Targeting glucocorticoid receptor signaling pathway for treatment of stress-related brain disorders.

The hypothalamic-pituitary-adrenal (HPA) axis plays a central role in governing stress-related disorders such as major depressive disorder (MDD), anxiety, and post-traumatic stress disorder. Chronic stress or early life trauma, known risk factors of disease, alter HPA axis activity and pattern of glucocorticoid (GC) secretion. These changes have consequences for physiological processes controlled by glucocorticoid receptor (GR) signaling, such as immune response and metabolism. In the brain, the aberrant GR signaling translates to altered behavior, making the GR pathway a viable target for therapies of stress-related disorders. One of the crucial elements of the pathway is FKBP5, a regulator of GR sensitivity and feedback control within the HPA axis, in which genetic variants were shown to moderate the risk of developing psychiatric conditions. The difficulty in targeting the GR-FKBP5 pathway stems from tailoring the intervention to specific brain regions and cell types, in the context of personalized genetic variations in GR and GR-associated genes, like FKBP5. The development of selective inhibitors, antagonists, and approaches based on targeted protein degradation offer insights into mechanistic aspects of disease and pave the way for improved therapy. These strategies can be employed either independently or in conjunction with conventional medications. Concomitant advancements in personalized drug screening (e.g. in vitro models exploiting induced pluripotent stem cells, iPSCs) bring the potential for optimization of therapy aiming to rescue central deficits originating from the HPA imbalance. In this mini-review, we discuss potential therapeutic strategies targeting GR signaling in stress-related disorders, with a focus on personalized approaches and advancements in drug development.

Phosphatidic acid is involved in regulation of autophagy in neurons in vitro and in vivo.

Major depressive disorder (MDD) is a common and severe psychiatric disease, which does not only lead to variety of neuropsychiatric symptoms, but unfortunately in a relatively large proportion of cases also to suicide. The pathogenesis of MDD still requires definition. We have previously shown that ceramide is increased in the blood plasma of patients with MDD. In mouse models of MDD, which are induced by treatment with corticosterone or application of chronic unpredictable stress, increased blood plasma ceramide also increased and caused an inhibition of phospholipase D in endothelial cells of the hippocampus and reduced phosphatidic acid levels in the hippocampus. Here, we demonstrated that corticosterone treatment of PC12 cells resulted in reduced cellular autophagy, which is corrected by treatment with phosphatidic acid. In vivo, treatment of mice with corticosterone or chronic unpredictable stress also reduced autophagy in hippocampus neurons. Autophagy was normalized upon i.v. injection of phosphatidic acid in these mouse models of MDD. In an attempt to identify targets of phosphatidic acid in neurons, we demonstrated that corticosterone reduced levels of the ganglioside GM1 in PC-12 cells and the hippocampus of mice, which were normalized by treatment of cells or i.v. injection of mice with phosphatidic acid. GM1 application also normalized autophagy in cultured neurons. Phosphatidic acid and GM1 corrected stress-induced alterations in behavior, i.e., mainly anxiety and anhedonia, in experimental MDD in mice. Our data suggest that phosphatidic acid may regulate via GM1 autophagy in neurons.

A novel approach to investigate the mechanism of electroconvulsive therapy in the treatment of major depression disorder: Diffusion kurtosis imaging.

BACKGROUND: Major depression disorder (MDD) exhibits a high global incidence; however, its pathogenesis remains elusive. In this prospective study, we employed diffusion kurtosis imaging (DKI) to investigate changes in brain function among patients with MDD both pre- and post-electroconvulsive therapy (ECT). METHODS: We divided a sample of 22 MDD patients into ECT group, which received six treatments over a span of two weeks, and control group (n = 12). DKI scanning was performed before and after treatment. The Hamilton Depression Rating Scale (HAMD) and Life Satisfaction Rating Scale (LSRS) were administered to assess depressive symptoms at baseline, on the 14th day, and at month three. RESULTS: Significant differences were found between group, time and time × group in terms of HAMD score and LSRS score. In the ECT group compared to pre- ECT measurement, changes in mean diffusivity (MD), fractional Anisotropy (FA), mean kurtosis (MK), radial kurtosis (RK), FA of kurtosis (KA), and anxia kurtosis (AK) value were detected in specific regions such as the frontal, temporal lobe, and hippocampus. In the control group only MD and RK value increased in a limited number of area. CONCLUSIONS: ECT holds the potential to elicit neuroplasticity in the brain, facilitating rapid structural modifications and amelioration of depressive symptoms in patients with MDD.

