Brain structure alterations in depression: Psychoradiological evidence

Aberrant white matter structural connectivity of nucleus accumbens in patients with major depressive disorder: A probabilistic fibre tracing study

BACKGROUND

Extensive neuroimaging studies have established that functional abnormalities and morphological alterations in the nucleus accumbens (NAc) are implicated in major depressive disorder (MDD), but changes in its white matter structural connectivity (SC) remain unclear. We aimed to elucidate the changes in the white matter fibre connectivity of the NAc in MDD patients.

METHODS

This study used probabilistic fibre tracking to analyze the diffusion tensor imaging (DTI) data of 125 MDD patients and 129 healthy controls (HCs), calculating the strength of SC (sSC) from bilateral NAc to the entire brain and its correlation with depressive symptoms.

RESULTS

Compared to HCs, MDD exhibited increased sSC between the left NAc (L.NAc) and regions involving the left middle frontal gyrus, bilateral cingulate gyrus (CG), bilateral hippocampus, left caudate, left medial superior occipital gyrus, right globus pallidus, right superior and middle temporal gyrus, right precuneus, right insula, and right posterior parietal thalamus. Enhanced sSC was also observed between the right NAc (R.NAc) and the left temporal lobe, left posterior superior temporal sulcus (pSTS), bilateral lateral occipital cortex, left hippocampus, right putamen and right ventral occipital cortex. The sSC of L.NAc-left CG and R.NAc-left pSTS was positively correlated with HAMD scores in MDD.

CONCLUSIONS

Abnormal white matter connectivity of the NAc primarily affects the cortico-limbic circuit, cortico-basal ganglia circuit, and the temporal-occipital cortical regions in patients with MDD, along with the asymmetrical features of the inter-hemispheric SC related to NAc. These alteration may underlie the dysfunction of reward processing and emotion regulation in MDD.

Depression vulnerability and gray matter integrity of interoceptive networks in remitted depressed outpatients

BACKGROUND

Interoception, the representation of internal body states, plays an important role in mental health. While functional neuroimaging links Major Depressive Disorder (MDD) relapse vulnerability to stress-induced inhibition of sensorimotor regions, its association with structural changes in interoceptive networks remains unclear.

METHODS

A secondary analysis explored relationships between gray matter volume and relapse vulnerability in remitted MDD patients (N = 85), with two data acquisitions surrounding eight-weeks of prophylactic psychotherapy followed by a two-year follow-up. Participants were randomly assigned to either Cognitive Behavioral Therapy or Mindfulness-Based Cognitive Therapy (MBCT). Mixed-effects models were applied to study the relationships between cortical thickness, time, and intervention type with clinical variables such as relapse status, residual symptoms, and decentering, adjusting for relevant covariates. Analyses were conducted at whole brain levels as well as in pre-defined regions of interest, focusing on sensory regions implicated by prior research.

RESULTS

Relapse was consistently linked to greater cortical thickness in the left superior circular sulcus of the insula and the left anterior occipital sulcus. Residual symptoms correlated with increased cortical thickness in the left insula and right precentral regions, while decentering was linked to reduced thickness in the middle temporal and inferior parietal regions. MBCT participants showed greater cortical thickness increases in the right superior temporal gyrus over time.

CONCLUSIONS

MDD vulnerability was unexpectedly linked to greater cortical thickness in sensory and prefrontal brain regions, suggesting that depression vulnerability may reflect maladaptive skill acquisition. MBCT may promote gray matter growth in the right superior temporal region.

TRIAL REGISTRATION

ClinicalTrials.govNCT01178424.

Transcriptional characteristics of human brain alterations in major depressive disorder: A systematic review

Many patients with major depressive disorder (MDD) experience limited treatment effectiveness due to an incomplete understanding of its neurobiological underpinnings. This review integrates neuroimaging and genetic data to examine structural and functional brain changes in MDD, alongside their genetic bases. A PRISMA-guided systematic review of imaging transcriptomics over the past decade was conducted using PubMed and Web of Science. Studies included MRI scans of both MDD patients and healthy controls, as well as brain-wide gene expression data, excluding those that were purely meta-analytical, lacked spatial correlations, or involved transdiagnostic analyses. Of the 206 studies reviewed, 20 met the inclusion criteria. Consistent patterns across studies reveal that key biological processes-such as synaptic signaling, calcium ion binding, neurodevelopment, immune regulation, and neurotransmitter transport-play a central role in brain alterations associated with MDD. Additionally, our findings suggest that electroconvulsive therapy (ECT) may alleviate symptoms by modulating these shared pathways. This review underscores the link between brain changes in MDD and specific gene expression profiles, offering insights that could inform more targeted therapeutic approaches.

Cognitive and metabolic signatures of early and late-onset depression: A comparative study

BACKGROUND

Early-onset depression (EOD) and late-onset depression (LOD) are prevalent subtypes of major depressive disorder (MDD), but the clinical distinction between EOD and LOD remains blurred due to nonspecific symptoms and lack of biomarkers. This study aims to elucidate the characteristics in cognitive function and biochemical metabolism of EOD and LOD, and to identify biological factors influencing age of onset (AOO).

METHODS

Seventy patients with MDD (40 with EOD and 30 with LOD) and sixty-eight age-matched healthy controls (HC) were included in this study. Participants were evaluated for clinical features, cognitive function, and serum trace elements levels. Proton magnetic resonance spectroscopy (1H-MRS) was employed to quantify neurometabolites levels, including N-acetyl aspartate (NAA), choline (Cho), and creatine (Cr).

RESULTS

Patients with LOD experienced more episodes and severe depressive symptoms than those with EOD (p = 0.025, p < 0.001). EOD patients performed significantly worse than LOD patients on social cognition (p = 0.005), while LOD patients performed worse than EOD patients on reasoning and problem solving (p = 0.005). Additionally, LOD patients displayed higher ceruloplasmin (Cp) levels compared to EOD patients (p = 0.004), but no difference was found in neurometabolic levels between EOD and LOD. Multiple linear regression indicated a positive correlation between serum Cp levels and AOO of depression (p < 0.001), while bilateral thalamic NAA/Cr showed a negative correlation with AOO (p = 0.012, p = 0.016).

CONCLUSIONS

Patients with EOD were characterized by social cognition impairments, while patients with LOD were marked by reasoning and problem-solving deficits. Serum Cp levels demonstrated an AOO-related effect and served as a positive predictor for the AOO of depression. Furthermore, a negative correlation has been established between bilateral thalamic NAA/Cr and the AOO of MDD.

LIMITATIONS

The limited sample size and the challenge in distinguishing whether observed results are attributed to age or AOO effects.

Structural and functional thalamic alterations in major depressive disorder with comorbid chronic pain

Major Depressive Disorder (MDD) is a prevalent mental health condition, often accompanied by chronic pain. This study investigates the structural and functional characteristics of the thalamus in individuals with MDD, both with and without comorbid pain, using magnetic resonance imaging (MRI) techniques. A total of 165 participants, including healthy controls, individuals with MDD, and those with comorbid depression and pain, were enrolled. The study found a reduction of the left thalamus in the MDD group, while no significant differences in thalamic volume were observed in the right thalamus or in the depression and pain comorbidity group. Functionally, no significant differences in fractional amplitude of low-frequency fluctuations (fALFF) and regional homogeneity (ReHo) were found between groups. However, correlation analysis revealed associations between thalamic structure and cognitive performance, as well as clinical symptom severity in the depression and pain comorbidity group. These findings highlight the thalamus's role in the pathophysiology of MDD and its interaction with chronic pain, suggesting potential targets for diagnostic and therapeutic strategies.

Temporal dynamic changes of intrinsic brain regional activity in depression with smoking

BACKGROUND

Depression is often accompanied by high levels of smoking behavior, and smoking can act as a risk factor for depression. However, there is limited neuroimaging evidence regarding the association between depression and smoking, especially the impact of this association on the brain stability remains unclear. Therefore, this study aimed to assess the interaction effect between smoking and depression from a neurodynamic perspective.

METHOD

We assessed the resting-state functional magnetic resonance imaging from 193 participants (55 depressed smokers; 51 depressed non-smokers; 25 healthy smokers; 62 healthy non-smokers) and calculated 3 regional activity dynamic indicators, including dynamic regional homogeneity (dReHo), dynamic amplitude of low-frequency fluctuations (dALFF), and dynamic fractional ALFF (dfALFF). Principal component analysis was conducted on these 3 dynamic indicators, and the first component was extracted for the subsequent 2 × 2 factor designs statistical analysis.

RESULT

We observed the interaction between smoking and depression increases the instability of regional activity in the precentral gyrus and precuneus. Compared with HCs, patients with depression showed increased instability of regional activity across widespread regions such as the precentral gyrus, thalamus, and medial frontal gyrus. No main effects of smoking were observed. In depressed smokers, the instability of regional activity in left precuneus is positively correlated with anxiety symptoms.

CONCLUSIONS

Our findings indicate that smoking potentially exacerbates brain abnormal instability in depression, implying a clinical need to require patients with depression to abstain from smoking.

