Use of renin-angiotensin system blockers and posttraumatic stress disorder risk in the UK Biobank: a retrospective cohort study.

BACKGROUND: Previous research has shown that the use of renin-angiotensin system (RAS) blockers is linked to a lower prevalence of posttraumatic stress disorder (PTSD), but longitudinal studies are scarce. We aimed to estimate the association between the use of RAS blockers and the risk of PTSD among individuals taking antihypertensive medications. METHODS: This longitudinal study included participants aged 40-69 from the UK Biobank. Exposure data were obtained from the initial assessment (2006-10), while outcome data were obtained from the online mental health questionnaire administered 6-11 years later (2016-17). We included participants who were under antihypertensive treatment and did not have a prior diagnosis of PTSD before the initial assessment. Use of RAS blockers was defined as self-reported regular use, at the initial assessment, of angiotensin-converting enzyme inhibitor (ACEi) or angiotensin receptor blocker (ARB). Among participants who experienced adverse life experiences, cases of probable PTSD were defined with the six-item PTSD Checklist-Civilian version score ≥ 14. Logistic regression with inverse probability of treatment weighting was used to estimate the odds ratios (ORs) and 95% confidence interval (CI) for the association between RAS blocker use and the risk of probable PTSD. RESULTS: Of the 15,954 participants (mean age = 59.9 years; 42.6% women) under antihypertensive treatment with no prior history of PTSD at the initial assessment, 64.5% were taking RAS blockers. After a mean follow-up of 7.5 years, 1,249 (7.8%) were newly identified with probable PTSD. RAS blocker users had a lower risk of probable PTSD than RAS blocker non-users (OR = 0.84 [95% CI: 0.75-0.94]), whereas the use of other antihypertensive medications showed no such association (users vs. non-users; calcium channel blockers, OR = 0.99 [95% CI: 0.88-1.11]; beta-blockers, 1.20 [1.08-1.34]; and thiazide-related diuretics, 1.15 [1.03-1.29]). The association between probable PTSD risk and the use of ACEi vs. ARB showed no significant difference (p = 0.96). CONCLUSIONS: Among individuals under antihypertensive treatment, the use of RAS blockers was associated with a decreased risk of probable PTSD. This added benefit of RAS blockers should be considered in the selection of antihypertensive medications.

Association between depressive symptoms and cardiovascular diseases in the Korean geriatric population: A nationwide retrospective cohort study.

INTRODUCTION: Depression has emerged as a modifiable risk factor for cardiovascular disease (CVD). However, evidence on whether depressive symptoms measured using a self-report questionnaire are associated with CVD incidence is scarce. Therefore, we aimed to investigate the association between depressive symptoms and CVD risk using data from national health examinations and insurance claim records. METHODS: This retrospective cohort study included participants who underwent the Korean National Screening Program for Transitional Ages at age 66 years between 2007 and 2017. The presence of depressive symptoms was defined as affirmative responses to any of three questions (loss of activities and interests, worthlessness, and hopelessness) selected from the Geriatric Depression Scale. Incident composite CVD event included myocardial infarction, stroke, heart failure, and CVD death. The association between depressive symptoms and CVD risk was evaluated using hazard ratios (HRs) and 95 % confidence intervals (CIs) estimated with Cox proportional hazards models. RESULTS: Among 88,765 participants (48.5 % women) aged 66 years, 4036 incident CVD events occurred during a mean follow-up of 6.8 years. Participants with depressive symptoms had a significantly higher risk of CVD than those without depressive symptoms (adjusted HR = 1.16 [95 % CI: 1.07-1.24]). The three individual depressive symptoms showed similar associations with CVD risk (loss of activities and interests, adjusted HR = 1.17 [95 % CI: 1.08-1.26]; worthlessness, 1.15 [1.03-1.29]; hopelessness, 1.13 [1.01-1.26]). LIMITATIONS: The study was limited to participants aged 66 years. Despite extensive adjustment for potential confounders and multiple sensitivity analyses, residual confounding and reverse causality could not be ruled out. CONCLUSION: The presence of depressive symptoms was associated with an increased risk of CVD. Screening for depressive symptoms in the general population may effectively mitigate the burden of CVD.

