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Epidemiological data on the association between mental disorders and the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and coronavirus disease 2019 (COVID-19) severity are limited.
To evaluate the association between mental disorders and the risk of SARS-CoV-2 infection and severe outcomes following COVID-19.
We performed a cohort study using the Korean COVID-19 patient database based on national health insurance data. Each person with a mental or behavioural disorder (diagnosed during the 6 months prior to their first SARS-CoV-2 test) was matched by age, gender and Charlson Comorbidity Index with up to four people without mental disorders. SARS-CoV-2-positivity risk and the risk of death or severe events (intensive care unit admission, use of mechanical ventilation and acute respiratory distress syndrome) post-infection were calculated using conditional logistic regression analysis.
Among 230 565 people tested for SARS-CoV-2, 33 653 (14.6%) had mental disorders; 928/33 653 (2.76%) tested SARS-CoV-2 positive and 56/928 (6.03%) died. In multivariable analysis using the matched cohort, there was no association between mental disorders and SARS-CoV-2-positivity risk (odds ratio OR = 0.95; 95% CI 0.87–1.04); however, a higher risk was associated with schizophrenia-related disorders (OR = 1.50; 95% CI 1.14–1.99). Among confirmed COVID-19 patients, the mortality risk was significantly higher in patients with than in those without mental disorders (OR = 1.99, 95% CI 1.15–3.43).
Mental disorders are likely contributing factors to mortality following COVID-19. Although the infection risk was not higher for people with mental disorders overall, those with schizophrenia-related disorders were more vulnerable to infection.
Over the past two decades, early detection and early intervention in psychosis have become essential goals of psychiatry. However, clinical impressions are insufficient for predicting psychosis outcomes in clinical high-risk (CHR) individuals; a more rigorous and objective model is needed. This study aims to develop and internally validate a model for predicting the transition to psychosis within 10 years.
Two hundred and eight help-seeking individuals who fulfilled the CHR criteria were enrolled from the prospective, naturalistic cohort program for CHR at the Seoul Youth Clinic (SYC). The least absolute shrinkage and selection operator (LASSO)-penalized Cox regression was used to develop a predictive model for a psychotic transition. We performed k-means clustering and survival analysis to stratify the risk of psychosis.
The predictive model, which includes clinical and cognitive variables, identified the following six baseline variables as important predictors: 1-year percentage decrease in the Global Assessment of Functioning score, IQ, California Verbal Learning Test score, Strange Stories test score, and scores in two domains of the Social Functioning Scale. The predictive model showed a cross-validated Harrell's C-index of 0.78 and identified three subclusters with significantly different risk levels.
Overall, our predictive model showed a predictive ability and could facilitate a personalized therapeutic approach to different risks in high-risk individuals.
Obsession and delusion are theoretically distinct from each other in terms of reality testing. Despite such phenomenological distinction, no extant studies have examined the identification of common and distinct neural correlates of obsession and delusion by employing biologically grounded methods. Here, we investigated dimensional effects of obsession and delusion spanning across the traditional diagnostic boundaries reflected upon the resting-state functional connectivity (RSFC) using connectome-wide association studies (CWAS).
Our study sample comprised of 96 patients with obsessive–compulsive disorder, 75 patients with schizophrenia, and 65 healthy controls. A connectome-wide analysis was conducted to examine the relationship between obsession and delusion severity and RFSC using multivariate distance-based matrix regression.
Obsession was associated with the supplementary motor area, precentral gyrus, and superior parietal lobule, while delusion was associated with the precuneus. Follow-up seed-based RSFC and modularity analyses revealed that obsession was related to aberrant inter-network connectivity strength. Additional inter-network analyses demonstrated the association between obsession severity and inter-network connectivity between the frontoparietal control network and the dorsal attention network.