Pramipexole, a D3 receptor agonist, increases cortical gamma power and biochemical correlates of cortical excitation; implications for mood disorders.

Major depressive disorder (MDD) has been associated with deficits in working memory as well as underlying gamma oscillation power. Consistent with this, overall reductions in cortical excitation have also been described with MDD. In previous work, we have demonstrated that the monoamine reuptake inhibitor venlafaxine increases gamma oscillation power in ex vivo hippocampal slices and that this is associated with concomitant increases in pyramidal arbour and reduced levels of plasticity-restricting perineuronal nets (PNNs). In the present study, we have examined the effects of chronic treatment with pramipexole (PPX), a D3 dopamine receptor agonist, for its effects on gamma oscillation power as measured by in vivo electroencephalography (EEG) recordings in female BALB/c and C57Bl6 mice. We observe a modest but significant increase in 20-50 Hz gamma power with PPX in both strains. Additionally, biochemical analysis of prefrontal cortex lysates from PPX-treated BALB/c mice shows a number of changes that could contribute to, or follow from, increased pyramidal excitability and/or gamma power. PPX-associated changes include reduced levels of specific PNN components as well as tissue inhibitor of matrix metalloproteases-1 (TIMP-1), which inhibits long-term potentiation of synaptic transmission. Consistent with its effects on gamma power, PNN proteins and TIMP-1, chronic PPX treatment also improves working memory and reduces anhedonia. Together these results add to an emerging literature linking extracellular matrix and/or gamma oscillation power to both mood and cognition.

Stressors during the prodromal phase of major depressive episode (CHR-D).

Introduction: Early recognition and indicated prevention is a promising approach to decrease the incidence of Major depressive episodes (MDE), targeting the patients during their clinical high-risk state of MDE (CHR-D). The identification of a set of stressors at the CHR-D increases the success of indicated prevention with personalized early interventions. The study evaluated stressors in the early phase of depression, developed on the basis of a patient survey on stressors. Methods: Sixty-eight inpatients (ICD10: F3x.xx) with a reported high risk state for major depressive episode (CHR-D) were included in the current study. Stressors during CHR-D were retrospectively explored using a semi-structured clinical interview supplemented by open-ended questions. A qualitative explorative content analysis was provided to identify a pattern of stressors during the prodromal phase of the patients, based on the patient's perspective. A frequency analysis was performed for the evaluation of the prevalence of reported source of stress. Results: All patients reported stressors in the prodromal phase of depression. Results demonstrates that patients with depressive disorder typically report multiple stressors, with the most common number being four. First, 18 stressors-groups were identified during coding. Interpersonal conflicts and disappointments in close relationships were most frequently reported stressors during the prodromal phase at 44.1%. The second most frequent stressor mentioned was the high qualitative or quantitative demands at work (38.2%). The third frequent source of stress was changes in close relationships and in family relationships (33.8%). Based on the categories of stressors described in the patient survey during the prodromal phase we suggested a model of stressors in CHR-D during the prodromal phase of the MDE. Discussion: The identification of a set of stressors at the early stage of MDE may increase opportunities for early intervention. In everyday clinical practice, preventive psychiatry needs clinical and adapted instruments for recording stressors in today's society. This knowledge is necessary in order to develop precisely indicated prevention for depressive disorders.

Exercise alleviates CUS-induced depressive-like behaviors by modulating paracellular and transcellular permeability of the blood-brain barrier in the prefrontal cortex.

