression analysis revealed that Internet addiction is associated with higher suicide risk and NSSI. Additionally, being female and academic stress were significant suicide risk factors, while male participants had a higher NSSI prevalence. Conclusion: Our results suggest that monitoring adolescents' Internet use and providing education to prevent Internet addiction would lower high suicide and NSSI risk. Moreover, suicide and NSSI risk screening in adolescents with Internet addiction and providing suitable interventions will be essential for the preventing suicide and NSSI.

A Review of Machine Learning and Deep Learning Approaches on Mental Health Diagnosis.

Combating mental illnesses such as depression and anxiety has become a global concern. As a result of the necessity for finding effective ways to battle these problems, machine learning approaches have been included in healthcare systems for the diagnosis and probable prediction of the treatment outcomes of mental health conditions. With the growing interest in machine and deep learning methods, analysis of existing work to guide future research directions is necessary. In this study, 33 articles on the diagnosis of schizophrenia, depression, anxiety, bipolar disorder, post-traumatic stress disorder (PTSD), anorexia nervosa, and attention deficit hyperactivity disorder (ADHD) were retrieved from various search databases using the preferred reporting items for systematic reviews and meta-analysis (PRISMA) review methodology. These publications were chosen based on their use of machine learning and deep learning technologies, individually assessed, and their recommended methodologies were then classified into the various disorders included in this study. In addition, the difficulties encountered by the researchers are discussed, and a list of some public datasets is provided.

Effects of Dietary Habits on General and Abdominal Obesity in Community-dwelling Patients with Schizophrenia.

Objective: To investigate the effects of dietary habits on general and abdominal obesity in community-dwelling patients with schizophrenia spectrum disorder according to sex. Methods: A total of 270 patients with schizophrenia spectrum disorder registered at mental health welfare centers and rehabilitation facilities were recruited. General obesity was defined as a body mass index ≥ 30 kg/m2, and abdominal obesity was defined as a waist circumstance ≥ 90 cm in men and ≥ 85 cm in women. Dietary habits were evaluated using dietary guidelines published by the Korean Ministry of Health and Welfare. Demographic and clinical characteristics along with dietary habits and information related to obesity were collected. Factors related to obesity were evaluated separately by sex. Results: Dietary habits differed according to sex, in that scores for healthy eating habits were lower in men than in women. In men, the prevalences of general and abdominal obesity were 17.0% and 37.3%, respectively. In women, the prevalences of general and abdominal obesity were 23.1% and 38.5%, respectively. Regression analysis showed that the scores of regular eating habits were negatively associated with general and abdominal obesity in men, and the scores of healthy eating habits were negatively associated with general and abdominal obesity in women. Conclusion: Among patients with schizophrenia, regular eating habits might reduce the risk of obesity in men, and healthy eating habits might reduce the risk of obesity in women. Nutrition education should be provided to community- dwelling patients with schizophrenia to prevent obesity in this population.

Effectiveness of group metacognitive training and cognitive-behavioural therapy in a transdiagnostic manner for young patients with psychotic and non-psychotic disorders.

AIM: To investigate group metacognitive training and cognitive-behavioural therapy (MCT/CBT) prospectively in a young population with various psychiatric disorders, including psychotic and mood disorders. METHODS: This was a prospective study to investigate the effectiveness of group MCT/CBT on quality of life, psychotic symptoms, depression, self-esteem, perceived stress, social function and social cognition. The objective measures included the Positive and Negative Syndrome Scale (PANSS), clinical global impression (CGI), personal and social performance scale for social functioning, a computerized continuous performance test for sustained attention and a computerized emotional recognition test for social cognition. Self-report measures administered included the Subjective Well-being under Neuroleptics for quality of life, Ambiguous Intentions Hostility Questionnaire for suspiciousness, Drug Attitude Inventory, Beck Depression Inventory, Perceived Stress Scale, Brief Resilience Scale, Rosenberg Self-esteem Scale and visual analogue scale for the EQ-5D. RESULTS: Among 110 young patients with early psychosis and mood disorders who participated, 82 (74.5%) completed the study. Social functioning, quality of life, self-esteem, resilience, depression, suspiciousness, social cognition, sustained attention and scores on the PANSS and CGI improved significantly after completing group MCT/CBT. Perceived stress, resilience and suspiciousness improved significantly only in participants with a non-psychotic disorder. Improvements in subjective well-being of the participants were associated with increases in self-esteem and resilience and decreases in depression and perceived stress. CONCLUSIONS: Our study showed that group transdiagnostic MCT/CBT for young patients with mental illness improved subjective wellbeing, self-esteem, resilience, social cognition and social functioning and significantly diminished suspiciousness, perceived stress and depression.

