Neural correlates of dysfunctional emotion regulation in major depressive disorder. A systematic review of neuroimaging studies

Mood and physiological effects of visual stimulation with images of the natural environment in individuals with depressive and anxiety disorders

BACKGROUND

Nature therapies are gaining attention as non-pharmacological treatments for depressive and anxiety disorders, but research on their effectiveness in patients is limited. This study investigates the mood-improving effects of visual stimulation with natural environmental images in patients with depressive and anxiety disorders.

METHODS

We conducted a randomized crossover comparison trial involving 60 right-handed adult participants with depressive or anxiety disorders and receiving outpatient treatment. Visual stimuli of natural environments consisted of green-themed nature images, while the control stimuli featured urban scenes dominated by buildings. The stimulation lasted for 3 min, during which orbital prefrontal brain activity was measured using a 2-channel Near-infrared Spectroscopy (NIRS) system, and heart rate variability was assessed using fingertip accelerated plethysmography.

RESULTS

Mood enhancement effects were observed in both the depressive and anxiety disorder groups following visual stimulation with nature images. In the depression group, orbital prefrontal oxygenated hemoglobin concentration significantly increased after visual stimulation with nature images, while there were no significant changes in the anxiety group. However, in the anxiety group, a correlation was found between reduced orbital prefrontal oxygenated hemoglobin in response to nature images and increased mood-enhancement. Furthermore, the severity of depressive symptoms did not significantly affect the intervention effects, whereas heightened anxiety symptoms was associated with a smaller mood enhancement effect.

DISCUSSION

Our study demonstrates the benefits of nature image stimulation for patients with depressive and anxiety disorders. Differential orbital prefrontal brain activity impacts notwithstanding, both conditions exhibited mood enhancement, affirming the value of nature image stimulation.

Sex differences in aberrant functional connectivity of three core networks and subcortical networks in medication-free adolescent-onset major depressive disorder

Major depressive disorder demonstrated sex differences in prevalence and symptoms, which were more pronounced during adolescence. Yet, research on sex-specific brain network characteristics in adolescent-onset major depressive disorder remains limited. This study investigated sex-specific and nonspecific alterations in resting-state functional connectivity of three core networks (frontoparietal network, salience network, and default mode network) and subcortical networks in adolescent-onset major depressive disorder, using seed-based resting-state functional connectivity in 50 medication-free patients with adolescent-onset major depressive disorder and 56 healthy controls. Irrespective of sex, compared with healthy controls, adolescent-onset major depressive disorder patients showed hypoconnectivity between bilateral hippocampus and right superior temporal gyrus (default mode network). More importantly, we further found that females with adolescent-onset major depressive disorder exhibited hypoconnectivity within the default mode network (medial prefrontal cortex), and between the subcortical regions (i.e. amygdala, striatum, and thalamus) with the default mode network (angular gyrus and posterior cingulate cortex) and the frontoparietal network (dorsal prefrontal cortex), while the opposite patterns of resting-state functional connectivity alterations were observed in males with adolescent-onset major depressive disorder, relative to their sex-matched healthy controls. Moreover, several sex-specific resting-state functional connectivity changes were correlated with age of onset, sleep disturbance, and anxiety in adolescent-onset major depressive disorder with different sex. These findings suggested that these sex-specific resting-state functional connectivity alterations may reflect the differences in brain development or processes related to early illness onset, underscoring the necessity for sex-tailored diagnostic and therapeutic approaches in adolescent-onset major depressive disorder.

Shared and distinct prefrontal cortex alterations of implicit emotion regulation in depression and anxiety: An fNIRS investigation

BACKGROUND

Emotion regulation deficits, particularly in cognitive reappraisal, are crucial in depression and anxiety. However, research on the neural mechanisms of implicit emotion regulation is lacking, and it remains unclear whether these mechanisms are shared or distinct between the two disorders.

METHODS

We investigated the neural mechanisms of implicit cognitive reappraisal in 28 individuals with major depressive disorder (MDD), 25 with generalized anxiety disorder (GAD), and 30 healthy controls (HC) using functional near-infrared spectroscopy (fNIRS). Participants completed an implicit cognitive reappraisal task and underwent neuropsychological and clinical assessments.

RESULTS

We found that MDD patients reported higher levels of rumination and lower utilization of cognitive reappraisal, while GAD patients reported reduced use of perspective-taking. Notably, both MDD and GAD patients exhibited decreased activation in the dorsolateral prefrontal cortex (DLPFC) and orbitofrontal cortex (OFC) compared to HC participants during implicit cognitive reappraisal. Specifically, inadequate OFC activation was observed in MDD patients, while GAD patients demonstrated OFC deactivation during the task. Furthermore, DLPFC activation showed a negative correlation with depression severity in MDD patients, while OFC activation was positively correlated with perspective-taking in GAD patients.

LIMITATIONS

fNIRS has limited depth and spatial resolution.

CONCLUSION

Our fNIRS study is the first to reveal shared and distinct neurobiological profiles of depression and anxiety in implicit emotion regulation. These findings underscore the significance of reduced DLPFC/OFC activation in emotion regulation impairment and highlight unique OFC activation patterns in these disorders. These insights have potential implications for developing cognitive-behavioral therapy and transcranial magnetic stimulation as treatment approaches.

EEG based functional connectivity in resting and emotional states may identify major depressive disorder using machine learning

OBJECTIVE

Disrupted brain network connectivity underlies major depressive disorder (MDD). Altered EEG based Functional connectivity (FC) with Emotional stimuli in major depressive disorder (MDD) in addition to resting state FC may help in improving the diagnostic accuracy of machine learning classification models. We explored the potential of EEG-based FC during resting state and emotional processing, for diagnosing MDD using machine learning approach.

METHODS

EEG was recorded during resting state and while watching emotionally contagious happy and sad videos in 24 drug-naïve MDD patients and 25 healthy controls. FC was quantified using the Phase Lag Index. Three Random Forest classifier models were constructed to classify MDD patients and healthy controls, Model-I incorporating FC features from the resting state and Model-II and Model-III incorporating FC features while watching happy and sad videos respectively.

RESULTS

Important features distinguishing MDD and healthy controls were from all frequency bands and represent functional connectivity between fronto-temporal, fronto-parietal and fronto occipital regions. The cross-validation accuracies for Model-I, Model-II and Model-III were 92.3%, 94.9% and 89.7% and test accuracies were 60%, 80% and 70% respectively. Incorporating emotionally contagious videos improved the classification accuracies.

CONCLUSION

Findings support EEG FC patterns during resting state and emotional processing along with machine learning can be used to diagnose MDD. Future research should focus on replicating and validating these results.

SIGNIFICANCE

EEG FC pattern combined with machine learning may be used for assisting in diagnosing MDD.

FlexDTI: flexible diffusion gradient encoding scheme-based highly efficient diffusion tensor imaging using deep learning

Objective. Most deep neural network-based diffusion tensor imaging methods require the diffusion gradients' number and directions in the data to be reconstructed to match those in the training data. This work aims to develop and evaluate a novel dynamic-convolution-based method called FlexDTI for highly efficient diffusion tensor reconstruction with flexible diffusion encoding gradient scheme.Approach. FlexDTI was developed to achieve high-quality DTI parametric mapping with flexible number and directions of diffusion encoding gradients. The method used dynamic convolution kernels to embed diffusion gradient direction information into feature maps of the corresponding diffusion signal. Furthermore, it realized the generalization of a flexible number of diffusion gradient directions by setting the maximum number of input channels of the network. The network was trained and tested using datasets from the Human Connectome Project and local hospitals. Results from FlexDTI and other advanced tensor parameter estimation methods were compared.Main results. Compared to other methods, FlexDTI successfully achieves high-quality diffusion tensor-derived parameters even if the number and directions of diffusion encoding gradients change. It reduces normalized root mean squared error by about 50% on fractional anisotropy and 15% on mean diffusivity, compared with the state-of-the-art deep learning method with flexible diffusion encoding gradient scheme.Significance. FlexDTI can well learn diffusion gradient direction information to achieve generalized DTI reconstruction with flexible diffusion gradient scheme. Both flexibility and reconstruction quality can be taken into account in this network.

Spectral Graph Neural Network-Based Multi-Atlas Brain Network Fusion for Major Depressive Disorder Diagnosis

Major Depressive Disorder (MDD) imposes a substantial burden within the healthcare domain, impacting millions of individuals worldwide. Functional Magnetic Resonance Imaging (fMRI) has emerged as a promising tool for the objective diagnosis of MDD, enabling the investigation of functional connectivity patterns in the brain associated with this disorder. However, most existing methods focus on a single brain atlas, which limits their ability to capture the complex, multi-scale nature of functional brain networks. To address these limitations, we propose a novel multi-atlas fusion method that incorporates early and late fusion in a unified framework. Our method introduces the concept of the holistic Functional Connectivity Network (FCN), which captures both intra-atlas relationships within individual atlases and inter-regional relationships between atlases with different brain parcellation scales. This comprehensive representation enables the identification of potential disease-related patterns associated with MDD in the early stage of our framework. Moreover, by decoding the holistic FCN from various perspectives through multiple spectral Graph Convolutional Neural Networks and fusing their results with decision-level ensembles, we further improve the performance of MDD diagnosis. Our approach is easily implemented with minimal modifications to existing model structures and demonstrates a robust performance across different baseline models. Our method, evaluated on public resting-state fMRI datasets, surpasses the current multi-atlas fusion methods, enhancing the accuracy of MDD diagnosis. The proposed novel multi-atlas fusion framework provides a more reliable MDD diagnostic technique. Experimental results show our approach outperforms both single- and multi-atlas-based methods, demonstrating its effectiveness in advancing MDD diagnosis.

