Impairment In Major Depressive Disorder Research Articles

Identifying the nature of episodic memory deficits in Major Depressive Disorder using a Real-World What-Where-When task

ABSTRACT Deficits in episodic memory have been reported in various psychiatric conditions, including Major Depressive Disorder (MDD). Many widely used episodic memory tests do not have the ability to distinguish between impaired memory of separate components of a real-life event (e.g., what happened, where it happened and when), and impaired binding of such real-life features. To address this issue, a naturalistic, real-world What-Where-When memory task was employed to assess the nature of episodic memory impairments in MDD. A validation study established that the task is sensitive to age-related episodic memory changes, and that intentional encoding does not invalidate the task. The main study then compared the performance of patients with depression and control participants on the intentionally encoded WWW task. Patients with MDD presented an overall episodic memory impairment arising from deficits in object memory and the ability to bind objects to temporal context. Taken together, our study confirms the episodic memory impairment in MDD, by providing evidence of deficient object memory and reduced ability to bind temporal context to objects in patients. Our naturalistic WWW task presents a promising approach for thorough identification of the nature of episodic memory impairments, under a real-world environment, in various conditions, including MDD.

Identifying the nature of episodic memory deficits in Major Depressive Disorder using a Real-World What-Where-When task

ABSTRACT Deficits in episodic memory have been reported in various psychiatric conditions, including Major Depressive Disorder (MDD). Many widely used episodic memory tests do not have the ability to distinguish between impaired memory of separate components of a real-life event (e.g., what happened, where it happened and when), and impaired binding of such real-life features. To address this issue, a naturalistic, real-world What-Where-When memory task was employed to assess the nature of episodic memory impairments in MDD. A validation study established that the task is sensitive to age-related episodic memory changes, and that intentional encoding does not invalidate the task. The main study then compared the performance of patients with depression and control participants on the intentionally encoded WWW task. Patients with MDD presented an overall episodic memory impairment arising from deficits in object memory and the ability to bind objects to temporal context. Taken together, our study confirms the episodic memory impairment in MDD, by providing evidence of deficient object memory and reduced ability to bind temporal context to objects in patients. Our naturalistic WWW task presents a promising approach for thorough identification of the nature of episodic memory impairments, under a real-world environment, in various conditions, including MDD.

The functional role of the pulvinar in discriminating between objective and subjective cognitive impairment in major depressive disorder.

Emotionally driven cognitive complaints represent a major diagnostic challenge for clinicians and indicate the importance of objective confirmation of the accuracy of depressive patients' descriptions of their cognitive symptoms. We compared cognitive status and structural and functional brain connectivity changes in the pulvinar and hippocampus between patients with total depression and healthy controls. The depressive group was also classified as "amnestic" or "nonamnestic," based on the members' subjective reports concerning their forgetfulness. We then sought to determine whether these patients would differ in terms of objective neuroimaging and cognitive findings. The right pulvinar exhibited altered connectivity in individuals with depression with objective cognitive impairment, a finding which was not apparent in depressive patients with subjective cognitive impairment. The pulvinar may play a role in depression-related cognitive impairments. Connectivity network changes may differ between objective and subjective cognitive impairment in depression and may play a role in the increased risk of dementia in patients with depression.

Choroidal vessel density in major depressive disorder using swept-source optical coherence tomography angiography