Selective KOR antagonist alters functional patch sizes in individualized brain system: results from the Fast-fail Trial in Mood and Anxiety Spectrum Disorders (FAST-MAS)

In our prior study involving a transdiagnostic sample of individuals with anhedonia, we showed that an 8-week administration of a selective κ-opioid receptor (KOR) antagonist enhanced fMRI ventral striatal activation during reward anticipation in the Monetary Incentive Delay task as compared to a placebo. However, individual differences in brain architecture may limit the translation of this finding to the context of precision medicine. Here, we adopted an individual-specific approach to elucidate the effects of selective KOR antagonism on cortical-subcortical reward circuits in individuals with anhedonia. Sixty-four participants with anhedonia (30 KOR Antagonist, 34 Placebo) who completed both pre- and post- treatment MRI scans in the FAST-MAS study were included in this analysis. Using an individualized-brain-systems-functional-brain-mapping approach, functional networks were mapped at the individual level, and individual-specific cortical patches and subcortical-cortical clusters were obtained. Statistical analyses were conducted to examine the pre- and post-treatment changes in patch and cluster sizes, as well as their relationships with clinical-cognitive measures. ROI analyses revealed a significant patch size decrease in the right medial posterior prefrontal cortex within the frontoparietal control network, and significant size increases in three right subcortical clusters - pallidum, amygdala, and thalamus - within the orbitofrontal-limbic network, following KOR antagonist treatment. In short, we applied recently developed computational neuroimaging approaches to examine changes in the individualized brain systems of FAST-MAS participants before and after eight weeks of KOR antagonist treatment for anhedonia. Our results revealed alterations in functional cortical patch and subcortical-cortical cluster sizes in anhedonia-related brain regions following KOR antagonist treatment.

Flavokawain B ameliorates depressive-like behaviors by inhibiting neddylation in the ventral hippocampus

Depression is a widespread and serious mental illness. Recent evidence suggests that post-translational modifications, particularly neddylation, play a significant role in the pathophysiology of mood disorders. Neddylation, similar to ubiquitination, involves the attachment of NEDD8 to target proteins, regulating their function. However, its role in depression remains unclear. This study aimed to explore the antidepressant effects of flavokawain B (FKB), a novel neddylation inhibitor, in mouse models of depression induced by lipopolysaccharide (LPS) and chronic unpredictable mild stress (CUMS). We assessed depressive- and anxiety-like behaviors using the sucrose preference test (SPT), open-field test (OFT), forced swimming test (FST), and tail suspension test (TST). Neddylation-related protein expression (NEDD8, NAE1, UBA3, UBC12) was measured in the dorsal and ventral hippocampus (DH, VH), prelimbic cortex (PrL), and nucleus accumbens (NAc). Results showed that FKB reversed the activation of neddylation anxiety- and depressive-like behaviors in both LPS- and CUMS-treated mice. The LPS and CUMS experimental paradigms only impacted the neddylation pathway in the VH and not other brain regions (DH, PrL, IL, NAc). In conclusion, these findings suggest that FKB ameliorates depressive-like behaviors by targeting the NAE1/UBA3/UBC12 pathway in the VH, providing a potential therapeutic approach for depression.

[1H-13C]-NMR-Based Metabolic Kinetics Reveals Brain Neurochemical Alterations in Mice After Retinal Ischemia-Reperfusion Injury

Retinal ischemia-reperfusion injury (RIRI) is a pathological process that occurs in various blinding eye diseases and is often accompanied by anxiety and depression. However, the underlying metabolic mechanism of mood disorders remains unclear. This study aimed to investigate the metabolic dynamics of the brain after RIRI. C57BL/6 J mice were used to establish the RIRI model and assessed after 1 and 7 days. Mood-related behaviors were examined using open-field, elevated plus-maze, and forced swimming tests. Retinal injury histology was assessed using retinal hematoxylin and eosin staining. Retinal apoptosis was measured via the TdT-mediated dUTP nick-end labeling staining. The 13C-labeled metabolite information for six brain regions of interest was obtained using the [1H-13C]-NMR technique. Retinal tissue damage and cell apoptosis in the retina were observed 1 and 7 days after RIRI. One day after RIRI, mice displayed anxiety- and depression-like behaviors, and multiple metabolites involved in the glutamine (Gln)/glutamate (Glu)-γ-aminobutyric acid (GABA) and tricarboxylic acid (TCA) cycles exhibited reductions in all studied brain regions, with frontal cortex (FC) and temporal cortex (TC) being the most markedly altered. Metabolites and behavioral indicators nearly returned to normal after 7 days. Significant positive correlations between Gln/Glu-GABA and TCA cycle metabolites were observed in the RIRI brain. The results revealed that within a short period after RIRI, there was a reduction in brain metabolites and a disruption of the Gln/Glu-GABA and TCA cycles, which may contribute to mood disorders in mice.

Blunted cortisol as a biomarker of depression based on the attenuation hypothesis: A Mendelian randomization analysis using depression as exposure

BACKGROUND

Both elevated and blunted cortisol responses have been associated with depression. Previous Mendelian randomization (MR) studies have largely ruled out cortisol as a cause of depression. Based on the attenuation hypothesis, this MR study used depression as exposure to assess whether cortisol might be a consequence and therefore a biomarker of depression.

METHODS

Strong (P < 5 × 10-8) and independent (r2 < 0.001) single nucleotide polymorphisms (SNPs) associated with broadly defined depression (294,322 cases, 741,438 controls) were used as instruments. These were applied to genetic associations with morning, fasting, and random plasma cortisol in the CORtisol NETwork (CORNET) consortium (n = 25,314), METabolic Syndrome in Men (METSIM) study (n = 6667), and Canadian Longitudinal Study on Aging (CLSA) cohort (n = 8299). Multivariable MR, adjusting for childhood maltreatment and major mental disorders, was conducted to address potential horizontal pleiotropy from dichotomous depression. Instruments were also selected by evidence of colocalization with major depressive disorder to address non-specificity.

RESULTS

Using 133 SNPs as instruments, depression was inversely associated with morning plasma cortisol (β per log-odds of genetic liability to depression = -0.107 [95 % CI, -0.181 to -0.032]) in the CORNET consortium. Replication in the METSIM study (β = -0.203 [95 % CI, -0.367 to -0.040]) and CLSA cohort (β = -0.091 [95 % CI, -0.220 to 0.039]) showed consistent but not always significant associations. Multivariable MR and follow-up analysis incorporating colocalization supported these findings.

CONCLUSIONS

Consistent with the attenuation hypothesis, blunted cortisol response appeared to be a consequence and potentially a biomarker of depression. Future studies are needed to provide more interpretable effect sizes and validate other biomarker measures.

A computational account of joint SSRI and anti-inflammatory treatment

Introduction

Depression is a chronic disorder that impacts millions worldwide. Traditional treatments may not always work. Inflammation seems to be an underlying cause for chronicity and treatment non-response.

Methods

We present a computational model that elucidates the interplay between inflammation, serotonin levels, and brain activity.

Results

The model delineates how inflammation impacts extracellular serotonin, while cerebral activity reciprocally influences serotonin concentration. Understanding the reciprocal interplay between the immune system and brain dynamics is important, as unabated inflammation can lead to relapsing depression. The model predicts dynamics within the prefrontal cortex (PFC) and subcallosal cingulate cortex (SCC), mirroring patterns observed in depressive conditions. It also accommodates pharmaceutical interventions that encompass anti-inflammatory and antidepressant agents, concurrently evaluating their efficacy with regard to the severity of depressive symptoms Our model shows that for mild and moderate levels of depression anti-depressant agents or anti-inflammatory agents acting in isolation can bring serotonergic levels and brain activity to control levels. However, for severe depression only joint treatment of anti-depressant and anti-inflammatory agents can bring the serotonergic levels and activity to control levels.

Discussion

This study is a first step to mechanistically understand the intricate link between the immune system and depression, the role of inflammation and potential treatments. It explores the impact of anti-depressant and anti-inflammatory drug treatments and assesses their relevance with regard to depression severity.

A retrospective analysis of combined treatment with escitalopram and Naoan dropping pills treatment for depression

This study evaluated the effectiveness of combining escitalopram with Naoan dropping pills for the treatment of depression, focusing on improvements in depressive symptoms, daily functional abilities, and cerebral hemodynamics. A total of 87 patients diagnosed with depression at The Third People's Hospital of Tianshui over a 2-year period were retrospectively analyzed. They were divided into 2 groups according to whether Naoan dropping pills were used or not. Group A (n = 43) received only escitalopram, while group B (n = 44) received a combination of escitalopram and Naoan dropping pills for a period of 2 months. Efficacy was determined using the Hamilton depression scale (HAMD), with a ≥50% reduction in HAMD score from baseline considered effective. The activities of daily living (ADL) scale was employed to assess daily functional abilities. Cerebral hemodynamics were evaluated using transcranial Doppler ultrasound (TCD). By the end of the 2-month treatment period, Group B demonstrated a significantly higher efficacy rate (90.91%) than Group A (72.09%). In addition, Group B showed more pronounced improvements in ADL scores, indicating enhanced day-to-day functioning. TCD measurements further revealed higher systolic and diastolic blood flow velocities in the major cerebral arteries of Group B, suggesting improved cerebral perfusion. The combination of escitalopram and Naoan dropping pills proved more efficacious in ameliorating depressive symptoms, enhancing daily functional abilities, and improving cerebral hemodynamics than escitalopram alone. These outcomes highlight the potential benefits of integrated treatment strategies for the management of depression, advocating the adoption of personalized and comprehensive treatment modalities.

Gray matter structural alterations in first-episode drug-naïve adolescents with major depressive disorder: a comprehensive morphological analysis study

BACKGROUND

Major depressive disorder (MDD) tends to emerge during adolescence; however, neurobiological research in adolescents has lagged behind that in adults. This study aimed to characterize gray matter (GM) structural alterations in adolescents with MDD using comprehensive morphological analyses.

METHODS

This study included 93 adolescent MDD patients and 77 healthy controls. Voxel-based morphometry (VBM), deformation-based morphometry (DBM), and surface-based morphometry (SBM) methods were used to analyze GM morphological alterations in adolescent MDD patients. Sex-by-group and age-by-group interactions, as well as the relationships between altered GM structure and clinical characteristics were also analyzed.