BACKGROUND: Increased blood-brain barrier (BBB) permeability is implicated in the pathophysiology of major depressive disorder (MDD). While aerobic exercise has shown promise in mitigating MDD symptoms by potentially preserving BBB integrity, the detailed mechanisms remain unclear. This study explores these mechanisms to assess aerobic exercise's therapeutic potential for MDD. METHODS: Male C57BL/6 J mice were used in this study to investigate the effects of aerobic exercise on CUS-induced BBB permeability and depressive-like behaviors. Chronic unpredictable stress (CUS)-induced MDD mouse models were divided into three groups: Control, CUS, and CUS+Exercise. We monitored body weight, blood S100ß levels, and cytokines via ELISA. Claudin-5 and Caveolin-1 (CAV-1) expressions in the medial prefrontal cortex were evaluated using Western blotting and immunofluorescence. BBB permeability was assessed using biocytin-TMR and Alb-Alexa 594 tracers. Transmission electron microscopy was used to observe ultrastructural changes in the BBB directly. Depression-related behaviors were tested through several behavioral assays. RESULTS: CUS significantly increased CAV-1 expression and Alb-Alexa 594 leakage, suggesting enhanced transcellular BBB permeability. Despite unchanged Claudin-5 levels, its tight junction ultrastructure was altered, leading to increased biocytin-TMR leakage. Aerobic exercise ameliorated these disruptions, reduced inflammatory cytokines, and improved behavioral outcomes in CUS mice. CONCLUSION: Disruptions in both paracellular and transcellular BBB pathways are pivotal in depression development. Aerobic exercise offers potential therapeutic benefits for MDD linked with BBB dysfunction by mitigating stress-induced structural and functional changes.

Mirtazapine blood levels and antidepressant response.

OBJECTIVE: Therapeutic drug monitoring (TDM) is an important tool for treatment optimisation. Its usefulness has recently been demonstrated for some first-line antidepressants; however, few studies have been reported on the relationship between blood levels of mirtazapine and its antidepressant effects. The aim of this study was to investigate the association between blood concentration of mirtazapine and antidepressant response. METHODS: 59 outpatients treated with mirtazapine for depression were recruited and followed up for three months in a naturalistic setting. Hamilton Depression Rating Scale-21 (HAMD-21) was administered at baseline, month 1, and month 3 to assess antidepressant response. Mirtazapine serum concentration was measured at steady state. Linear regression analysis and nonlinear least-squares regression were used to estimate association between serum concentration of mirtazapine and antidepressant response. RESULTS: Our results showed no overall association between serum concentration of mirtazapine and symptom improvement at month 1 and month 3. A marginally significantly higher serum concentration of mirtazapine was found in responders vs non-responders at month 3. CONCLUSIONS: The study suggests that serum concentration of mirtazapine is not strongly associated with the antidepressant efficacy of mirtazapine. This is probably attributed to its pharmacodynamic profile, even though higher blood levels seem to be marginally more effective.

Mirtazapine plasma levels association with response is mild and do not follow the same curve of other antidepressantsMirtazapine higher plasma levels may show some benefit in a subgroup of patientsTherapeutic drug monitoring may help during antidepressant treatment.

Peer-led intervention for individuals with major depression: study protocol for a randomized controlled trial (SUPEERMood).

BACKGROUND: Major Depressive Disorder (MDD) is one of the most disabling mental health problems worldwide. The Recovery Model emphasizes peer support to empower individuals with MDD, improve self-management, and patients' quality of life. Despite the demonstrated efficacy of peer-led interventions, further research is needed due to methodological limitations and variability in interventions across studies. Therefore, the objective of this trial is to evaluate the effectiveness of an adjuvant peer-led intervention for the reduction of depressive symptoms in individuals diagnosed with MDD attended in primary care mental health units. METHODS: A controlled, parallel, randomized clinical trial will be conducted. The intervention group (n = 35) will receive 6 weeks of peer-led sessions based on a peer support program drive whilst supervised by nurses, while the control group (n = 35) will use a mobile Health (mHealth) application for emotional wellness based on CBT for 6 weeks. Measurements will be collected at baseline, at 6 weeks, at 6 and 12 months after the intervention to evaluate post-intervention effects. The primary outcome is the reduction of depressive symptoms through the Beck Depression Inventory (BDI-II) after the intervention. Secondary outcomes will involve measures such as adherence to psychiatric treatment, quality of life, adherence to mediterranean diet, alcohol consumption and physical activity. DISCUSSION: We hypothesize that this peer-led intervention, in contrast to the mHealth, will show improvement in BDI-II score reduction of 6 points after six weeks, 6 and 12 months. Standardized peer-led programs can benefit patients and professionals in terms of efficacy and feasibility of clinical treatment of depression, healthy habits, self-care and quality of life. In addition, they can provide recovery and relapse reduction, improved psychosocial support, minimization of intensive care use, and support for patient autonomy through self-management. TRIAL REGISTRATION: The trial protocol is prospectively registered with ClinicalTrials.gov under protocol registration number NCT06398561. Date of registration: May 01, 2024. Recruitment is ongoing.