BackgroundPrevious studies have revealed the retinal structural impairment in major depressive disorder (MDD). The choroid is more affected by systemic changes compared to the retina and provides nutrients to the retina. It is uncertain whether the choroidal structure was damaged in MDD. Therefore, this study aimed to investigate choroidal vessel density (VD) in MDD patients using swept-source optical coherence tomography angiography (SS-OCTA). MethodsThis study investigated the choroidal and retinal VD of subjects with SS-OCTA. MDD was identified based on the Diagnostic and International Classification of Diseases, 10th edition (ICD-10). The VD was automatically calculated as the ratio of the pixel areas of the vessels divided by the total area of the regions by the device. ResultsCompared with healthy controls (HCs) (n = 45 eyes), the MDD group (n = 66 eyes) demonstrated significantly lower supranasal and temporal choroidal vessel volume (CVV), temporal choroidal vessel volume index (CVI), and supranasal and temporal choroidal stroma volume (CSV) (all p < 0.05). After adjustment for age and sex, we found that temporal CVV (β = −9.31, p = 0.040) and supranasal (β = −15.28, p = 0.034) and temporal CSV (β = −11.82, p = 0.036) were significantly associated with MDD. Both choroidal thickness and retinal VD indicators did not differ significantly between MDD patients and HCs (both p > 0.05). LimitationsConclusions about progressive changes in choroidal vascular structures during the course of MDD are limited by the our cross-sectional study. ConclusionsWe found the choroidal VD in MDD was lower compared with HCs, which suggests that decreased choroidal VD is associated with the MDD.

Exploring Associations between C-Reactive Protein and Self-Reported Interoception in Major Depressive Disorder: A Bayesian Analysis.

Major depressive disorder (MDD) is associated with dysfunctional self-reported interoception (i.e., abnormal perception of the body's physiological state) and systemic inflammation, both of which adversely affect treatment response. In this study, we explored associations between C-reactive protein (CRP) and self-reported interoception, to gain more insight into the pathophysiology of interoceptive impairments in MDD. We also aimed to replicate previous findings on the associations of depression and fatigue severity with CRP. The study included 97 depressed individuals, who completed self-administered questionnaires (Multidimensional Assessment of Interoceptive Awareness (MAIA-2); Beck Depression Inventory-II, Multidimensional Fatigue Inventory). CRP concentrations were analyzed in the serum using a particle-enhanced turbidimetric immunoassay. We applied Bayesian inference to estimate robust effect parameters from posterior distributions based on MCMC sampling, and computed Bayes factors (BF10) as indices of relative evidence. The bivariate analysis supported evidence against associations between CRP and self-reported interoception (BF10 ≤ 0.32), except for one dimension (Not-Distracting: r = 0.11, BF10 > 0.43, absence of evidence). Positive correlations with overall depression (r = 0.21, BF10 = 3.19), physical fatigue (r = 0.28, BF10 = 20.64), and reduced activity (r = 0.22, BF10 = 4.67) were found. The multivariate analysis showed moderate evidence that low-grade inflammation predicted higher scores on the MAIA-2 Not-Worrying scale (β = 0.28, BF10 = 3.97), after controlling for relevant confounders. Inflammatory responses, as measured by CRP, may not be involved in the pathophysiology of dysfunctional self-reported interoception. However, systemic low-grade inflammation could potentially exert a protective effect against worries about pain or discomfort sensations. An immunological involvement in interoceptive impairments cannot be ruled out until future studies considering additional biomarkers of inflammation replicate our findings.

Childhood Adversity, Cognition, and Response to Cognitive Remediation in Major Depressive Disorder.

Cognitive impairment is experienced by many individuals with major depressive disorder (MDD) and is significantly related to sustained disability. Recent work has begun to explore the relationship between childhood adversity (CA) and cognitive impairment in MDD, but this work is limited by unreliable measures of CA. Furthermore, no previous research has examined whether CA relates to cognitive remediation response. The current study clarifies how CA and clinical characteristics of illness explain cognitive variance. In addition, we investigate whether CA is associated with response to cognitive remediation. Thirty-nine individuals who completed cognitive remediation were rerecruited to complete a retrospective interview on CA. Results showed that CA, repeated depressive episodes, and earlier age at diagnosis were associated with poorer cognition. We did not observe a difference in treatment response based on CA. Findings suggest that CA is an important variable to consider when examining the expression of depressive illness and areas for intervention.

