Research progress of brain magnetic resonance imaging related to suicide in bipolar disorder patients

Bipolar disorder, as a major mental illness, has a high lifetime suicide attempt rate in patients, and suicidal behavior is most likely to occur during depressive episodes. Therefore, in-depth study of its mechanism is essential for prevention, early detection and intervention of suicide. With the development of magnetic resonance imaging (MRI) technology, it has been found that there are abnormalities in the brain structure and function in suicidal patients with bipolar disorder. This article reviews the studies on suicide in bipolar disorder patients by MRI from four aspects: structure, function, structure-function, and central metabolism and cerebral blood flow perfusion, and summarizes the suicide-related changes. This review focuses on distinguishing the brain MRI changes under different mood states and diverse definitions of suicide, aiming to provide reference for further exploration of the pathophysiological mechanism of suicide in bipolar disorder

Altered brain network modules induce helplessness in major depressive disorder

The abnormal brain functional connectivity (FC) has been assumed to be a pathophysiological aspect of major depressive disorder (MDD). However, it is poorly understood, regarding the underlying patterns of global FC network and their relationships with the clinical characteristics of MDD

Aberrant neural activity in patients with bipolar depressive disorder distinguishing to the unipolar depressive disorder: a resting-state functional magnetic resonance imaging study

This study aims to explore the intrinsic patterns of spontaneous activity of bipolar depression (BD) patients by analyzing the fractional amplitude of low frequency fluctuation (fALFF) that help differentiate BD from unipolar depressive disorder(UD). Twenty eight patients with BD, 47 patients with UD and 29 healthy controls were enrolled to receive the resting-state functional magnetic resonance imaging (rs-fMRI) scans. The group differences of fALFF values were calculated among three groups. In addition, the correlations between the clinical variables and mfALFF values were estimated. The brain regions with activation discrepancies among three groups are located in precuneus, the left middle temporal gyrus (MTG) and left inferior parietal lobe (IPL) and lingual gyrus. Compared with HC group, BD group shows decreased fALFF in precuneus, the left IPL and increased fALFF in lingual gyrus remarkably; UD group shows significantly decreased fALFF in precuneus, the left MTG and the left IPL. On the contrast of patients with UD, patients with BD have significantly increased fALFF value in the left precuneus, the left MGT and lingual gyrus. Furthermore, a negative correlation is found between the mfALFF values in precuneus and the scores of cognitive impairment factor in the UD group. The similar pattern of intrinsic activity in PCC suggests depressive state-dependent change. The aberrant patterns of intrinsic activity in precuneus, the IPL and lingual gyrus might be provide quantitative nodes that help to conduct further study for better distinguishing between BD and UD

Correction: Surface Vulnerability of Cerebral Cortex to Major Depressive Disorder

Major depressive disorder (MDD) is accompanied by atypical brain structure. This study first presents the alterations in the cortical surface of patients with MDD using multidimensional structural patterns that reflect different neurodevelopment. Sixteen first-episode, untreated patients with MDD and 16 matched healthy controls underwent a magnetic resonance imaging (MRI) scan. The cortical maps of thickness, surface area, and gyrification were examined using the surface-based morphometry (SBM) approach. Increase of cortical thickness was observed in the right posterior cingulate region and the parietal cortex involving the bilateral inferior, left superior parietal and right paracentral regions, while decreased thickness was noted in the parietal cortex including bilateral pars opercularis and left precentral region, as well as the left rostral-middle frontal regions in patients with MDD. Likewise, increased or decreased surface area was found in five sub-regions of the cingulate gyrus, parietal and frontal cortices (e.g., bilateral inferior parietal and superior frontal regions). In addition, MDD patients exhibited a significant hypergyrification in the right precentral and supramarginal region. This integrated structural assessment of cortical surface suggests that MDD patients have cortical alterations of the frontal, parietal and cingulate regions, indicating a vulnerability to MDD during earlier neurodevelopmental process

Effects of tumor necrosis factor-α polymorphism on the brain structural changes of the patients with major depressive disorder

Single Nucleotide Polymorphic (SNP) variations of proinflammatory cytokines such as Tumor Necrosis Factor-α (TNF-α) have been reported to be closely associated with the major depressive disorder (MDD). However, it is unclear if proinflammatory genetic burden adversely affects the regional gray matter volume in patients with MDD. The aim of this study was to test whether rs1799724, an SNP of TNF-α, contributes to the neuroanatomical changes in MDD. In this cross-sectional study, a total of 144 MDD patients and 111 healthy controls (HC) well matched for age, sex and education were recruited from Shanghai Mental Health Center. Voxel-based morphometry (VBM) followed by graph theory based structural covariance analysis was applied to locate diagnosis x genotype interactions. Irrespective of diagnosis, individuals with the high-risk genotype (T-carriers) had reduced volume in left angular gyrus (main effect of genotype). Diagnosis x genotype interaction was exclusively localized to the visual cortex (right superior occipital gyrus). The same region also showed reduced volume in patients with MDD than HC (main effect of diagnosis), with this effect being most pronounced in patients carrying the high-risk genotype. However, neither global nor regional network of structural covariance was found to have group difference. In conclusion, a genetic variation which can increase TNF-α expression selectively affects the anatomy of the visual cortex among the depressed subjects, with no effect on the topographical organization of multiple cortical regions. This supports the notion that anatomical changes in depression are in part influenced by the genetic determinants of inflammatory activity