Prediction of 12-Week Remission by Psychopharmacological Treatment Step in Patients With Depressive Disorders.

OBJECTIVE: To investigate the predictors of remission by 4 treatment steps in depressive outpatients receiving 12-week psychopharmacotherapy. METHODS: Patients were consecutively recruited at a university hospital in South Korea from March 2012 to April 2017. At baseline, 1,262 patients were evaluated for sociodemographic and clinical data including assessments scales, and were received antidepressant monotherapy. For patients with an insufficient response or uncomfortable side effects, next treatment steps (1, 2, 3, and 4) with alternative strategies (switching, augmentation, combination, and mixtures of these approaches) were administered considering measurements and patient preference at every 3 weeks in the acute treatment phase (3, 6, 9, and 12 weeks). Remission was defined as a Hamilton Depression Rating Scale score of ≤7. RESULTS: In the multi-variate logistic regression analyses, remission was predicted by higher functional levels in patients received Step 1 and 2 treatment; by lower life stressors in Step 1; by higher social support in Step 3 and 4; and by lower suicidality in Step 1-3. CONCLUSION: Differential associations were found between symptoms or functions and treatment steps, which suggested that multi-faceted evaluations at baseline could predict remission by treatment steps.

Trends in suicide deaths before and after the COVID-19 outbreak in Korea.

We investigated the effect of the coronavirus disease-2019 (COVID-19) pandemic on suicide trends in Korea via a time-series analysis. We used Facebook Prophet to generate forecasting models based on the monthly numbers of suicide deaths in Korea between 1997 and 2018, validated the models by comparison with the 2019 numbers, and predicted the numbers of suicides in 2020. We compared the expected and observed numbers of suicides during the COVID-19 pandemic. The total numbers of suicides during the COVID-19 pandemic did not deviate from projections based on the pre-pandemic period. However, the number of suicides among women and those under the age of 34 years significantly exceeded the expected level. The COVID-19 pandemic did not increase the overall suicide rate significantly. However, suicides among women and young people increased, suggesting that the pandemic might drive more members of these groups to suicide. Further studies are needed to verify the long-term impact of the COVID-19 pandemic on suicide.

Factors Associated With Depression and Anxiety in Korean Adolescents During the COVID-19 Pandemic.

OBJECTIVE: This study was performed to identify factors associated with depression and anxiety among Korean adolescents during the coronavirus disease (COVID-19) pandemic. METHODS: We conducted a cross-sectional study of 1,898 Korean adolescents (55.2% male, 44.8% female) ranging in age from 12 to 17 years (mean±standard deviaion age, 15.4±2.6 years). Depression and anxiety were defined as a Patient Health Questionnaire-9 score ≥10 and Generalized Anxiety Disorder-7 score ≥10, respectively. Other questionnaires included sociodemographic data, psychosocial stresses, and experiences in association with COVID-19. Psychiatric scales included Gratitude Questionnaire-6, Perceived Stress Scale-10, and UCLA Loneliness Scale-3. RESULTS: The prevalence rates of depressive and anxiety symptoms among participants were 13.8% and 21.0%, respectively. Multivariable logistic regression analysis revealed that female sex, fear of COVID-19 infection, low gratitude were risk factors for depression. Fear of COVID-19 infection, increased TV watching time, and academic-related stress were risk factors for anxiety. CONCLUSION: Depression and anxiety were prevalent during the pandemic in Korean adolescents, and were associated with fear of COVID-19 infection. Providing appropriate information on COVID-19, helping adolescents manage academic-related stress and maintain daily life patterns, and implementing interventions to foster gratitude are important for preventing depression and anxiety in Korean adolescents.

Development of a Checklist for Predicting Suicidality Based on Risk and Protective Factors: The Gwangju Checklist for Evaluation of Suicidality.

