Neurological and metabolic related pathophysiologies and treatment of comorbid diabetes with depression

Insulin resistance: The role in comorbid type 2 diabetes mellitus and depression

Insulin resistance (IR) plays a significant role in the pathophysiology of comorbid type 2 diabetes mellitus (T2DM) and depression (CDD) through multifaceted mechanisms, including dysregulation of insulin signaling (both central and peripheral), neuroendocrine disturbances (hypothalamic-pituitary-adrenal axis dysfunction and monoaminergic neurotransmission impairment), chronic inflammation, oxidative stress, disruption of the microbiota-gut-brain axis, reduced brain-derived neurotrophic factor levels, and altered synaptic plasticity. These IR-related pathways may predispose individuals to depressive symptoms or exacerbate existing mood disorders. A comprehensive understanding of these mechanisms is critical for developing integrated therapeutic strategies that concurrently target metabolic and psychiatric dysfunction. Antidepressant medications exhibit divergent effects on glucose metabolism. Tricyclic antidepressants, particularly amitriptyline and nortriptyline, worsen metabolic profiles by exacerbating IR, promoting weight gain, and inducing hyperglycemia, thereby increasing diabetes risk with prolonged use. Consequently, tricyclic antidepressants should be avoided in metabolically vulnerable populations unless alternatives are unavailable. Mirtazapine presents a paradoxical profile-while its appetite-stimulating effects often lead to weight gain (a known IR risk factor), some evidence suggests potential β-cell function preservation, necessitating cautious use of mirtazapine in individuals with metabolic syndrome. Among selective serotonin reuptake inhibitors, fluoxetine and escitalopram demonstrate favorable metabolic effects, including improved insulin sensitivity and glycemic control, though hypoglycemia risk (particularly with concomitant sulfonylureas) warrants monitoring. Bupropion, a norepinephrine-dopamine reuptake inhibitor, uniquely promotes weight loss and enhances glycemic control, making it a preferred option for depression comorbid with obesity or T2DM. Agomelatine, with its neutral metabolic profile and circadian rhythm-modulating properties, represents a safer alternative for patients with metabolic concerns. Concurrently, certain antidiabetic agents show promise in managing depression. Metformin and sodium-glucose cotransporter-2 inhibitors may be prioritized for diabetic patients at risk for depression, while glucagon-like peptide-1 receptor agonists appear particularly beneficial for obesity-related mood disturbances. Thiazolidinediones offer value in treatment-resistant cases, whereas insulin secretagogues should be used cautiously in psychiatrically vulnerable individuals. Future research should prioritize three key directions: (1) Mechanistic investigations using advanced neuroimaging to elucidate the contribution of IR to depressive phenotypes and evaluate novel interventions (such as intranasal insulin); (2) Precision medicine approaches incorporating biomarkers, including genetic polymorphisms, inflammatory markers, and gut microbiome signatures, to optimize antidepressant selection and develop personalized treatment algorithms; and (3) Therapeutic innovation, including dual GLP-1/GIP agonists and anti-inflammatory-antidepressant combinations, as well as integrating digital health technologies (e.g., continuous glucose monitoring coupled with mood tracking), will enable real-time, data-driven management. These advances will be instrumental in establishing integrated care paradigms for this comorbidity, which intertwines metabolic and psychiatric conditions.

The Ferroptosis-Mitochondrial Axis in Depression: Unraveling the Feedforward Loop of Oxidative Stress, Metabolic Homeostasis Dysregulation, and Neuroinflammation