RESULTS

Whole-brain VBM and DBM analyses revealed GM atrophy in the left thalamus and bilateral midbrain in adolescent MDD patients. Whole-brain SBM analysis revealed that adolescent MDD patients, relative to controls, showed decreased thickness in the left postcentral gyrus and left precentral gyrus; increased thickness in the bilateral superior temporal gyrus, left parahippocampal gyrus and right lateral orbitofrontal gyrus; and decreased fractal dimension in the right lateral occipital gyrus. A significant sex-by-group interaction effect was found in the fractal dimension of the left lateral occipital gyrus. The volume of the left thalamus and the thickness of the left superior temporal gyrus were correlated with the duration of disease in adolescent MDD patients.

CONCLUSIONS

This study suggested that adolescent MDD had GM morphological abnormalities in the frontal-limbic, subcortical, perceptual network and midbrain regions, with some morphological abnormalities associated with disease duration and sex differences. These findings provide new insight into the neuroanatomical substrates underlying adolescent MDD.

Neural effect of childhood maltreatment on neurovascular coupling in adolescent depression

Childhood maltreatment (CM) is a pivotal risk factor for depression, yet its potential contribution to major depressive disorder (MDD) in adolescents requires further investigation. This study aims to scrutinize the specific impact of CM on neurovascular coupling (NVC) in adolescents with MDD. A cohort of 189 adolescents, comprising 54 MDD with CM, 45 MDD without CM, 33 healthy controls (HC) with CM, and 57 HC without CM, underwent multimodal MRI scans. Cerebral blood flow (CBF) was computed to evaluate vascular responses, while functional connectivity strength (FCS) and amplitude of low-frequency fluctuation (ALFF) were measured to assess neuronal activity. NVC was calculated using whole gray matter CBF-neuronal activity correlation coefficients and regional CBF/neuronal activity ratios. MDD×CM interactions on NVC, CBF, and neuronal activity were analyzed, with further exploration of the associations between these abnormal NVC ratios and CM experience. Support vector machine classifiers were employed to differentiate MDD adolescents. Results revealed a significant MDD×CM interactive effect on CBF-FCS coefficients at whole gray matter level. Regionally, these interactions on NVC ratios primarily occurred in the reward systems, including bilateral anterior cingulate/orbitofrontal cortex, thalamus/mesial temporal lobe, and left occipitotemporal lobe, correlating with CM measurements. Notably, the integration of NVC ratio, CBF, and neuronal activity yielded robust classification performance in distinguishing MDD adolescents. These findings reinforce the importance of reward system for MDD adolescents related to CM, proposing a novel neuroimaging biomarker for early recognition of adolescent depression.

Impaired unfolded protein response, BDNF and synuclein markers in postmortem dorsolateral prefrontal cortex and caudate nucleus of patients with depression and Parkinson's disease

Major depressive disorder (MDD) is characterized by significant impairment in social, emotional, and cognitive functioning. Its precise pathophysiology remains poorly understood. Alterations in protein homeostasis and some misfolded proteins have been identified within the brains of patients diagnosed with neuropsychiatric disorders. In contrast to neurodegenerative processes such as Parkinson's disease (PD), where the accumulation of aggregated α-synuclein (α-Syn) protein is a primary cause of significant neuronal loss, altered proteostasis in MDD may result in loss-of-function effects by modifying synaptic neuroplasticity. Moreover, aberrant activation of endoplasmic reticulum (ER) pathways may intensify the pathological alterations due to altered proteostasis. In this study, dorsolateral prefrontal cortex (dlPFC) and caudate nucleus from MDD patients and non-psychiatric controls were used. Postmortem samples of same brain areas from PD patients (Braak 2-3 and 5-6) and controls were also included. Protein levels of ER and unfolded protein response (UPR), synucleins (α-, β- and γ-Syn), and brain-derived neurotrophic factor (BDNF) were measured by Western-Blot. Phospho-eIF2α/eIF2α ratio was increased in the dlPFC and caudate nucleus of MDD and PD patients compared to their respective controls. Brain area-dependent changes in BiP and GRP94 levels were also found. We further detected accumulation of immature BDNF precursors and opposite changes in α- and β-Syn levels in the dlPFC of MDD and PD patients compared to controls. Our findings suggest that alterations in proteostasis contribute to the pathophysiology of MDD, as previously described in PD. A deeper understanding of the pathways involved will identify other candidate proteins and new targets with therapeutic potential.

Ghrelin in Depression: A Promising Therapeutic Target

Depression is a widespread disease affecting over 300 million individuals of various ethnicities and socioeconomic backgrounds globally. It frequently strikes early in life and becomes a chronic or recurring lifelong illness. Out of the various hypotheses for the pathophysiology of depression, the gut-brain axis and stress hypothesis are the ones that need to be researched, as psychological stress impairs one or more pathways of the brain-gut axis and is likely to cause brain-gut axis dysfunction and depression. A dysfunctional reciprocal gut-brain relationship may contribute to many diseases, including inflammatory disorders, abnormal stress responses, impaired behavior, and metabolic changes. The hormone ghrelin is a topic of interest concerning the gut-brain axis as it interacts with the gut-brain axis indirectly via the central nervous system or via crossing the blood-brain barrier. Ghrelin release is also affected by the gut microbes, which has also been discussed in the review. This review elaborates on Ghrelin's role in depression and its effect on various aspects like neurogenesis, HPA axis, and neuroinflammation. Furthermore, this review focuses on ghrelin as a potential target for alleviation of depressive symptoms.

Natural disaster-induced dementia and cognitive decline: A meta-analysis and systematic review

Recently, some studies have noted a negative cognitive impact on individuals in the aftermath of large-scale natural disasters; however, the causal relationship between disasters and cognitive/neurodegenerative effects remains widely unexplored. This review analyzes the impact of natural disasters on the development of cognitive decline (CD), all-cause dementia, and Alzheimer's disease (AD) in disaster-affected individuals. Studies reported from their inception to August 2023 were obtained via public online databases. All data presented in this review was derived from precalculated study results, data presented within/alongside articles, or statistics calculated using data obtained by contacting the articles' authors for ancillary information. Data from 28 studies, representing 4,606,561 individuals, 158,994 CD events, 179,694 dementia events, and 47,193 AD events was included for analysis. The pooled odds ratio (OR) and 95% confidence interval (CI) estimates showed that natural disasters significantly increased the risk of CD (OR: 1.25, CI: 1.20-1.30), all-cause dementia (OR: 1.07, CI: 1.05-1.08), and AD (OR: 1.07, CI: 1.05-1.10) in disaster victims as opposed to less- or non-impacted individuals. The greatest effects were noted following hurricanes, earthquakes with tsunamis, and heat waves. The findings from this meta-analysis indicate that natural disasters are significantly associated with the development of CD, all-cause dementia, and AD.

Multiple dimensions approach in polysubstance use: An ESEM analysis based on the RDoC framework

Substance use disorders (SUD) are associated with cognitive alterations, influenced by genetic, neurodevelopmental, and environmental factors, and frequently co-occur with emotional disorders, complicating treatment strategies. Employing the Research Domain Criteria (RDoC) framework and Exploratory Structural Equation Modeling (ESEM), this study investigated the direct and indirect relationships between drug abuse, neurocognitive performance, emotional indicators, and structural changes in brain regions implicated in emotional regulation and executive functions in SUD patients and healthy controls. High-resolution magnetic resonance imaging (MRI) scans were acquired from patients with SUD (n=50) and healthy controls (HC=50). Group differences were assessed using voxel-based morphometry (VBM) and regions of interest (ROIs). Participants were evaluated for substance use (ASSIST) and completed a battery of cognitive tasks and emotional tests. The SUD group exhibited higher levels of depression and anxiety, as well as cognitive deficits, compared to the control group. Additionally, the SUD group showed significantly lower gray matter volume (GMV) in cortical and limbic areas. However, the ESEM analysis indicated that limbic areas indirectly and negatively impacted ASSIST scores. Thus, we can conclude that structural impairments in limbic areas strongly influenced substance use patterns, even when reductions in cortical volume and impaired cognitive performance were also present.

Effects of group music therapy on depressive symptoms in women - The MUSED-study: Results from a randomized-controlled trial

BACKGROUND

Music can directly influence emotions, the regulation of which are known to be impaired in major depressive disorder (MDD). While music therapy (MT) could be an effective complement to treat MDD, studies investigating such effects have not yet yielded conclusive results. We hypothesized that group music therapy (GMT) might lead to a significant reduction of depressive symptoms (DS).

METHODS

In a randomized controlled trial, 102 women with current MDD were randomly assigned to an intervention group receiving GMT or a waitlist control group. Data assessment was conducted pre- (T0), post- (T1), and at a 10-week follow-up to (T2) the intervention. DS as the primary outcome were assessed via observer-rated (Hamilton Depression Rating Scale, T0-T1), self-rated (Beck Depression Inventory, T0-T1-T2), and ecological momentary (T0-T1) assessments. Secondary effects on emotion and mood regulation strategies, and quality of life (QoL), were measured T0-T1-T2.

RESULTS

The results suggest non-significant effects of the GMT on a descriptive level on self-reported and observer rated DS and statistically significant effects on DS in everyday life, QoL, and regulation strategies, with larger effects from T0-T1 than from T0-T1-T2.

LIMITATIONS

The generalizability is limited by the high dropout rate and data loss due to the COVID-19 pandemic, the fact that long-term effects of GMT are not assured, and the homogeneous gender (female) of the sample.

CONCLUSIONS

GMT is an economical approach to treat MDD, yielding health-promoting effects regarding DS, emotion regulation, and QoL. Manualization and further evaluation of MT is strongly recommended.

The trajectory of depressive symptoms and the association with quality of life and suicidal ideation in patients with major depressive disorder

BACKGROUND

Major depressive disorder (MDD) is the most prevalent mental health disorder globally. However, the association between depressive symptom trajectories in the early period and subsequent mental health outcomes remains not fully elucidated. This study aimed to delineate the depressive symptom trajectories during the initial phase of treatment, identify baseline characteristics associated with these trajectories, and explore the association of trajectories with subsequent quality of life and suicidal ideation.