Cognitive dysfunction and neurometabolic alternations in major depressive disorder with gastrointestinal symptoms

BackgroundBrain biochemical abnormalities have been associated with major depressive disorder (MDD) and cognitive impairments. However, the cognitive performance and neurometabolic alterations of MDD patients accompanied by gastrointestinal (GI) symptoms remain to be elucidated. We aimed to reveal the features and correlation between cognitive impairments and brain biochemical abnormalities of depressed patients with GI symptoms. MethodsFifty MDD patients with GI symptoms (GI group), 46 patients without GI symptoms (NGI group) and 50 demographically matched healthy controls (HCs) underwent Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) Consensus Cognitive Battery (MCCB) assessments. In addition, proton magnetic resonance spectroscopy (1H-MRS) was used to obtain ratios of N-acetyl aspartate to creatine (NAA/Cr) and choline-containing compounds to creatine (Cho/Cr) in the thalamus, putamen and anterior cingulate cortex (ACC). Finally, association analysis was conducted to investigate the relationships of these measurements. ResultsCompared to HCs, participants in both the GI and NGI groups had significantly reduced performance in the six MCCB cognitive domains (all p < 0.05), except for reasoning and problem solving. Higher Cho/Cr ratios in the right thalamus (p < 0.05) and lower NAA/Cr ratios in the left putamen (p < 0.05) were found in the NGI group than in the GI group. The severity of GI symptoms was negatively correlated with Cho/Cr ratios in the right ACC (r = −0.288, p = 0.037). In addition, the T-scores of visual learning were negatively correlated with NAA/Cr ratios in the right ACC (r = −0.443, p = 0.001) and right thalamus (r = −0.335, p = 0.015). ConclusionOur findings suggest that MDD patients with GI symptoms may exhibit greater neurometabolic alternations than those without GI symptoms, while both show similar cognitive dysfunction. In addition, neurometabolic alterations in the ACC and thalamus may underlie the neural basis of GI symptoms and cognitive impairment in MDD.

Association between cognitive impairments and aberrant dynamism of overlapping brain sub-networks in unmedicated major depressive disorder: A resting-state MEG study

ObjectiveLittle is known about the pathogenesis underlying cognitive impairment in major depressive disorder (MDD). We aimed to explore the mechanisms of cognitive impairments among patients with MDD by investigating the dynamics of overlapping brain sub-networks. MethodsForty unmedicated patients with MDD and 28 healthy controls (HC) were enrolled in this study. Cognitive function was measured using the Chinese versions of MATRICS Consensus Cognitive Battery (MCCB). All participants were scanned using a whole-head resting-state magnetoencephalography (MEG) machine. The dynamism of neural sub-networks was analyzed based on the detection of overlapping communities in five frequency bands of oscillatory brain signals. ResultsMDD demonstrated poorer cognitive performance in six domains compared to HC. The difference in community detection (functional integration mode) in MDD was frequency-dependent. MDD showed significantly decreased community dynamics in all frequency bands compared to HC. Specifically, differences in the visual network (VN) and default mode network (DMN) were detected in all frequency bands, differences in the cognitive control network (CCN) were detected in the alpha2 and beta frequency bands, and differences in the bilateral limbic network (BLN) were only detected in the beta frequency band. Moreover, community dynamics in the alpha2 frequency band were positively correlated with verbal learning and reasoning problem solving abilities in MDD. ConclusionsOur study found that decreasing in the dynamics of overlapping sub-networks may differ by frequency bands. The aberrant dynamics of overlapping neural sub-networks revealed by frequency-specific MEG signals may provide new information on the mechanism of cognitive impairments that result from MDD.