Internet-based therapist-supported interpersonal psychotherapy for depression: A randomized controlled trial.

BACKGROUND: Depression is a common disorder for which there are several treatments options including different psychological treatments. The aim of this study was to investigate the effects of internet-based interpersonal psychotherapy (IPT) for symptoms of depression in randomized controlled trial. METHODS: Following recruitment via advertisement a total of 113 participants with mild to moderate symptoms of depression were included and randomized to either a ten-week internet-based IPT with weekly therapist guidance or a waitlist control condition. The primary outcome was symptoms of depression measured weekly with the Montgomery Åsberg Depression Rating Scale (MADRS-S) and at pre- and post-treatment assessment with the Beck's Depression Inventory (BDI-II). Secondary outcomes were self-rated quality of life and symptoms of generalized anxiety disorder. We also measured therapeutic alliance and treatment credibility. Outcomes were evaluated with a latent growth curve model (for MADRS-S) and robust linear regression models (for the other measures). The trial was conducted during the Covid-19 pandemic in the spring of 2021. RESULTS: Significant differences favoring the treatment group were found on three of the four outcomes: BDI-II, quality of life ratings, and ratings of generalized anxiety. Between-group effect sizes for these outcomes were moderate (BDI-II, quality of life) or small (generalized anxiety). The latent growth curve model did not indicate a significant difference on the weekly MADRS-S ratings. Exploratory analyses did not show an association between therapeutic alliance, treatment credibility and outcome. LIMITATIONS: Missing data at post-treatment was high in the treatment group (37 %), though the missingness was not significantly related to observed ratings at pre-treatment or estimated trajectories during the treatment. Few participants completed all modules. The Covid-19 pandemic situation may have affected both effects and dropout rates. CONCLUSIONS: Internet-based IPT can lead to significant improvements, though the reductions in symptoms of depression were not consistent across the two measures used. Completion rates and dropout patterns suggest a need for improved acceptability. TRIAL REGISTRATION: The trial was preregistered at Clinicaltrials.gov (Identifier: NCT04721678). Registered January 2021.https://clinicaltrials.gov/study/NCT04721678.

Fasting insulinemia as biomarker of illness relapse in patients with severe mental illness?

Severe Mental Illness (SMI) is often associated with metabolic alteration and/or metabolic syndrome, which may determine an increased mortality due to a further increased cardiovascular risk. The relationship with metabolic syndrome is often bidirectional, resulting in a pathoplastic effect of these dysmetabolisms. Among the several hormones involved, insulin appears to play a key role, albeit not entirely clear. The aim of our real-world cross-sectional observational study is to investigate a set of metabolic biomarkers of illness relapse/recurrence/onset in a cohort of 310 adult SMI inpatients consecutively admitted to the Psychiatry Clinic of the Azienda Ospedaliero Universitaria of Marche, in Ancona (Italy), between February 2021 and February 2024. According to the stepwise multivariate regression model, a higher number of acute episodes per year was positively predicted by the age of illness onset, the lifetime number of suicidal attempts and fasting insulinemia and negatively by the participant's age. A second stepwise multivariate regression model using only the metabolic characteristics as independent variables, found that a higher number of acute episodes per year was predicted positively by the fasting insulinemia and red blood cells and negatively by the abdominal circumference. Overall, our findings could provide practical implications for the treatment and management of SMI patients, emphasizing the importance of monitoring and managing metabolic factors, particularly insulinemia, metabolic syndrome and insulin resistance. Finally, insulinemia could potentially act as metabolic biomarker of illness relapse, though more larger and longitudinal studies should be carried out to confirm these results.

Low-Grade Inflammation Associated with Major Depression Subtypes: A Cross-Sectional Study.