METHODS

Participants were from the Depression Cohort in China. The diagnosis of MDD was assessed using the Mini-International Neuropsychiatric Interview (M.I.N.I.). Information on depressive symptom severity, quality of life, suicidal ideation and other demographics were collected. Latent class trajectory modeling was used to identify distinct classes of depressive symptom trajectories.

RESULTS

A total of 566 patients with MDD were included, and we identified 3 categories with differential trajectories characterized by improving class (66.7%), moderate decreasing class (27.7%), and persistent high class (5.6%). Compared to the improving class, severer anxiety and depressive symptoms at baseline increased the odds of belonging to the moderate decreasing class and persistent high class. Both moderate decreasing class and persistent high class were associated with increased risks of subsequent diminished quality of life. Additionally, only persistent high class was associated with a higher risk of subsequent suicidal ideation.

CONCLUSION

Severe baseline anxiety and depressive symptoms identify a subpopulation of persons living with MDD who evince a greater likelihood of symptom worsening over time as well as greater decrements in quality of life and worsening measures of suicidality.

From Stress to Synapse: The Neuronal Atrophy Pathway to Mood Dysregulation

Mood disorders, including major depressive disorder and bipolar disorder, are among the most prevalent mental health conditions globally, yet their underlying mechanisms remain incompletely understood. This review critically examines the neuronal atrophy hypothesis, which posits that chronic stress and associated neurobiological changes lead to structural and functional deficits in critical brain regions, contributing to mood disorder pathogenesis. Key mechanisms explored include dysregulation of neurotrophic factors such as brain-derived neurotrophic factor (BDNF), elevated glucocorticoids from stress responses, neuroinflammation mediated by cytokines, and mitochondrial dysfunction disrupting neuronal energy metabolism. These processes collectively impair synaptic plasticity, exacerbate structural atrophy, and perpetuate mood dysregulation. Emerging evidence from neuroimaging, genetic, and epigenetic studies underscores the complexity of these interactions and highlights the role of environmental factors such as early-life stress and urbanization. Furthermore, therapeutic strategies targeting neuroplasticity, including novel pharmacological agents, lifestyle interventions, and anti-inflammatory treatments, are discussed as promising avenues for improving patient outcomes. Advancing our understanding of the neuronal atrophy hypothesis could lead to more effective, sustainable interventions for managing mood disorders and mitigating their global health burden.

Associations between low food security and subjective memory complaints among Latino adults

BACKGROUND

Low food security is related with worse cognitive outcomes and poor mental health (e.g., higher anxiety and depression) may explain these associations. Subjective memory complaints may be important indicators of everyday memory problems. Despite a higher prevalence of food insecurity among Latinos, few have explored the links between low food security and subjective memory complaints in Latinos, or potential mechanisms underlying the associations.

METHODS

We used the Sangre Por Salud Biobank sample of 2,481 self-reported Latino patients aged 18-85 from a federally qualified community health center in Phoenix, AZ. Food security was assessed using the 6-item Household Food Security Survey Module and subjective memory complaints were measured using the Frequency of Forgetting Scale. We used linear regressions to test associations between low food security and subjective memory complaints, whether associations were explained by anxiety and depression, and whether associations differed by age or biological sex.

RESULTS

Around 76% of the sample were food secure, with 18% and 6% experiencing low and very low food security, respectively. In multivariate analyses, compared to the food secure, both low and very low food security related with higher subjective memory complaints and these associations were not modified by age or biological sex. Associations between low food security and subjective memory complaints were no longer significant after adjusting for anxiety and depression, suggesting that poor mental health may mediate associations between low food security and subjective memory complaints.

CONCLUSIONS

Experiences of low food security were related with more frequent memory complaints. Subjective memory complaints are related with future cognitive impairment and dementia, making them important early markers of cognitive problems. Future studies should evaluate potential cognitive benefits of addressing food insecurity and its downstream effects on mental health.

6-Shogaol, a neuro-nutraceutical derived from ginger, alleviates motor symptoms and depression-like behaviors and modulates the release of monoamine neurotransmitters in Parkinson's disease mice

PURPOSE

Parkinson's disease (PD) disrupts the regulation of neurotransmitters in the brain, causing patients to experience not only motor symptoms but also non-motor symptoms such as depression. 6-shogaol (6S) is a potential neuro-nutraceutical derived from ginger, and is known to ameliorate motor symptoms by suppressing inflammation in PD mice. In this study, we investigated whether 6S can attenuate motor symptoms and depression-like behaviors through neurotransmitter regulation and to elucidate which neurotransmitters are intimately correlated with these effects.

METHODS

C57BL/6 J mice were injected with 30 mg/kg of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) for 5 d to induce PD. 6S was administered via oral gavage for 11 d, including the MPTP injection period.

RESULTS

6S alleviated MPTP-induced motor symptoms and depression-like behaviors. MPTP injection decreased the levels of seven neurotransmitters in the striatum and four neurotransmitters in the hippocampus. Administration of 6S increased striatal dopamine, serotonin, and norepinephrine levels and hippocampal dopamine, norepinephrine, serotonin, and γ-aminobutyric acid levels. Moreover, correlation analysis shown that the motor symptom improvement effect of 6S was associated with striatal dopamine, norepinephrine, serotonin, and 5-hydroxyindoleacetic acid levels. The effect of 6S on depressive-like behavior was significantly correlated with striatal dopamine metabolites and serotonin and hippocampal dopamine, norepinephrine, and serotonin. Immunohistochemistry showed that 6S upregulated the expression of the vesicular monoamine transporter 2, which was reduced by MPTP in the striatum and hippocampus.

CONCLUSION

This study demonstrated that 6S improved motor symptoms and depression-like behaviors by regulating the release of monoamine neurotransmitters.

Prediction model for psychological disorders in ankylosing spondylitis patients based on multi-label classification

Objective

This study aims to develop a predictive model to assess the likelihood of psychological disorders in patients with ankylosing spondylitis (AS) and to explore the relationships between different factors and psychological disorders.

Methods

Patients were randomly divided into training and test sets in an 8:2 ratio. The Boruta algorithm was applied to select predictive factors, and a multi-label classification learning algorithm based on association rules (AR) was developed. Models were constructed using Random Forest (RF), K-Nearest Neighbor (KNN), RF-AR, and KNN-AR, and their performance was assessed through receiver operating characteristic (ROC) curves on the test set.

Results

A total of 513 AS patients were included, with 410 in the training set and 103 in the test set. The Boruta algorithm identified five key variables for the model: fatigue, ASAS-HI score, disease duration, disease activity, and BMI. The RF-AR model performed best, with an accuracy of 0.89 ± 0.06, recall of 0.78 ± 0.1, F1-score of 0.86 ± 0.08, Hamming loss of 0.05 ± 0.03, and a Jaccard similarity coefficient of 0.75 ± 0.12. The area under the curve (AUC) for the training set was 0.94.

Conclusion

This study developed a predictive model for assessing the risk of psychological disorders in AS patients. The model effectively captures the presence of psychological disorders, providing clinicians with valuable insights for adjusting treatment strategies.

Melatonin Alleviates Behavioral and Neurodevelopmental Abnormalities in Offspring Caused by Prenatal Stress

BACKGROUND

Prenatal stress (PNS) is a significant risk factor impacting the lifelong health of offspring, and it has been widely recognized as being closely linked to the increased prevalence of neurodevelopmental disorders and psychiatric illnesses. However, effective pharmacological interventions to mitigate its detrimental effects remain limited. Melatonin (Mel), an endogenous hormone, has demonstrated considerable potential in treating neurological diseases due to its anti-inflammatory, antioxidant, and neuroprotective properties, as well as its favorable safety profile and broad clinical applicability.

OBJECTIVE

This study aims to investigate the protective effects and mechanisms of melatonin on neurodevelopmental and behavioral abnormalities in offspring induced by prenatal stress.

METHODS

Using a prenatal stress mouse model, we evaluated the effects of melatonin on emotional and cognitive deficits in offspring. Neurogenesis and synaptic development were assessed, and RNA sequencing was performed to analyze microglial gene enrichment and immune-related pathways. Both in vivo and in vitro experiments were conducted to validate the findings, focusing on the PI3K/AKT/NF-κB signaling pathway in microglia.

RESULTS

Melatonin administration alleviated emotional and cognitive deficits in offspring mice exposed to prenatal stress, addressing abnormalities in neurogenesis and synaptic development. Additionally, RNA sequencing revealed that melatonin suppresses microglial gene enrichment and the upregulation of immune-related pathways. Both in vivo and in vitro validation indicated that melatonin modulates the PI3K/AKT/NF-κB signaling pathway in microglia, reducing the elevated expression of CXCL10 in the dentate gyrus, thereby restoring normal neuro-supportive functions and optimizing the neurodevelopmental environment.

CONCLUSION

These findings suggest that melatonin significantly improves neurodevelopmental disorders and behavioral abnormalities caused by prenatal stress by inhibiting pathological microglial activation and promoting hippocampal neurogenesis and synaptic plasticity. This provides new insights into melatonin's potential as a neuroprotective agent for treating prenatal stress-related disorders.

Spaced Transcranial Direct Current Stimulation for Major Depression

OBJECTIVE

This study investigated spaced transcranial direct current stimulation for major depressive disorder, focusing on feasibility.

METHODS

In a prospective open-label study, 30 participants with major depressive disorder were enrolled to receive a 50-session transcranial direct current stimulation (tDCS) treatment over 2 weeks. The feasibility, safety, tolerability, and preliminary therapeutic effects of this tDCS protocol were assessed using the 17-item Hamilton Depression Rating Scale (HAM-D-17) and the Montgomery-Åsberg Depression Rating Scale (MADRS) at baseline and 1-week and 4-week follow-ups, as well as with the 6-item HAM-D (HAM-D-6) daily during treatment.