OBJECTIVE: The aim of the study was to develop a checklist for mental health clinicians to predict and manage suicidality. METHODS: A literature review of the risk and protective factors for suicide was conducted to develop a checklist for evaluating suicidality. RESULTS: The fixed risk factors included sex (male), age (older individuals), history of childhood adversity, and a family history of suicide. Changeable risk factors included marital status (single), economic status (poverty), physical illness, history of psychiatric hospitalization, and history of suicide attempts. Recent discharge from a mental hospital and a recent history of suicide attempts were also included. Manageable risk factors included depression (history and current), alcohol problems (frequent drinking and alcohol abuse), hopelessness, agitation, impulsivity, impaired reality testing, and command hallucinations. Protective factors included responsibility to family, social support, moral objections to suicide, religiosity, motivation to get treatment, ability to cope with stress, and a healthy lifestyle. A final score was assigned based on the sum of the risk and protective factor scores. CONCLUSION: We believe that the development of this checklist will help mental health clinicians to better assess those at risk for suicidal behavior. Further studies are necessary to validate the checklist.

Prospective associations of multimodal serum biomarkers with 12-week and 12-month remission in patients with depressive disorders receiving stepwise psychopharmacotherapy.

Prognostic biomarkers for depression treatment outcomes have yet to be elucidated. This study sought to evaluate whether a multi-modal serum biomarker panel was prospectively associated with 12-week and 12-month remission in outpatients with depressive disorders receiving stepwise psychopharmacotherapy. At baseline, 14 serum biomarkers and socio-demographic/clinical characteristics were evaluated in 1094 patients. They received initial antidepressant monotherapy followed, as required by a protocol of successive alternative pharmacological strategies administered in 3-week steps during the acute (3-12 week) phase (N = 1086), and in 3-month steps during the continuation (6-12 month) phase (N = 884). Remission was defined as a Hamilton Depression Rating Scale score of ≤ 7. Remission was achieved in 490 (45.1%) over the 12-week, and in 625 (70.7%) over the 12-month, treatment periods. Combination scores of four serum biomarkers (high-sensitivity C-reactive protein, interleukin-1 beta, interleukin-6, and leptin) were prospectively associated with 12-week remission; and four (high-sensitivity C-reactive protein, tumor necrosis factor-alpha, interleukin-1 beta, and brain-derived neurotrophic factor) were prospectively associated with 12-month remission in a clear gradient manner (P-values < 0.001) and after adjustment for relevant covariates. These associations were evident after the Step 1 treatment monotherapy but weakened with increasing treatment steps, falling below statistical significance after 4 + treatment steps. Application of combined multiple serum biomarkers, particularly on inflammatory markers, could improve predictability of remission at acute and continuation treatment phases for depressive disorders. Patients with unfavourable biomarkers might require alternative treatment regimes for better outcomes.

Interaction effect between childhood abuse and interleukin-1ß levels on suicidality in depressed patients.

INTRODUCTION: The roles of childhood abuse and interleukin (IL)-1ß levels, a representative pro-inflammatory cytokine, in suicidal behavior are unclear. This study investigated the main and interactive effects of childhood abuse and IL-1ß levels on suicidal behavior in patients with a depressive disorder before and after pharmacological treatment. METHODS: At baseline, exposure to self-reported childhood abuse, including emotional, physical, and sexual abuse, before the age of 16 years, and IL-1ß levels, were measured in 1,094 outpatients with a depressive disorder, 884 of whom were followed for 1 year. Suicidal behavior was evaluated, including previous suicide attempts (at baseline), suicidal ideation (at baseline and follow-up), and fatal/non-fatal suicide attempts (at follow-up). The main and interaction effects of self-reported childhood abuse and IL-1ß level on the four types of suicidal behavior were analyzed using logistic regression after adjusting for covariates. RESULTS: Individual associations of self-reported childhood abuse were significant only with previous suicidal attempt but not with other suicidal behaviors. There was no significant association of plasma IL-1ß level with any suicidal behavior. There were significant interactive associations of self-reported childhood abuse and a high IL-1ß level on previous suicide attempts, baseline suicidal ideation, and fatal/non-fatal suicidal attempts during follow-up. CONCLUSION: Suicidal behavior in patients with a depressive disorder could be influenced by considering the interactive effect of childhood abuse and IL-1ß levels. Our study suggests that childhood trauma and biochemical factors play roles in the pathology of suicide in depressed patients.

Effects of COVID-19-related stress and fear on depression in schizophrenia patients and the general population.