Disrupted limbic-prefrontal effective connectivity in response to fearful faces in lifetime depression

BACKGROUND

Multiple brain imaging studies of negative emotional bias in major depressive disorder (MDD) have used images of fearful facial expressions and focused on the amygdala and the prefrontal cortex. The results have, however, been inconsistent, potentially due to small sample sizes (typically N<50). It remains unclear if any alterations are a characteristic of current depression or of past experience of depression, and whether there are MDD-related changes in effective connectivity between the two brain regions.

METHODS

Activations and effective connectivity between the amygdala and dorsolateral prefrontal cortex (DLPFC) in response to fearful face stimuli were studied in a large population-based sample from Generation Scotland. Participants either had no history of MDD (N=664 in activation analyses, N=474 in connectivity analyses) or had a diagnosis of MDD during their lifetime (LMDD, N=290 in activation analyses, N=214 in connectivity analyses). The within-scanner task involved implicit facial emotion processing of neutral and fearful faces.

RESULTS

Compared to controls, LMDD was associated with increased activations in left amygdala (PFWE=0.031,kE=4) and left DLPFC (PFWE=0.002,kE=33), increased mean bilateral amygdala activation (β=0.0715,P=0.0314), and increased inhibition from left amygdala to left DLPFC, all in response to fearful faces contrasted to baseline. Results did not appear to be attributable to depressive illness severity or antidepressant medication status at scan time.

LIMITATIONS

Most studied participants had past rather than current depression, average severity of ongoing depression symptoms was low, and a substantial proportion of participants were receiving medication. The study was not longitudinal and the participants were only assessed a single time.

CONCLUSIONS

LMDD is associated with hyperactivity of the amygdala and DLPFC, and with stronger amygdala to DLPFC inhibitory connectivity, all in response to fearful faces, unrelated to depression severity at scan time. These results help reduce inconsistency in past literature and suggest disruption of 'bottom-up' limbic-prefrontal effective connectivity in depression.

Enhancing ventrolateral prefrontal cortex activation mitigates social pain and modifies subsequent social attitudes: Insights from TMS and fMRI

Social pain, a multifaceted emotional response triggered by interpersonal rejection or criticism, profoundly impacts mental well-being and social interactions. While prior research has implicated the right ventrolateral prefrontal cortex (rVLPFC) in mitigating social pain, the precise neural mechanisms and downstream effects on subsequent social attitudes remain elusive. This study employed transcranial magnetic stimulation (TMS) integrated with fMRI recordings during a social pain task to elucidate these aspects. Eighty participants underwent either active TMS targeting the rVLPFC (n = 41) or control stimulation at the vertex (n = 39). Our results revealed that TMS-induced rVLPFC facilitation significantly reduced self-reported social pain, confirming the causal role of the rVLPFC in social pain relief. Functional connectivity analyses demonstrated enhanced interactions between the rVLPFC and the dorsolateral prefrontal cortex, emphasizing the collaborative engagement of prefrontal regions in emotion regulation. Significantly, we observed that negative social feedback led to negative social attitudes, whereas rVLPFC activation countered this detrimental effect, showcasing the potential of the rVLPFC as a protective buffer against adverse social interactions. Moreover, our study uncovered the impact role of the hippocampus in subsequent social attitudes, a relationship particularly pronounced during excitatory TMS over the rVLPFC. These findings offer promising avenues for improving mental health within the intricate dynamics of social interactions. By advancing our comprehension of the neural mechanisms underlying social pain relief, this research introduces novel intervention strategies for individuals grappling with social distress. Empowering individuals to modulate rVLPFC activation may facilitate reshaping social attitudes and successful reintegration into communal life.

Change in brain activation after transcranial pulsed electromagnetic fields in treatment-resistant depression

BACKGROUND

Preliminary evidence suggests antidepressant effects of transcranial pulsed electromagnetic fields (tPEMF). However, the precise mechanism of action in the brain is still unknown. The aim of this study was to investigate the influence of tPEMF on brain activation in patients with treatment-resistant depression (TRD) by studying two processes that might be of particular interest in relation to the symptoms of depression: emotional processing and reward processing.

METHODS

Eligible participants (n = 50) with TRD in this sham-controlled double-blind multicenter trial [registered at the Dutch Trial Register ( http://www.trialregister.nl ), NTR3702] were randomly assigned to five weeks daily active or sham tPEMF. Pre- and post-treatment functional MR-scans were made during which participants performed a social-emotional task and a reward task.

RESULTS

Participants in the active treatment group showed a stronger decrease in activation post-treatment compared to sham during reward-outcome processing in the left inferior frontal gyrus and in a cluster comprising the right lingual gyrus and the posterior part of the middle temporal gyrus. No effect of tPEMF was found on activation during the social-emotional task. Neurostimulation with tPEMF did also not affect behavioral performance for both tasks.

CONCLUSIONS

We found a decrease in reward-related activation as a result of tPEMF stimulation, while no effect of tPEMF on social-emotional processing was found. The treatment-related reduction in activation of regulatory regions may reflect normalization and may have implications for anhedonia. These findings suggest that there is an effect of tPEMF on brain activation of relevant circuits, albeit in the absence of a clinical antidepressant effect.

One size does not fit all: notable individual variation in brain activity correlates of antidepressant treatment response

Introduction

To date, no robust electroencephalography (EEG) markers of antidepressant treatment response have been identified. Variable findings may arise from the use of group analyses, which neglect individual variation. Using a combination of group and single-participant analyses, we explored individual variability in EEG characteristics of treatment response.

Methods

Resting-state EEG data and Montgomery-Åsberg Depression Rating Scale (MADRS) symptom scores were collected from 43 patients with depression before, at 1 and 12 weeks of pharmacotherapy. Partial least squares (PLS) was used to: 1) identify group differences in EEG connectivity (weighted phase lag index) and complexity (multiscale entropy) between eventual medication responders and non-responders, and 2) determine whether group patterns could be identified in individual patients.

Results

Responders showed decreased alpha and increased beta connectivity, and early, widespread decreases in complexity over treatment. Non-responders showed an opposite connectivity pattern, and later, spatially confined decreases in complexity. Thus, as in previous studies, our group analyses identified significant differences between groups of patients with different treatment outcomes. These group-level EEG characteristics were only identified in ~40-60% of individual patients, as assessed quantitatively by correlating the spatiotemporal brain patterns between groups and individual results, and by independent raters through visualization.

Discussion

Our single-participant analyses suggest that substantial individual variation exists, and needs to be considered when investigating characteristics of antidepressant treatment response for potential clinical applicability.

Clinical trial registration

https://clinicaltrials.gov, identifier NCT00519428.

Distinctive intrinsic functional connectivity alterations of anterior cingulate cortex subdivisions in major depressive disorder: A systematic review and meta-analysis

Evidence of whether the intrinsic functional connectivity of anterior cingulate cortex (ACC) and its subregions is altered in major depressive disorder (MDD) remains inconclusive. A systematic review and meta-analysis were therefore performed on the whole-brain resting-state functional connectivity (rsFC) studies using the ACC and its subregions as seed regions in MDD, in order to draw more reliable conclusions. Forty-four ACC-based rsFC studies were included, comprising 25 subgenual ACC-based studies, 11 pregenual ACC-based studies, and 17 dorsal ACC-based studies. Specific alterations of rsFC were identified for each ACC subregion in patients with MDD, with altered rsFC of subgenual ACC in emotion-related brain regions, of pregenual ACC in sensorimotor-related regions, and of dorsal ACC in cognition-related regions. Furthermore, meta-regression analysis revealed a significant negative correlation between the pgACC-caudate hypoconnectivity and percentage of female patients in the study cohort. This meta-analysis provides robust evidence of altered intrinsic functional connectivity of the ACC subregions in MDD, which may hold relevance to understanding the origin of, and treating, the emotional, sensorimotor and cognitive dysfunctions that are often observed in these patients.

Distinct MRI-based functional and structural connectivity for antidepressant response prediction in major depressive disorder

OBJECTIVE

Emerging studies have identified treatment-related connectome predictors in major depressive disorder (MDD). However, quantifying treatment-responsive patterns in structural connectivity (SC) and functional connectivity (FC) simultaneously remains underexplored. We aimed to evaluate whether spatial distributions of FC and SC associated treatment responses are shared or unique.

METHODS

Diffusion tensor imaging and resting-state functional magnetic resonance imaging were collected from 210 patients with MDD at baseline. We separately developed connectome-based prediction models (CPM) to predict reduction of depressive severity after 6-week monotherapy based on structural, functional, and combined connectomes, then validated them on the external dataset. We identified the predictive SC and FC from CPM with high occurrence frequencies during the cross-validation.

RESULTS

Structural connectomes (r = 0.2857, p < 0.0001), functional connectomes (r = 0.2057, p = 0.0025), and their combined CPM (r = 0.4, p < 0.0001) can significantly predict a reduction of depressive severity. We didn't find shared connectivity between predictive FC and SC. Specifically, the most predictive FC stemmed from the default mode network, while predictive SC was mainly characterized by within-network SC of fronto-limbic networks.

CONCLUSIONS

These distinct patterns suggest that SC and FC capture unique connectivity concerning the antidepressant response.

SIGNIFICANCE

Our findings provide comprehensive insights into the neurophysiology of antidepressants response.