Cognitive factor structure and measurement invariance between healthy controls and patients with major depressive disorder

Cognitive impairments are crucial in functional outcomes of major depressive disorder (MDD). The effectiveness of currently available treatment methods for cognitive deficits is suboptimal. A cognitive test battery is often applied to evaluate cognition with multiple interrelated and difficult-to-interpret outcomes. Generating cognitive factor scores after the confirmation of a common cognitive structure and measurement invariance between healthy controls (HCs) and patients may aid in understanding cognition further. This methodology has been applied for several neuropsychiatric disorders, but not for MDD. Therefore, we conducted a series of exploratory factor analyses (EFA), confirmatory factor analyses (CFA), and multiple groups CFA (MGCFA) for a cognitive test battery in HCs and patients with MDD. The initial EFA of 106 HCs yielded a three-factor model—comprising attention, memory, and executive function. The CFA confirmed the initial model in other 94 HCs with revisions, which reasonably fit the cognitive data of 54 patients with MDD. MGCFA supported the measurement invariance of the determined model between HCs and patients with MDD. The associations of cognitive factor scores with age or education and the effect sizes of group differences in cognitive factor scores externally validated the determined model. In conclusion, this is the first study to demonstrate the measurement invariance of a cognitive model between HCs and patients with MDD using MGCFA. The measurement invariance substantiated valid group comparisons of factor scores and their relationships with other markers. The current results may be applicable for the development of improved treatment strategies for cognitive impairments in MDD.

Contributors of Functional Impairment in Major Depressive Disorder: a Biopsychosocial Approach

Contributors of Functional Impairment in Major Depressive Disorder: a Biopsychosocial Approach

Similarities and differences in working memory and neurometabolism of obsessive-compulsive disorder and major depressive disorder

BackgroundObsessive-compulsive disorder (OCD) and major depressive disorder (MDD) both showed cognitive impairment, and the altered neurometabolic may associate with cognitive impairment. However, there are limited comparative working memory (WM) and neuroimaging studies on these two disorders. Therefore, we investigated the characteristics of WM and neurometabolic changes in patients with OCD and MDD. MethodsA total of 64 unmedicated patients (32 OCD and 32 MDD), and 33 healthy controls (HC) were included to conduct WM assessment comprising Digit Span Test (DST), 2-back task and Stroop Color and Word Test (SCWT). Additionally, all subjects underwent protons magnetic resonance spectroscopy (1H-MRS) to collect neurometabolic ratios of N-acetyl aspartate (NAA) and choline-containing compounds (Cho) to creatine (Cr) in the prefrontal cortex (PFC) and lentiform nucleus (LN). Finally, differential and correlation analysis were conducted to investigate their characteristics and relationships. ResultsCompared with HC, both OCD and MDD patients exhibited a lower accuracy rate in the 2-back task, and only MDD patients performed worse in DST scores and longer reaction times in SCWT (all p < 0.05). Both OCD and MDD patients had lower NAA/Cr ratios in bilateral PFC (all p < 0.05). And the decreased NAA/Cr ratios in right PFC were positively correlated to DST scores in MDD group (r = 0.518, p = 0.003). ConclusionsBoth OCD and MDD showed WM impairment and neurometabolic alterations in PFC. Besides, MDD performed more severe and broader WM impairment compared to OCD. Moreover, the dysfunction of PFC may underlie the neural basis of WM impairment in MDD.

Brain function mediates the association between low vitamin D and neurocognitive status in female patients with major depressive disorder.

Vitamin D is engaged in various neural processes, with low vitamin D linked to depression and cognitive dysfunction. There are gender differences in depression and vitamin D level. However, the relationship between depression, gender, vitamin D, cognition, and brain function has yet to be determined. One hundred and twenty-two patients with major depressive disorder (MDD) and 119 healthy controls underwent resting-state functional MRI and fractional amplitude of low-frequency fluctuations (fALFF) was calculated to assess brain function. Serum concentration of vitamin D (SCVD) and cognition (i.e. prospective memory and sustained attention) were also measured. We found a significant group-by-gender interaction effect on SCVD whereby MDD patients showed a reduction in SCVD relative to controls in females but not males. Concurrently, there was a female-specific association of SCVD with cognition and MDD-related fALFF alterations in widespread brain regions. Remarkably, MDD- and SCVD-related fALFF changes mediated the relation between SCVD and cognition in females. Apart from providing insights into the neural mechanisms by which low vitamin D contributes to cognitive impairment in MDD in a gender-dependent manner, these findings might have clinical implications for assignment of female patients with MDD and cognitive dysfunction to adjuvant vitamin D supplementation therapy, which may ultimately advance a precision approach to personalized antidepressant choice.