Our CWAS study based on the Research Domain Criteria (RDoC) provides novel evidence for the circuit-level functional dysconnectivity associated with obsession and delusion severity across diagnostic boundaries. Further refinement and accumulation of biomarkers from studies embedded within the RDoC framework would provide useful information in treating individuals who have some obsession or delusion symptoms but cannot be identified by the category of clinical symptoms alone.
Given that only a subgroup of patients with schizophrenia responds to first-line antipsychotic drugs, a key clinical question is what underlies treatment response. Observations that prefrontal activity correlates with striatal dopaminergic function, have led to the hypothesis that disrupted frontostriatal functional connectivity (FC) could be associated with altered dopaminergic function. Thus, the aim of this study was to investigate the relationship between frontostriatal FC and striatal dopamine synthesis capacity in patients with schizophrenia who had responded to first-line antipsychotic drug compared with those who had failed but responded to clozapine.
Twenty-four symptomatically stable patients with schizophrenia were recruited from Seoul National University Hospital, 12 of which responded to first-line antipsychotic drugs (first-line AP group) and 12 under clozapine (clozapine group), along with 12 matched healthy controls. All participants underwent resting-state functional magnetic resonance imaging and [18F]DOPA PET scans.
No significant difference was found in the total PANSS score between the patient groups. Voxel-based analysis showed a significant correlation between frontal FC to the associative striatum and the influx rate constant of [18F]DOPA in the corresponding region in the first-line AP group. Region-of-interest analysis confirmed the result (control group: R2 = 0.019, p = 0.665; first-line AP group: R2 = 0.675, p < 0.001; clozapine group: R2 = 0.324, p = 0.054) and the correlation coefficients were significantly different between the groups.
The relationship between striatal dopamine synthesis capacity and frontostriatal FC is different between responders to first-line treatment and clozapine treatment in schizophrenia, indicating that a different pathophysiology could underlie schizophrenia in patients who respond to first-line treatments relative to those who do not.
We demonstrate the tungsten disulfide (WS2) thin film catalysts prepared by the sulfurization of vacuum deposited WO3 thin films for efficient hydrogen production with over 90% Faradaic efficiency. The 23-nm-thick WS2 thin film catalyst heterojunction with p-type silicon photocathode could exhibit a photocurrent density of 8.3 mA/cm2 at 0 V versus a reversible hydrogen electrode (RHE), a low onset potential of 0.2 V versus RHE when photocurrent density reaches −1 mA/cm2 and long-term stability over 10 h. The enhanced catalytic activities of WS2/p-Si photocathodes compared with the bare p-Si photocathode originate from a number of edge sites in the synthesized polycrystalline thin films, which could act as hydrogen evolution catalyst.
There is accumulating evidence for the role of fronto-striatal and associated circuits in obsessive–compulsive disorder (OCD) but limited and conflicting data on alterations in cortical thickness.
To investigate alterations in cortical thickness and subcortical volume in OCD.
In total, 412 patients with OCD and 368 healthy adults underwent magnetic resonance imaging scans. Between-group analysis of covariance of cortical thickness and subcortical volumes was performed and regression analyses undertaken.
Significantly decreased cortical thickness was found in the OCD group compared with controls in the superior and inferior frontal, precentral, posterior cingulate, middle temporal, inferior parietal and precuneus gyri. There was also a group x age interaction in the parietal cortex, with increased thinning with age in the OCD group relative to controls.
Our findings are partially consistent with earlier work, suggesting that group differences in grey matter volume and cortical thickness could relate to the same underlying pathology of OCD. They partially support a frontostriatal model of OCD, but also suggest that limbic, temporal and parietal regions play a role in the pathophysiology of the disorder. The group x age interaction effects may be the result of altered neuroplasticity.
Pathological gambling (PG) is a severe and persistent pattern of problem gambling that has been aligned with obsessive-compulsive disorder (OCD). However, no study has compared the neurocognitive profiles of individuals with PG and OCD.