Emerging evidence links ferroptosis-mitochondrial dysregulation to depression pathogenesis through an oxidative stress-energy deficit-neuroinflammation cycle driven by iron overload. This study demonstrates that iron accumulation initiates ferroptosis via Fenton reaction-mediated lipid peroxidation, compromising neuronal membrane integrity and disabling the GPx4 antioxidant system. Concurrent mitochondrial complex I/IV dysfunction impairs ATP synthesis, creating an AMPK/mTOR signaling imbalance and calcium dyshomeostasis that synergistically impair synaptic plasticity. Bidirectional crosstalk emerges: lipid peroxidation derivatives oxidize mitochondrial cardiolipin, while mitochondrial ROS overproduction activates ACSL4 to amplify ferroptotic susceptibility, forming a self-reinforcing neurodegenerative loop. Prefrontal-hippocampal metabolomics reveal paradoxical metabolic reprogramming with glycolytic compensation suppressing mitochondrial biogenesis (via PGC-1α/TFAM downregulation), trapping neurons in bioenergetic crisis. Clinical data further show that microglial M1 polarization through cGAS-STING activation sustains neuroinflammation via IL-6/TNF-α release. We propose a "ferroptosis-mitochondrial fragmentation-metabolic maladaptation" triad as mechanistic subtyping criteria for depression. Preclinical validation shows that combinatorial therapy (iron chelators + SIRT3 agonists) rescues neuronal viability by restoring mitochondrial integrity and energy flux. This work shifts therapeutic paradigms from monoaminergic targets toward multimodal strategies addressing iron homeostasis, organelle dynamics, and metabolic vulnerability-a framework with significant implications for developing neuroprotective antidepressants.

Exploring potential diagnostic markers and therapeutic targets for type 2 diabetes mellitus with major depressive disorder through bioinformatics and in vivo experiments

Type 2 diabetes mellitus (T2DM) and Major depressive disorder (MDD) act as risk factors for each other, and the comorbidity of both significantly increases the all-cause mortality rate. Therefore, studying the diagnosis and treatment of diabetes with depression (DD) is of great significance. In this study, we progressively identified hub genes associated with T2DM and depression through WGCNA analysis, PPI networks, and machine learning, and constructed ROC and nomogram to assess their diagnostic efficacy. Additionally, we validated these genes using qRT-PCR in the hippocampus of DD model mice. The results indicate that UBTD1, ANKRD9, CNN2, AKT1, and CAPZA2 are shared hub genes associated with diabetes and depression, with ANKRD9, CNN2 and UBTD1 demonstrating favorable diagnostic predictive efficacy. In the DD model, UBTD1 (p > 0.05) and ANKRD9 (p < 0.01) were downregulated, while CNN2 (p < 0.001), AKT1 (p < 0.05), and CAPZA2 (p < 0.01) were upregulated. We have discussed their mechanisms of action in the pathogenesis and therapy of DD, suggesting their therapeutic potential, and propose that these genes may serve as prospective diagnostic candidates for DD. In conclusion, this work offers new insights for future research on DD.

The relationship between body roundness index (BRI) and suicidal ideation: evidence from NHANES 2013-2018

IMPORTANCE

Emerging research suggests a complex interplay between physical health metrics and mental health outcomes, including suicidal ideation. The body roundness index (BRI), a novel measure of body size, may offer insights into this relationship. This study seeks to investigate the intricate connection between BRI and suicidal ideation in a sample that reflects the entire U.S. population-working to validate the potential of BRI as a predictor of suicidal ideation.

METHODS

Data from the NHANES spanning 2013 to 2018 was used in this cross-sectional study to analyze a sample of 14,058 participants. BRI was calculated based on height and waist circumference measurements. Suicidal ideation was assessed using the Mental Health-Depression Screener Questionnaire ninth question. To investigate potential non-linear relationships between BRI and suicidal ideation, we employed generalized additive models and smooth curve fitting, and used ROC curves to compare the predictive ability of BMI and BRI for suicidal ideation. Subgroup analyses and interaction tests were utilized to study the moderating effects of categorical covariates.

RESULTS

Multiple logistic regression analysis revealed a significant positive correlation between increased BRI and heightened suicidal ideation, with a nonlinear pattern persisting even after adjustment for covariates. This nonlinear relationship was reinforced by a sharp increase in the prevalence of suicidal ideation when the BRI exceeded 6.7. Based on ROC curve analysis, BRI demonstrates a slightly stronger predictive ability for suicide ideation compared to BMI. Subgroup analyses confirmed the relative robustness of this association across populations, including age, education and PRI, etc. However, the interaction between the two was influenced by gender, coronary artery disease and angina pectoris.