Changes in interoceptive accuracy related to emotional interference in somatic symptom disorder.

OBJECTIVE: The somatic symptom disorder (SSD) is characterized by one or more distressing or disabling somatic symptoms accompanied by an excessive amount of time, energy and emotion related to the symptoms. These manifestations of SSD have been linked to alterations in perception and appraisal of bodily signals. We hypothesized that SSD patients would exhibit changes in interoceptive accuracy (IA), particularly when emotional processing is involved. METHODS: Twenty-three patients with SSD and 20 healthy controls were recruited. IA was assessed using the heartbeat perception task. The task was performed in the absence of stimuli as well as in the presence of emotional interference, i.e., photographs of faces with an emotional expression. IA were examined for correlation with measures related to their somatic symptoms, including resting-state heart rate variability (HRV). RESULTS: There was no significant difference in the absolute values of IA between patients with SSD and healthy controls, regardless of the condition. However, the degree of difference in IA without emotional interference and with neutral facial interference was greater in patients with SSD than in healthy controls (p = 0.039). The IA of patients with SSD also showed a significant correlation with low-frequency HRV (p = 0.004) and high-frequency HRV (p = 0.007). CONCLUSION: SSD patients showed more significant changes in IA when neutral facial interference was given. These results suggest that bodily awareness is more affected by emotionally ambiguous stimuli in SSD patients than in healthy controls.

Psychometric Analysis of the Obsessive-Compulsive Spectrum Self-Report and Social Anxiety Spectrum Self-Report in the Korean Population.

OBJECTIVE: The present study aimed to assess the psychometric properties of the Korean versions of the Obsessive-Compulsive Spectrum Self Report (OBS-SR) and the Social Anxiety Spectrum Self Report (SHY-SR) questionnaires, along with determining their optimal cut-off points in a Korean population. METHODS: The study included outpatients with obsessive-compulsive disorder (OCD) (n=86), or social anxiety disorder (SAD) (n=52), those with major depressive disorder (MDD) (n=27), and 33 healthy controls. Participants were administered the Korean versions of the OBS-SR and SHY-SR questionnaires. Clinical symptoms were also assessed with several self-rating scales. RESULTS: The Korean versions of the OBS-SR and SHY-SR demonstrated good internal consistency, test-retest reliability, and convergent validity. Both questionnaires effectively differentiated between individuals with OCD or SAD and normal controls or those with MDD. Receiver-operating characteristic analyses of the OBS-SR and SHY-SR yielded area under the curve values of 0.89 and 0.96 for Diagnostic and Statistical Manual of Mental Disorders, Forth Edition diagnosis, respectively, and showed optimal threshold values of 50 and 44. CONCLUSION: The Korean versions of OBS-SR and SHY-SR demonstrate good reliability and validity in assessing manifestations of obsessive-compulsive and social anxiety psychopathology in Korean populations.

Serial mediating effects of childhood trauma and conduct behaviors on the impact of family history among patients with alcohol use disorder.

Family history (FH) of alcoholism increases the risk of alcohol use disorder (AUD); however, the contribution of childhood trauma (CT) in this respect remains unclear. This study investigated the relationship between FH and AUD-related clinical characteristics (social onset, antisocial tendency, and severity of problematic alcohol consumption) through the mediating effects of childhood trauma (CT) and conduct behaviors (CB) in a Korean male population with AUD. A total of 304 patients hospitalized for AUD at 16 psychiatric hospitals completed standardized questionnaires, including self-rated scales. Mediation analyses were performed using the SPSS macro PROCESS. Individuals with positive FH (133, 44%) had greater CT and CB and more severe AUD-related clinical characteristics than those without FH (171, 56%). In the present serial mediation model, FH had significant direct and indirect effects on AUD-related clinical characteristics through CT and CB. Indirect effects were 21.3% for social onset, 46.3%, antisocial tendency, and 37.9% for problematic drinking. FH directly contributed to AUD-related clinical characteristics, and CT and CB played mediating roles. This highlights the importance of careful intervention and surveillance of adverse childhood experiences and conduct disorder to prevent and mitigate alcohol-related problems in individuals with FH of AUD.