A potential brain functional biomarker distinguishing patients with Crohn's disease with different disease stages: a resting-state fMRI study

Background

The previous studies have demonstrated that patients with Crohn's disease in remission (CD-R) have abnormal alterations in brain function. However, whether brain function changes in patients with Crohn's disease in activity (CD-A) and the relationship with CD-R are still unclear. In this study, we aimed to investigate whether the different levels of disease activity may differentially affect the brain function and to find the brain functional biomarker distinguishing patients with different disease stages by measuring the amplitude of low frequency fluctuations (ALFF).

Methods

121 patients with CD and 91 healthy controls (HCs) were recruited. The clinical and psychological assessment of participants were collected. The criteria for the disease activity were the Crohn's disease activity index (CDAI) scores. CD-R refers to CD patients in remission which the CDAI score is less than 150. Conversely, CD-A refers to CD patients in activity which the CDAI score is ≥150. The ALFF was compared among three groups by performing one-way analysis of variance, followed by a post hoc two-sample t-test. Differences among the groups were selected as seeds for functional connectivity analyses. We also investigated the correlation among clinical, psychological scores and ALFF. Binary logistic regression analysis was used to examine the unique contribution of the ALFF characteristics of the disease stages.

Results

There were widespread differences of ALFF values among the 3 groups, which included left frontal pole (FP_L), right supramarginal gyrus (SG_R), left angular gyrus (AG_L), right cingulate gyrus (CG_R), right intracalcarine cortex (IC_R), right parahippocampal gyrus (PG_R), right lingual gyrus (LG_R), right precuneous cortex (PC_R), left occipital fusiform gyrus (OFG_L). Significant brain regions showing the functional connections (FC) increased in FP_L, SG_R, PC_R and OFG_L between CD-A and HCs. The erythrocyte sedimentation rate had a negative correlation with the ALFF values in PC_R in the patients with CD. The phobic anxiety values had a negative correlation with the ALFF values in OFG_L. The psychoticism values had a negative correlation with ALFF values in the IC_R. And the hostility values had a positive correlation with the ALFF values in CG_R. Significant brain regions showing the FC increased in FP_L, SG_R, CG_R, PG_R, LG_R and OFG_L between CD-R and HCs. In binary logistic regression models, the LG_R (beta = 5.138, p = 0.031), PC_R (beta = 1.876, p = 0.002) and OFG_L (beta = 3.937, p = 0.044) was disease stages predictors.

Conclusion

The results indicated the significance of the altered brain activity in the different disease stages of CD. Therefore, these findings present a potential identify neuroimaging-based brain functional biomarker in CD. Additionally, the study provides a better understanding of the pathophysiology of CD.

Influence of PCDH9 (rs9540720) and narcissistic personality traits on the incidence of major depressive disorder in Chinese first-year university students: findings from a 2-year cohort study

Objective: The objective of this study was to explore the influence of the polymorphism of the protocadherin 9 (PCDH9) gene and the narcissistic personality trait (NPT) on the risk of major depressive disorder (MDD) in Chinese first-year university students. Methods: A 2-year cohort study was conducted among Chinese first-year university students who were enrolled in 2018 from two universities in Shandong Province, China. The snapshot technique was used to detect the genotypes of PCDH9 (rs9540720). The Chinese version of the Composite International Diagnostic Interview was used for the MDD assessment. The NPTs were measured by 11 items based on DSM-IV. Patient Health Questionnaire-9 and the Beck Anxiety Inventory were used to assess depressive and anxiety symptoms, respectively. Logistic regression modeling was carried out to examine the relationship between rs9540720, NPTs, and the incidence of MDD. Results: A total of 5,327 students participated in the baseline and follow-up studies and provided their blood samples. PCDH9 (rs9540720) (ORGG+GA = 2.33, 95% CI: 1.35-4.02) and NPTs (OR5-9 = 2.26, 95% CI: 1.40-3.64) increased the risk of MDD onset. There was no multiplicative interaction between NPTs and Rs9540720 (OR = 1.51, 95% CI: 0.30-7.63). Furthermore, there was no additive interaction between them (RERI = 2.40, 95% CI: -0.82-5.62; AP = 0.47, 95% CI: -0.04-0.97; and S = 2.37, 95% CI: 0.54-10.33). Conclusion: PCDH9 (rs9540720) and more NPTs are the risk factors for the incidence of MDD in Chinese first-year university students.

Major depressive disorder associated alterations in the effective connectivity of the face processing network: a systematic review

Major depressive disorder (MDD) is marked by altered processing of emotional stimuli, including facial expressions. Recent neuroimaging research has attempted to investigate how these stimuli alter the directional interactions between brain regions in those with MDD; however, methodological heterogeneity has made identifying consistent effects difficult. To address this, we systematically examined studies investigating MDD-associated differences present in effective connectivity during the processing of emotional facial expressions. We searched five databases: PsycINFO, EMBASE, PubMed, Scopus, and Web of Science, using a preregistered protocol (registration number: CRD42021271586). Of the 510 unique studies screened, 17 met our inclusion criteria. These studies identified that compared with healthy controls, participants with MDD demonstrated (1) reduced connectivity from the dorsolateral prefrontal cortex to the amygdala during the processing of negatively valenced expressions, and (2) increased inhibitory connectivity from the ventromedial prefrontal cortex to amygdala during the processing of happy facial expressions. Most studies investigating the amygdala and anterior cingulate cortex noted differences in their connectivity; however, the precise nature of these differences was inconsistent between studies. As such, commonalities observed across neuroimaging modalities warrant careful investigation to determine the specificity of these effects to particular subregions and emotional expressions. Future research examining longitudinal connectivity changes associated with treatment response may provide important insights into mechanisms underpinning therapeutic interventions, thus enabling more targeted treatment strategies.

Neural connectivity moderators and mechanisms of ketamine treatment among treatment-resistant depressed patients: a randomized controlled trial

BACKGROUND

Intravenous (IV) ketamine has emerged as a rapid and effective treatment for TRD. However, the specific neural mechanisms of ketamine's effects in humans remains unclear. Although neuroplasticity is implicated as a mechanism of action in animal models, relatively few randomized controlled trials (RCTs) in TRD patients have examined ketamine's impact on functional connectivity, a posited functional marker of neuroplasticity-particularly in the context of a mood-induction paradigm (termed miFC).

METHODS

152 adults with TRD (63% female; 37% male) were randomly allocated to receive a single infusion of ketamine or saline in a 2:1 ratio. We examined changes in connectivity (from baseline to 24-h post-infusion) that differed by treatment, and whether clinical treatment response at 24-h post-infusion was uniquely related (among patients allocated to ketamine relative to saline) to (1) pre-treatment connectivity and (2) changes in connectivity. We examined both miFC and rsFC, using prefrontal cortex and limbic seed regions. We also conducted a multiverse analysis to examine findings most robust against analytic decisions.

FINDINGS

Across both miFC and rsFC, ketamine was associated with greater in prefrontal/limbic connectivity compared to saline, and lower baseline connectivity of limbic and prefrontal regions predicted greater treatment response in patients receiving ketamine. Greater connectivity increases in participants receiving ketamine was uniquely related to greater treatment response. In addition, certain findings were identified as being reproducible against different analytic decisions in multiverse analyses.

INTERPRETATION

Our findings identify specific neural connectivity patterns impacted by ketamine and were uniquely related to outcomes following ketamine (relative to saline). These findings generally support prominent neuroplasticity models of ketamine's therapeutic efficacy. These findings lay new groundwork for understanding how to enhance and optimize ketamine treatments and develop novel rapid-acting treatments for depression.

FUNDING

This research was supported by NIH grant R01MH113857 and by the Clinical and Translational Sciences Institute at the University of Pittsburgh (UL1-TR-001857).

Electroencephalography findings in menstrually-related mood disorders: A critical review

The female reproductive years are characterized by fluctuations in ovarian hormones across the menstrual cycle, which have the potential to modulate neurophysiological and behavioral dynamics. Menstrually-related mood disorders (MRMDs) comprise cognitive-affective or somatic symptoms that are thought to be triggered by the rapid fluctuations in ovarian hormones in the luteal phase of the menstrual cycle. MRMDs include premenstrual syndrome (PMS), premenstrual dysphoric disorder (PMDD), and premenstrual exacerbation (PME) of other psychiatric disorders. Electroencephalography (EEG) non-invasively records in vivo synchronous activity from populations of neurons with high temporal resolution. The present overview sought to systematically review the current state of task-related and resting-state EEG investigations on MRMDs. Preliminary evidence indicates lower alpha asymmetry at rest being associated with MRMDs, while one study points to the effect being luteal-phase specific. Moreover, higher luteal spontaneous frontal brain activity (slow/fast wave ratio as measured by the delta/beta power ratio) has been observed in persons with MRMDs, while sleep architecture results point to potential circadian rhythm disturbances. In this review, we discuss the quality of study designs as well as future perspectives and challenges of supplementing the diagnostic and scientific toolbox for MRMDs with EEG.

Reviewing the neurobiology of electroconvulsive therapy on a micro- meso- and macro-level

BACKGROUND

Electroconvulsive therapy (ECT) remains the one of the most effective of biological antidepressant interventions. However, the exact neurobiological mechanisms underlying the efficacy of ECT remain unclear. A gap in the literature is the lack of multimodal research that attempts to integrate findings at different biological levels of analysis METHODS: We searched the PubMed database for relevant studies. We review biological studies of ECT in depression on a micro- (molecular), meso- (structural) and macro- (network) level.

RESULTS

ECT impacts both peripheral and central inflammatory processes, triggers neuroplastic mechanisms and modulates large scale neural network connectivity.

