Association between cerebral artery stenosis and depressive symptoms in elderly patients.

OBJECTIVE: To examine the association between cerebral artery stenosis and depressive symptoms in elderly patients. METHODS: The study participants were 365 patients aged ≥65 years who visited the psychiatric outpatient clinic, Samsung Medical Center between January 1, 2000, and December 31, 2019, and were diagnosed with depressive disorder. They had brain imaging tests including magnetic resonance angiography (MRA), psychological evaluations including the 15-item Geriatric Depression Scale (GDS-15), and lab tests. Individuals' cerebral artery stenosis was identified and the association with significant depressive symptoms was examined. RESULTS: Of the 365 subjects, 108 had at least one location of cerebral artery stenosis (29.6 %). The mean score of GDS-15 in the stenosis group was 8.1 (SD, 3.8), higher than the mean GDS-15 score of 6.5 (SD, 4.0) for the group without stenosis (p < 0.001). Compared to no middle cerebral artery (MCA) stenosis, having MCA stenosis was associated with significant depressive symptoms (p = 0.005). Compared to no posterior cerebral artery (PCA) stenosis, having left PCA stenosis was associated with significant depressive symptoms (p = 0.022). In the multivariable linear regression analysis, only bilateral MCA stenosis had a positive association with the score of GDS-15 (p = 0.013). CONCLUSION: Bilateral MCA stenosis and left PCA stenosis are associated with significant depressive symptoms among elderly patients, with bilateral MCA stenosis positively associated with the severity of depression.

Effect of virtual reality-based biofeedback for depressive and anxiety symptoms: Randomized controlled study.

BACKGROUND: The use of virtual reality (VR)-based biofeedback (BF), a relatively new intervention, is a non-pharmacological treatment of depressive and anxiety symptoms. However, studies on VR-based BF are lacking and inconclusive. METHODS: A total of 131 adults were recruited from the community. Participants who scored ≥10 on the Patient Health Questionnaire-9 (PHQ-9) or ≥9 on the Panic Disorder Severity Scale (PDSS) were included in the group with depressive or anxiety symptoms (DAS group), and others as the healthy control group (HC group). Participants from the DAS group were randomly assigned to VR-based or conventional BF intervention. All individuals visited at three times (weeks 0, 2, and 4), and completed the Montgomery-Asberg Depression Rating Scale (MADRS), the State-Trait Anxiety Inventory (STAI), and a visual analog scale (VAS) before and after the intervention, and PHQ-9 at the beginning and final visit. RESULTS: The analysis included a total of 118 participants (DAS/VR: 40, DAS/BF: 38, HC/VR: 40). There was no significant difference in demographic variables among the three groups. After the intervention, the DAS/VR group exhibited significant decreases in MADRS (70.0 %), PHQ-9 (64.1 %), STAI (29.5 %), and VAS (61.7 %) scores compared to the baseline (p <0.001). There were no significant differences between the effects of VR-based BF and conventional BF with a therapist. The HC group also showed significant decreases in the measures of depression and anxiety after receiving VR-based BF. CONCLUSION: VR-based BF was effective in reducing depressive and anxiety symptoms, even for subthreshold depression and anxiety symptoms in the HC group.

Risk of depression and anxiety in multiple sclerosis and neuromyelitis optica spectrum disorder: A nationwide cohort study in South Korea.