We compared neurocognitive functioning, including executive function, verbal learning and memory, and visual–spatial organization and memory among 16 pathological gamblers, 31 drug-naïve OCD subjects, and 52 healthy controls.
The only neurocognitive marker common to both groups was increased fragmentation errors on the Rey–Osterrieth Complex Figure Test (ROCF). The PG subjects showed increased nonperseverative error on the Wisconsin Card Sorting Test and organization difficulties in the ROCF, whereas the OCD subjects revealed longer response times on the Stroop test and retention difficulties on the immediate recall scale of the ROCF.
A more careful approach is required in considering whether PG is a part of the OCD spectrum, as little evidence of neurocognitive overlap between PG and OCD has been reported.
Bon-Mi Gu, Interdisciplinary Program in Brain Science Seoul National University College of Medicine Seoul, Korea,
Do-Hyung Kang, Department of Psychiatry Seoul National University College of Medicine Seoul, Korea,
Jun Soo Kwon, Interdisciplinary Program in Brain Science and Department of Psychiatry Seoul National University College of Medicine Seoul, Korea
Functional magnetic resonance imaging (fMRI) research in obsessive-compulsive disorder (OCD) has explored a broad range of cognitive functions, in addition to the neural correlates of symptom provocation and symptom improvement after treatment. There are some discrepancies between findings of symptom provocation fMRI research, which might be caused by the heterogeneous character of OCD, such as the variety of the symptoms and comorbidity, or the diversity of applied cognitive paradigms in neuroimaging research. Future research on symptom-specific neural correlates and related cognitive dysfunctions will bring better understanding to the pathophysiology of OCD. In addition, genetic or family studies will give information regarding traits or state-related characteristics as well as putative vulnerabilities to the disorder. Finally, considering the current model of cortico basal ganglia-thalamo-cortical loop dysfunction of OCD, functional connectivity research that examines the functional relationships between these brain areas will facilitate the understanding of the disorder.
We investigated Korean language processing based on event-related potentials (ERPs) under congruent and incongruent conditions with semantic, syntactic, and combined errors. Fifteen participants were presented with visual stimuli consisting of 180 sentences ending in expected words (the congruent condition), 60 under the semantic condition, 60 under the syntactic condition, and 60 under the combined condition. The semantically incongruent condition was shown to elicit an N400 response, distributed in the right frontocentral region, as in semantic studies administered with Indo-European (IE) languages. The syntactically incongruent condition elicited P600 followed by N400 components but no early left-anterior negativity (ELAN) was detected, reflecting structural differences in Korean and IE languages. The doubly incongruent combined condition evoked N400 and P600 components with faster latency and higher amplitude compared to the syntactic conditions. The differences suggest that syntactic integration is influenced by semantic processing, but also that the semantic structure is independent of the syntactic context in the absence of semantic anomalies.
Event-related brain potentials (ERPs) have been widely used to investigate the neurophysiological mechanisms of human language. ERP studies of language processes have indicated three main language-associated ERP components: the N400, early left-anterior negativity (ELAN) /left-anterior negativity (LAN), and P600 components (Hagoort et al., 1993; Kutas & Hillyard, 1980; Osterhout, 1994).
Kutas and Hillyard (1980) presented visual sentence stimuli with unexpected or incongruent endings and found a negative peak around 400 ms, observing that N400 is an “electrophysiological marker of the ‘reprocessing’ of semantically incongruent information.