CONCLUSIONS

Integrating this vast body of existing evidence, we are tempted to speculate that ECT may have neuroplastic effects resulting in the modulation of connectivity between and among specific large-scale networks that are altered in depression. These effects could be mediated by the immunomodulatory properties of the treatment. A better understanding of the complex interactions between the micro-, meso- and macro- level might further specify the mechanisms of action of ECT.

Loneliness is related to smaller gray matter volumes in ACC and right VLPFC in people with major depression: a UK biobank study

The anterior cingulate cortex (ACC) and right ventrolateral prefrontal cortex (VLPFC) are thought to have important roles in loneliness (feeling of social isolation/exclusion) experience or regulation and in the pathophysiology of their disturbance in major depressive disorder (MDD). However, the structural abnormalities of these regions and the correlates with loneliness in MDD across the healthy population have not fully been clarified. The study analyzed the link between loneliness and gray matter volumes (GMVs) in the ACC and right VLPFC among 1,005 patients with MDD and 7,247 healthy controls (HCs) using UK Biobank data. Significant reductions in GMV in the right VLPFC were found in MDD males compared to HCs. MDD males also showed a higher association between loneliness and reduced GMVs in the right VLPFC and bilateral ACC than HCs. No such associations were found in MDD females. The findings suggest that loneliness may influence brain structures crucial for emotion experience and regulation, particularly in middle-older aged men with MDD. This highlights the potential adverse effects of loneliness on brain structure in MDD and suggests that social engagement could have a positive impact.

Volume changes of the subcortical limbic structures in major depressive disorder patients with and without anhedonia

Anhedonia is a core feature of major depressive disorder (MDD) and the limbic system has been indicated to be associated with anhedonia in MDD due to its crucial role within the reward circuit. However, the relationship between different regions of the limbic system and MDD, particularly anhedonic symptoms, remains unclear. Therefore, the purpose of this study was to investigate volume changes of various parts of the subcortical limbic (ScLimbic) system in MDD with and without anhedonia. A total of 120 individuals, including 30 MDD patients with anhedonia, 43 MDD patients without anhedonia, and 47 healthy controls (HCs) were enrolled in this study. All subjects underwent structural magnetic resonance imaging scans. After that, ScLimbic system segmentation was performed using the FreeSurfer pipeline ScLimbic. Analysis of covariance (ANCOVA) was performed to identify brain regions with significant volume differences among three groups, and then, post hoc tests were calculated for inter-group comparisons. Finally, correlations between volumes of different parts of the ScLimbic and clinical characteristics in MDD patients were further analyzed. The ANCOVA revealed significant volume differences of the ScLimbic system among three groups in the bilateral fornix (Fx), and the right basal forebrain (BF). As compared with HCs, both groups of MDD patients showed decreased volume in the right Fx, meanwhile, MDD patients with anhedonia further exhibited volume reductions in the left Fx and right BF. However, no significant difference was found between MDD patients with and without anhedonia. No significant association was observed between subregion volumes of the ScLimbic system and clinical features in MDD. The present findings demonstrated that MDD patients with and without anhedonia exhibited segregated brain structural alterations in the ScLimbic system and volume loss of the ScLimbic system might be fairly extensive in MDD patients with anhedonia.

Depression recurrence is accompanied by longer periods in default mode and more frequent attentional and reward processing dynamic brain-states during resting-state activity

Recurrence in major depressive disorder (MDD) is common, but neurobiological models capturing vulnerability for recurrences are scarce. Disturbances in multiple resting-state networks have been linked to MDD, but most approaches focus on stable (vs. dynamic) network characteristics. We investigated how the brain's dynamical repertoire changes after patients transition from remission to recurrence of a new depressive episode. Sixty two drug-free, MDD-patients with ≥2 episodes underwent a baseline resting-state fMRI scan when in remission. Over 30-months follow-up, 11 patients with a recurrence and 17 matched-remitted MDD-patients without a recurrence underwent a second fMRI scan. Recurrent patterns of functional connectivity were characterized by applying Leading Eigenvector Dynamics Analysis (LEiDA). Differences between baseline and follow-up were identified for the 11 non-remitted patients, while data from the 17 matched-remitted patients was used as a validation dataset. After the transition into a depressive state, basal ganglia-anterior cingulate cortex (ACC) and visuo-attentional networks were detected significantly more often, whereas default mode network activity was found to have a longer duration. Additionally, the fMRI signal in the basal ganglia-ACC areas underlying the reward network, were significantly less synchronized with the rest of the brain after recurrence (compared to a state of remission). No significant changes were observed in the matched-remitted patients who were scanned twice while in remission. These findings characterize changes that may be associated with the transition from remission to recurrence and provide initial evidence of altered dynamical exploration of the brain's repertoire of functional networks when a recurrent depressive episode occurs.

Aberrant degree centrality profiles during rumination in major depressive disorder

Rumination is closely linked to the onset and maintenance of major depressive disorder (MDD). Prior neuroimaging studies have identified the association between self-reported rumination trait and the functional coupling among a network of brain regions using resting-state functional magnetic resonance imaging (MRI). However, little is known about the underlying neural circuitry mechanism during active rumination in MDD. Degree centrality (DC) is a simple metric to denote network integration, which is critical for higher-order psychological processes such as rumination. During an MRI scan, individuals with MDD (N = 45) and healthy controls (HC, N = 46) completed a rumination state task. We examined the interaction effect between the group (MDD vs. HC) and condition (rumination vs. distraction) on vertex-wise DC. We further characterized the identified brain region's functional involvement with Neurosynth and BrainMap. Network-wise seed-based functional connectivity (FC) analysis was also conducted for the identified region of interest. Finally, exploratory correlation analysis was conducted between the identified region of interest's network FCs and self-reported in-scanner affect levels. We found that a left superior frontal gyrus (SFG) region, generally overlapped with the frontal eye field, showed a significant interaction effect. Further analysis revealed its involvement with executive functions. FCs between this region, the frontoparietal, and the dorsal attention network (DAN) also showed significant interaction effects. Furthermore, its FC to DAN during distraction showed a marginally significant negative association with in-scanner affect level at the baseline. Our results implicated an essential role of the left SFG in the rumination's underlying neural circuitry mechanism in MDD and provided novel evidence for the conceptualization of rumination in terms of impaired executive control.

Decreased cortical gyrification in major depressive disorder

BACKGROUND

Early neurodevelopmental deviations, such as abnormal cortical folding patterns, are candidate biomarkers of major depressive disorder (MDD). We aimed to investigate the association of MDD with the local gyrification index (LGI) in each cortical region at the whole-brain level, and the association of the LGI with clinical characteristics of MDD.

METHODS

We obtained T1-weighted images from 234 patients with MDD and 215 healthy controls (HCs). The LGI values from 66 cortical regions in the bilateral hemispheres were automatically calculated according to the Desikan-Killiany atlas. We compared the LGI values between the MDD and HC groups using analysis of covariance, including age, sex, and years of education as covariates. The association between the clinical characteristics and LGI values was investigated in the MDD group.

RESULTS

Compared with HCs, patients with MDD showed significantly decreased LGI values in the cortical regions, including the bilateral ventrolateral and dorsolateral prefrontal cortices, medial and lateral orbitofrontal cortices, insula, right rostral anterior cingulate cortex, and several temporal and parietal regions, with the largest effect size in the left pars triangularis (Cohen's f2 = 0.361; p = 1.78 × 10-13). Regarding the association of clinical characteristics with LGIs within the MDD group, recurrence and longer illness duration were associated with increased gyrification in several occipital and temporal regions, which showed no significant difference in LGIs between the MDD and HC groups.

CONCLUSIONS

These findings suggest that the LGI may be a relatively stable neuroimaging marker associated with MDD predisposition.

Functional MRI correlates of emotion regulation in major depressive disorder related to depressive disease load measured over nine years

Major Depressive Disorder (MDD) often is a recurrent and chronic disorder. We investigated the neurocognitive underpinnings of the incremental risk for poor disease course by exploring relations between enduring depression and brain functioning during regulation of negative and positive emotions using cognitive reappraisal. We used fMRI-data from the longitudinal Netherlands Study of Depression and Anxiety acquired during an emotion regulation task in 77 individuals with MDD. Task-related brain activity was related to disease load, calculated from presence and severity of depression in the preceding nine years. Additionally, we explored task related brain-connectivity. Brain functioning in individuals with MDD was further compared to 35 controls to explore overlap between load-effects and general effects related to MDD history/presence. Disease load was not associated with changes in affect or with brain activity, but with connectivity between areas essential for processing, integrating and regulating emotional information during downregulation of negative emotions. Results did not overlap with general MDD-effects. Instead, MDD was generally associated with lower parietal activity during downregulation of negative emotions. During upregulation of positive emotions, disease load was related to connectivity between limbic regions (although driven by symptomatic state), and connectivity between frontal, insular and thalamic regions was lower in MDD (vs controls). Results suggest that previous depressive load relates to brain connectivity in relevant networks during downregulation of negative emotions. These abnormalities do not overlap with disease-general abnormalities and could foster an incremental vulnerability to recurrence or chronicity of MDD. Therefore, optimizing emotion regulation is a promising therapeutic target for improving long-term MDD course.

GluCEST Imaging and Structural Alterations of the Bilateral Hippocampus in First-Episode and Early-Onset Major Depression Disorder

BACKGROUND

Glutamate dysregulation is one of the key pathogenic mechanisms of major depressive disorder (MDD), and glutamate chemical exchange saturation transfer (GluCEST) has been used for glutamate measurement in some brain diseases but rarely in depression.