RESULTS

The protocol demonstrated good feasibility, with a retention rate of 93.3% and an adherence rate of 99.7%. There were no serious adverse events. The most common side effect was a mild tingling and itching sensation during stimulation (100%) and temporary skin redness following stimulation (100%). Additionally, 64.3% of participants presented with mild irritative contact dermatitis, which had disappeared by the 1-week follow-up for most participants and completely resolved by the 4-week follow-up for the remaining cases; this was not treatment limiting and did not require specific treatment. HAM-D-17 scores decreased from a mean of 21.3 (SD=3.0) at baseline to 15.3 (SD=6.3) at 1 week and 13.2 (SD=7.1) at 4 weeks. Depressive symptom severity, as measured by the HAM-D-17, showed significant reductions over time, with similar trends observed on the MADRS. HAM-D-6 scores highlighted important differences between response groups, particularly during the later stages of treatment, suggesting a potential for differential response patterns between the 1-week and 4-week follow-ups.

CONCLUSIONS

The protocol was feasible, safe, and well-tolerated and led to significant reductions in depressive symptoms. These results will need to be validated in a sham-controlled randomized trial. The inclusion of neurophysiological measures in future trials for purposes of biological target engagement might also contribute to our understanding of underlying mechanisms and biomarker discovery.

The effectiveness of non-invasive brain stimulation in treatment of major depressive disorder (MDD): a systematic review and transfer analysis

This study aimed to analyze the transferability of non-invasive brain stimulation (NIBS) interventions in individuals with major depressive disorder (MDD) based on the FIELD model (Function, Implementation, Ecology, Level, and Duration), encompassing function, implement, ecology, level, and duration. A systematic search of electronic databases yielded a total of 21 eligible studies, comprising 12 transcranial direct current stimulation (tDCS) and 9 transcranial magnetic stimulation (TMS) trials, involving 1029 individuals with MDD. The meta-analysis of effect sizes revealed positive transfer effects across all domains of the FIELD model, suggesting that NIBS interventions have potential efficacy in improving various facets of MDD. The subgroup analysis highlighted that bilateral dlPFC stimulation exhibited the highest effect size for transferability, indicating greater transferability for rTMS, a higher dose of stimulation, and the integration of additional interventions. Additionally, the study discusses the implications of bilateral dorsolateral prefrontal cortex (dlPFC) stimulation and the integration of complementary therapies for optimizing treatment efficacy.

Moderating effect of instrumental activities of daily living on the relationship between loneliness and depression in people with cognitive frailty

BACKGROUND

The identification of depression and loneliness among people with cognitive frailty (CF) could prevent negative psychological and physical health outcomes. Few studies have focused on physical and mental health together, and little is known about the role of daily activity in the association between depression and loneliness among elderly individuals with CF.

OBJECTIVES

To determine the positive effect of loneliness on depression among community-dwelling older adults with CF as well as the moderating effect of instrumental activities of daily living (IADL) on this association.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

This cross-sectional study included 529 adults aged 65 years and older from a community-dwelling population who were screened for CF and was conducted from July 2023 to December 2023. The participants were assessed via validation instruments for the following main variables: Short-form Geriatric Depression Scale, Loneliness Questionnaire, Athens Insomnia Scale, Instrumental Activities of Daily Living (IADL), Social Support Scale, and sociodemographic characteristics. The participants were classified as having reversable CF (RCF) or potentially reversable CF (PRCF).

RESULTS

The IADL, depression, insomnia, and loneliness scores were lower among individuals with RCF than among individuals PRCF. The moderating effect of IADL scores shows that the relationship between loneliness and depression has a steeper and positive slope when lower levels of IADL exist, compared with a straight line when there are higher levels of IADL, for this case, the line is less steep and showed negative association.

CONCLUSIONS

The integrity of physical and social connections has a protective effect on the mental health of elderly people with CF. It is necessary to pay attention to disability and loneliness among elderly individuals. Targeted interventions for improving physical activity and social participation seem to be practical and feasible solutions to alleviate depressive symptoms.

Three-protein signature is associated with baseline and persistently elevated or recurrent depressive symptoms in individuals with recent-onset diabetes

Depression is associated with diabetes, but the underlying causes remain unclear. To better understand depression in diabetes, this study investigated associations between 135 inflammatory and neurological protein biomarkers and depressive symptoms in individuals with diabetes.This cross-sectional study included 430 adults with a known diabetes duration <1 year from the German Diabetes Study (GDS), in whom biomarkers were measured in serum and depressive symptoms were evaluated at baseline and annually over 5 years using the Center for Epidemiological Studies Depression Scale (CES-D). Based on the information on depressive symptoms from the baseline and follow-up visits (n=305, ≥3 time points), we subdivided the sample into individuals with persistent or recurrent and transient or never depressive symptoms. We assessed the associations of each biomarker with baseline CES-D score (continuous) and persistent/recurrent depressive symptoms using multiple linear and logistic regression models, respectively.After adjustment for covariates, we identified a three-protein signature associated with baseline CES-D score and persistent/recurrent depressive symptoms. CUB domain-containing protein 1 (CDCP1) and NAD-dependent protein deacetylase sirtuin-2 (SIRT2) were positively associated with baseline (β 1.24 (95% CI 0.19 to 2.29); β 0.89 (95% CI 0.06 to 1.72)), respectively) and persistent/recurrent depressive symptoms (OR 1.58 (95% CI 1.08 to 2.31); OR 1.32 (95% CI 1.03 to 1.71), respectively), whereas leptin receptor (LEPR) was inversely associated with baseline (β -0.99 (95% CI -1.87 to -0.11)) and persistent/recurrent depressive symptoms (OR 0.70 (95% CI 0.49 to 0.99)). However, results were not significant after adjustment for multiple testing.In conclusion, the three-protein signature identified may provide insights into mechanisms underlying depressive symptoms in diabetes and might open new therapeutic avenues.The trial registration number of the study is NCT01055093.

The Use of MRI and TMS in Treatment-Resistant Depression: Advances in Pediatric Applications

Treatment-resistant depression (TRD) is a substantial burden for psychiatric care, affecting approximately one-third of patients with major depressive disorder (MDD). Adolescent populations with depression are a particularly challenging demographic to treat as early intervention is crucial to prevent treatment resistance, but treatment options are limited. Transcranial magnetic stimulation (TMS) has emerged as a promising non-invasive option for TRD in adults as well as adolescents, offering hope for patients who have not responded to conventional therapies. This review examines the convergence of functional magnetic resonance imaging (fMRI) as a tool to examine how TMS modulates functional connectivity in adolescents with MDD. Such analyses have led to advances in our understanding of the pathophysiology of MDD, TRD, and the mechanisms of TMS. We review this evidence, evaluate methodological approaches, and identify critical gaps in the existing literature, highlighting how neuroimaging-guided TMS protocols offer a promising therapeutic avenue for adolescent TRD, particularly in cases where conventional treatments have proven ineffective.

Traditional Chinese herbal formula, Fuzi-Lizhong pill, produces antidepressant-like effects in chronic restraint stress mice through systemic pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Fuzi-Lizhong pill (FLP) is a well-validated traditional Chinese medicine (TCM) formula that has long been used in China for gastrointestinal disease and adjunctive therapy for depression. In our previous study, we reported that the principal herb of FLP, Aconitum carmichaelii Debx. (Fuzi), exhibits antidepressant-like effects. However, there have been no reports on whether FLP produces antidepressant-like effects and its potential molecular mechanisms.

AIM OF THE STUDY

We aim to demonstrate the antidepressant-like effects of FLP in chronic restraint stress (CRS) mice and to explore the associated molecular mechanisms.

MATERIALS AND METHODS

The active components and probable molecular targets of FLP, as well as the targets related to depression, were identified through network pharmacology. A protein-protein interaction (PPI) network was generated using the overlapping targets, followed by the visualization as well as identification of the core targets associated with the antidepressant-like action of FLP. Subsequently, KEGG and GO enrichment analyses were conducted. UHPLC-MS/MS was employed to further detect the active compounds in FLP. Molecular docking was applied to assess the connections between the active components as well as the core targets. The efficacy of FLP in treating depression and its molecular mechanisms were examined using western blotting, ELISA, 16S rRNA sequencing, HE staining, Nissl staining, and Golgi-Cox staining in a CRS-induced mouse model.

RESULTS

Network pharmacology and UHPLC-MS/MS analyses indicated that the active compounds of FLP comprised taraxerol, songorine, neokadsuranic acid B, ginkgetin, hispaglabridin B, quercetin, benzoylmesaconine and liquiritin. KEGG pathway analysis implicated that the PI3K/Akt/mTOR as well as MAPK signaling pathways are closely related to the therapeutic effects of FLP on depression. Molecular docking analysis demonstrated that the main components of FLP bind to PI3K, AKT, mTOR, BDNF and MAPK. FLP significantly decreased immobility in mice that were elevated by CRS in the FST and the TST. FLP also significantly increased sucrose preference in mice after CRS in the SPT. FLP upregulated proteins associated with BDNF-TrkB and PI3K/Akt/mTOR signaling and downregulated proteins associated with MAPK signaling. Serum levels of CORT, IL-6, IL-1β, and TNF-α in CRS mice were significantly decreased following treatment with FLP. In addition, FLP ameliorated CRS-induced gut microbiota dysbiosis as demonstrated by 16S rRNA sequencing analysis. FLP ameliorated CRS-induced intestinal inflammation and neuronal damage. Finally, antidepressant-like effects and concomitant increases in dendritic spine density induced by FLP administration were also reduced after rapamycin treatment.