The Metabolic Factor Kynurenic Acid of Kynurenine Pathway Predicts Major Depressive Disorder

Background: Metabolic factors in the kynurenine pathway (KP) have been widely accepted as being a major mechanism in Major Depressive Disorder (MDD). However, the effects of these metabolites on the degree and pattern of MDD are still poorly understood, partly due to the elusiveness of the level of metabolites when diagnosing depression. This study aimed to explore a novel diagnostic method analyzing peripheral blood with mass spectrometry to assess metabolites from KP in patients with MDD and Bipolar Depression (BD).Methods: Thirty-three patients with MDD, 20 patients with BD, and 23 healthy control participants were enrolled Metabolic factors of KP from plasma including tryptophan (TRP), kynurenine (KYN), kynurenic acid (KYNA), and quinolinic acid (QUIN) were analyzed by UPLC-3Q-MS, and levels compared across three groups. Correlation between HAMD scores and metabolite levels conducted. Receiver operating characteristic (ROC) curve was used to determine the diagnostic value of metabolic factors in MDD.Results: Levels of KYNA, QUIN, KYNA/QUIN, and KYNA/KYN were statistically different across the three groups (P < 0.05); HAMD scores and TRP, KYN, KYNA/QUIN levels were negatively correlated in the MDD group (r = −0.633, −0.477, −0.418, P < 0.05); Accuracy of KYNA diagnosing MDD was 82.5% with the optimal diagnostic value being 15.48 ng/ml. Diagnostic accuracy was increased to 83.6% when KYNA and QUIN levels were used in combination.Conclusion: This results indicate that metabolic factors of KP play a crucial role in the occurrence and development of MDD, supporting the metabolic imbalance hypothesis of MDD. Furthermore, our study also provides a new diagnostic method to study MDD based on plasma KYNA level, and suggests that KYNA would be a potential biomarker in diagnosing depression patients

Study on Motion and Deposition of Nanoparticles in Rotary MOCVD Reactors of Gallium Nitride

Nanoparticles have a negative effect on the preparation of Gallium Nitride (GaN) by Metal-Organic Chemical Vapor Deposition (MOCVD). We developed a particle tracking and particle-wall collision model coupled with the bulk gas flow solver to investigate the motion and deposition of nanoparticles in single-wafer and multi-wafer reactors. The results indicated that for the single-wafer reactor, there is no particle deposition on the reactor wall and susceptor, but there is the endless movement of some particles within the reactor, which should be avoided. For the multi-wafer reactors, some of the nanoparticles are deposited near the axis, and those whose initial position is beyond a certain position from the axis are trapped in a vortex above the receptor, resulting in more complex by-products, although no particles are trapped in endless motion. Moreover, the effects of the rotational speed of the susceptor on the deposition rate for both the single-wafer reactor and the multi-wafer reactor were also simulated and analyzed

Does practice make perfect? Results from a Chinese feasibility study of cognitive remediation in schizophrenia

Patients with schizophrenia often receive little by way of non-pharmacological interventions. Despite this, promising outcomes in programmes targeting cognitive deficits have been reported, suggesting that this is an area worthy of further investigation. The aim of the study was to implement and evaluate a brief computerised cognitive remediation programme designed to improve memory and attention in a male Chinese sample with chronic schizophrenia. Pre-testing was completed on a number of clinical and cognitive measures for intervention (n = 14) and treatment as usual (n = 17) participants. The intervention group then completed six weeks ( x no. of sessions = 12.78) of the computer-based cognitive remediation programme. Post-test measures for both groups were then collected again. Following the six week intervention, we found, contrary to our expectations, the intervention group improved on several of the clinical variables. The intervention group also performed better than the control group on the post-test measure of attention, but not verbal memory. These findings suggest that it is feasible to improve some aspects of cognitive abilities with a simple computerised training programme for people with serious mental illness

Potential mechanisms of non-suicidal self-injury (NSSI) in major depressive disorder: a systematic review

Background Non-suicidal self-injury (NSSI) is a frequent and prominent phenomenon in major depressive disorder (MDD). Even though its prevalence and risk factors are relatively well understood, the potential mechanisms of NSSI in MDD remain elusive.Aims To review present evidence related to the potential mechanisms of NSSI in MDD.Methods According to Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines, articles for this systematic review were searched on Medline (through PubMed), Embase (through Elsevier), PsycINFO (through OVID) and Web of Science databases for English articles, as well as China National Knowledge Infrastructure (CNKI), SinoMed, Wanfang Data, and the Chongqing VIP Chinese Science and Technology Periodical (VIP) Databases for Chinese articles published from the date of inception to 2 August 2022. Two researchers (BW, HZ) independently screened studies based on inclusion and exclusion criteria and assessed their quality.Results A total of 25 157 studies were searched. Only 25 of them were ultimately included, containing 3336 subjects (1535 patients with MDD and NSSI, 1403 patients with MDD without NSSI and 398 HCs). Included studies were divided into 6 categories: psychosocial factors (11 studies), neuroimaging (8 studies), stress and hypothalamic-pituitary-adrenal (HPA) axis (2 studies), pain perception (1 study), electroencephalogram (EEG) (2 studies) and epigenetics (1 study).Conclusions This systematic review indicates that patients with MDD and NSSI might have specific psychosocial factors, aberrant brain functions and neurochemical metabolisms, HPA axis dysfunctions, abnormal pain perceptions and epigenetic alterations