CONCLUSION

In conclusion, our cross-sectional study reveals a significant positive correlation between increased BRI and heightened suicidal ideation, with a sharp increase in prevalence when BRI exceeds 6.7. It is recommended that appropriate BRI be maintained to minimize suicidal ideation.

Metformin as a disease-modifying therapy in osteoarthritis: bridging metabolism and joint health

Background

Osteoarthritis (OA) and impaired glucose tolerance (IGT) frequently coexist, leading to compounded clinical and metabolic challenges. This study investigates the effects of metformin in improving both clinical outcomes (pain, stiffness, physical function) and metabolic parameters (inflammatory markers, lipid profile, BMI) in patients with knee OA and IGT.

Methods

The study included 60 patients diagnosed with knee OA and IGT. Participants were divided into two groups: 26 patients received standard OA treatment without metformin (Without Metf), while 34 received metformin (500 mg twice daily) for 3 months, in addition to standard treatment (With Metf). Clinical assessments (WOMAC, Lequesne Algofunctional Index, KOOS, VAS) and metabolic markers (CRP, NLR, SOD, lipid profile, BMI) were measured before treatment, after 1 month, and after 3 months.

Results

The With Metf group showed significantly greater improvements in pain, stiffness, physical function, and quality of life compared to the Without Metf group. Metformin also led to significant reductions in inflammatory markers and improvements in lipid profiles and metabolic health indicators. The With Metf group demonstrated enhanced BMI, waist-to-hip ratio, and waist-to-height ratio. Furthermore, the need for increased NSAID doses was predicted by factors such as pain severity and inflammatory markers.

Conclusion

Metformin effectively alleviates osteoarthritis symptoms and improves metabolic health in patients with both OA and IGT. Further research is needed to explore its long-term effects on joint health, inflammatory markers, and its potential role in OA management in patients without IGT.

Biological mechanism and functional verification of key genes related to major depressive disorder and type 2 diabetes mellitus

Major depressive disorder (MDD) and type 2 diabetes (T2D) have been shown to be linked, but a comprehensive understanding of the underlying molecular mechanisms remains elusive. The purpose of this study was to explore the biological relationship between MDD and T2D and verify the functional roles of key genes. We used the Gene Expression Omnibus database to investigate the targets associated with MDD and T2D. Using linear models for microarray data, differentially expressed genes associated with MDD and T2D were identified in GSE76826 and GSE95849, respectively, and 126 shared genes were significantly upregulated. Weighted gene coexpression network analysis identified modules associated with MDD and T2D in the GSE38206 and GSE20966 datasets and identified 8 common genes. Functional enrichment analysis revealed that these genes were enriched in cell signaling, enzyme activity, cell structure and amino acid biosynthesis and involved in cell death pathways. Finally, combined with the CTD and GeneCards databases, lysophosphatidylglycerol acyltransferase 1 (LPGAT1) was identified as a key gene. LPGAT1 was validated in GSE201332 and GSE182117, and the subject operating characteristic curve showed good diagnostic potential for MDD and T2D. Additionally, we used an in vitro model of MDD related to T2D to verify the expression of LPGAT1. A subsequent gene knockdown assay revealed that the downregulation of LPGAT1 improved mitochondrial function and reduced apoptosis in damaged neurons. Taken together, our results highlight the role of LPGAT1 in the connection between MDD and T2D, and these findings provide new insights into potential therapeutic targets for depression associated with diabetes.

Glucose metabolism impairment in major depressive disorder

Major depressive disorder (MDD) is a common mental disorder with chronic tendencies that seriously affect regular work, life, and study. However, its exact pathogenesis remains unclear. Patients with MDD experience systemic and localized impairments in glucose metabolism throughout the disease course, disrupting various processes such as glucose uptake, glycoprotein transport, glycolysis, the tricarboxylic acid cycle (TCA), and oxidative phosphorylation (OXPHOS). These impairments may result from mechanisms including insulin resistance, hyperglycemia-induced damage, oxidative stress, astrocyte abnormalities, and mitochondrial dysfunction, leading to insufficient energy supply, altered synaptic plasticity, neuronal cell death, and functional and structural damage to reward networks. These mechanical changes contribute to the pathogenesis of MDD and severely interfere with the prognosis. Herein, we summarized the impairment of glucose metabolism and its pathophysiological mechanisms in patients with MDD. In addition, we briefly discussed potential pharmacological interventions for glucose metabolism to alleviate MDD, including glucagon-like peptide-1 receptor agonists, metformin, topical insulin, liraglutide, and pioglitazone, to encourage the development of new therapeutics.