Major depressive disorder (MDD) is associated with inflammation and a high level of comorbidities. Atypical depression (AD) is a MDD subtype based on DSM criteria, that could have specific underlying biological mechanisms. AD is associated with elevated cardiovascular (CVD) comorbidities, higher risk of suicide attempts, hypersomnia, and anxiety disorder. In this study, we aim to investigate if AD and polysomnographic parameters could be associated with low-grade inflammation (LGI). LGI is defined by a range from 3 to 10 mg/L of C-reactive protein levels. We carried out a retrospective cohort study in which 765 individuals with MDD were split into two groups: with and without LGI. Our results exhibit differences between the groups for the polysomnographic parameters, with the LGI group showing parameters already associated with inflammation such as reduced rapid eye movement sleep and elevated hypoxemia markers (identified as CVD risk factor). We found that AD is associated with LGI (OR 1.48; p = 0.047) after adjustment. Likewise, we found an LGI prevalence in AD higher (34.8%) than in MDD without atypical features (26.8%). Overall, these results confirm the low-grade inflammation feature of AD and highlight polysomnographic parameters associated with LGI that could also act as risk factors in this context.

Insulin Resistance, Temperament and Personality Traits Are Associated with Anhedonia in a Transdiagnostic Sample.

Anhedonia constitutes a core symptom of major depressive disorder (MDD) mediating the ultimate goal of MDD treatment: functional remission. Anhedonia is also present in other clinical populations, including patients with chronic pain. Recent data links anhedonia to insulin resistance (IR). Some researchers have underlined a different dimension of anhedonia as a temperament/personality trait. The objective of this post-hoc analysis was to explore the links between anhedonia (main outcome) and (1) IR, (2) temperamental, personality, and schizotypy traits (exposures). The study population included patients with MDD, fibromyalgia, and healthy controls. Participants were split into groups: (1) insulin resistant (IR[+] n = 69, HOMA-IR ≥ 2.1) and (2) insulin sensitive (IR[-] n = 69, HOMA-IR < 2.1). Anhedonia was significantly higher in the IR[+] group than the IR[-] group. IR was a predictor of higher anhedonia levels. IR[+] vs. IR[-] participants showed higher levels of anxiety and lower levels of hyperthymic affective temperaments, as well as conscientiousness and emotional stability personality traits. Depressive, irritable, and anxious temperaments, cognitive disorganization, and introvertive anhedonia positively predicted anhedonia, while hyperthymic temperament, conscientiousness, extraversion, and emotional stability traits negatively predicted anhedonia. IR partially mediated the relationship between depressive temperament and anhedonia. In sum, IR, affective temperaments, and personality traits are predictors of anhedonia.

Transcutaneous Auricular Vagus Nerve Stimulation Modulating the Brain Topological Architecture of Functional Network in Major Depressive Disorder: An fMRI Study.

BACKGROUND: Transcutaneous auricular vagus nerve stimulation (taVNS) is effective in regulating mood and high-level cognition in patients with major depressive disorder (MDD). This study aimed to investigate the efficacy of taVNS treatment in patients with MDD and an altered brain topological organization of functional networks. METHODS: Nineteen patients with MDD were enrolled in this study. Patients with MDD underwent 4 weeks of taVNS treatments; resting-state functional magnetic resonance imaging (rs-fMRI) data of the patients were collected before and after taVNS treatment. The graph theory method and network-based statistics (NBS) analysis were used to detect abnormal topological organizations of functional networks in patients with MDD before and after taVNS treatment. A correlation analysis was performed to characterize the relationship between altered network properties and neuropsychological scores. RESULTS: After 4 weeks of taVNS treatment, patients with MDD had increased global efficiency and decreased characteristic path length (Lp). Additionally, patients with MDD exhibited increased nodal efficiency (NE) and degree centrality (DC) in the left angular gyrus. NBS results showed that patients with MDD exhibited reduced connectivity between default mode network (DMN)-frontoparietal network (FPN), DMN-cingulo-opercular network (CON), and FPN-CON. Furthermore, changes in Lp and DC were correlated with changes in Hamilton depression scores. CONCLUSIONS: These findings demonstrated that taVNS may be an effective method for reducing the severity of depressive symptoms in patients with MDD, mainly through modulating the brain's topological organization. Our study may offer insights into the underlying neural mechanism of taVNS treatment in patients with MDD.