BACKGROUND: We investigated the risks of depression/anxiety in patients with multiple sclerosis (pwMS) or patients with neuromyelitis optica spectrum disorder (pwNMOSD). OBJECTIVES: MS/NMOSD cohorts were collected from Korean National Health Insurance Service, using the International Classification of Diseases-10th and information on Rare Intractable Disease program. Patients who were younger than 20 years, had a previous depression/anxiety, or died in the index year were excluded. METHODS: Hazard ratios (HRs) of depression/anxiety in pwMS and pwNMOSD from controls matched 1:5 for age, sex, hypertension, diabetes, and dyslipidemia were calculated using Cox regressions with a 1-year lag period and estimated over time. RESULTS: During a mean follow-up of 4.1 years, adjusted hazard ratios (aHR) for depression were 3.25 (95% confidence interval (CI) = 2.59-4.07) in MS and 2.17 (1.70-2.76) in NMOSD, and aHRs for anxiety were 1.83 (1.49-2.23) in MS and 1.56 (1.26-1.91) in NMOSD. The risks of anxiety/depression did not differ between MS and NMOSD and were highest in the second year after diagnosis of MS/NMOSD. The relative risk of depression was higher in younger pwMS/pwNMOSD, and the relative risk of anxiety was higher in pwMS who was male, had low income, or lived in a non-urban area. CONCLUSION: The risk of depression and anxiety was increased in pwMS/pwNMOSD.

A Delphi consensus on clinical features, diagnosis and treatment of major depressive disorder patients with anhedonia amongst psychiatrists in the Asia-Pacific.

Background: Anhedonia, a core diagnostic feature for major depressive disorder (MDD), is defined as the loss of pleasure and interest in daily activities. Its prevalence in MDD patients vary from 35 to 70%. Anhedonia in MDD negatively impacts functioning and is associated with treatment resistance and poorer prognosis for various clinical outcomes. Owing to its complexity, there remains considerable heterogeneity in the conceptualization, diagnosis and clinical management of anhedonia in MDD. Methods: This modified Delphi panel was conducted to elicit expert opinion and establish consensus on concepts relating to clinical features, diagnosis and treatment of MDD with anhedonia (MDDwA) amongst psychiatrists in the Asia-Pacific region. Seven themes were covered. A three-stage process was adopted for consensus generation (two online survey rounds, followed by a moderated consensus meeting). Statements were developed based on a literature review and input from a steering committee of six regional experts. The panel included 12 psychiatrists practicing in Australia, China, Hong Kong, Japan, South Korea and Taiwan with ≥5 years of specialist clinical experience, including assessment or management of patients with MDDwA. Results: Overall, consensus was achieved (median ≥8) on 89/103 statements (86%). About half of the statements (55/103, 53%) achieved consensus in Round 1, and 29/36 modified statements achieved consensus in Round 2. At the moderated consensus meeting, five modified statements were discussed by the steering committee and consensus was achieved on all statements (5/5). The findings highlighted a lack of clear and practical methods in clinical practice for assessing anhedonia in MDD patients and limited physician awareness of anhedonia in Asia-Pacific. Conclusion: Insights from this Delphi consensus provide a reference point for psychiatrists in Asia-Pacific to optimize their strategies for personalized diagnosis and management of patients with MDDwA. Identification of distinct and clinically relevant subtypes in MDD may be valuable for guiding personalized diagnosis and management approaches, including type-specific therapies.

Association between depression, antidepressant use, and the incidence of atherosclerotic cardiovascular diseases.

OBJECTIVE: To examine the association between depression, the use of antidepressants, and atherosclerotic cardiovascular disease (ASCVD). METHODS: The South Korean national claims data was used. Among a nationally representative population, 273,656 subjects who had been diagnosed with depression and prescribed antidepressants ("DEP with antidepressants") and 78,851 subjects who had been diagnosed with depression but not prescribed antidepressants ("DEP without antidepressants") were identified to be eligible. Healthy controls (HCs) were 1:1 matched with DEP with antidepressants group for age and sex. We followed up on the occurrence of ASCVD including ischemic heart diseases and ischemic stroke. RESULTS: The risk of ASCVD was increased in the DEP with antidepressants group and decreased in the DEP without antidepressants group compared to HCs. Among those under antidepressants, tricyclic antidepressant users showed the highest risk of ASCVD compared to HCs. Among young adults, the risk of ASCVD was increased in both groups. CONCLUSION: The risk of ASCVD increased in depression patients taking antidepressants, while it decreased in depression patients not taking antidepressants. However, the relationship showed differences according to drug class and age group.