Association between triglyceride-glucose (TyG) index and the incidence of depression in US adults with diabetes or pre-diabetes

BACKGROUND

The relationship between the triglyceride glucose (TyG) index and the incidence of depression in populations with diabetes or pre-diabetes remains unclear. This study aims to investigate the association between the TyG index and depression incidence in diabetic/pre-diabetic populations.

METHOD

Data from the 2005-2018 National Health and Nutrition Examination Survey (NHANES) were analyzed. After adjustment for confounders, multivariate logistic regression models were fitted to investigate the association between TyG index and depression incidence. Restricted cubic splines (RCS), subgroup analysis, interaction analysis, and mediation analysis were also constructed.

RESULTS

A total of 8,970 participants with diabetes or pre-diabetes were enrolled. The linear positive association between TyG index and the incidence of depression was observed. Insulin resistance partly mediates this association in mediation analysis. There is a U-shape association between TyG index and the incidence of depression in diabetic/pre-diabetic populations whose ethnicity is Other Hispanic (p for nonlinearity =0.0237). Subgroup analysis evaluated the robustness of our findings and interaction analysis showed that this association can be modified by race/ethnicity.

CONCLUSION

There is a linear positive association between the TyG index and the incidence of depression in populations with diabetes or pre-diabetes.

Abnormal insulin metabolism and decreased levels of mindfulness in type 2 diabetes mellitus

OBJECTIVE

Disorders of insulin metabolism are strongly associated with a variety of psychological problems. The aim of this study was to investigate the differences in mindfulness levels among type 2 diabetes mellitus (T2DM) patients categorized based on their insulin resistance and β-cell function.

METHODS

A total of 157 T2DM patients were included in this study and divided into four groups according to their levels of insulin resistance and β-cell function. The Five Facet Mindfulness Questionnaire (FFMQ) was employed to assess the mindfulness levels of the patients. Linear regression models were utilized to investigate the relationships between various T2DM categories and mindfulness levels and dimensions. Furthermore, subgroup analyses of key variables were conducted, and mediation analysis was performed to evaluate the sources of differences.

RESULTS

Significant differences were observed among the four groups in terms of total mindfulness scores and in the dimensions of "Describing," "Non-judging of Inner Experience," and "Acting with Awareness" (P < 0.05). Compared to the control group (low HOMA-IR/high HOMA-β), the high HOMA-IR/low HOMA-β group exhibited markedly lower scores in "Non-judging of Inner Experience" (P = 0.02) and "Acting with Awareness" (P < 0.001). The low HOMA-IR/low HOMA-β group demonstrated weaker performance in "Non-judging of Inner Experience" (P = 0.005) and "Describing" (P = 0.002).

CONCLUSION

Significant differences in mindfulness levels were found to exist among T2DM patients with varying degrees of insulin resistance and β-cell function. Early-stage diabetes patients, particularly those with lower β-cell function or higher insulin resistance levels, may require additional psychological intervention support to enhance their mindfulness and overall well-being.

The Comorbidity of Depression and Diabetes Is Involved in the Decidual Protein Induced by Progesterone 1 (Depp1) Dysfunction in the Medial Prefrontal Cortex

BACKGROUND

There is a high rate of depressive symptoms such as irritability, anhedonia, fatigue, and hypersomnia in patients with type 2 diabetes mellitus (T2DM). However, the causes and underlying mechanisms of the comorbidity of depression and diabetes remain unknown.

METHODS

For the first time, we identified Decidual protein induced by progesterone 1 (Depp1), also known as DEPP autophagy regulator 1, as a hub gene in both depression and T2DM models. Depp1 levels were increased in the mPFC but not in other brain regions, such as the hippocampus or nucleus accumbens, according to Western blot and PCR assays.