Sex-dependent association of DNA methylation of HPA axis-related gene FKBP5 with obsessive-compulsive disorder.

AIMS: Although hypothalamic-pituitary-adrenal (HPA) axis dysregulation in obsessive-compulsive disorder (OCD) has been reported, epigenetic changes in HPA axis-related genes have not been well studied in OCD. The present study investigated whether the epigenetic regulation of FK506-binding protein 51 gene (FKBP5) intron 7 is associated with OCD status in each sex. In addition, relationships among the DNA methylation levels of FKBP5 intron 7, OCD status and early-life trauma were explored. METHODS: A total of 267 patients with OCD and 201 controls aged between 18 and 40 years were recruited. Demographic and clinical assessment, FKBP5 rs1360780 genotyping, and pyrosequencing of FKBP5 intron 7 were conducted. DNA was extracted from peripheral blood leucocytes. First, multivariate analysis of covariance for differential DNA methylation levels between OCD patients and controls was conducted with adjustment for FKBP5 rs1360780 genotype, early-life trauma, depressive symptoms, and age as covariates in each sex. Next, path analysis was conducted to determine the mediation effects of DNA methylation levels of FKBP5 between early-life trauma and OCD status. In addition, sensitivity analyses for medication and lifetime major depression were also performed. RESULTS: DNA methylation at the FKBP5 intron 7 CpG site was significantly lower in men with OCD, compared to controls (mean difference -1.33%, 95% CI -2.11 to -0.55, p < 0.001). The results remained significant for drug naïve or free subjects (mean difference -1.27%, 95% CI -2.18 to -0.37, p = 0.006, in men) and for subjects without lifetime major depressive disorder (mean difference -1.60%, 95% CI -2.54 to -0.66, p < 0.001, in men). The mediation effect of DNA methylation levels was not significant between early-life trauma and OCD status. CONCLUSION: These findings suggest that epigenetic factors of HPA axis-related gene FKBP5 may play a role in the pathogenesis of OCD. Further studies are needed to determine how altered DNA methylation of FKBP5 intron 7 and HPA axis function are involved in OCD.

Altered prefrontal beta oscillatory activity during removal of information from working memory in obsessive-compulsive disorder.

BACKGROUND: Obsessive-compulsive disorder (OCD) is related to working memory impairment. Since patients with OCD have difficulty controlling their obsessive thoughts, removal of irrelevant information might be important in the pathophysiology of OCD. However, little is known about brain activity during the removal of information from working memory in patients with OCD. Our goal was to explore potential deficits in inhibitory function related to working memory processes in patients with OCD. METHODS: Sixteen OCD patients and 20 healthy controls (HCs) were recruited. We compared in prefrontal alpha and beta band activity derived from magnetoencephalography (MEG) between patients with OCD and HCs during multiple phases of information processing associated with working memory, especially in post-trial period of the visuospatial working memory task (the delayed matching-to-sample task), which is presumed to be related to the information removal process of working memory. RESULTS: Prefrontal post-trial beta power change (presumed to occur at high levels during the post-trial period) exhibited significant reductions in patients with OCD compared to HCs. In addition, the post-trial beta power change was negatively correlated with Obsessive-Compulsive Inventory-Revised total scores in patients with OCD. CONCLUSIONS: These findings suggest that impairment in the removal of information from working memory might be a key mechanism underlying the inability of OCD patients to rid themselves of their obsessions.

Microbiome analysis of circulating bacterial extracellular vesicles in obsessive-compulsive disorder.