Weight change in people with depression and the risk of dementia: a nationwide cohort study.

BACKGROUND: Depression is a risk factor for dementia and weight change can appear as a symptom of depression. However, the association between weight change after the diagnosis of depression and the risk of dementia is poorly established. This study aimed to investigate the association between weight change before and after a diagnosis of depression with the subsequent risk of dementia. METHODS: The National Health Insurance Sharing Service database was used. 1 308 730 patients aged ⩾40 years diagnosed with depression were identified to be eligible. Weight changes after their depression diagnosis were categorized and subsequent incidence of dementia was followed up. RESULTS: During an average follow-up period of 5.2 years (s.d., 2.0 years), 69 373 subjects were newly diagnosed with all-cause dementia (56 351 were Alzheimer's disease and 6877 were vascular dementia). Regarding all outcomes, compared to those with a minimal weight change (-5 to 5%), all groups with weight gain or loss showed increased risks of dementia after adjusting potential risk factors for dementia, in all analysis models with a dose-response relationship, showing a U-shaped association. CONCLUSIONS: Weight change as a symptom of depression could be a predictor for the future development of dementia.

Psychotic Disorders and the Risk of Type 2 Diabetes Mellitus, Atherosclerotic Cardiovascular Diseases, and All-Cause Mortality: A Population-Based Matched Cohort Study.

BACKGRUOUND: The effects of psychotic disorders on cardiometabolic diseases and premature death need to be determined in Asian populations. METHODS: In this population-based matched cohort study, the Korean National Health Insurance Service database (2002 to 2018) was used. The risk of type 2 diabetes mellitus (T2DM), acute myocardial infarction (AMI), ischemic stroke, composite of all cardiometabolic diseases, and all-cause death during follow-up was compared between individuals with psychotic disorders treated with antipsychotics (n=48,162) and 1:1 matched controls without psychiatric disorders among adults without cardiometabolic diseases before or within 3 months after baseline. RESULTS: In this cohort, 53,683 composite cases of all cardiometabolic diseases (during median 7.38 years), 899 AMI, and 1,216 ischemic stroke cases (during median 14.14 years), 7,686 T2DM cases (during median 13.26 years), and 7,092 deaths (during median 14.23 years) occurred. The risk of all outcomes was higher in subjects with psychotic disorders than matched controls (adjusted hazard ratios [95% confidence intervals]: 1.522 [1.446 to 1.602] for T2DM; 1.455 [1.251 to 1.693] for AMI; 1.568 [1.373 to 1.790] for ischemic stroke; 1.595 [1.565 to 1.626] for composite of all cardiometabolic diseases; and 2.747 [2.599 to 2.904] for all-cause mortality) during follow-up. Similar patterns of associations were maintained in subgroup analyses but more prominent in younger individuals (P for interaction <0.0001) when categorized as those aged 18-39, 40-64, or ≥65 years. CONCLUSION: Patients with psychotic disorders treated with antipsychotics were associated with increased risk of premature allcause mortality and cardiometabolic outcomes in an Asian population. This relationship was more pronounced in younger individuals, especially aged 18 to 39 years.

Bipolar disorder and the risk of cardiometabolic diseases, heart failure, and all-cause mortality: a population-based matched cohort study in South Korea.