RESULTS

Glucose dysregulation and synaptic loss occur in both depression and T2DM. The typical hyperglycemia in T2DM was observed in two models of depression, namely, chronic social defeat stress (CSDS) and chronic restraint stress (CRS). Hyperglycemia, which occurred in T2DM, was observed, and metabolomics data clearly showed the perturbation of glucose levels and glucose metabolism in the medial prefrontal cortex (mPFC). Decreased protein levels of BDNF and PSD95 suggested significant synaptic loss in depressed and diabetic mice.

CONCLUSION

These findings suggest that the comorbidity of depression and diabetes is involved in the dysfunction of Depp1 in the mPFC.

Antidepressants and Weight Gain: An Update on the Evidence and Clinical Implications

PURPOSE OF REVIEW

To highlight recent research on antidepressant use and weight change and explore best clinical practices for reducing weight gain and obesity risk in individuals with depression.

RECENT FINDINGS

Research on antidepressant use and weight gain suggests that genetic and biological factors including metabolizer phenotypes and inflammation can help to predict an individual's threshold for weight change among specific agents. For individuals with increased susceptibility to metabolic complications, medications including bupropion, fluoxetine, and newer agents (e.g., gepirone) have shown to be efficacious in improving depressive symptoms while concurrently reducing metabolic risks. Additional areas of focus following antidepressant related weight gain include switching to a weight neutral drug alternative, integrated behavioral interventions, and/or pharmacotherapy including GLP-1 receptor agonists (e.g., metformin, liraglutide). Individuals experiencing depression are at heightened risk of metabolic disorders and weight gain, which may be further exacerbated by antidepressant treatment. The increased support of weight neutral antidepressant agents in addition to innovative lifestyle interventions, breakthroughs in drug mechanisms, anti-obesity medications and overall familiarity with the side effects of each antidepressant class will help clinicians make appropriate decisions when treating patients with depression.

Bidirectional relationship between diabetes mellitus and depression: Mechanisms and epidemiology

Diabetes mellitus and depression exhibit a complex bidirectional relationship that profoundly impacts patient health and quality of life. This review explores the physiological mechanisms, including inflammation, oxidative stress, and neuroendocrine dysregulation, that link these conditions. Psychosocial factors such as social support and lifestyle choices also contribute significantly. Epidemiological insights reveal a higher prevalence of depression among diabetics and an increased risk of diabetes in depressed individuals, influenced by demographic variables. Integrated management strategies combining mental health assessments and personalized treatments are essential. Future research should focus on longitudinal and multi-omics studies to deepen understanding and improve therapeutic outcomes.

The Effectiveness and Safety Analysis of Duloxetine in Treating Comorbid Depression in Parkinson's Disease: A Retrospective Study

BACKGROUND

Parkinson's disease (PD) is a neurodegenerative disorder characterized by both motor and non-motor symptoms, including depression, which significantly impacts the quality of life of affected individuals. This study aims to investigate the real-world effectiveness and safety of duloxetine in treating comorbid depression in patients with Parkinson's disease and to compare its outcomes with traditional treatment approaches.

METHODS

This study included adult patients diagnosed with Parkinson's disease combined with depression from December 2020 to December 2023. Based on the use of duloxetine, the cohort was divided into a traditional treatment group and a duloxetine group (traditional treatment combined with duloxetine). Patients with incomplete medical records, concurrent antidepressant therapy, or major psychiatric or neurological disorders were excluded. Retrospective data, including demographic information, treatment adherence, and various assessment scores, were collected from medical records by trained research staff.

RESULTS

In total, 106 patients were analyzed, with 50 patients receiving traditional treatment and 56 patients receiving duloxetine. The duloxetine group exhibited significantly lower scores than the traditional treatment group in the Unified PD Rating Scale (p = 0.015), Hamilton Depression Rating Scale (p = 0.013), Beck Depression Inventory (p = 0.031), Parkinson's disease Questionnaire-39 (p = 0.006), and Clinical Global Impression-Improvement (p < 0.001) scores. In motor function assessment, the duloxetine group demonstrated improvements in kinetic tremor scores (p = 0.017), gait speed (p < 0.001), Timed Up and Go Test performance (p < 0.001), dyskinesia severity (p = 0.017), and rigidity (p = 0.019) compared to the traditional treatment group. Additionally, the duloxetine group exhibited better cognitive function across various assessments, including the Symbol Digit Modalities Test (p = 0.024), Stroop Color-Word Test (p = 0.048), and Montreal Cognitive Assessment (p = 0.024).