CONCLUSION

These results demonstrate that FLP has antidepressant-like effects in mice exposed to CRS that involve activation of the PI3K/Akt/mTOR signaling pathway, increase in spinogenesis, inhibition of the MAPK signaling pathway, decrease in inflammation, and amelioration of gut microbiota dysbiosis. These findings provide novel evidence for the clinical application of FLP on depression.

Lifestyle factors and other predictors of common mental disorders in diagnostic machine learning studies: A systematic review

BACKGROUND

Machine Learning (ML) models have been used to predict common mental disorders (CMDs) and may provide insights into the key modifiable factors that can identify and predict CMD risk and be targeted through interventions. This systematic review aimed to synthesise evidence from ML studies predicting CMDs, evaluate their performance, and establish the potential benefit of incorporating lifestyle data in ML models alongside biological and/or demographic-environmental factors.

METHODS

This systematic review adheres to the PRISMA statement (Prospero CRD42023401194). Databases searched included MEDLINE, EMBASE, PsycInfo, IEEE Xplore, Engineering Village, Web of Science, and Scopus from database inception to 28/08/24. Included studies used ML methods with feature importance to predict CMDs in adults. Risk of bias (ROB) was assessed using PROBAST. Model performance metrics were compared. The ten most important variables reported by each study were assigned to broader categories to evaluate their frequency across studies.

RESULTS

117 studies were included (111 model development-only, 16 development and validation). Deep learning methods showed best accuracy for predicting CMD cases. Studies commonly incorporated features from multiple categories (n = 56), and frequently identified demographic-environmental predictors in their top ten most important variables (63/69 models). These tended to be in combination with psycho-social and biological variables (n = 15). Lifestyle data were infrequently examined as sole predictors of CMDs across included studies (4.27 %). Studies commonly had high heterogeneity and ROB ratings.

CONCLUSION

This review is the first to evaluate the utility of diagnostic ML for CMDs, assess their ROB, and evaluate predictor types. CMDs were able to be predicted, however studies had high ROB and lifestyle data were underutilised, precluding full identification of a robust predictor set.

Influence of depression severity on interhemispheric functional integration: an analysis from the REST-meta-MDD database

Major depressive disorder (MDD) is a pervasive mental disorder that significantly impairs functional capabilities, underscoring the necessity for precise stratification of its severity to facilitate tailored treatment. This study investigated the utility of voxel-mirrored homotopic connectivity (VMHC) derived from resting-state functional magnetic resonance imaging (fMRI) data as a neuroimaging biomarker to differentiate varying severities of MDD in a sample drawn from the REST-meta-MDD project, which included 392 first-episode MDD patients and 440 healthy controls (HC) from 9 sites. Patients were classified into mild to moderate and severe depression groups according to the 17-item Hamilton Depression Scale (HAMD) scores. VMHC differences between these subgroups and their associations with HAMD scores were further examined. The results revealed significant reductions in VMHC within the fusiform gyrus for patients with mild to moderate depression compared to HCs, alongside more extensive reductions across the insula, postcentral gyrus, and angular gyrus in severe depression. Notably, increased VMHC in the middle cingulate cortex was identified in severe MDD patients relative to those with mild to moderate depression, with this increase showed a significant positive correlation with the HAMD scores. Additionally, receiver operating characteristic (ROC) curve analysis demonstrated that VMHC values in these regions effectively differentiate patients from HCs and across varying severities of MDD. These findings suggest that VMHC could serve as a valuable metric for clinical diagnosis and the stratification of depression severity, providing insights into the underlying neurobiological mechanisms associated with the disorder.

Structural connectivity of thalamic subnuclei in major depressive disorder: An ultra-high resolution diffusion MRI study at 7-Tesla

BACKGROUND

The thalamus serves as a central relay station within the brain, and thalamic connectional anomalies are increasingly thought to be present in major depressive disorder (MDD). However, the use of conventional MRI scanners and acquisition techniques has prevented a thorough examination of the thalamus and its subnuclear connectional profile. We combined ultra-high field diffusion MRI acquired at 7.0 Tesla to map the white matter connectivity of thalamic subnuclei.

METHODS

Fifty-three MDD patients and 12 healthy controls (HCs) were involved in the final analysis. FreeSurfer was used to segment the thalamic subnuclei, and MRtrix was used to perform the preprocessing and tractography. Fractional anisotropy, axial diffusivity, mean diffusivity, radial diffusivity, and streamline count of thalamic subnuclear tracts were measured as proxies of white matter microstructure. Bayesian multilevel model was used to assess group differences in white matter metrics for each thalamic subnuclear tract and the association between these white matter metrics and clinical features in MDD.

RESULTS

Evidence was found for reduced whiter matter metrics of the tracts spanning from all thalamic subnuclei among MDD versus HC participants. Moreover, evidence was found that white matter in various thalamic subnuclear tracts is related to medication status, age of onset and recurrence in MDD.

CONCLUSIONS

Structural connectivity was generally reduced in thalamic subnuclei in MDD participants. Several clinical characteristics are related to perturbed subnuclear thalamic connectivity with cortical and subcortical circuits that govern sensory processing, emotional function, and goal-directed behavior.

Unpredictable chronic mild stress induced anxio-depressive disorders and enterobacteria dysbiosis: Potential protective effects of Detariummicrocarpum

ETHNOPHARMACOLOGICAL RELEVANCE

Detarium microcarpum Guill. & Perr. is used traditionally in Far North Cameroun to treat stomach aches, anxiety, epilepsy, and other mental disorders.

AIM OF THE STUDY

Evaluate the anxiolytic and antidepressant-like effects of D. microcarpum (DM) in unpredictable chronic mild stress (UCMS) model of depression in male rats and its impact on fecal enterobacteria of stressed rats.

MATERIALS AND METHODS

Rats were handled daily (control) or subjected to the UCMS procedure for 42 days. Anxiety-like behaviors were assessed using the light and dark box test (LBD) and the open field test (OFT). Depressive-like behaviors were assessed using the forced swimming test (FST), the sucrose preference test (SPT), and the novelty suppressed feeding test (NSFT). Feces were then collected, followed by blood, brain, and duodenum sections after sacrifice. Monoamine levels, pro-inflammatory cytokines, oxidative stress factors, and nitrosative stress were assessed. Feces were introduced into Hectoen enteric agar for the identification of enterobacteria. An in vitro growth test was performed.

RESULTS

The DM ethanolic extract has significantly increased the time spent in the light box, in the LBD, and in the center area of the OFT. Moreover, the extract has significantly reduced the preference for sucrose in the SPT, the time of immobility in the FST, and the latency period to consume the pet in the NSFT. DM extract has significantly reduced serum cortisol levels. It also significantly decreased the pro-inflammatory cytokines TNF-α and Il-1β in both brain and duodenum homogenate. DM has increased the brain's serotonin, GABA, and dopamine levels. The DM extract also decreased the MDA and nitrite levels. It also increased the SOD and CAT activities in both brain and duodenal homogenate. Histologically, the DM extract restored the cell's density in hippocampi sections and prevented gut inflammation and peroxidation characterizing leaky gut syndrome. DM extract has no effect on the growth of enterobacteria species isolated in vitro.

CONCLUSION

The ethanolic extract of DM would have anxiolytic and antidepressant effects via the modulation of the HPA axis, brain antioxidant enzyme activities, inflammation, and nitrosative stress. Moreover, it could act by preventing leaky gut syndrome.

The immunological perspective of major depressive disorder: unveiling the interactions between central and peripheral immune mechanisms

Major depressive disorder is a prevalent mental disorder, yet its pathogenesis remains poorly understood. Accumulating evidence implicates dysregulated immune mechanisms as key contributors to depressive disorders. This review elucidates the complex interplay between peripheral and central immune components underlying depressive disorder pathology. Peripherally, systemic inflammation, gut immune dysregulation, and immune dysfunction in organs including gut, liver, spleen and adipose tissue influence brain function through neural and molecular pathways. Within the central nervous system, aberrant microglial and astrocytes activation, cytokine imbalances, and compromised blood-brain barrier integrity propagate neuroinflammation, disrupting neurotransmission, impairing neuroplasticity, and promoting neuronal injury. The crosstalk between peripheral and central immunity creates a vicious cycle exacerbating depressive neuropathology. Unraveling these multifaceted immune-mediated mechanisms provides insights into major depressive disorder's pathogenic basis and potential biomarkers and targets. Modulating both peripheral and central immune responses represent a promising multidimensional therapeutic strategy.

Depressive symptoms are linked to age-specific neuroanatomical and cognitive variations

Depression is a heterogeneous disorder, both in terms of patient symptomatology and in patient sociodemographic factors. Here, we examine the contribution of age to this heterogeneity, by characterizing the associations of depressive symptoms with cognitive performance and brain structure across the lifespan. We analyzed data from the Cambridge Centre for Aging Neuroscience (Cam-CAN) cohort (N = 2591, age 18-99). A subset of this cohort (N = 647) underwent structural MRI. Depressive symptoms were measured using the Hospital Anxiety and Depression Scale. Cognitive assessments were performed using The Addenbrooke's Cognitive Examination Revised. Generalized linear models were employed to examine the relationship between depressive symptoms and cognitive performance. Statistical parametric mapping explored age-dependent associations between depressive symptoms and grey matter volume. Cognitive performance was associated with a significant age by depression by cognitive domain interaction, indicating that older individuals with more depressive symptoms had a lower cognitive performance, particularly in the fluency domain. Structural MRI revealed preferential depression-related reduction in grey matter volume in the left and right hippocampi in older adults. By contrast, in younger adults, depressive symptoms were more strongly associated with grey matter volume reduction in the left superior frontal gyrus and left middle frontal gyrus. Collectively, these findings indicate that the associations of depression with cognitive performance and brain structure are age-dependent, suggesting that the pathophysiological mechanisms underlying depression may differ between young and older adults. Recognizing these differences will support the development of better diagnostic tools and therapeutic interventions for depression across the lifespan.