The association of bipolar disorder (BD) with the risk of cardiometabolic diseases and premature death in Asians needs to be further determined. Relatively less attention has been paid to heart failure (HF) among cardiometabolic outcomes. We analyzed the Korean National Health Insurance Service database (2002-2018) for this population-based, matched cohort study. The hazards of ischemic stroke, ischemic heart disease (IHD), hospitalization for HF (hHF), composite cardiometabolic diseases, and all-cause mortality during follow-up were compared between individuals with BD (n = 11,329) and 1:1-matched controls without psychiatric disorders among adults without cardiometabolic disease before or within 3 months of baseline. Hazards of outcomes were higher in individuals with BD than in matched controls (adjusted hazard ratios [95% confidence intervals]: 1.971 [1.414-2.746] for ischemic stroke, 1.553 [1.401-1.721] for IHD, 2.526 [1.788-3.567] for hHF, 1.939 [1.860-2.022] for composite cardiometabolic diseases, and 2.175 [1.875-2.523] for all-cause mortality) during follow-up. Associations between BD and outcome hazards were more prominent in younger individuals (p for interaction < 0.02, except for ischemic stroke) and women (p for interaction < 0.04, except for hHF). Screening and preventive measures for cardiometabolic deterioration and early mortality may need to be intensified in individuals with BD, even in young adults, especially women.

Changes in physical activity and the risk of heart failure in newly diagnosed patients with depression: A nationwide cohort study.

BACKGROUND: Depression is known to increase the risk of heart failure (HF), and physical activity could be a potential mediator of their linkage. In this study, we examined the risk of incident HF according to changes in the level of physical activity before and after the diagnosis of depression. METHODS: A South Korean National Health Insurance Sharing Service database was used. A total of 1,405,655 patients with newly diagnosed depression were included in the analyses. According to the changes in physical activity based on the recommended level of regular physical activity, participants were divided into four groups: never, beginning, maintenance, and discontinuation. The main outcome was the occurrence of HF. RESULTS: During the average follow-up period of 5.28 years (SD, 2.00 years), 69,338 participants were diagnosed with HF, with an incidence rate of 9.34 per 1000 person-years. Compared to the never group, the beginning group showed a decreased risk of HF (aHR, 0.88; 95% CI, 0.86-0.90). Compared to the maintenance group, the discontinuation group showed an increased risk of HF (aHR, 1.16; 95% CI, 1.11-1.20). CONCLUSIONS: In the patients with depression, beginning regular physical activity was associated with a decreased risk of HF, and discontinuing regular physical activity was associated with an increased risk.

Depression, antidepressant use, and the risk of type 2 diabetes: a nationally representative cohort study.

Background: Previous studies have reported that depression can increase the risk of type 2 diabetes. However, they did not sufficiently consider antidepressants or comorbidity. Methods: The National Health Insurance Sharing Service database was used. Among the sample population, 276,048 subjects who had been diagnosed with depression and prescribed antidepressants (DEP with antidepressants group) and 79,119 subjects who had been diagnosed with depression but not prescribed antidepressants (DEP without antidepressants group) were found to be eligible for this study. Healthy controls (HCs) were 1:1 matched with the DEP with antidepressants group for age and sex. We followed up with them for the occurrence of type 2 diabetes. Results: In the group of DEP with antidepressants, although the risk of type 2 diabetes increased compared to HCs in a crude analysis, it decreased when comorbidity was adjusted for. In the group of DEP without antidepressants, the risk of type 2 diabetes decreased both in the crude model and the adjusted models. The risk varied by age group and classes or ingredients of antidepressants, with young adult patients showing an increased risk even in the fully adjusted model. Conclusion: Overall, those with depression had a reduced risk of type 2 diabetes. However, the risk varied according to the age at onset, comorbidity, and type of antidepressants.

Association of physical activity with the risk of Parkinson's disease in depressive disorder: A nationwide longitudinal cohort study.