CONCLUSION

Duloxetine is associated with superior efficacy in improving motor and non-motor symptoms, overall clinical status, and cognitive function. These findings support the potential utility of duloxetine as a comprehensive treatment option for comorbid depression in Parkinson's disease.

Association of dietary antioxidant intake with depression risk and all-cause mortality in people with prediabetes

People with diabetes has an elevated risk of depression, and depression contributes to a worse prognosis for people with diabetes. Dietary antioxidants have been shown to reduce the risk of depression in the general population. Therefore, we hypothesized that dietary antioxidants would also help to reduce the risk of depression and all-cause mortality in people with prediabetes. A total of 8789 participants aged 20 years and older from the 2005-2018 National Health and Nutrition Examination Surveys who met the diagnostic criteria for prediabetes were included in our study. The associations between six dietary antioxidant intakes and the composite dietary antioxidant index (CDAI) with depression risk and all-cause mortality were assessed using weighted logistic and Cox regression. Possible nonlinear associations were further explored using restricted cubic spline. To ensure the reliability of the findings, the multiple imputations by chained equation were applied to missing covariates to avoid potential bias. Our study found that moderate dietary antioxidant intake prevents depression and improves prognosis in people with prediabetes. Moreover, a CDAI score near three allows for maximum benefit. Our findings could provide clues for early intervention in people with diabetes.

A Randomized Controlled Trial Comparing the Effects of Vilazodone, Escitalopram, and Vortioxetine Monotherapy on the Metabolic Parameters in Patients With Major Depressive Disorder

BACKGROUND AND OBJECTIVES

The coexistence of major depressive disorder (MDD) and metabolic illness could culminate in an aberrant metabolic profile. Individuals with MDD and type 2 diabetes mellitus (T2DM) are more likely to have impaired metabolic indicators. Effective antidepressant therapy can alleviate depressive symptoms and metabolic abnormalities. We focused on the effects of vilazodone, escitalopram, and vortioxetine on metabolic indices. Our research aimed to examine changes after 16 weeks of intervention in the glycemic indices, serum creatinine, lipid profile, hepatic parameters, and the Hamilton Depression Rating Scale (HDRS) 17-item version.

METHODS

A three-arm, randomized, open-label trial with 96 MDD patients was executed. Participants were divided into three distinct groups in a 1:1:1 ratio for 16 weeks and issued tablets of vilazodone (20-40 mg/day), escitalopram (10-20 mg/day), or vortioxetine (5-20 mg/day). Vilazodone and vortioxetine were the two test medications, while escitalopram served as the control. We stratified the participants as non-diabetics and diabetics. Follow-up appointments were slated four weeks after the initial visit. HDRS scores and other metabolic indicators were assessed at each visit in the per-protocol (PP) population. After 12 weeks, glycated hemoglobin (HbA1c) levels were measured. Lower HDRS scores indicated that depression-related symptoms had improved. We investigated the relationship between the 16-week differences in the fasting blood sugar (FBS) and HDRS scores. The Kruskal-Wallis test, Bonferroni correction, and Pearson correlation were all used in our analysis. We registered our trial prospectively in the Clinical Trial Registry of India (CTRI) (2022/07/043808).

RESULTS

Of the 134 people we screened, 119 (81.34%) were deemed eligible. The PP population included 96 (88.07%) of those who completed the 16-week study. The population's average age was 46.3 ± 6.2 years. Across all study groups, the median baseline HDRS score was 30.0 (p = 0.964). At 16 weeks, the equivalent scores dropped to 15.0, 14.0, and 13.0 (p = 0.002). The median FBS levels at baseline and 16 weeks were 100.5, 104.0, and 98.0 (p = 0.491) and 91.5, 98.5, and 91.5 (p = 0.561), respectively. The post hoc analysis manifested no statistically significant changes between any parameters. Except for the reductions in glycemic indices in diabetic patients, no other data differed significantly. There was a positive relationship between FBS and HDRS scores.