PURPOSE

To investigate the GluCEST changes in hippocampus in MDD and the relationship between glutamate and hippocampal subregional volumes.

STUDY TYPE

Cross-sectional.

SUBJECTS

Thirty-two MDD patients (34% males; 22.03 ± 7.21 years) and 47 healthy controls (HCs) (43% males; 22.00 ± 3.28 years).

FIELD STRENGTH/SEQUENCE

3.0 T; magnetization prepared rapid gradient echo (MPRAGE) for three-dimensional T1-weighted images, two-dimensional turbo spin echo GluCEST, and multivoxel chemical shift imaging (CSI) for proton magnetic resonance spectroscopy (1 H MRS).

ASSESSMENT

GluCEST data were quantified by magnetization transfer ratio asymmetry (MTRasym ) analysis and assessed by the relative concentration of 1 H MRS-measured glutamate. FreeSurfer was used for hippocampus segmentation.

STATISTICAL TESTS

The independent sample t test, Mann-Whitney U test, Spearman's correlation, and partial correlation analysis were used. P < 0.05 was considered statistically significant.

RESULTS

In the left hippocampus, GluCEST values were significantly decreased in MDD (2.00 ± 1.08 [MDD] vs. 2.62 ± 1.41 [HCs]) and showed a significantly positive correlation with Glx/Cr (r = 0.37). GluCEST values were significantly positively correlated with the volumes of CA1 (r = 0.40), subiculum (r = 0.40) in the left hippocampus and CA1 (r = 0.51), molecular_layer_HP (r = 0.50), GC-ML-DG (r = 0.42), CA3 (r = 0.44), CA4 (r = 0.44), hippocampus-amygdala-transition-area (r = 0.46), and the whole hippocampus (r = 0.47) in the right hippocampus. Hamilton Depression Rating Scale scores showed significantly negative correlations with the volumes of the left presubiculum (r = -0.40), left parasubiculum (r = -0.47), and right presubiculum (r = -0.41).

DATA CONCLUSION

GluCEST can be used to measure glutamate changes and help to understand the mechanism of hippocampal volume loss in MDD. Hippocampal volume changes are associated with disease severity.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY: Stage 1.

Normative modeling analysis reveals corpus callosum volume changes in early and mid-to-late first episode major depression

BACKGROUND

It has been widely accepted that major depressive disorder (MDD) impacts brain structures including the Corpus Callosum (CC). However, this assumption is based on scarce literature data involving small sample sizes. Furthermore, it is still unclear whether such CC volume changes may already be present at a first depressive episode.

METHODS

To further investigate this question, we compared 369 first-episode MDD patients (mean age = 35 years (sd = 12), 249 females; 283 early onset, 86 mid-to-late onset) from the open-source REST meta-MDD database closely matched for age and gender to 490 never-depressed individuals (mean age = 37 years (sd = 14); 309 females) using Z-scores obtained from normative neuroanatomical modeling to assess individual variability in CC (sub)volumes.

RESULTS

Relative to the norms established by the healthy controls, first-episode MDD patients displayed CC volume (z-score) reductions in the entire CC (including the body), as did mid-to-late-onset first-episode MDD patients (age ≥ 45 y). In early-onset first-episode MDD patients (age ≤ 44 y), depression severity symptoms were related to volume increases in the entire CC, as well as the body and splenium.

LIMITATIONS

No data on depressive episode duration. Relatively small sample size for mid-to-late first-episode MDD patients.

CONCLUSIONS

Our data revealed CC (sub)volume differences in early versus mid-to-late onset first episode MDD. Especially at early onset, depression severity may result in neural white matter activity as potential reaction to stress influences. Our results underline the importance of prompt clinical interventions at early onset MDD.

Emotion regulation of social pain: double dissociation of lateral prefrontal cortices supporting reappraisal and distraction

The dorsolateral prefrontal cortex (DLPFC) and ventrolateral prefrontal cortex (VLPFC) are both crucial regions involved in voluntary emotion regulation. However, it remains unclear whether the two regions show functional specificity for reappraisal and distraction. This study employed transcranial magnetic stimulation (TMS) to explore, in a real social interactive scenario, whether different lateral prefrontal regions play relatively specific roles in downregulating social pain via reappraisal and distraction. Participants initially took part in a social interactive game, followed by receiving either active (the DLPFC- or VLPFC-activated group, n = 100 per group) or control (the vertex-activated group, n = 100) TMS session. They were then instructed to use both distraction and reappraisal strategies to downregulate any negative emotions evoked by the social evaluation given by their peers who interacted with them previously. Results demonstrated that the TMS-activated DLPFC has a greater beneficial effect during distraction, whereas the activated VLPFC has a greater beneficial effect during reappraisal. This result investigated the direct experience of social pain and extended previous findings on empathy-related responses to affective pictures while also controlling for confounding factors such as empathic concern. Therefore, we are now confident in the double dissociation proposal of the DLPFC and VLPFC in distraction and reappraisal.

Automatic Positive and Negative Emotion Regulation in Adolescents with Major Depressive Disorder

INTRODUCTION

Adolescents with major depressive disorder (MDD) exhibit hypoactivity to positive stimuli and hyperactivity to negative stimuli in terms of neural responses. Automatic emotion regulation (AER) activates triple networks (i.e., the central control network, default mode network, and salience network). Based on previous studies, we hypothesized that adolescents with MDD exhibit dissociable spatiotemporal deficits during positive and negative AER.

METHODS

We first collected EEG data from 32 adolescents with MDD and 35 healthy adolescents while they performed an implicit emotional Go/NoGo task. Then, we characterized the spatiotemporal dynamics of cortical activity during AER.

RESULTS

In Go trials, MDD adolescents exhibited reduced N2 amplitudes, enhanced theta power for positive pictures, and stronger bottom-up information flow from the left orbitofrontal cortex (OFC) to the right superior frontal gyrus compared to top-down information flow than the controls. In contrast, in NoGo trials, MDD adolescents exhibited elevated P3 amplitudes, enhanced theta power, and stronger top-down information flows from the right middle frontal gyrus to the right OFC and the left insula than the controls.

CONCLUSION

Overall, adolescents with MDD exhibited impaired automatic attention to positive emotions and impaired automatic response inhibition. These findings have potential implications for the clinical treatment of adolescents with MDD.

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.

Volumes of hippocampal subfields suggest a continuum between schizophrenia, major depressive disorder and bipolar disorder

Objective

There is considerable debate as to whether the continuum of major psychiatric disorders exists and to what extent the boundaries extend. Converging evidence suggests that alterations in hippocampal volume are a common sign in psychiatric disorders; however, there is still no consensus on the nature and extent of hippocampal atrophy in schizophrenia (SZ), major depressive disorder (MDD) and bipolar disorder (BD). The aim of this study was to verify the continuum of SZ - BD - MDD at the level of hippocampal subfield volume and to compare the volume differences in hippocampal subfields in the continuum.

Methods

A total of 412 participants (204 SZ, 98 MDD, and 110 BD) underwent 3 T MRI scans, structured clinical interviews, and clinical scales. We segmented the hippocampal subfields with FreeSurfer 7.1.1 and compared subfields volumes across the three diagnostic groups by controlling for age, gender, education, and intracranial volumes.

Results

The results showed a gradual increase in hippocampal subfield volumes from SZ to MDD to BD. Significant volume differences in the total hippocampus and 13 of 26 hippocampal subfields, including CA1, CA3, CA4, GC-ML-DG, molecular layer and the whole hippocampus, bilaterally, and parasubiculum in the right hemisphere, were observed among diagnostic groups. Medication treatment had the most effect on subfields of MDD compared to SZ and BD. Subfield volumes were negatively correlated with illness duration of MDD. Positive correlations were found between subfield volumes and drug dose in SZ and MDD. There was no significant difference in laterality between diagnostic groups.

Conclusion

The pattern of hippocampal volume reduction in SZ, MDD and BD suggests that there may be a continuum of the three disorders at the hippocampal level. The hippocampus represents a phenotype that is distinct from traditional diagnostic strategies. Combined with illness duration and drug intervention, it may better reflect shared pathophysiology and mechanisms across psychiatric disorders.

The role of ventrolateral prefrontal cortex on voluntary emotion regulation of social pain

The right ventrolateral prefrontal cortex (rVLPFC) is highly engaged in emotion regulation of social pain. However, there is still lack of both inhibition and excitement evidence to prove the causal relationship between this brain region and voluntary emotion regulation. This study used high-frequency (10 Hz) and low-frequency (1 Hz) repetitive transcranial magnetic stimulation (rTMS) to separately activate or inhibit the rVLPFC in two groups of participants. We recorded participants' emotion ratings as well as their social attitude and prosocial behaviors following emotion regulation. Also, we used eye tracker to record the changes of pupil diameter to measure emotional feelings objectively. A total of 108 healthy participants were randomly assigned to the activated, inhibitory or sham rTMS groups. They were required to accomplish three sequential tasks: the emotion regulation (cognitive reappraisal) task, the favorability rating task, and the donation task. Results show that the rVLPFC-inhibitory group reported more negative emotions and showed larger pupil diameter while the rVLPFC-activated group showed less negative emotions and reduced pupil diameter during emotion regulation (both compared with the sham rTMS group). In addition, the activated group gave more positive social evaluation to peers and donated more money to a public welfare activity than the rVLPFC-inhibitory group, among which the change of social attitude was mediated by regulated emotion. Taken together, these findings reveal that the rVLPFC plays a causal role in voluntary emotion regulation of social pain and can be a potential brain target in treating deficits of emotion regulation in psychiatric disorders.