This study compared the coronavirus disease 2019 (COVID-19)-related stress, fear of infection, loneliness, and depression between patients with schizophrenia and the general population. A face-to-face survey was administered to 1340 patients with a schizophrenia spectrum disorder and online survey of the general population (n = 2000) was conducted. The information gathered included the level of COVID-19-related stress, fear of infection, the Patient Health Questionnaire-9 score, and the three-item UCLA Loneliness Scale score. Structural equation modeling revealed a significant effect of fear of COVID-19 infection on depression among the general population and on loneliness among patients with schizophrenia. Loneliness experienced during COVID-19 exacerbated depression in both groups. In the COVID-19-related stress-loneliness-depression pathway, the partial mediating effect of loneliness was significant in both groups. Conversely, in the COVID-19-related fear-loneliness-depression pathway, the full mediating effect of loneliness was only significant in patients with schizophrenia. In conclusion, the loneliness associated with COVID-19-related stress and fear of infection was an important factor influencing depression, and the impact was greater in patients with schizophrenia compared with the general population. Thus, different mental health intervention plans are needed for patients with schizophrenia during the COVID-19 pandemic. During the long-lasting COVID-19 pandemic, social support and provision of mental health services to prevent loneliness and consequent depression are required in patients with schizophrenia.

Childhood Abuse, Social Support, and Long-Term Pharmacological Treatment Outcomes in Patients With Depressive Disorders.

OBJECTIVES: This study was performed to investigate the roles of childhood abuse and social support in predicting short- and long-term pharmacological treatment outcomes in outpatients with depressive disorders in a naturalistic 1-year prospective design. METHODS: Patients were recruited at a university hospital in South Korea between March 2012 and April 2017. Subjects with stepwise pharmacotherapy (switching, augmentation, combination, and mixture of these approaches) included 1246 patients at 12-week points in the acute treatment response and 1,015 patients at 12-months in the long-term treatment response. Remission was defined as Hamilton Depression Rating Scale score ≤ 7. Exposure to three types of childhood abuse (physical, emotional, and sexual) before the age of 16 and perceived social support were assessed at baseline. RESULTS: Individual associations of childhood abuse were associated with poorer treatment outcomes in the 12-month long-term phase, and no significant individual associations were found for social support level with any period outcome. In combination, any child abuse, emotional abuse, and physical abuse were significantly associated with long-term 12-month remission rate in the presence of higher level of social support after adjustment with significant interaction terms. However, no significant interactions were found with sexual abuse. CONCLUSION: Synergistic interactive effects of child abuse and social support levels on treatment outcomes in depressive patients were found during long-term pharmacotherapy. Thus, depressed patients with a history of childhood abuse may require specialized clinical approaches, including social support, to enhance the long-term treatment outcomes.

Subacute Thyroiditis After Receiving the mRNA COVID-19 Vaccine (Moderna): The First Case Report and Literature Review in Korea.

Subacute thyroiditis (SAT) is a painful thyroiditis that often requires steroid therapy. Here, we report the first case of severe SAT in a patient who received the first dose of mRNA coronavirus disease 2019 (COVID-19) vaccination. A 34-year-old man without a viral prodrome felt a lump when swallowing 5 days after his first dose of mRNA-1273 (Moderna) vaccination. Ten days after vaccination, the patient visited the hospital and was advised to rest and take nonsteroidal anti-inflammatory drugs. He revisited the hospital 10 days later as symptoms aggravated with anterior neck pain, headache, fatigue, muscle weakness, and weight loss. Thyroid hormone levels and inflammatory markers were consistent with thyrotoxicosis. A thyroid ultrasound scan revealed typical SAT findings. His symptoms rapidly improved after receiving prednisone. A week later, the patient successfully completed his second dose of the vaccine. The thyroid function test results were nearly normal 1 month after the completion of the vaccination. We report this case to raise awareness of the occurrence of SAT after COVID-19 vaccination. As the risk of COVID-19 outweighs the minor risks of the vaccine, managing the side effects of the first vaccine dose is crucial to complete COVID-19 vaccination.

Decline in Hospital Visits by Patients with Schizophrenia Early in the COVID-19 Outbreak in Korea.

OBJECTIVE: This study investigated trends in hospital utilization by patients with schizophrenia during the first wave of the COVID-19 outbreak in Korea. METHODS: The Prophet algorithm was used to predict the monthly number of patients with schizophrenia in 2020 based on medical insurance data between 2010 and 2019. The projected expectations were compared with the actual number of patients receiving outpatient and inpatient treatment each month in the first half of 2020. We conduct interrupted time series analyses of short-term data to determine the significance of recent changes in the trend of hospital visits by patients with schizophrenia. RESULTS: The prediction model showed that the actual number of patients receiving treatment each month during the early COVID-19 outbreak decreased by up to 3.6% compared to the projected expectations. The interrupted time series model also revealed a significant change in hospital utilization compared to the year before the onset of COVID-19 in Korea (F = 8.961, p = 0.010). CONCLUSION: This suggests that many patients with schizophrenia were not receiving adequate treatment during the COVID-19 outbreak. A strategy should be developed to keep treating patients with schizophrenia during the COVID-19 pandemic.