Cognitive Dysfunction in Mood Disorder: Similarities and Differences Between Depression Subtypes

Cognitive dysfunction is common in depression. Depression is heterogeneous conditions that comprise biologically diverse subtypes. This manuscript reviewed the similarities and differences in cognitive function between major depressive disorder (MDD) and bipolar disorder (BD). Relatively few studies have compared the cognitive function in BD and MDD; furthermore, the differences might exist between BD types I and II. The neurobiological background of cognitive impairment in MDD and BD involves structural and functional disturbances in neural circuits, as well as disturbances in the connectivity of cognitive networks. Several clinical factors such as symptom severity, onset age, premorbid IQ, psychotic features, and illness course may influence cognitive dysfunction in depression. To understand the differences between the cognitive dysfunctions of MDD and BD, the aforementioned features should be controlled. Setting a standard of evaluating cognitive functions in various mood disorders will be a critical step for future studies. [ Psychiatr Ann . 2022;52(3):100–104.]

A Multi-Center Study for the Development of the Taiwan Cognition Questionnaire (TCQ) in Major Depressive Disorder.

Cognitive dysfunction is associated with functional impairment of patients with Major Depressive Disorder (MDD). The goals were to explore the associated factors of cognitive impairment in MDD and to develop and validate a brief and culture-relevant questionnaire, the Taiwan Cognition Questionnaire (TCQ), among patients with MDD. This was a cross-sectional, multi-center observational study of MDD patients in Taiwan. Participants of Group 1 from 10 centers contributed to the validation of the TCQ by their response and sociodemographics. The participants of Group 2 from one center received an objective cognitive assessment for clarification of the relationship between the TCQ score and its associated factors. In Group 1, 493 participants were recruited. As for Group 2, an extra 100 participants were recruited. The global Cronbach’s alpha for the TCQ was 0.908. According to the coordinates of the ROC curve, 9/10 was the ideal cut-off point. With the criteria, the sensitivity/specificity of the TCQ was 0.610/0.689. The TCQ score was positively associated with a history of being admitted to acute psychiatric care and the severity of depression and negatively associated with objective cognitive measures. The TCQ provides a reliable, valid, and convenient measure of subjective cognitive dysfunction in patients with MDD.

Gut Microbiome Composition Linked to Inflammatory Factors and Cognitive Functions in First-Episode, Drug-Naive Major Depressive Disorder Patients.

ObjectiveThe microbiota–gut–brain axis, especially the inflammatory pathway, may play a critical role in the pathogenesis of cognitive impairment in major depressive disorder (MDD). However, studies on the microbiota-inflammatory-cognitive function axis in MDD are lacking. The aim of the present study was to analyze the gut microbiota composition and explore the correlation between gut microbiota and inflammatory factors, cognitive function in MDD patients.MethodStudy participants included 66 first-episode, drug naïve MDD patients as well as 43 healthy subjects (HCs). The composition of fecal microbiota was evaluated using16S rRNA sequencing and bioinformatics analysis. The cytokines such as hs-CRP, IL-1β, IL-6, IL-10, and TNF-α in peripheral blood were detected via enzyme linked immunosorbent assay (ELISA); assessment of cognitive functions was performed using the Color Trail Test (CTT), The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and the Stroop Color-Word Test (SCWT).ResultsWe found that compared with HCs, MDD patients had cognitive impairments and showed different α-diversity and β-diversity of gut microbiota composition. LDA effect size (LEfSe) analysis found MDD have higher Deinococcaceae and lower Bacteroidaceae, Turicibacteraceae, Clostridiaceae and Barnesiellaceae at family level. Deinococcus and Odoribacter was higher in the MDD group, however, Bacteroides, Alistipes, Turicibacter, Clostridium, Roseburia, and Enterobacter were lower at genus level. Furthermore, In MDD patients, the Bacteroidaceae and Bacteroides were both positively correlated with hsCRP, CCT1, CCT2. Alistipes was positively correlated with IL-6, Word time, Color time, Word-Color time, Color-Word time and negatively correlated with Delayed Memory, Total score and Standardized score. Turicibacteraceae and Turicibacter were both negatively correlated with IL-1β and IL-6.ConclusionThe present findings confirm that the gut microbiota in MDD patients have altered gut microbes that are closely associated with inflammatory factors and cognitive function in MDD patients.