Regular physical activity (PA) has been suggested as effective disease preventable strategies for Parkinson's disease (PD). Depression often precedes PD but whether PA also would reduce the risk of PD in patients with depression has not been known. The aim of study is to examine the association of regular PA with risk of PD among patients with depressive disorder. A total of 1,342,282 patients with depressive disorder were identified from a nationwide health screening cohort from 2010 to 2016. The exposure was changes in pattern of regular PA between pre-and post-diagnosis of depressive disorder, categorized as four groups; 1) no PA, 2) increased PA, 3) decreased PA, and 4) maintaining PA. The outcome was risk of incident PD, calculated using multivariate adjusted Cox proportional hazards regressions according to the PA categorization. Total of 8901 PD cases (0.66%) were developed during 5.3 years of follow-up period. Maintaining PA group was associated with the lowest risk of PD (adjusted hazard ratio [aHR] 0.89, 95% CI 0.83-0.97) among all other PA groups with depressive disorder (with no PA group as reference). Otherwise, decreased PA group significantly increased the risk of PD (aHR 1.10, 95% CI 1.03-1.16). Those who maintained PA before and after diagnosis of depressive disorder were associated with lower risk of incident PD.

Association between anxiety and skin conductance according to the intensity of shaking of virtual reality images.

Introduction: Despite the advantages of virtual reality (VR), cyber sickness makes it difficult to apply VR to those who are already anxious and in distress. Skin conductance (SC) is widely used as a bio-signal reflecting anxiety. It is positively correlated with anxiety. The objective of this study was to determine the association between SC and anxiety in VR. Methods: Healthy volunteers with moderate-to-high stress defined as a Perceived Stress Scale-10 (PSS-10) score ≥20 were enrolled. STAI-X-1 was used to measure anxiety, and galvanic skin response was used to measure SC. This study used an open, randomized, crossover design. In this study, 360° videos consisted of two types, namely, less dizzying video (G1) and more dizzying video (G2). We randomized subjects into two groups according to video exposure order: G1 after watching G2 (Order 1) and G2 after watching G1 (Order 2). Of 81 subjects, the average age (±SD) was 39.98 ± 10.94 years for the Order 1 group and 36.54 ± 12.44 years for the Order 2 group. Results: Anxiety was significantly decreased in the Order 2 group (p < 0.035) after watching videos, whereas there was no significant change in anxiety in the Order 1 group. In both groups, SC was significantly increased after exposure to a dizzying video. Mean difference (SD) between the second VR video and baseline SC was 1.61 (1.07) (p < 0.0001) in the Order 1 group and 0.92 (0.90) (p < 0.0001) in the Order 2 group, showing a significant difference between the two groups (p < 0.003). However, there was no significant difference between the two groups (p < 0.077) after baseline correction. Conclusion: Anxiety was decreased significantly in the Order 2 group. The Order 1 group showed a high rate of change in skin conductivity. It is possible to reduce SC and anxiety by viewing a less dizzying VR video first and then viewing a more dizzying video later.

Prevalence of Loneliness and Its Association With Suicidality in the General Population: Results From a Nationwide Survey in Korea.

BACKGROUND: Although it is known that a substantial proportion of the population experience loneliness, the consequence of loneliness remains unclear by countries and ages. Accordingly, this study aimed to assess the association between loneliness and suicidality in the general population of Korea. METHOD: A total of 5,511 Koreans aged 18-79 completed a tablet-assisted personal interview using the Korean version of the Composite International Diagnostic Interview and responded to questions about loneliness and lifetime suicidal ideation, plans, and attempts. A logistic regression analysis was used to examine the association between loneliness and suicidality. RESULTS: Approximately one-third of the Korean general population reported loneliness. Being older, never married, widowed, separated, or divorced, unemployed, and having a part-time job were all significantly related to loneliness. After adjusting for sociodemographic factors, individuals with loneliness were significantly associated with increased suicidal ideation (adjusted odd ratio [aOR], 4.05; 95% confidence interval [CI], 3.36-4.88), suicidal plans (aOR, 4.91; 95% CI, 3.34-7.21), and suicidal attempts (aOR, 4.82; 95% CI, 3.03-7.66). Even after adjusting for sociodemographic factors and mental disorders, suicidality remained statistically significant. Moreover, frequent, moderate-to-severe, and long-term loneliness were all associated with increased ORs for suicidality, regardless of sociodemographic factors and mental disorders. CONCLUSION: Loneliness was associated with suicidal ideation, plans, and attempts. This study lays the foundation for public health policymakers to establish early intervention and mental health care support for lonely people.