CONCLUSION

Irrespective of the diabetic situation, all three drugs substantially lowered HDRS scores. People with diabetes experienced noticeable declines in glycemic indices. Despite this, the patients' other metabolic indicators showed no significant alterations. We urge additional research with a larger sample size to investigate these medications' long-term impact on various metabolic indicators.

The Antidiabetic Drug Metformin Attenuated Depressive and Anxiety-like Behaviors and Oxidative Stress in the Brain in a Rodent Model of Inflammation Induced by Lipopolysaccharide in Male Rats

BACKGROUND

Inflammation is considered to be a link between diabetes and central nervous system (CNS) disorders, including depression and anxiety. Metformin is suggested to have antioxidant, anti-inflammatory, and mood-improving effects. The aim of the current research was to investigate the effects of the antidiabetic drug metformin on depressive- and anxiety- like behaviors and oxidative stress in the brain in a rodent model of inflammation induced by lipopolysaccharide (LPS) in male rats.

MATERIALS AND METHODS

The rats were treated as follows: (1) Vehicle instead of metformin and lipopolysaccharide, (2) Lipopolysaccharide (1 mg/ kg) + vehicle instead of metformin, (3-5) Lipopolysaccharide + 50, 100, or 150 mg/ kg of metformin. After the behavioral tests, including open field (OF), elevated pulse maze (EPM), and force swimming (FS) tests, the brains were removed, and malondialdehyde (MDA), nitric oxide (NO) metabolites, total thiol, catalase (CAT) activity, interleukin-6 (IL-6) and superoxide dismutase (SOD) activity were determined.

RESULTS

In the EPM, metformin increased the open arm time and entry and decreased closed arm time and entry. In the FS test, metformin lowered the immobility and increased active time compared to lipopolysaccharide. In the OF test, metformin increased total crossing and total distance, time spent, traveled distance, and crossing number in the central zone. As a result of metformin administration, IL-6, MDA, and NO metabolites were decreased while thiol content, SOD, and CAT activity were increased.

CONCLUSION

The results indicated that the well-known antidiabetic drug metformin attenuated depressive- and anxiety-like behaviors induced by inflammation in rats. These beneficial effects are suggested to be due to their attenuating effects on neuroinflammation, oxidative stress, and NO in the brain.

Uncovering the Neural Correlates of Anhedonia Subtypes in Major Depressive Disorder: Implications for Intervention Strategies

Major depressive disorder (MDD) represents a serious public health concern, negatively affecting individuals' quality of life and making a substantial contribution to the global burden of disease. Anhedonia is a core symptom of MDD and is associated with poor treatment outcomes. Variability in anhedonia components within MDD has been observed, suggesting heterogeneity in psychopathology across subgroups. However, little is known about anhedonia subgroups in MDD and their underlying neural correlates across subgroups. To address this question, we employed a hierarchical cluster analysis based on Temporal Experience of Pleasure Scale subscales in 60 first-episode, drug-naive MDD patients and 32 healthy controls. Then we conducted a connectome-wide association study and whole-brain voxel-wise functional analyses for identified subgroups. There were three main findings: (1) three subgroups with different anhedonia profiles were identified using a data mining approach; (2) several parts of the reward network (especially pallidum and dorsal striatum) were associated with anticipatory and consummatory pleasure; (3) different patterns of within- and between-network connectivity contributed to the disparities of anhedonia profiles across three MDD subgroups. Here, we show that anhedonia in MDD is not uniform and can be categorized into distinct subgroups, and our research contributes to the understanding of neural underpinnings, offering potential treatment directions. This work emphasizes the need for tailored approaches in the complex landscape of MDD. The identification of homogeneous, stable, and neurobiologically valid MDD subtypes could significantly enhance our comprehension and management of this multifaceted condition.