The Emotion-Regulation Benefits of Implicit Reappraisal in Clinical Depression: Behavioral and Electrophysiological Evidence

Major depressive disorder (MDD) is characterized by emotion dysregulation. Whether implicit emotion regulation can compensate for this deficit remains unknown. In this study, we recruited 159 subjects who were healthy controls, had subclinical depression, or had MDD, and examined them under baseline, implicit, and explicit reappraisal conditions. Explicit reappraisal led to the most negative feelings and the largest parietal late positive potential (parietal LPP, an index of emotion intensity) in the MDD group compared to the other two groups; the group difference was absent under the other two conditions. MDD patients showed larger regulatory effects in the LPP during implicit than explicit reappraisal, whereas healthy controls showed a reversed pattern. Furthermore, the frontal P3, an index of voluntary cognitive control, showed larger amplitudes in explicit reappraisal compared to baseline in the healthy and subclinical groups, but not in the MDD group, while implicit reappraisal did not increase P3 across groups. These findings suggest that implicit reappraisal is beneficial for clinical depression.

Frequency-dependent and time-variant alterations of neural activity in post-stroke depression: A resting-state fMRI study

BACKGROUND

Post-stroke depression (PSD) is one of the most frequent psychiatric disorders after stroke. However, the underlying brain mechanism of PSD remains unclarified. Using the amplitude of low-frequency fluctuation (ALFF) approach, we aimed to investigate the abnormalities of neural activity in PSD patients, and further explored the frequency and time properties of ALFF changes in PSD.

METHODS

Resting-state fMRI data and clinical data were collected from 39 PSD patients (PSD), 82 S patients without depression (Stroke), and 74 age- and sex-matched healthy controls (HC). ALFF across three frequency bands (ALFF-Classic: 0.01-0.08 Hz; ALFF-Slow4: 0.027-0.073 Hz; ALFF-Slow5: 0.01-0.027 Hz) and dynamic ALFF (dALFF) were computed and compared among three groups. Ridge regression analyses and spearman's correlation analyses were further applied to explore the relationship between PSD-specific alterations and depression severity in PSD.

RESULTS

We found that PSD-specific alterations of ALFF were frequency-dependent and time-variant. Specially, compared to both Stroke and HC groups, PSD exhibited increased ALFF in the contralesional dorsolateral prefrontal cortex (DLPFC) and insula in all three frequency bands. Increased ALFF in ipsilesional DLPFC were observed in both slow-4 and classic frequency bands which were positively correlated with depression scales in PSD, while increased ALFF in the bilateral hippocampus and contralesional rolandic operculum were only found in slow-5 frequency band. These PSD-specific alterations in different frequency bands could predict depression severity. Moreover, decreased dALFF in contralesional superior temporal gyrus were observed in PSD group.

LIMITATIONS

Longitudinal studies are required to explore the alterations of ALFF in PSD as the disease progress.

CONCLUSIONS

The frequency-dependent and time-variant properties of ALFF could reflect the PSD-specific alterations in complementary ways, which may assist to elucidate underlying neural mechanisms and be helpful for early diagnosis and interventions for the disease.

Unbalanced amygdala communication in major depressive disorder

BACKGROUND

Previous studies suggested an association between functional alteration of the amygdala and typical major depressive disorder (MDD) symptoms. Examining whether and how the interaction between the amygdala and regions/functional networks is altered in patients with MDD is important for understanding its neural basis.

METHODS

Resting-state functional magnetic resonance imaging data were recorded from 67 patients with MDD and 74 age- and sex-matched healthy controls (HCs). A framework for large-scale network analysis based on seed mappings of amygdala sub-regions, using a multi-connectivity-indicator strategy (cross-correlation, total interdependencies (TI), Granger causality (GC), and machine learning), was employed. Multiple indicators were compared between the two groups. The altered indicators were ranked in a supporting-vector machine-based procedure and associated with the Hamilton Rating Scale for Depression scores.

RESULTS

The amygdala connectivity with the default mode network and ventral attention network regions was enhanced and that with the somatomotor network, dorsal frontoparietal network, and putamen regions in patients with MDD was reduced. The machine learning analysis highlighted altered indicators that were most conducive to the classification between the two groups.

LIMITATIONS

Most patients with MDD received different pharmacological treatments. It is difficult to illustrate the medication state's effect on the alteration model because of its complex situation.

CONCLUSION

The results indicate an unbalanced interaction model between the amygdala and functional networks and regions essential for various emotional and cognitive functions. The model can help explain potential aberrancy in the neural mechanisms that underlie the functional impairments observed across various domains in patients with MDD.

Glucocorticoid Receptor (GR) antagonism as disease-modifying treatment for MDD with childhood trauma: protocol of the RESET-medication randomized controlled trial

BACKGROUND

Major depressive disorder (MDD) is a heterogeneous psychiatric disorder. Childhood trauma (CT, emotional/physical/sexual abuse or neglect before the age of 18) is one of the largest and most consistent risk factors for development and poor course of MDD. Overactivity of the HPA-axis and the stress hormone cortisol is thought to play a role in the vulnerability for MDD following exposure to CT. Rodent experiments showed that antagonism of the glucocorticoid receptor (GR) at adult age reversed the effects of early life stress. Similarly, we aim to target MDD in individuals with CT exposure using the GR antagonist mifepristone.

METHODS

The RESET-medication study is a placebo-controlled double-blind randomized controlled trial (RCT) which aims to include 158 adults with MDD and CT. Participants will be randomized (1:1) to a 7-day treatment arm of mifepristone (1200 mg/day) or a control arm (placebo). Participants are allowed to receive usual care for MDD including antidepressants. Measurements include three face-to-face meetings at baseline (T0), day 8 (T1), week 6 (T2), and two online follow-up meetings at 12 weeks (T3) and 6 months (T4). A subgroup of participants (N = 80) are included in a fMRI sub-study (T0, T2). The main study outcome will be depressive symptom severity as measured with the Inventory of Depressive Symptomatology-Self Rated (IDS-SR) at T2. Secondary outcomes include, among others, depressive symptom severity at other time points, disability, anxiety, sleep and subjective stress. To address underlying mechanisms mifepristone plasma levels, cortisol, inflammation, epigenetic regulation and fMRI measurements are obtained.

DISCUSSION

The RESET-medication study will provide clinical evidence whether GR antagonism is a disease-modifying treatment for MDD in individuals exposed to CT. If effective, this hypothesis-driven approach may extend to other psychiatric disorders where CT plays an important role.

TRIAL REGISTRATION

The trial protocol has been registered 01-02-2022 on ClinicalTrials.gov with ID "NCT05217758".

Abnormal dynamic functional connectivity of hippocampal subregions associated with working memory impairment in melancholic depression

BACKGROUND

Previous studies have demonstrated structural and functional changes of the hippocampus in patients with major depressive disorder (MDD). However, no studies have analyzed the dynamic functional connectivity (dFC) of hippocampal subregions in melancholic MDD. We aimed to reveal the patterns for dFC variability in hippocampus subregions - including the bilateral rostral and caudal areas and its associations with cognitive impairment in melancholic MDD.

METHODS

Forty-two treatment-naive MDD patients with melancholic features and 55 demographically matched healthy controls were included. The sliding-window analysis was used to evaluate whole-brain dFC for each hippocampal subregions seed. We assessed between-group differences in the dFC variability values of each hippocampal subregion in the whole brain and cognitive performance on the MATRICS Consensus Cognitive Battery (MCCB). Finally, association analysis was conducted to investigate their relationships.

RESULTS

Patients with melancholic MDD showed decreased dFC variability between the left rostral hippocampus and left anterior lobe of cerebellum compared with healthy controls (voxel p < 0.005, cluster p < 0.0125, GRF corrected), and poorer cognitive scores in working memory, verbal learning, visual learning, and social cognition (all p < 0.05). Association analysis showed that working memory was positively correlated with the dFC variability values of the left rostral hippocampus-left anterior lobe of the cerebellum (r = 0.338, p = 0.029) in melancholic MDD.

CONCLUSIONS

These findings confirmed the distinct dynamic functional pathway of hippocampal subregions in patients with melancholic MDD, and suggested that the dysfunction of hippocampus-cerebellum connectivity may be underlying the neural substrate of working memory impairment in melancholic MDD.

Neural correlates of daily-life affective stress reactivity in early psychosis: A study combining functional MRI and experience sampling methodology

Affective reactivity to daily stressors are increased in individuals in the early stages of psychosis. Studies in psychosis patients and healthy individuals at increased psychosis risk show altered neural reactivity to stress in limbic (i.e., hippocampus [HC] and amygdala), prelimbic (i.e., ventromedial prefrontal cortex [vmPFC] and ventral anterior cingulate cortex [vACC]), and salience areas (i.e., Anterior Insula [AI]). We investigated whether a similar pattern of neural reactivity is present in early psychosis individuals and if brain activity in these regions is associated with daily-life stress reactivity. Twenty-nine early psychosis individuals (11 at-risk mental state and 18 first-episode psychosis) completed the Montreal Imaging Stress Task in conjunction with functional MRI. The study was part of a large-scale randomized controlled trial on the efficacy of an acceptance and commitment therapy-based ecological momentary intervention for early psychosis. All participants also provided experience sampling methodology (ESM) data on momentary affect and stressful activities in their everyday environment. Multilevel regression models were used to estimate if daily-life stress reactivity was moderated by activity in (pre)limbic and salience areas. Task-induced stress was associated with increased activation of the right AI and decreased activation in the vmPFC, vACC, and HC. Task-induced changes in vmPFC and vACC activity were associated with affective stress reactivity, whereas changes in HC and amygdala activity were associated with higher overall stress ratings. These preliminary results suggest region-specific roles in affective and psychotic daily-life stress reactivity in early psychosis. The observed pattern suggests that chronic stress plays a role in neural stress reactivity.