Dual Approach to Depression: The Combined Efficacy of Intermittent Hypoxia and Fluoxetine in Modulating Behavioral and Inflammatory Responses.

Background/Objectives: Mental disorders pose a significant public health challenge, affecting millions worldwide. Given the limitations of current therapies, many patients experience inadequate responses and adverse effects. Intermittent hypoxia (IH) has demonstrated anxiolytic, antidepressant, and neuroprotective properties in various protocols. This study investigated the effects of acute IH (13% O2, 1 h), fluoxetine (FLX) and their combination on depression-like behavior, serum corticosterone, and inflammatory cytokine levels induced by acute restraint stress in C57BL/6 female mice. Methods: Behavioral assessments included the tail suspension test, forced swim test, and open field test. Results: The combined IH + FLX treatment exhibited a synergistic effect, reducing immobility time and increasing latency time, respectively, in the tail suspension test (46%, p = 0.0014; 73%, p = 0.0033) and forced swim test (56%, p = 0.0082; 48%, p = 0.0322) compared to the ARS group. Biochemical analysis revealed that individual and combined treatments significantly reduced most inflammatory interleukins by up to 96%. Corticosterone levels were reduced by 30% only in the IH group. Conclusions: These findings highlight the potential of a one-hour IH session, particularly when combined with fluoxetine, to alleviate depressive-like behaviors and exert anti-inflammatory effects, suggesting a promising therapeutic approach for depression.

State of the Art in Sub-Phenotyping Midbrain Dopamine Neurons.

Dopaminergic neurons in the ventral tegmental area (VTA) and the substantia nigra pars compacta (SNpc) comprise around 75% of all dopaminergic neurons in the human brain. While both groups of dopaminergic neurons are in close proximity in the midbrain and partially overlap, development, function, and impairments in these two classes of neurons are highly diverse. The molecular and cellular mechanisms underlying these differences are not yet fully understood, but research over the past decade has highlighted the need to differentiate between these two classes of dopaminergic neurons during their development and in the mature brain. This differentiation is crucial not only for understanding fundamental circuitry formation in the brain but also for developing therapies targeted to specific dopaminergic neuron classes without affecting others. In this review, we summarize the state of the art in our understanding of the differences between the dopaminergic neurons of the VTA and the SNpc, such as anatomy, structure, morphology, output and input, electrophysiology, development, and disorders, and discuss the current technologies and methods available for studying these two classes of dopaminergic neurons, highlighting their advantages, limitations, and the necessary improvements required to achieve more-precise therapeutic interventions.

Divergent transcriptomic profiles in depressed individuals with hyper- and hypophagia implicating inflammatory status.

BACKGROUND: Major Depressive Disorder (MDD) is a heterogenous and etiologically complex disease often presenting with divergent appetitive phenotypes including Hyperphagic MDD (characterized by an increased appetite) and Hypophagic MDD (characterized by a decrease in appetite) which are closely related to comorbidities, including cardiometabolic disorders. Hyperphagia is associated with atypical depression, decreased stress-hormone signaling, a pro-inflammatory status, hypersomnia, and poorer clinical outcomes. Yet, our understanding of associated biological correlates of Hyperphagic and Hypophagic MDD remain fragmented. METHODS: We performed an exploratory study on peripheral blood RNA profiling using bulk RNAseq in unmedicated individuals with Hyperphagic and Hypophagic MDD (n = 7 and n = 13, respectively). RESULTS: At baseline, we discovered an increased expression of TADA2B in hyperphagic MDD with the significant enrichment of 72 gene ontology pathways mainly related to inflammation. In addition, we used the Maastricht Acute Stress Task to uncover stress-related transcriptomic profiles in Hyper- and Hypophagic MDD and discovered the upregulation of CCDC196 and the downregulation of SPATA33 in hyperphagic MDD. Gene ontology enrichment analysis after stress exposure showed pathways related to ribosomal activity. LIMITATIONS: The present findings are tempered primarily by the limited sample size, which requires independent replication of this exploratory study. However, stringent methods controlling for false positive findings mitigate the risk associated with sample size limitations. DISCUSSION: Limitations notwithstanding, findings suggest that hyper- and hypophagic MDD is associated with divergent RNA expression profiles in peripheral blood that are amplified by exposure to a controlled stress test. Our findings in a well-controlled study provide evidence for peripheral markers of a relevant endophenotype of MDD.