Olfactory Dysfunction: Its Association With Subjective Cognitive Impairment in Patients With Major Depression.

Olfactory disorders may be observed together with cognitive impairment in patients with major depressive disorder (MDD). This study compared olfactory performances between patients with MDD and healthy controls and investigated the relationship between olfactory performance and subjective cognitive impairment in these patients. This study included 52 patients diagnosed with MDD and 46 healthy controls. The participants were evaluated in terms of their olfactory capacities (threshold, discrimination, and identification), subjective cognitive impairment, and depression. Although the olfactory threshold (OT) and olfactory discrimination scores were lower in patients with MDD compared with those in the control group, their olfactory identification scores did not differ significantly. OT was negatively correlated with subjective cognitive impairment and may serve as a determinant for subjective cognitive changes. Consequently, patients with MDD had lower olfactory performances compared with healthy controls. Finally, OT may be a component of subjective cognitive impairment in MDD.

Anomalous functional connectivity within the default-mode network in treatment-naive patients possessing first-episode major depressive disorder.

Background and Objective:Previous studies have shown that the default-mode network (DMN) has a substantial role in patients with major depressive disorder (MDD). However, there is a shortage of information regarding variations in the functional connectivity (FC) of the DMN of treatment-naive patients with first-episode MDD. The present study aims to explore the FC of the DMN in such patients.Methods:The study population consisted of 33 patients and 35 controls, paired regarding age, gender, education level, and health condition. Depression severity was assessed through the Hamilton Depression Scale (HAM-D), and subjects underwent evaluation during the resting-state through functional magnetic resonance imaging (rs-fMRI). To assess the result, we used FC and ICA. We used Spearman's correlation test to detect potential correlations between anomalous FC and severity of HAM-D scores.Results:We have found a decreased FC in the left medial orbitofrontal gyrus (MOFG) and right marginal gyrus (SMG) in depressive patients compared to controls. There was a negative correlation between abnormal FC in the right SMG and HAM-D scores. We have not found any increase in FC of the DMN in treatment-naive, first-episode of MDD patients.Conclusions:Our study provided evidence of a negative correlation between abnormal FC in the DMN and severity of depression symptoms measured by HAM-D in treatment-naive MDD patients. This finding could shed some light on the relevance of DMN for understanding the pathophysiology of cognitive impairment in MDD.

Social cognition and major depressive disorder: impact on psychosocial function and therapeutic opportunities