AIM: The present study examined the microbiome abundance and composition of drug-naive or drug-free patients with obsessive-compulsive disorder (OCD) compared with healthy controls. In addition, in the OCD group, the microbiome composition was compared between early-onset and late-onset OCD. METHODS: Serum samples were collected from 89 patients with OCD and 107 age- and sex-matched healthy controls. Bacterial DNA was isolated from bacteria-derived extracellular vesicles in serum and then amplified and quantified using primers specific to the V3-V4 hypervariable region of the 16S ribosomal RNA gene. The 16S ribosomal DNA gene amplicon sequencing was performed. RESULTS: The pooled estimate showed that α-diversity was significantly reduced in patients with OCD compared with that in healthy controls (PShannon = 0.00015). In addition, a statistically significant difference was observed in ß-diversity between patients with OCD and healthy controls at the order (P = 0.012), family (P = 0.003), genus (P < 0.001), and species (P = 0.005) levels. In the microbiome composition, Pseudomonas, Caulobacteraceae (f), Streptococcus, Novosphingobium, and Enhydrobacter at the genus level were significantly less prevalent in patients with OCD than in controls. In addition, among patients with OCD, the microbial composition in the early-onset versus late-onset types was significantly different with respect to the genera Corynebacterium and Pelomonas. CONCLUSION: The present study showed an aberrant microbiome in patients with OCD, suggesting a role of the microbiota-brain interaction in the pathophysiology of OCD. Further longitudinal studies with larger sample sizes adjusting for various confounders are warranted.

Psychological factors associated with COVID-19 related anxiety and depression in young adults during the COVID-19 pandemic.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic and the corresponding lockdown have drastically changed our lives and led to high psychological distress and mental health problems. This study examined whether psychological factors such as loneliness, perfectionism, and health anxiety are associated with COVID-19 related anxiety and depression during the pandemic in young Korean adults, after controlling for various socio-demographic factors and early life stress. METHODS: A total of 189 participants (58.2% women) completed a cross-sectional online survey including the Fear of COVID-19 Scale, Center for Epidemiologic Studies Depression Scale, 3-item Revised UCLA Loneliness Scale, Frost Multidimensional Perfectionism Scale, and Whiteley Index-6. Hierarchical linear regression analyses with three blocks were employed to identify the factors that contributed to COVID-19 related anxiety and depressive symptoms. RESULTS: Hierarchical regression analyses showed that higher health anxiety was significantly associated with more severe COVID-19 related anxiety (standardized regression coefficient, ß = 0.599, p < 0.001). Additionally, higher levels of loneliness (ß = 0.482, p < 0.001), perfectionism (ß = 0.124, p = 0.035), and health anxiety (ß = 0.228, p < 0.001) were significantly associated with higher depression scores. The three psychological factors explained 32.8% of the total variance in depressive symptom scores, after taking all covariates into account. CONCLUSION: The results showed that health anxiety was a risk factor for both COVID-19 related anxiety and depression in young adults. Loneliness was the strongest predictor of depressive symptoms during the COVID-19 pandemic. These findings highlight the importance of identifying vulnerable individuals and encouraging psychological counselling and social connections to reduce the burden of psychiatric disorders during the pandemic.

COVID-19 pandemic's impact on networks of depression and anxiety in naturalistic transdiagnostic sample of outpatients with non-psychotic mental illness.

Background: The 2019 coronavirus disease (COVID-19) pandemic has caused an unprecedented disruption of daily lives and a mental health crisis. The present study examined how the depression and anxiety symptom network changed during the COVID-19 pandemic in a naturalistic transdiagnostic sample with non-psychotic mental illness. Materials and methods: A total of 224 psychiatric outpatients before the pandemic and 167 outpatients during the pandemic were included in the study and were assessed for the Patient Health Questionnaire and the Beck Anxiety Inventory. The network of depression and anxiety symptoms before and during the pandemic were estimated separately and were assessed differences. Results: The network comparison analysis showed a significant structural difference between the networks before and during the pandemic. Before the pandemic, the most central symptom in the network was feelings of worthlessness, while in the during pandemic network, somatic anxiety emerged as the most central node. Somatic anxiety, which showed the highest strength centrality during the pandemic, showed significantly increased correlation with suicidal ideation during the pandemic. Limitations: The two cross-sectional network analyses of individuals at one point in time cannot demonstrate causal relationships among measured variables and cannot be assumed to generalize to the intraindividual level. Conclusion: The findings indicate that the pandemic has brought a significant change in the depression and anxiety network and somatic anxiety may serve as a target for psychiatric intervention in the era of the pandemic.