Major depression recurrence is associated with differences in obesity-related traits in women, but not in men.

BACKGROUND: Obesity-related cardiometabolic comorbidity is common in major depressive disorder (MDD). However, sex differences and MDD recurrence may modify the MDD-obesity-link. METHODS: Sex-specific associations of MDD recurrence (single [MDDS] or recurrent episodes [MDDR]) and obesity-related traits were analyzed in 4.100 adults (51.6% women) from a cross-sectional population-based cohort in Germany (SHIP-Trend-0). DSM-IV-based lifetime MDD diagnoses and MDD recurrence status were obtained through diagnostic interviews. Obesity-related outcomes included anthropometrics (weight, body mass index, waist- and hip-circumference, waist-to-hip ratio, waist-to-height ratio), bioelectrical impedance analysis of body fat mass and fat-free mass, and subcutaneous (SAT) and visceral adipose tissue (VAT) from abdominal magnetic resonance imaging. Sex-stratified linear regression models predicting obesity-related traits from MDD recurrence status were adjusted for age, education, and current depressive symptoms. RESULTS: 790 participants (19.3%) fulfilled lifetime MDD criteria (23.8% women vs. 14.5% men, p<0.001). In women, MDDS was inversely associated with anthropometric indicators of general and central obesity, while MDDR was positively associated with all obesity-related traits, except waist-to-hip ratio and fat-free mass. In women, MDDR versus MDDS was associated with higher levels of obesity across all outcomes except fat-free mass. In men, MDD was positively associated with SAT regardless of MDD recurrence. Additionally, lifetime MDD was positively associated with VAT in men. Results remained significant in sensitivity analyses after exclusion of participants with current use of antidepressants. CONCLUSIONS: The MDD-obesity association is modified by MDD recurrence and sex independent of current depressive symptoms. Accounting for sex and MDD recurrence may identify individuals with MDD at increased cardiometabolic risk.

Glymphatic function assessment with diffusion tensor imaging along the perivascular space in patients with major depressive disorder and its relation to cerebral white-matter alteration.

Background: The link between glymphatic system function in the brain and alterations in white-matter microstructure among individuals with major depressive disorder (MDD) remains unclear. This study aimed to examine the assessment of glymphatic system function in patients with MDD using the diffusion tensor imaging along the perivascular space (DTI-ALPS) index and to evaluate its association with cerebral-white-matter abnormalities and neuropsychological scores. Methods: From February 2023 to November 2023, this cross-sectional study recruited 35 patients with MDD from the Psychosomatic Diseases Department of the First Affiliated Hospital of Dalian Medical University. In this time period, 23 healthy controls (HCs) were enlisted from the community and matched with the MDD cohort in terms of years of education, gender, and age. All participants underwent magnetic resonance imaging, depression, anxiety, and cognitive assessments. The tract-based spatial statistics (TBSS) analyzed DTI parameters and identified significant clusters. Automated fiber quantification (AFQ) was used to automatically identify fiber bundles with statistical differences. Mann-Whitney tests or two-sample t-tests were used for comparisons. Interobserver consistency of the DTI-ALPS measurements was evaluated using the interclass correlation coefficient (ICC). Partial correlation analyses and linear regression analyses were used to examine relationships. A comparison of the DTI-ALPS index was made between the two groups. Correlations among diffusion characteristics, neuropsychological scores, and the DTI-ALPS index were analyzed. Results: Compared to HCs, patients with MDD exhibited a lower DTI-ALPS score (P=0.001). According to using linear regression analysis, the ALPS index was found to be an independent predictor of the Hamilton Depression Rating Scale [B=-25.32; P=0.001; 95% confidence interval (CI): -40.35 to -11.55], Hamilton Anxiety Rating Scale (B=-33.48; P=0.003; 95% CI: -55.38 to -11.24), and Montreal Cognitive Assessment total score (B=8.59; P=0.008; 95% CI: 2.38 to 14.79). According to the TBSS analysis, there were clusters of increased axial diffusivity (AD), mean diffusivity (MD), and radial diffusivity (RD) in patients with MDD as compared to HCs (all P values <0.05). A lower DTI-ALPS score was correlated with higher AD (r=-0.592; P<0.001), MD (cluster 1: r=-0.567, P=0.001; cluster 2: r=-0.581, P<0.001), and RD (r=-0.491; P=0.004) values. AFQ analysis identified the significantly different diffusion indicators in the left cingulum bundle (CB_L), left inferior longitudinal fasciculus (ILF_L), and left uncinate fasciculus (UF_L) between the two groups (all false discovery rate P values <0.05). DTI-ALPS score was negatively correlated with the AD value of CB_L (r=-0.304; P=0.024), ILF_L (r=-0.35; P=0.008), and UF_L (r=-0.354; P=0.008) in AFQ tract-level analysis. In point-wise analysis, the MD value of CB_L at nodes 33 to 36 was negatively correlated with DTI-ALPS score (r ranging from -0.504 to -0.535; P<0.01). Conclusions: Our results indicated a decrease in DTI-ALPS index score in patients with MDD. DTI-ALPS score was associated with depression, anxiety, declined cognitive ability, and white-matter microstructural abnormalities and may thus be a promising biomarker for the partial evaluation of glymphatic system function in patients with MDD.