Depressed mood, associated factors, and understanding of delirium among caregivers of patients with delirium.

OBJECTIVE: Delirium is stressful for both the patient and caregiver. However, caregivers have attracted minimal attention. We here identify depressed moods and associated factors among caregivers and caregiver knowledge of the delirium and non-pharmacological management. METHODS: This was a cross-sectional study. Caregiver and patient demographic characteristics, and patient clinical data, were collected. Caregiver depressed mood was analysed using the Hospital Anxiety and Depression Scale-depression subscale (HADS-D). We explored caregiver understanding of delirium and knowledge of non-pharmacological management. We used a multivariate linear regression model to identify factors associated with caregiver depressed mood. RESULTS: For 224 caregivers, the median (interquartile range) HADS-D score was 8.0 (4.0-11.8). More than half (54.9%) had scores ≥8. Answers to multiple choice questions revealed that delirium was frequently misinterpreted as "anxiety" (25.9%) or "dementia" (25.4%). Of all caregivers, 74% had received no information on non-pharmacological delirium management. Younger age of patient, a longer time from delirium detection to consultation, a patient past history of depression, a spousal relation with the patient, and misinterpretation of delirium as dementia were associated with the depressed mood of caregivers. CONCLUSIONS: The mental health of caregivers of patients with delirium requires more attention; they should be recommended to be informed and educated about delirium. Also, the clinicians need to find an easier term for the delirium to help caregivers understand.

The association of gratitude with perceived stress among nurses in Korea during COVID-19 outbreak.

BACKGROUND: During the COVID-19 pandemic, nurses might experience added emotional stress. This study examined the relationship between gratitude and psychological stress to explore effective psychological support among nurses. METHODS: A cross-sectional survey assessed the level of psychological distress in 646 nurses in Gwangju, South Korea, using the Perceived Stress Scale-10 (PSS-10), Gratitude Questionnaire-6 (K-GQ-6), Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), and Maslach Burnout Inventory-General Survey (MBI-GS). Sociodemographic factors and COVID-19-related experiences were also examined. A linear regression model was used to determine the factors influencing perceived stress. RESULTS: The mean PSS-10 score was 19.0 ± 4.4. Linear regression analyses revealed that the MBI-GS-Exhaustion, PHQ-9, and GAD-7 scores were positively associated with perceived stress, while the MBI-GS-Professional efficacy score was inversely associated with perceived stress. Gratitude disposition using the K-GQ-6 score negatively predicted PSS-10 (ß = 0.829, p < 0.001). CONCLUSIONS: Psychological interventions that help cultivate gratitude and professional efficacy among nurses can help promote stress resilience throughout the course of the COVID-19 pandemic.

Risk and protective factors of depression in the general population during the COVID-19 epidemic in Korea.

BACKGROUND: The risk of depression has risen in the general population during the COVID-19 epidemic. This study was conducted to explore risk and protective factors associated with depression among the general population uninfected by COVID-19. METHODS: A cross-sectional study was conducted with 1,500 representative South Korean citizens aged 19-65 years through an anonymous online survey. Depression was defined as a Patient Health Questionnaire-9 score of 10 or higher. Other questionnaires included one measuring psycho-behavioural and social changes, and stress, due to COVID-19, a six-item version of the Gratitude Questionnaire (GQ-6), and a three-item version of the UCLA loneliness scale. RESULTS: Of the 1492 participants not infected by COVID-19, 312 (20.9%) exhibited depression. Multiple logistic regression analysis revealed that depression was positively associated with COVID-19-related stress and psycho-behavioural variables such as disturbances in eating and sleeping, younger age, smoking, underlying mental illness, and loneliness scale scores. In contrast, exercise three or more times per week and GQ-6 scale scores were inversely associated with depression. CONCLUSION: During the COVID-19 pandemic, maintaining daily routines including eating, sleeping, and regular exercise and focusing on gratitude may be important for the prevention of depression. In addition, more attention should be paid to vulnerable populations, including young people, those with mental illnesses, and smokers, who might be more susceptible to depression.