Core clinical symptoms and suicidal ideation in patients with obsessive-compulsive disorder: A network analysis.

INTRODUCTION: Suicidality in obsessive-compulsive disorder (OCD) is underestimated and it is important for clinicians to understand the factors that contribute to suicidal ideation. The present study aimed to estimate a network of the core clinical symptoms of OCD including obsessions, compulsions, and obsessive-compulsive (OC) symptom dimensions, depressive symptoms, and psychological traits, and to examine which symptoms contribute to suicidal ideation in patients with a primary diagnosis of obsessive-compulsive disorder. METHODS: A total of 444 patients with OCD were assessed with the Yale-Brown Obsessive-Compulsive Scale, the Montgomery-Asberg Depression Rating Scale, and various other measures. Network analysis was conducted to estimate the network of obsessive-compulsive and depressive symptoms, psychological traits including alexithymia and impulsivity, and demographic covariates. Symptoms directly related to suicidal ideation in the network were examined for their relative contribution to suicidal ideation. RESULTS: Suicidal ideation was directly related to degree of control over compulsive behaviors, distress associated with compulsive behaviors, time spent performing compulsive behaviors, and unacceptable thoughts, along with depressive symptoms and alexithymia. In the network of OC and depressive symptoms the most central symptoms among the former were interference due to compulsive behaviors and interference due to obsessive thoughts, and among the latter were pessimistic thoughts and reported sadness. CONCLUSION: The findings suggest that along with depressive symptoms and alexithymia, compulsions and unacceptable thoughts dimension may contribute to suicidality, and thus, should be carefully monitored in patients with OCD.

Medical students' perceived stress and perceptions regarding clinical clerkship during the COVID-19 pandemic.

BACKGROUND: It is important to ensure that both the qualitative and quantitative aspects of clinical education are maintained during the pandemic. Understanding students' views on clinical rotations and the extent of their perceived pandemic-related stress would thus be useful for designing and implementing effective clerkship programs. Therefore, this study aimed to investigate perceived stress and perceptions regarding clinical clerkship among incoming clinical students (third year) and senior clinical students (fourth year) during the COVID-19 pandemic. METHODS: After completing orientation programs at the beginning of the academic year, we surveyed students on their perceived stress, their general perspectives regarding the appropriate scope of clinical clerkship, and their preferences regarding level of participation in clerkship. We examined the differences in stress and clerkship-related perceptions based on the students' study year and sex using independent t-test, chi-squared test, and Fisher's exact test. In addition, the influences of stress, sex, and study year on clerkship-related perceptions were examined using multinomial logistic regression. RESULTS: The independent t-test indicated that third-year students experienced lower stress than did fourth-year students. Clerkship-related perceptions also differed significantly between third- and fourth-year students. Multinomial logistic regression analyses on the scope of and participation levels in clinical clerkship revealed that third-year students had significantly lower odds of preferring a limited range of clinical rotations and lower engagement in clerkships compared to fourth-year students. CONCLUSION: The COVID-19 pandemic has affected clinical education and, consequently, medical students' inclination toward active participation in clinical rotations. It is thus essential to understand students' views and provide them with relevant intra-pandemic educational supports.

Dysfunctional coronavirus anxiety in nonpsychotic psychiatric outpatients during the COVID-19 pandemic: A network analysis.

BACKGROUND: The 2019 coronavirus disease (COVID-19) pandemic has had a profound impact on the mental health of people worldwide. This study examined dysfunctional coronavirus anxiety in nonpsychotic psychiatric outpatients during the pandemic using the coronavirus anxiety scale (CAS) and examined the relationship between coronavirus anxiety and clinical symptoms using network analysis. METHODS: In this cross-sectional study, 192 patients who first visited the psychiatric outpatient clinic of Severance Hospital during the COVID-19 pandemic with chief complaints of depressed mood, anxiety, somatic symptoms, or insomnia were included. We compared the clinical characteristics of patients with and without dysfunctional coronavirus anxiety. Network analysis was conducted to estimate the network of coronavirus anxiety and depressive, anxious, and hypochondriacal psychopathology. RESULTS: The results showed that 7.8% of patients exhibited dysfunctional coronavirus anxiety (CAS ≥ 5). Patients with dysfunctional coronavirus anxiety showed higher levels of health worry, somatic preoccupation, and subjective anxiety compared to patients without dysfunctional coronavirus anxiety. In the network analysis, the health worry node (Item 6 of the WI) showed the greatest number of connections with coronavirus anxiety nodes. CONCLUSIONS: These findings suggest that health worry may be an important bridge symptom that connects coronavirus anxiety and other clinical psychopathology. Patients with elevated health worries should be carefully monitored during the COVID-19 pandemic for exacerbation of previous symptoms and COVID-19-related psychopathology. Understanding the psychological factors in the face of the pandemic and their relationships with clinical psychiatric symptoms would help people prevent and overcome mental health problems during the pandemic.