Higher metabolic variability increases the risk of depressive disorder in type 2 diabetes mellitus: a longitudinal nationwide cohort study.

Background and objectives: While variabilities in metabolic parameters (METv) have been linked to adverse health outcomes in type 2 DM, their association with depression is yet to be studied. This research aimed to investigate the association between METv and depressive disorder in patients with type 2 DM. Methods: The study involved a nationwide cohort of 1,119,631 type 2 DM patients who had undergone three or more serial health examinations between 2005 and 2012. At each visit, body mass index (BMI), fasting glucose (FG), systolic blood pressure (BP), and total cholesterol (TC) were measured and stratified into quartiles, with Q4 being the highest and Q1 the lowest. The risk of depressive disorder was evaluated using Cox proportional hazard regression models, which accounted for METs in the indexes, after adjusting for sex, income status, lifestyle habits, medical comorbidities, DM severity, and baseline levels of BMI, FG, BP, and TC. Results: During a mean follow-up period of 6.00 ± 2.42 years, 239,477 (21.4%) cases of type 2 DM patients developed depressive disorder. The risk of developing depressive disorder was gradually increased as the number of METv increased (HR 1.18; 95% CI 1.13, 1.23 for the group with the highest METv in all parameters compared to those with the lowest METv in all parameters). In the subgroup analysis, the risk of developing depressive disorder was 43% higher in men (HR 1.43; 95% CI 1.34, 1.51), and 31% higher in those younger than 65 years of age (HR 1.31; 95% CI 1.23, 1.39) in the group with the highest number of METv compared to the group with the lowest number of METv. Conclusion: In type 2 DM, higher METv was an independent risk factor for depressive disorder. This risk is notably elevated in men and individuals under the age of 65 years.

A study on the functional near-infrared spectroscopy on impaired prefrontal activation and impulsivity during cognitive task in patients with major depressive disorder.

BACKGROUND: This study aimed to examine the association between prefrontal activation during a verbal fluency task (VFT) and impulsivity among patients with major depressive disorder (MDD), using functional near-infrared spectroscopy (fNIRS). METHODS: We enrolled a total of 119 participants, 60 with MDD patients and 59 with healthy controls (HCs), aged 18 to 34 years. The Barratt Impulsiveness Scale-11 (BIS-11) was used to assess impulsivity after completing baseline demographic, clinical, and physical assessments. A VFT was used to examine prefrontal activation during cognitive executions while fNIRS was monitored. The changing values of oxygenated hemoglobin (oxy-Hb) and their associations with the BIS-11 score were analyzed. RESULTS: The data analysis comprised 109 participants in total (54 MDD; 55 HCs). Spearman's correlation analysis of the MDD group showed a negative correlation between changes in oxy-Hb and BIS-11 values in the right prefrontal cortex, notably the right frontopolar cortex (FPC) and ventromedial prefrontal cortex (VMPFC). After adjusting for sex, age, years of education, and Hamilton Depression Rating Scale (HAMD), significance was maintained in the right FPC [ρ = -0.317, p = 0.027], and the right VMPFC [ρ = -0.327, p = 0.022]. Furthermore, multivariate linear regression suggested a significant association in the right prefrontal cortex with BIS-11 score [ß = -1.904, SE = 0.799, p = 0.0214]. CONCLUSIONS: Impaired prefrontal activation during a verbal fluency task, led to higher impulsivity in patients with MDD.

Temporal priority of lifetime alcohol use disorders and comorbid psychiatric disorders in adults: Results from a population-based nationwide survey in Korea.