Oxidative modification of LDL is causally involved in the development of atherosclerosis and occurs in vivo in the blood as well as within the vascular wall. The present study attempted to explore whether polyphenolic flavonoids influence monocyte-endothelium interaction and lectin-like oxidised LDL receptor 1 (LOX-1) expression involved in the early development of atherosclerosis. The flavones luteolin and apigenin inhibited THP-1 cell adhesion onto oxidised LDL-activated human umbilical vein endothelial cells (HUVEC), while the flavanols of ( − )epigallocatechin gallate and (+)catechin, the flavonols of quercetin and rutin, and the flavanones of naringin, naringenin, hesperidin and hesperetin did not have such effects. Consistently, Western blot analysis revealed that the flavones at 25 μm dramatically and significantly abolished HUVEC expression of vascular cell adhesion molecule-1 and E-selectin evidently enhanced by oxidised LDL; these inhibitory effects were exerted by drastically down regulating mRNA levels of these cell adhesion molecules. In addition, quercetin and luteolin significantly attenuated expression of LOX-1 protein up regulated in oxidised LDL-activated HUVEC with a fall in transcriptional mRNA levels of LOX-1. In addition, quercetin and luteolin clearly blunted oxidised LDL uptake by HUVEC treated with oxidised LDL. The results demonstrate that the flavones luteolin and apigenin as well as quercetin were effective in the different initial steps of atherosclerosis process by inhibiting oxidised LDL-induced endothelial monocyte adhesion and/or oxidised LDL uptake. Therefore, certain flavonoids qualify as anti-atherogenic agents in LDL systems, which may have implications for strategies attenuating endothelial dysfunction-related atherosclerosis.
In this study, we assess the neuropsychological profiles of both early
and late symptom-onset obsessive-compulsive disorder (OCD) patients. The
early and late-onset OCD patients are compared to the control group with a
series of neuropsychological measurements. The late-onset OCD patients
exhibited impaired performance on the immediate and the delayed recall
conditions of the Rey-Osterrieth Complex Figure Test (RCFT) and the letter
and category fluency of the Controlled Oral Word Association Test (COWA),
compared to the normal controls and the early-onset OCD patients. The
controls and early-onset OCD patients did not differ on any of the
neuropsychological measurements taken in this study. These results suggest
that different neurophysiological mechanisms are in play in early and
late-onset OCD patients, and age of onset can serve as a potential marker
for the subtyping of OCD. (JINS, 2007, 13,
The present study investigates the twinning rate trends in South Korea for the years 1981 to 2002 utilizing the birth record data from the South Korea National Statistical Office. The twinning rates between 1981 and 1991 remained nearly constant and were slightly less than 10 twin individuals, that is, approximately five pairs per thousand births. Since the early 1990s, however, the twinning rate has increased sharply and reached 19.30 twin individuals, that is, around 10 pairs per thousand births in the year 2002. Application of the Weinberg method to birth data for the years 2000 to 2002 revealed that the dizygotic twin rate in South Korea increased almost threefold between 1981 to 1991 and 2002. In the 1980s the effect of maternal age on twinning rates appeared to be minimal. In the 1990s, however, increases in twinning rates occurred more markedly among older mothers than among younger mothers. We speculate that the rapid rise in twinning rates in South Korea in the 1990s is probably attributable to the spread of Assisted Reproductive Technologies among older mothers who seek treatments for infertility. The present study also examined whether residing in industrial areas is associated with multiple births in the South Korean population. The results did not support the recent finding of higher twinning incidence in industrialized regions.
Although a number of functional imaging studies are in agreement in suggesting orbitofrontal and subcortical hyperfunction in the pathophysiology of obsessive–compulsive disorder (OCD), the structural findings have been contradictory.
To investigate grey matter abnormalities in patients with OCD by employing a novel voxel-based analysis of magnetic resonance images.
Statistical parametric mapping was utilised to compare segmented grey matter images from 25 patients with OCD with those from 25 matched controls.
Increased regional grey matter density was found in multiple cortical areas, including the left orbitofrontal cortex, and in subcortical areas, including the thalamus. On the other hand, regions of reduction were confined to posterior parts of the brain, such as the left cuneus and the left cerebellum.
Increased grey matter density of frontal–subcortical circuits, consonant with the hypermetabolic findings from functional imaging studies, seems to exist in patients with OCD, and cerebellar dysfunction may be involved in the pathophysiology of OCD.
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