Serum brain-derived neurotrophic factor remains elevated after long term follow-up of combat veterans with chronic post-traumatic stress disorder.

Attempts to correlate blood levels of brain-derived neurotrophic factor (BDNF) with post-traumatic stress disorder (PTSD) have provided conflicting results. Some studies found a positive association between BDNF and PTSD diagnosis and symptom severity, while others found the association to be negative. The present study investigated whether serum levels of BDNF are different cross-sectionally between combat trauma-exposed veterans with and without PTSD, as well as whether longitudinal changes in serum BDNF differ as a function of PTSD diagnosis over time. We analyzed data of 270 combat trauma-exposed veterans (230 males, 40 females, average age: 33.29 ± 8.28 years) and found that, at the initial cross-sectional assessment (T0), which averaged 6 years after the initial exposure to combat trauma (SD=2.83 years), the PTSD positive group had significantly higher serum BDNF levels than the PTSD negative controls [31.03 vs. 26.95 ng/mL, t(268) = 3.921, p < 0.001]. This difference remained significant after excluding individuals with comorbid major depressive disorder, antidepressant users and controlling for age, gender, race, BMI, and time since trauma. Fifty-nine of the male veterans who participated at the first timepoint (T0) were re-assessed at follow-up evaluation (T1), approximately 3 years (SD=0.88 years) after T0. A one-way ANOVA comparing PTSD positive, "subthreshold PTSD" and control groups revealed that serum BDNF remained significantly higher in the PTSD positive group than the control group at T1 [30.05 vs 24.66 ng/mL, F(2, 56)= 3.420, p = 0.040]. Serum BDNF levels did not correlate with PTSD symptom severity at either time point within the PTSD group [r(128) = 0.062, p = 0.481 and r(28) = 0.157, p = 0.407]. Serum BDNF did not significantly change over time within subjects [t(56) = 1.269, p = 0.210] nor did the change of serum BDNF from T0 to T1 correlate with change in PTSD symptom severity within those who were diagnosed with PTSD at T0 [r(27) = -0.250, p = 0.192]. Our longitudinal data are the first to be reported in combat PTSD and suggest that higher serum BDNF levels may be a stable biological characteristic of chronic combat PTSD independent of symptom severity.

Genetic association of FKBP5 with trait resilience in Korean male patients with alcohol use disorder.

The FKBP5 gene is known to have an important role in alcohol use disorder (AUD) in response to stress and has been reported to affect stress responses by interacting with childhood trauma. This study investigated the effects of the FKBP5 polymorphism rs1360780 and childhood trauma on trait resilience in male patients with AUD. In addition, allele-specific associations between FKBP5 DNA methylation and resilience were examined. In total, 297 men with AUD were assessed for alcohol use severity, childhood trauma, resilience, and impulsivity. Genotyping for FKBP5 rs1360780 and DNA methylation were analyzed. The effects of the rs1360780 single nucleotide polymorphism (SNP) and clinical variables on resilience were tested using linear regression analysis. Possible associations between FKBP5 DNA methylation and resilience were tested with partial correlation analysis. The rs1360780 risk allele, a low education level, and high impulsivity were associated with diminished resilience, whereas no significant main or interaction effect of childhood trauma with the SNP rs1360780 genotype on resilience was shown. No significant association between FKBP5 DNA methylation and resilience was found. The present study demonstrated the involvement of the rs1360780 risk allele in trait resilience in men with AUD, suggesting that the genetic vulnerability of FKBP5 may influence resilience related to AUD.