BACKGROUND: Despite the high prevalence of alcohol use disorders (AUDs) in Korea, few studies have been conducted on the temporal priority with comorbid mental disorders. We investigated the temporal priority of lifetime AUDs and comorbid mood and anxiety disorders among the general population of Korea. METHODS: Data of 18,807 respondents aged 18 years or older, collected from three national epidemiological surveys comprising face-to-face interviews using the Korean version of the Composite International Diagnostic Interview for DSM-IV mental disorders. For each mood or anxiety disorder, the extent to which one mental disorder precedes another was investigated by calculating the proportion of primary AUDs by that of primary mood or anxiety disorder. RESULTS: Regarding alcohol dependence, dysthymic disorder is 5.6 times more likely to occur before alcohol dependence. Moreover, generalized anxiety disorder, social phobia, and specific phobia are 3.6 times, 4.5 times, and 6.3 times more likely to occur before, respectively. Regarding alcohol abuse, specific phobia is 6.3 times more likely to occur before, whereas major depressive disorder is two times more likely to occur after. Moreover, the lag times between primary alcohol abuse and subsequent mood or anxiety disorders were longer than those between primary alcohol dependence and the latter. LIMITATIONS: The age of onset might be subject to recall bias. The presence of non-respondents could have influenced the results. CONCLUSION: We need to recognize that one of the mental disorders could lead to another and consider it in the management of people with AUDs or mood and anxiety disorders.

Assessment of Disability and Depression Following Amputation Among Adults in Korea.

This nationwide, population-based, retrospective cohort study assesses the risk of depression following amputation among adults in Korea.

Standardized Suicide Prevention Program for Gatekeeper Intervention of North Korean Defectors in South Korea.

OBJECTIVE: North Korean defectors (NKDs) have experienced substantial difficulties during the migration and settlement in South Korea. They have a high prevalence of depression, post-traumatic stress disorder, and suicidal behaviors. The high prevalence of mental disorders among NKDs can lead to a high suicide rate. However, there are no suicide prevention programs for NKDs. This study aims to customize a suicide prevention program with content suitable for NKDs' particular circumstances. METHODS: A multidisciplinary research team developed this program based on domestic and international gatekeeper training programs for suicide prevention and articles related to suicide prevention. RESULTS: We developed a multi-part gatekeeper training program, "Suicide CARE for NKDs." In the "Introduction," trainees learn about the need for the program and its importance. In "Careful observation," trainees learn to recognize linguistic, behavioral, and situational signals of suicide risk. In "Active listening," trainees learn how to ask about suicidal thoughts and to listen empathetically. In "Risk evaluation and expert referral," trainees learn to evaluate suicide risk and to connect NKDs with institutes or services. CONCLUSION: We expect this program to become useful for training gatekeepers to prevent suicide among NKD. A future follow-up study is needed to confirm the efficacy of the program.

Two-channel EEG based diagnosis of panic disorder and major depressive disorder using machine learning and non-linear dynamical methods.

The current study aimed to investigate the possibility of rapid and accurate diagnoses of Panic disorder (PD) and Major depressive disorder (MDD) using machine learning. The support vector machine method was applied to 2-channel EEG signals from the frontal lobes (Fp1 and Fp2) of 149 participants to classify PD and MDD patients from healthy individuals using non-linear measures as features. We found significantly lower correlation dimension and Lempel-Ziv complexity in PD patients and MDD patients in the left hemisphere compared to healthy subjects at rest. Most importantly, we obtained a 90% accuracy in classifying MDD patients vs. healthy individuals, a 68% accuracy in classifying PD patients vs. controls, and a 59% classification accuracy between PD and MDD patients. In addition to demonstrating classification performance in a simplified setting, the observed differences in EEG complexity between subject groups suggest altered cortical processing present in the frontal lobes of PD patients that can be captured through non-linear measures. Overall, this study suggests that machine learning and non-linear measures using only 2-channel frontal EEGs are useful for aiding the rapid diagnosis of panic disorder and major depressive disorder.