Depression core network-based individualized targeting for transcranial magnetic stimulation

BACKGROUND

Transcranial magnetic stimulation (TMS) of the dorsolateral prefrontal cortex (DLPFC) is an established treatment for major depressive disorder (MDD). Recent attempts to improve TMS efficacy by individually targeting DLPFC subregions that are functionally connected to the subgenual anterior cingulate cortex (sgACC) appear promising. However, sgACC covers only a small subset of core MDD-related areas. Further, fMRI connectivity of sgACC is poorly repeatable within subjects.

METHODS

Based on an fMRI database analysis, we first constructed a novel core network model (CNM), capturing voxelwise emotion regulation- and MDD-related DLPFC connectivity. Then, in a sample of 15 healthy subjects and 29 MDD patients, we assessed (i) within-subject repeatability of the DLPFC connectivity patterns computed from time segments of varying lengths of individual-level fMRI data and (ii) association of MDD severity with the individual DLPFC connectivity strengths. We extracted group-level connectivity strengths in CNM from individual DLPFC coordinates stimulated with neuronavigated TMS in a separate sample of 25 MDD patients. These connectivity strengths were then correlated with individual TMS efficacy.

RESULTS

Compared with sgACC connectivity, CNM increased intraindividual repeatability 5-fold. DLPFC connectivity strength from CNM was associated with MDD severity and TMS efficacy. While the locations of CNM-based individual TMS targets remained constant within individuals, they varied considerably between individuals.

CONCLUSIONS

CNM increased repeatability of functional targeting to a clinically feasible level. The observed association of MDD severity and TMS efficacy with DLPFC connectivity supports the validity of the CNM. The interindividual differences in target locations motivate future individualized clinical trials leveraging the CNM.

Excitatory brain stimulation over the left dorsolateral prefrontal cortex enhances voluntary distraction in depressed patients

BACKGROUND

While implicit distraction could ameliorate negative feelings in patients with major depressive disorders (MDD), it remains unclear whether patients could benefit from explicit, voluntary distraction. Meanwhile, though the dorsolateral prefrontal cortex (DLPFC) is established as a crucial brain region involved in attentional control, the causal relationship between the DLPFC and voluntary distraction is unexplored in patients.

METHODS

Combing explicit distraction and transcranial magnetic stimulation (TMS), this study investigated whether TMS-activated DLPFC facilitates voluntary distraction in MDD patients. Eighty patients diagnosed with current MDD underwent either active (n = 40) or sham (n = 40) TMS sessions, followed by receiving negative social feedback from other patients, during which they were requied to use distraction strategy to down-regulate their painful feelings. Electroencephalogram was recorded during the task.

RESULTS

Both the subjective emotional rating and the amplitude of late positive potential showed that depressed patients successfully down-regulate their negative emotions via voluntary distraction, and the TMS-activated left DLPFC produced a larger benefit of emotion regulation compared to the sham TMS group. Results also revealed that while emotion regulation effect was negatively associated with depressive symptoms in the sham TMS group, this correlation was largely diminished when patients' left DLPFC was activated by TMS during the voluntary distraction.

CONCLUSIONS

These findings demonstrated that distraction is valuable for emotion regulation in MDD patients and they could be beneficial in voluntary distraction by activating their left DLPFC using neural modulation techniques. This study has valuable implications for clinical treatement of emotional dysregulation in MDD patients.

Effect of high-definition transcranial direct current stimulation on improving depression and modulating functional activity in emotion-related cortical-subcortical regions in bipolar depression

Preliminary studies have suggested that transcranial direct current stimulation (tDCS) is effective for bipolar depression, However, brain correlates of the depression alleviating are unclear. To determine the efficacy and safety of tDCS as an add-on treatment for patients with bipolar depression and further to identify the effect of tDCS on the resting-state brain activities, we recruited fifty patients with bipolar depression to complete the double-blind, sham-controlled and randomized clinical trial. Fourteen sessions of tDCS were performed once a day for 14 days. The anode was placed over F3 with return electrodes placed at FP1, FZ, C3 and F7. Regional homogeneity (ReHo) was examined on 50 patients with bipolar depression before and after 14-day active or sham tDCS. Patients in the active group showed significantly superior alleviating the depression symptoms compared with those receiving sham. The active group after 14-day active tDCS showed increased ReHo values in the orbitofrontal cortex and middle frontal gyrus and decreased ReHo values in subcortical structures including hippocampus, parahippocampa gyrus, amygdala, putamen and lentiform nucleus. The reduction of depression severity showed positive correlation of increased ReHo values in the orbitofrontal cortex and middle frontal gyrus and negative correlation of altered ReHo values in the putamen and lentiform. TDCS was an effective and safe add-on intervention for this small bipolar depression sample. The reduction of depression induced by tDCS is associated with a modulation of neural synchronization in the cortical and subcortical structures (ReHo values) within an emotion-related brain network.

Automatic emotion regulation prompts response inhibition to angry faces in sub-clinical depression: An ERP study

The neurocognitive mechanism by which automatic emotion regulation (AER) affects emotion processing remains understudied in the context of psychopathology, such as depression. Participants with sub-clinical depression and healthy controls were randomly assigned to an emotion regulation priming group or a neutral priming group. All participants completed an emotional Go/No-go task by judging the gender of angry or happy faces. During the Go/No-go task, each trial was preceded by subliminal presentation of words describing emotion regulation goals or neutral goals as a manipulation of priming. The behavioral results showed that compared with neutral priming, subliminal priming of regulation goals increased the accuracy in No-go trials with angry faces only for sub-clinically depressed participants. In the ERP results, the main effect of regulation priming was significant in sub-clinically depressed participants, such that showing subliminal priming of regulation goals decreased the amplitude of N2 compared to the neutral priming. Similarly, for the sub-clinically depressed participants, regulation goal priming evoked smaller P3 in response to angry faces than to happy faces. No such pattern was found in neutral goal priming condition or for healthy controls. According to the automotive model of emotion regulation, once goals or norms related to emotion regulations are formed in the mind, a related regulation response could be activated without awareness. Our results suggest that subliminal priming of regulation goals could change the response inhibition to angry faces in sub-clinically depressed participants.

From study abroad to study at home: Spontaneous neuronal activity predicts depressive symptoms in overseas students during the COVID-19 pandemic

The objective of this study was to evaluate symptoms of depression and anxiety as well as changes in spontaneous neuronal activity in college students studying abroad during the coronavirus 2019 (COVID-19) pandemic. We examined functional brain changes using resting-state functional magnetic resonance imaging (fMRI), the amplitude of low-frequency fluctuations (ALFF), and regional homogeneity (ReHo) in overseas students with enforced isolation due to the COVID-19 pandemic. Additionally, emotional assessments were administered to determine the severity of depression and anxiety. The questionnaire results showed that anxiety and depressive symptoms differed between overseas students (i.e., those attending an overseas college virtually) and local students (i.e., those attending a local college in person). The fMRI data revealed higher ALFF values in the bilateral superior medial frontal gyrus, bilateral pre-central gyrus, left insula, and left superior temporal gyrus as well as lower ALFF values in the bilateral paracentral lobule (supplementary motor area) in overseas students. Moreover, ReHo analysis also revealed significant differences between overseas students and local students. Compared with local students, overseas students showed significantly increased ReHo in the right inferior frontal and superior temporal gyri and decreased ReHo in the bilateral paracentral lobule, bilateral superior medial frontal gyrus (supplementary motor area), and bilateral pre-central gyrus. In addition, in overseas students, altered ReHo in the cluster including the left superior and medial frontal gyri, pre-central gyrus, and paracentral lobule was significantly positively correlated with Self-Rating Depression Scale scores. Thus, spontaneous brain activity in overseas students changed during the COVID-19 pandemic. This change in brain function might be related to depression and anxiety symptoms. These results suggest that mental health services are needed to decrease the risk of anxiety and depression among college students studying abroad during the COVID-19 pandemic.

Functional and structural alterations as diagnostic imaging markers for depression in de novo Parkinson's disease

Background

Depression in Parkinson's disease (PD) is identified and diagnosed with behavioral observations and neuropsychological measurements. Due to the large overlaps of depression and PD symptoms in clinical manifestations, it is challenging for neurologists to distinguish and diagnose depression in PD (DPD) in the early clinical stage of PD. The advancement in magnetic resonance imaging (MRI) technology provides potential clinical utility in the diagnosis of DPD. This study aimed to explore the alterations of functional and structural MRI in DPD to produce neuroimaging markers in discriminating DPD from non-depressed PD (NDPD) and healthy controls (HC).

Methods

We recruited 20 DPD, 37 NDPD, and 41 HC matched in age, gender, and education years. The patients' diagnosis with PD was de novo. The differences in regional homogeneity (ReHo), voxel-wise degree centrality (DC), cortical thickness, cortical gray matter (GM) volumes, and subcortical GM volumes among these groups were detected, and the relationship between altered indicators and depression was analyzed. Moreover, the receiver operating characteristic (ROC) analysis was performed to assess the diagnostic efficacy of altered indicators for DPD.