A nationwide nested case-control study of new-onset obsessive-compulsive disorder following antipsychotics use in schizophrenia.

OBJECTIVE: A substantial proportion of patients with schizophrenia suffer from comorbid obsessive-compulsive disorder (OCD) possibly associated with antipsychotics. However, little is known about the comparative risks of the antipsychotics. The present study aimed to investigate the risk of new-onset OCD following the initiation of different antipsychotic medications for schizophrenia relative to haloperidol. METHODS: Using the Korean national claims data, patients aged 15-60 years newly diagnosed with schizophrenia between 2010 and 2018 were identified. Of the 47,808 patients with schizophrenia treated with nine commonly prescribed antipsychotics, 775 new-onset OCD patients were matched to 3,100 patients without OCD using nested case-control design with 1:4 case-control matching based on the sex, age of index date, date of schizophrenia diagnosis, observation period, locations of medical institutions, and level of medical facilities. Using multivariable conditional logistic regression analysis, odd ratios (ORs) for new-onset OCD comparing each antipsychotic agent relative to haloperidol were computed. RESULTS: The risk for new-onset OCD during treatment with clozapine was significantly higher than that with haloperidol (adjusted OR 2.86; 95% confidence interval [1.63-5.03]). The risks for new-onset OCD with other antipsychotics were not significantly different from that with haloperidol. In subgroup analysis, the early and intermediate, but not late-onset schizophrenia group showed significant risk for OCD associated with clozapine use. CONCLUSION: The present findings, based on real-world national representative data, provide reliable evidence for the risk of new-onset OCD in patients with schizophrenia receiving clozapine at a population level.

Possible Association of Polymorphisms in Ubiquitin Specific Peptidase 46 Gene With Post-traumatic Stress Disorder.

Introduction: Dynamic proteolysis, through the ubiquitin-proteasome system, has an important role in DNA transcription and cell cycle, and is considered to modulate cell stress response and synaptic plasticity. We investigated whether genetic variants in the ubiquitin carboxyl-terminal hydrolase 46 (USP46) would be associated with post-traumatic stress disorder (PTSD) in people with exposure to combat trauma using a case-control candidate gene association design. Methods: Korean male veterans exposed to the Vietnam War were grouped into those with (n = 128) and without (n = 128) PTSD. Seven tagging SNPs of USP46 were selected, and single-marker and haplotype-based association analyses were performed. All analyses were adjusted for sociodemographic factors and levels of combat exposure severity and alcohol problem. Results: One single-marker (rs2244291) showed nominal evidence of association with PTSD status and with the "re-experiencing" cluster, although the association was not significant after Bonferroni correction. No significant association with the other SNPs or the haplotypes was detected. Conclusion: The present finding suggests preliminarily that genetic vulnerability regarding the ubiquitin-proteasome system may be related to fear memory processes and the development of PTSD symptoms after trauma exposure. Further studies with a larger sample size will be needed to examine the role of the ubiquitin-proteasome system including USP46 in PTSD.

Alterations of cellular aging markers in obsessive- compulsive disorder: mitochondrial DNA copy number and telomere length.