MDD brain network analysis based on EEG functional connectivity and graph theory.

Background: Existing studies have shown that the brain network of major depression disorder (MDD) has abnormal topologies. However, constructing reliable MDD brain networks is still an open problem. New method: This paper proposed a reliable MDD brain network construction method. First, seven connectivity methods are used to calculate the correlation between channels and obtain the functional connectivity matrix. Then, the matrix is binarized using four binarization methods to obtain the EEG brain network. Besides, we proposed an improved binarization method based on the criterion of maximizing differences between groups: the adaptive threshold (AT) method. The AT can automatically set the optimal binarization threshold and overcome the artificial influence of traditional methods. After that, several network metrics are extracted from the brain network to analyze inter-group differences. Finally, we used statistical analysis and Fscore values to compare the performance of different methods and establish the most reliable method for brain network construction. Results: In theta, alpha, and total frequency bands, the clustering coefficient, global efficiency, local efficiency, and degree of the MDD brain network decrease, and the path length of the MDD brain network increases. Comparison with existing methods: The results show that AT outperforms the existing binarization methods. Compared with other methods, the brain network construction method based on phase-locked value (PLV) and AT has better reliability. Conclusions: MDD has brain dysfunction, particularly in the frontal and temporal lobes.

Effectiveness of an affect-adjusted, supervised, multimodal, online and home-based exercise group protocol for major depression: A randomized controlled trial.

This randomized controlled trial investigated the effectiveness of an affect-adjusted, supervised, multimodal, online, and home-based exercise group protocol as an adjunct therapy to antidepressants on depressive symptoms, cardiorespiratory fitness, and side effects related to antidepressants in adults with major depression (MDD, diagnosed by a clinician). Depressive symptom scales were administered by a psychiatrist and self-reported. A health-related measure (i.e., cardiorespiratory fitness), was also administered. The exercise intervention was adjusted by perceived effort and affect (pleasure and enjoyment) toward exercise and lasted 12 weeks. In total, 59 adults with MDD were divided into two groups: the exercise-group (EG; exercise + pharmacotherapy) with 26-patients (76.9 % females, mean age 28.5 years) and the control-group (CG, pharmacotherapy) with 33-patients (78.7 % females, mean age 25.6 years). The EG had a lower dropout rate (15.3 %) than CG and an increase in cardiorespiratory fitness (CRF), which was not observed in the CG. Both groups showed a decrease in self-reported depressive symptoms. However, the EG had significantly lower depressive symptom scores at t1 and t2. The EG also had higher remission rates (t1, EG: = 42.3 % and CG = 27.2 %) and remission rates (t2, EG: = 72.7 % and CG = 48.1 %) than CG, which were maintained during the four month follow-up. Side effects from anti-depressant medication were larger in the EG compared to CG. Complementing usual care for MDD with exercise resulted in better clinical outcomes and supports the use of this type of exercise protocol in the clinical management of depression.