Results

Compared to NDPD and HC, DPD showed significantly increased ReHo in left dorsolateral superior frontal gyrus (DSFG) and DC in left inferior temporal gyrus (ITG), and decreased GM volumes in left temporal lobe and right Amygdala. Among these altered indicators, ReHo value in left DSFG and DC values in left ITG and left DSFG were significantly correlated with the severity of depression in PD patients. Comparing DPD and NDPD, the ROC analysis revealed a better area under the curve value for the combination of ReHo value in left DSFG and DC value in left ITG, followed by each independent indicator. However, the difference is not statistically significant.

Conclusion

This study demonstrates that both functional and structural impairments are present in DPD. Among them, ReHo value of left DSFG and DC value of left ITG are equally well suited for the diagnosis and differential diagnosis of DPD, with a combination of them being slightly preferable. The multimodal MRI technique represents a promising approach for the classification of subjects with PD.

Concurrent TMS-EEG and EEG reveal neuroplastic and oscillatory changes associated with self-compassion and negative emotions

Background/Objective

Self-compassion has a consensual relevance for overall mental health, but its mechanisms remain unknown. Using intermittent theta burst stimulation (iTBS) and concurrent transcranial magnetic stimulation-electroencephalography (TMS-EEG), this study investigated the causal relationship of the dorsolateral prefrontal cortex (DLPFC) with self-compassion and explored the changes in neuroplasticity and neural dynamics.

Method

Thirty-two healthy participants received iTBS or sham stimulation over the DLPFC, before and after which they were instructed to either use self-compassionate strategies or to be rejected in the context of social rejection and to report the level of self-compassion or negative affect. TMS-evoked potentials were evaluated as novel neuroplastic techniques with N45, P60, N100, and P180.

Results

iTBS uniquely decreased P180 amplitude measured with TMS-EEG whereby sham stimulation had no effect on neuroplasticity. In line with neuroplasticity changes, iTBS enhanced a widespread gamma band power and coherence, which correlated consistently with increased engagement in self-compassion. Meanwhile, iTBS demonstrated opposite effects on theta activity dependent on the social contexts whereby self-compassion decreased and social rejection enhanced it respectively. This unique effect of iTBS on theta activity was also supplemented by the enhancement of theta band coherence following iTBS.

Conclusions

We found a causal relationship between DLPFC and self-compassion. We also provide evidence to indicate widespread gamma activity and connectivity to correlate with self-compassion as well as the critical role of the DLPFC in modulating theta activity and negative emotions.

FMRI study of implicit emotional face processing in patients with MDD with melancholic subtype

Introduction

The accurate perception of facial expressions plays a vital role in daily life, allowing us to select appropriate responses in social situations. Understanding the neuronal basis of altered emotional face processing in patients with major depressive disorder (MDD) may lead to the appropriate choice of individual interventions to help patients maintain social functioning during depressive episodes. Inconsistencies in neuroimaging studies of emotional face processing are caused by heterogeneity in neurovegetative symptoms of depressive subtypes. The aim of this study was to investigate brain activation differences during implicit perception of faces with negative and positive emotions between healthy participants and patients with melancholic subtype of MDD. The neurobiological correlates of sex differences of MDD patients were also examined.

Methods

Thirty patients diagnosed with MDD and 21 healthy volunteers were studied using fMRI while performing an emotional face perception task.

Results

Comparing general face activation irrespective of emotional content, the intensity of BOLD signal was significantly decreased in the left thalamus, right supramarginal gyrus, right and left superior frontal gyrus, right middle frontal gyrus, and left fusiform gyrus in patients with melancholic depression compared to healthy participants. We observed only limited mood-congruence in response to faces of differing emotional valence. Brain activation in the middle temporal gyrus was significantly increased in response to fearful faces in comparison to happy faces in MDD patients. Elevated activation was observed in the right cingulate for happy and fearful faces, in precuneus for happy faces, and left posterior cingulate cortex for all faces in depressed women compared to men. The Inventory for Depressive Symptomatology (IDS) score was inversely correlated with activation in the left subgenual gyrus/left rectal gyrus for sad, neutral, and fearful faces in women in the MDD group. Patients with melancholic features performed similarly to controls during implicit emotional processing but showed reduced activation.

Discussion and conclusion

This finding suggests that melancholic patients compensate for reduced brain activation when interpreting emotional content in order to perform similarly to controls. Overall, frontal hypoactivation in response to implicit emotional stimuli appeared to be the most robust feature of melancholic depression.

Somatic symptoms mediate the association between subclinical anxiety and depressive symptoms and its neuroimaging mechanisms

BACKGROUND

Subclinical anxiety, depressive and somatic symptoms appear closely related. However, it remains unclear whether somatic symptoms mediate the association between subclinical anxiety and depressive symptoms and what the underlying neuroimaging mechanisms are for the mediating effect.

METHODS

Data of healthy participants (n = 466) and participants in remission of major depressive disorder (n = 53) were obtained from the Human Connectome Project. The Achenbach Adult Self-Report was adopted to assess anxiety, depressive and somatic symptoms. All participants completed four runs of resting-state functional magnetic resonance imaging. Mediation analyses were utilized to explore the interactions among these symptoms and their neuroimaging mechanisms.

RESULTS

Somatic symptoms partially mediated the association between subclinical anxiety and depressive symptoms in healthy participants (anxiety→somatic→depression: effect: 0.2785, Boot 95% CI: 0.0958-0.3729; depression→somatic→anxiety: effect: 0.0753, Boot 95% CI: 0.0232-0.1314) and participants in remission of MDD (anxiety→somatic→depression: effect: 0.2948, Boot 95% CI: 0.0357-0.7382; depression→somatic→anxiety: effect: 0.0984, Boot 95% CI: 0.0007-0.2438). Resting-state functional connectivity (FC) between the right medial superior frontal gyrus and the left thalamus and somatic symptoms as chain mediators partially mediated the effect of subclinical depressive symptoms on subclinical anxiety symptoms in healthy participants (effect: 0.0020, Boot 95% CI: 0.0003-0.0043). The mean strength of common FCs of subclinical depressive and somatic symptoms, somatic symptoms, and the mean strength of common FCs of subclinical anxiety and somatic symptoms as chain mediators partially mediated the effect of subclinical depressive symptoms on subclinical anxiety symptoms in remission of MDD (effect: 0.0437, Boot 95% CI: 0.0024-0.1190). These common FCs mainly involved the insula, precentral gyri, postcentral gyri and cingulate gyri. Furthermore, FC between the triangular part of the left inferior frontal gyrus and the left postcentral gyrus was positively associated with subclinical anxiety, depressive and somatic symptoms in remission of MDD (FDR-corrected p < 0.01).

CONCLUSIONS

Somatic symptoms partially mediate the interaction between subclinical anxiety and depressive symptoms. FCs involving the right medial superior frontal gyrus, left thalamus, triangular part of left inferior frontal gyrus, bilateral insula, precentral gyri, postcentral gyri and cingulate gyri maybe underlie the mediating effect of somatic symptoms.

Prolonged Longitudinal Transcutaneous Auricular Vagus Nerve Stimulation Effect on Striatal Functional Connectivity in Patients with Major Depressive Disorder

BACKGROUND

Transcutaneous auricular vagus nerve stimulation (taVNS) is effective for treating major depressive disorder (MDD). We aimed to explore the modulating effect of prolonged longitudinal taVNS on the striatal subregions' functional connectivity (FC) in MDD patients.

METHODS

Sixteen MDD patients were enrolled and treated with taVNS for 8 weeks. Sixteen healthy control subjects (HCs) were recruited without intervention. The resting-state FC (rsFC) based on striatal subregion seed points and the Hamilton Depression Scale (HAMD) were evaluated in the MDD patients and HCs at baseline and after 8 weeks. A two-way ANCOVA test was performed on each rsFC metric to obtain the (group-by-time) interactions.

RESULTS

The rsFC values between the left ventral caudate (vCa) and right ventral prefrontal cortex (vPFC), and between the right nucleus accumbens (NAc) and right dorsal medial prefrontal cortex (dmPFC) and ventrolateral prefrontal cortex (vlPFC) are lower in the MDD patients compared to the HCs at baseline, and increase following taVNS; the rsFC values between the left vCa and right, superior occipital gyrus (SOG), and between the left dorsal caudate (dCa) and right cuneus are higher in MDD patients and decrease following taVNS.

CONCLUSIONS

Prolonged longitudinal taVNS can modulate the striatum rsFC with the prefrontal cortex, occipital cortex, temporal cortex, and intra-striatum, and these changes partly underlie any symptomatic improvements. The results indicate that prolonged longitudinal taVNS may produce beneficial treatment effects by modulating the cortical striatum circuitry in patients with MDD.

Empathy and depression among a Chinese sample: The moderating role of rumination and attentional shift

Background

Although previous studies have explored the moderating role of emotional regulation strategies in the relationship between empathy and depression, no studies have studied the moderating role of attentional control in the relationship between empathy and depression. To address this research gap, the present study investigated the moderating roles of rumination and attentional control in the relationship between empathy and depression.

Methods

423 participants filled out questionnaires anonymously, including Interpersonal Reactivity Index, Attention Control Scale, Self-rating Depression Scale, and Rumination Response Scale. PROCESS macro for SPSS was used for moderating effect analysis.

Results

Rumination and attentional shift moderated the relationship between emotional empathy and depression. Specifically, the lower rumination or the higher attentional shift, the stronger the negative association between emotional empathy and depression. Attentional shift moderated the relationship between cognitive empathy and depression, and cognitive empathy was significantly associated with depression only among participants whose attentional shift is high.

Conclusion

The study showed that rumination and attentional shift play important roles in the relationship between empathy and depression. The findings implicated that the positive role of good emotional regulation strategies and executive function for individuals in the relationship between empathy and depression.