BACKGROUND: The present study examined whether mitochondrial DNA copy number (mtDNAcn) and telomere length - key markers of cellular aging - were altered in male and female participants with obsessive-compulsive disorder (OCD) compared to healthy controls. We also tested for associations between these alterations and OCD-related clinical features and inflammatory index. METHODS: A total of 235 patients with OCD (38.7% female) and 234 healthy controls (41.5% female) were included. We quantified whole-blood mtDNAcn and leukocyte telomere length using quantitative polymerase chain reaction. We also calculated the neutrophil-to-lymphocyte ratio from complete blood cell counts. RESULTS: Multivariate analysis of covariance showed that OCD status had a significant overall effect on cellular aging markers in men (Wilks λ = 0.889, F2,275 = 17.13, p < 0.001) and women (Wilks λ = 0.742, F2,182 = 31.61, p < 0.001) after controlling for age, body mass index and childhood trauma. In post-hoc comparisons, men with OCD had lower mtDNAcn than controls (p < 0.001), but we found no between-group difference for telomere length (p = 0.55). Women with OCD had a significantly lower mtDNAcn (p < 0.001) and shortened telomere length (p = 0.023) compared to controls. Moreover, the lower mtDNAcn shown in the OCD group was significantly correlated with an increase in systemic inflammation for both sexes, as measured by neutrophil-to-lymphocyte ratio. LIMITATIONS: The present cross-sectional design did not allow us to infer a causal relationship between OCD disease status and cellular aging markers. CONCLUSION: The present study is, to our knowledge, the first to demonstrate alterations in mtDNAcn and telomere shortening in OCD. These results suggest that aging-associated molecular mechanisms may be important in the pathophysiology of OCD.

Use of serotonin reuptake inhibitors and risk of subsequent bone loss in a nationwide population-based cohort study.

This study examined whether the use of SRIs is associated with an increased risk of bone loss using a nested case-control design with a nationwide population-based cohort in Korea. Using the Korean National Health Screening Cohort, subjects newly diagnosed with osteoporosis or osteopenia (n = 55,799) were matched with controls (n = 278,995) at a ratio of 1:5. We stratified the participants by their time-dependent use of SRIs and sex and controlled for various confounders, including lifestyle habits, laboratory data, and comorbidities. Conditional logistic regression showed that both recent and former users of SRIs had an increased risk of subsequent bone loss compared with non-users: men [recent users: odds ratio (OR) 1.35, 95% confidential interval (CI) 1.20, 1.53; former-users: OR 1.10, 95% CI 1.01, 1.20]; women (recent users: OR 1.38, 95% CI 1.28-1.48; former-users: OR 1.07, 95% CI 1.02, 1.21). The use of SRIs was associated with an increased risk of bone loss in both men and women. In particular, the association was stronger in recent users. These findings provide population-level evidence for the risk of bone loss associated with SRI exposure and highlight the importance of monitoring the bone health of SRI users.

Discovery of Depression-Associated Factors From a Nationwide Population-Based Survey: Epidemiological Study Using Machine Learning and Network Analysis.

BACKGROUND: In epidemiological studies, finding the best subset of factors is challenging when the number of explanatory variables is large. OBJECTIVE: Our study had two aims. First, we aimed to identify essential depression-associated factors using the extreme gradient boosting (XGBoost) machine learning algorithm from big survey data (the Korea National Health and Nutrition Examination Survey, 2012-2016). Second, we aimed to achieve a comprehensive understanding of multifactorial features in depression using network analysis. METHODS: An XGBoost model was trained and tested to classify "current depression" and "no lifetime depression" for a data set of 120 variables for 12,596 cases. The optimal XGBoost hyperparameters were set by an automated machine learning tool (TPOT), and a high-performance sparse model was obtained by feature selection using the feature importance value of XGBoost. We performed statistical tests on the model and nonmodel factors using survey-weighted multiple logistic regression and drew a correlation network among factors. We also adopted statistical tests for the confounder or interaction effect of selected risk factors when it was suspected on the network. RESULTS: The XGBoost-derived depression model consisted of 18 factors with an area under the weighted receiver operating characteristic curve of 0.86. Two nonmodel factors could be found using the model factors, and the factors were classified into direct (P<.05) and indirect (P≥.05), according to the statistical significance of the association with depression. Perceived stress and asthma were the most remarkable risk factors, and urine specific gravity was a novel protective factor. The depression-factor network showed clusters of socioeconomic status and quality of life factors and suggested that educational level and sex might be predisposing factors. Indirect factors (eg, diabetes, hypercholesterolemia, and smoking) were involved in confounding or interaction effects of direct factors. Triglyceride level was a confounder of hypercholesterolemia and diabetes, smoking had a significant risk in females, and weight gain was associated with depression involving diabetes. CONCLUSIONS: XGBoost and network analysis were useful to discover depression-related factors and their relationships and can be applied to epidemiological studies using big survey data.