Glutamate chemical exchange saturation transfer (GluCEST) MRI to evaluate the relationship between demyelination and glutamate content in depressed mice

Glutamatergic alteration is one of the potential mechanisms of depression. However, there is no consensus on whether glutamate metabolism changes affect the myelin structure of depression in mouse models. Glutamate chemical exchange saturation transfer (GluCEST) is a novel and powerful molecular imaging technique that can visualize glutamate distribution. In this study, we used the GluCEST imaging technique to look at glutamate levels in mice under chronic unpredictable mild stress (CUMS) and how they relate to demyelination. The CUMS mice were exposed to different stress factors for 6 weeks. Evaluated of depression in CUMS mice by behavioral tests. MRI scans were then performed, including T2-mapping, GluCEST, and diffusion tensor imaging (DTI) sequences. Brain tissues were collected for Luxol Fast Blue staining and immunofluorescence staining to analyze the changes in the myelin sheath. Artificially sketched regions of interest (ROI) (corpus callosum, hippocampus, and thalamus) were used to calculate the GluCEST value, fractional anisotropy (FA), and T2 value. Compared with the control group, the GluCEST value in the ROIs of CUMS mice significantly decreased. Similarly, the FA value in ROIs was lower in the CUMS group than in the CTRL group, but the T2 value did not differ significantly between the two groups. The histological results showed that ROIs in the CUMS group had demyelination compared with the CTRL group, indicating that DTI was more sensitive than T2 mapping in detecting myelin abnormalities. Furthermore, the GluCEST value in the ROIs correlates positively with the FA value. These findings suggest that altered glutamate metabolism may be one of the important factors leading to demyelination in depression, and GluCEST is expected to serve as an imaging biological marker for the diagnosis of demyelination in depression.

In vivo evidence of increased vascular endothelial growth factor in patients with major depressive disorder

BACKGROUND

Vascular endothelial growth factor (VEGF) is a candidate mediator of blood-brain barrier (BBB) disruption in depression. However, previous studies have mainly focused on peripheral blood VEGF levels, and the results are heterogeneous. Here we use astrocyte-derived extracellular vesicles (ADEVs) isolated from plasma to explore the in vivo changes of VEGF levels in patients with major depressive disorder (MDD).

METHODS

Thirty-five unmedicated patients with MDD and 35 healthy controls (HCs) were enrolled, and plasma ADEVs were isolated from each participant. VEGF levels in ADEVs and glial fibrillary acidic protein (GFAP) in plasma were measured. Additionally, Alix and CD81, two established extracellular vesicle markers, were quantified in ADEVs.

RESULTS

At baseline, MDD patients exhibited significantly increased levels of VEGF in ADEVs and GFAP in plasma. Following four weeks of selective serotonin reuptake inhibitor treatment, these target protein levels did not significantly change. ROC curve analysis revealed an AUC of 0.711 for VEGF in ADEVs. In exploratory analysis, VEGF levels in ADEVs were positively correlated with Alix and CD81.

LIMITATIONS

Multiple factors regulate BBB permeability. This study focused solely on VEGF and the sample size for longitudinal analysis was relatively small.

CONCLUSION

Our study is the first to confirm increased ADEV-derived VEGF levels in patients with MDD, thereby providing preliminary evidence supporting the hypothesis that the BBB is disrupted in depression.

Fasting the brain for mental health

Unfavorable socioeconomic and geopolitical conditions such as poverty, violence and inequality increase vulnerability to mental disorders. Also, exposure to a poor nutrition such as high-energy dense (HED) diets has been linked to alterations in brain function, leading to anxiety, addiction, and depression. HED diets rich in saturated fatty acids or obesity can activate the innate immune system in the brain, especially microglia, increasing proinflammatory cytokines such as interleukin 1 beta (IL1-β) and interleukin 6 (IL-6), in part, by the stimulation of toll-like receptor 4 (TLR4) and the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) pathway. Intermittent fasting (IF), an eating protocol characterized by alternating periods of fasting with periods of eating, has gained recognition as a weight-management strategy to reduce obesity. Accordingly, during IF inflammation and brain function can be modulated by production of ketone bodies and modulation of the intestinal microbiota, which also promote the induction of brain-derived neurotrophic factor (BDNF), which is involved in neurogenesis and neuronal plasticity. Although IF has contributed to reduce body weight and improve metabolic profiles, its influence on mental health remains an evolving field of research. Here, we provide experimental evidence supporting the role of IF reducing neuroinflammation as a valuable approach to improve mental health.

The association between childhood adversity and hippocampal volumes is moderated by romantic relationship experiences

Reduced hippocampal volumes are a feature of many mental disorders. Childhood maltreatment is a known risk factor for the development of psychopathology and has consistently been linked to hippocampal volume reductions in adults, but not in children and adolescents. We propose that maltreatment-related difficulties in coping with developmental tasks in adolescence and young adulthood might underlie the delayed emergence of hippocampal volume reductions in maltreated individuals. In a study with 196 healthy young adults (mean age [years]: 24.0 ± 3.2, 50% female, 20.6% living with a partner (missings: n = 2)), we investigated the interaction between childhood maltreatment (Childhood Trauma Screener) and the breakup of a steady romantic relationship (List of Threatening Experiences Questionnaire) on hippocampal magnetic resonance imaging grey matter volumes. The experience of a romantic relationship breakup moderated the association between childhood maltreatment and bilateral hippocampal volumes, revealing more negative associations with hippocampal volumes in participants with at least one breakup compared to those with no breakup experience (right hippocampus: β = - 0.05 ± 0.02, p = 0.031, p (FDR) = 0.031; left hippocampus: β = -0.06 ± 0.02, p = 0.005, p (FDR) = 0.009). Moreover, our findings provide some evidence that childhood maltreatment is related to smaller bilateral hippocampal volumes only in those adults who suffered from a relationship breakup (right hippocampus: β = -0.23 ± 0.10, p = 0.018, p (FDR) = 0.018; left hippocampus: β = -0.24 ± 0.10, p = 0.016, p (FDR) = 0.018;). Our study highlights the interaction of adult social bonds with early adversity on vulnerability to psychopathology.

Fatty acid-binding protein 7 gene deletion promotes decreases in brain cannabinoid type 1 receptor binding

Fatty acid-binding protein 7 (FABP7) aids in the intracellular transport of endogenous cannabinoids and is involved in regulating the stress response system. This study examined the role of FABP7 in chronic stress exposure through the binding of CB1 receptors. Adult male FABP7+/+ and FABP7-/- mice were treated with the unpredictable chronic mild stress (UCMS) procedure. After 28 days of treatment, mice were euthanized, and CB1 was measured with in vitro autoradiography using [3H] SR141716A. FABP7-/- mice, irrespective of stress treatment, showed reduced [3H] SR141716A binding in the amygdala, secondary somatosensory cortex, and ventral caudate putamen compared with the FABP7+/+ mice. Additionally, FABP7-/- mice treated with UCMS exhibited a reduction in CB1 binding in the globus pallidus and ventral caudate putamen compared with UCMS-treated FABP7+/+ mice. Genetic deletion of FABP7 can decrease CB1 expression in various brain regions; however, the underlying mechanism remains unclear.

Research Review: Shared and distinct structural and functional brain alterations in adolescents with major depressive disorder' - a multimodal meta-analysis

BACKGROUND

Neuroimaging studies have identified brain structural and functional alterations in adolescents with major depressive disorder (MDD); however, the results are inconsistent, and whether patients exhibit spatially convergent structural and functional brain abnormalities remains unclear.

METHODS

We conducted voxel-wise meta-analysis of voxel-based morphometry (VBM) and resting-state functional studies, respectively, to identify regional gray matter volume (GMV) and brain activity alterations in adolescent MDD patients. Multimodal analysis was performed to examine the overlap of regional GMV and brain activity alterations. Meta-regression analysis was conducted to evaluate the potential effects of clinical variables.

RESULTS

Ten whole-brain VBM studies (403 patients and 319 controls) and 14 resting-state functional studies (510 patients and 474 controls) were included. Adolescent MDD patients showed conjoint structural and functional alterations in the left medial/dorsolateral prefrontal cortex, lateral temporal cortex and sensorimotor regions, and left insula. Adolescent MDD patients showed structural-specific abnormalities in the subcortical and prefrontal-limbic regions and functional-specific abnormalities in the right insula, right superior occipital gyrus, left inferior frontal gyrus and left precuneus. Meta-regression analyses revealed that the mean age of adolescents with MDD was positively associated with GMV in the right superior temporal gyrus and negatively associated with brain activity in the right insula, and the symptom severity of adolescents with MDD was positively associated with brain activity in the right superior occipital gyrus.

CONCLUSIONS

This meta-analysis identified complicated patterns of conjoint and dissociated brain alterations in adolescent MDD patients, which may advance our understanding of the neurobiology of adolescent MDD.

Accelerated biological brain aging in major depressive disorder

Major depressive disorder (MDD) patients commonly encounter multiple types of functional disabilities, such as social, physical, and role functioning. MDD is related to an accreted risk of brain atrophy, aging-associated brain diseases, and mortality. Based on recently available studies, there are correlations between notable biological brain aging and MDD in adulthood. Despite several clinical and epidemiological studies that associate MDD with aging phenotypes, the underlying mechanisms in the brain remain unknown. The key areas in the study of biological brain aging in MDD are structural brain aging, impairment in functional connectivity, and the impact on cognitive function and age-related disorders. Various measurements have been used to determine the severity of brain aging, such as the brain age gap estimate (BrainAGE) or brain-predicted age difference (BrainPAD). This review summarized the current results of brain imaging data on the similarities between the manifestation of brain structural changes and the age-associated processes in MDD. This review also provided recent evidence of BrainPAD or BrainAGE scores in MDD, brain structural abnormalities, and functional connectivity, which are commonly observed between MDD and age-associated processes. It serves as a basis of current reference for future research on the potential areas of investigation for diagnostic, preventive, and potentially therapeutic purposes for brain aging in MDD.