AimsThis poster aims to examine the impact of social cognitive deficits on psychosocial functioning in depressed patients, as well as summarise the utility of various evidence-based therapeutic interventions employed to target these deficits. The stated hypotheses were twofold: (1) that social cognitive impairment in major depressive disorder will correlate with poorer psychosocial functioning; and (2) that these deficits will respond to existing anti-depressant therapies.BackgroundSocial cognition is an important adaptive trait that incorporates the identification, perception and interpretation of socially relevant information from the external world. It is frequently affected in major depressive disorder such that depressed patienMethodA review of the existing literature was performed in order to test the stated hypotheses. Pertinent sources were identified via the MEDLINE, EMBASE, PsycINFO, PubMed, Scopus and Google Scholar databases. A total of 107 studies met inclusion criteria for review.ResultImpaired social cognitive performance in depressed patients correlated with poorer psychosocial functioning across the key domains of general cognitive functioning and quality of life. Many current anti-depressant therapies were found to have a normalising effect on the social cognitive abilities of depressed subjects, both at a neural and functional level. Anti-depressant medications, in particular citalopram and reboxetine, appeared to correct facial affect recognition deficits, while a psychotherapeutic approach demonstrated improvements in theory of mind and negative interpretive bias. Data relating to other common treatments, such as electroconvulsive therapy, are limited.ConclusionThe impact and treatment of social cognitive deficits in major depressive disorder is an important emerging field. The social cognitive deficits evident in depressed patients are sometimes subtle, but afford a significant functional impact. Additionally, it appears these impairments are at least partially reversible using anti-depressants or psychotherapy.

Altered spontaneous neural activity in the precuneus, middle and superior frontal gyri, and hippocampus in college students with subclinical depression

BackgroundSubclinical depression (ScD) is a prevalent condition associated with relatively mild depressive states, and it poses a high risk of developing into major depressive disorder (MDD). However, the neural pathology of ScD is still largely unknown. Identifying the spontaneous neural activity involved in ScD may help clarify risk factors for MDD and explore treatment strategies for mild stages of depression.MethodsA total of 34 ScD subjects and 40 age-, sex-, and education-matched healthy controls were screened from 1105 college students. The amplitude of low-frequency fluctuation (ALFF) and regional homogeneity (ReHo) of resting-state fMRI were calculated to reveal neural activity. Strict statistical strategies, including Gaussian random field (GRF), false discovery rate (FDR), and permutation test (PT) with threshold-free cluster enhancement (TFCE), were conducted. Based on the altered ALFF and ReHo, resting-state functional connectivity (RSFC) was further analyzed using a seed-based approach.ResultsThe right precuneus and left middle frontal gyrus (MFG) both showed significantly increased ALFF and ReHo in ScD subjects. Moreover, the left hippocampus and superior frontal gyrus (SFG) showed decreased ALFF and increased ReHo, respectively. In addition, ScD subjects showed increased RSFC between MFG and hippocampus compared to healthy controls, and significant positive correlation was found between the Beck Depression Inventory-II (BDI-II) score and RSFC from MFG to hippocampus in ScD group.ConclusionSpontaneous neural activities in the right precuneus, left MFG, SFG, and hippocampus were altered in ScD subjects. Functional alterations in these dorsolateral prefrontal cortex and default mode network regions are largely related to abnormal emotional processing in ScD, and indicate strong associations with brain impairments in MDD, which provide insight into potential pathophysiology mechanisms of subclinical depression.

The Effects of Bilateral Theta-burst Stimulation on Executive Functions and Affective Symptoms in Major Depressive Disorder

Major depressive disorder (MDD) is characterized by severe affective as well as cognitive symptoms. Moreover, cognitive impairment in MDD can persist after the remission of affective symptoms. Theta-burst stimulation (TBS) is a promising tool to manage the affective symptoms of major depressive disorder (MDD); however, its cognition-enhancing effects are sparsely investigated. Here, we aimed to examine whether the administration of bilateral TBS has pro-cognitive effects in MDD. Ten daily sessions of neuronavigated active or sham TBS were delivered bilaterally over the dorsolateral prefrontal cortex to patients with MDD. The n-back task and the attention network task were administered to assess working memory and attention, respectively. Affective symptoms were measured using the 21-item Hamilton Depression Rating Scale. We observed moderate evidence that the depressive symptoms of patients receiving active TBS improved compared to participants in the sham stimulation. No effects of TBS on attention and working memory were detected, supported by a moderate-to-strong level of evidence. The effects of TBS on psychomotor processing speed should be further investigated. Bilateral TBS has a substantial antidepressive effect with no immediate adverse effects on executive functions.