Incidence of psychiatric disorders after total knee or hip arthroplasty by anesthesia type: A nationwide cohort study

BACKGROUND

Evidence is lacking of an association between anesthetic choice and the risk of psychiatric disorders. Therefore, this study aimed to examine the impact of regional anesthesia (R/A) versus general anesthesia (G/A) on the occurrence of psychiatric disorders in patients undergoing total knee arthroplasty (TKA) or total hip arthroplasty (THA).

METHODS

Data for this population-based cohort study were sourced from the National Health Insurance Service of South Korea. The study included adult patients who underwent TKA or THA between January 1, 2016, and December 31, 2021. The endpoint was the diagnosis of postoperative psychiatric disorders within 1 year postoperative.

RESULTS

This study included 411,967 patients who underwent THA or TKA. Among them, 290,476 (70.5 %) underwent THA or TKA under R/A (R/A group), while 121,491 (29.5 %) underwent THA or TKA under G/A (G/A group). In multivariate logistic regression, the R/A group had an 8 % lower incidence of postoperative psychiatric disorders (odds ratio [OR], 0.92; 95 % confidence interval [CI], 0.90-0.94; P < 0.001) than the G/A group. Specifically, a lower incidence of postoperative psychiatric disorder for depression (OR, 0.89; 95 % CI, 0.86-0.92; P < 0.001), bipolar disorder (OR, 0.88; 95 % CI, 0.83-0.94; P < 0.001), anxiety disorder (OR, 0.95; 95 % CI, 0.92-0.98; P = 0.001), and insomnia disorder (OR, 0.95; 95 % CI, 0.80-1.11; P = 0.496) was observed in the R/A versus G/A group.

CONCLUSIONS

Among these South Korean patients who underwent TKA or THA, the R/A group had a lower incidence of postoperative psychiatric disorders than the G/A group.

Neutrophil activation and related disrupted frontolimbic circuit may contribute to cognitive progression of minimal depressive symptoms in non-dementia elderly

BACKGROUND

As a more common but easily neglected disorder, minimal depressive symptoms (MDS), it is unclear whether and why it increases the risk of cognitive progression in non-dementia elderly.

METHODS

The Alzheimer's disease Neuroimaging Initiative (ADNI) database was used to assign 1065 non-dementia elderly into normal control (n = 380) and MDS (n = 685) groups via the Geriatric Depression Scale (GDS). Blood neutrophils, transcriptomics and metabolomics, cerebrospinal fluid (CSF) proteomics, and magnetic resonance imaging (MRI) data were analyzed.

RESULTS

MDS was found to increase the risk of cognitive progression independently of multiple psychological symptoms. Increased levels of blood neutrophils were associated with cognitive progression in MDS, as supported by neutrophil-related pathways by transcriptomic enrichment analysis and multi-omics joint analysis. A disrupted frontolimbic circuit was associated with neutrophil activation in MDS.

LIMITATIONS

The heterogeneity of the sample limited the generalizability of results, and the lack of follow-up data limited the research on the mechanism of neutrophil activation influencing cognitive function in MDS.

CONCLUSIONS

Cognitive progression occurs as early as the MDS stage. And this phenomenon may attribute to the neutrophil activation and the related disrupted frontolimbic circuit.

Comorbidity of concussion and depression alters brain functional connectivity in collegiate student-athletes

Depression and concussion are highly prevalent neuropsychological disorders that often occur simultaneously. However, due to the high degree of symptom overlap between the two events, including but not limited to headache, sleep disturbances, appetite changes, fatigue, and difficulty concentrating, they may be treated in isolation. Thus, clinical awareness of additive symptom load may be missed. This study measures neuropsychological and electroencephalography (EEG) alpha band coherence differences in collegiate student-athletes with history of comorbid depression and concussion, in comparison to those with a single morbidity and healthy controls (HC). 35 collegiate athletes completed neuropsychological screenings and EEG measures. Participants were grouped by concussion and depression history. Differences in alpha band coherence were calculated using two-way ANOVA with post hoc correction for multiple comparisons. Comorbid participants scored significantly worse on neuropsychological screening, BDI-FS, and PCSS than those with a single morbidity and HC. Two-way ANOVA by group revealed significant main effects of alpha band coherence for concussion, depression, and their interaction term. Post-hoc analysis showed that comorbid participants had more abnormal alpha band coherence than single morbidity, when compared to HC. Comorbidity of concussion and depression increased symptom reporting and revealed more altered alpha band coherence than single morbidity, compared to HC. The abnormalities of the comorbid group exclusively showed decreased alpha band coherence in comparison to healthy controls. The comorbidity of depression and SRC has a compounding effect on depression symptoms, post-concussion symptoms, and brain functional connectivity. This research demonstrates a promising objective measure in comorbid individuals, previously only measured via subjective symptom reporting.

Application of a localized morphometrics approach to imaging-derived brain phenotypes for genotype-phenotype associations in pediatric mental health and neurodevelopmental disorders

Introduction

Quantitative global or regional brain imaging measurements, known as imaging-specific or -derived phenotypes (IDPs), are commonly used in genotype-phenotype association studies to explore the genomic architecture of the brain and how it may be affected by neurological diseases (e.g., Alzheimer's disease), mental health (e.g., depression), and neurodevelopmental disorders (e.g., attention-deficit hyperactivity disorder [ADHD]). For this purpose, medical images have been used as IDPs using a voxel-wise or global approach via principal component analysis. However, these methods have limitations related to multiple testing or the inability to isolate high variation regions, respectively.

Methods

To address these limitations, this study investigates a localized, principal component analysis-like approach for dimensionality reduction of cross-sectional T1-weighted MRI datasets utilizing diffeomorphic morphometry. This approach can reduce the dimensionality of images while preserving spatial information and enables the inclusion of spatial locality in the analysis. In doing so, this method can be used to explore morphometric brain changes across specific components and spatial scales of interest and to identify associations with genome regions in a multivariate genome-wide association study. For a first clinical feasibility study, this method was applied to data from the Adolescent Brain Cognitive Development (ABCD) study, including adolescents with ADHD (n = 1,359), obsessive-compulsive disorder (n = 1,752), and depression (n = 1,766).

Results

Meaningful associations of specific morphometric features with genome regions were identified with the data and corresponded to previous found brain regions in the respective mental health and neurodevelopmental disorder cohorts.

Discussion

In summary, the localized, principal component analysis-like approach can reduce the dimensionality of medical images while still being able to identify meaningful local brain region alterations that are associated with genomic markers across multiple scales. The proposed method can be applied to various image types and can be easily integrated in many genotype-phenotype association study setups.

Neural Modulation Alteration to Positive and Negative Emotions in Depressed Patients: Insights from fMRI Using Positive/Negative Emotion Atlas

BACKGROUND

Although it has been noticed that depressed patients show differences in processing emotions, the precise neural modulation mechanisms of positive and negative emotions remain elusive. FMRI is a cutting-edge medical imaging technology renowned for its high spatial resolution and dynamic temporal information, making it particularly suitable for the neural dynamics of depression research.

METHODS

To address this gap, our study firstly leveraged fMRI to delineate activated regions associated with positive and negative emotions in healthy individuals, resulting in the creation of the positive emotion atlas (PEA) and the negative emotion atlas (NEA). Subsequently, we examined neuroimaging changes in depression patients using these atlases and evaluated their diagnostic performance based on machine learning.

RESULTS

Our findings demonstrate that the classification accuracy of depressed patients based on PEA and NEA exceeded 0.70, a notable improvement compared to the whole-brain atlases. Furthermore, ALFF analysis unveiled significant differences between depressed patients and healthy controls in eight functional clusters during the NEA, focusing on the left cuneus, cingulate gyrus, and superior parietal lobule. In contrast, the PEA revealed more pronounced differences across fifteen clusters, involving the right fusiform gyrus, parahippocampal gyrus, and inferior parietal lobule.

CONCLUSIONS

These findings emphasize the complex interplay between emotion modulation and depression, showcasing significant alterations in both PEA and NEA among depression patients. This research enhances our understanding of emotion modulation in depression, with implications for diagnosis and treatment evaluation.

Comparative transcriptional analyses of the striatum in the chronic social defeat stress model in C57BL/6J male mice and the gut microbiota-dysbiosis model in Kumming mice

Depression is a complex disorder with multiple contributing factors, and chronic stress has previously been recognized as a major causative factor, while gut microbes have also been found to be involved in depression recently. However, gene expression in depression models with different etiologies is unclear. Here, we compared the transcriptomes of the striatum in chronic social defeat stress (CSDS) model of C57BL/6J male mice and fecal microbiota transplant (FMT) model of Kumming male mice. We found that the proportion of shared differentially expressed genes (DEGs) between the two models was only 24 %. The specific DEGs of FMT model were enriched in immune and inflammatory, and are associated with changes in vascular and ciliated ependymal cells. The specific DEGs of CSDS model were enriched in neuron and synapse. The results of network analysis suggested the expression patterns and biological function of depressive-like behaviors-related modules in the two models are different. Further, the alternative splicing events of CSDS are more than FMT. Our results suggested models of depression induced by different etiologies differ significantly in gene expression and biological function. Our study also suggested us to pay attention to the characteristics of models of depression of different etiologies and provided a more comprehensive understanding of the heterogeneity of depression.