Longitudinal Association Between Depression and Inflammatory Markers: Results From the Netherlands Study of Depression and Anxiety

Exploring the use of immunomethylomics in the characterization of depressed patients: A proof-of-concept study

Alterations in DNA methylation and inflammation could represent valid biomarkers for the stratification of patients with major depressive disorder (MDD). This study explored the use of DNA-methylation based immunological cell-type profiles in the context of MDD and symptom severity over time. In 119 individuals with MDD, DNA-methylation was assessed on whole blood using the Illumina Infinium MethylationEPIC 850 k BeadChip. Quality control and data processing, as well as cell type estimation was conducted using the RnBeads package. The cell type composition was estimated using epigenome-wide DNA methylation signatures, applying the Houseman method, considering six cell types (neutrophils, natural killer cells (NK), B cells, CD4+ T cells, CD8+ T cells and monocytes). Two cytokines (IL-6 and IL-1β) and hsCRP were quantified in serum. We performed a hierarchical cluster analysis on the six estimated cell-types and tested the differences between these clusters in relation to the two cytokines and hsCRP, depression severity at baseline, and after 6 weeks of treatment (celecoxib/placebo + vortioxetine). We performed a second cluster analysis with cell-types and cytokines combined. ANCOVA was used to test for differences across clusters. We applied the Bonferroni correction. After quality control, we included 113 participants. Two clusters were identified, cluster 1 was high in CD4+ cells and NK, cluster 2 was high in CD8+ T-cells and B-cells, with similar fractions of neutrophils and monocytes. The clusters were not associated with either of the two cytokines and hsCRP, or depression severity at baseline, but cluster 1 showed higher depression severity after 6 weeks, corrected for baseline (p = 0.0060). The second cluster analysis found similar results: cluster 1 was low in CD8+ T-cells, B-cells, and IL-1β. Cluster 2 was low in CD4+ cells and natural killer cells. Neutrophils, monocytes, IL-6 and hsCRP were not different between the clusters. Participants in cluster 1 showed higher depression severity at baseline than cluster 2 (p = 0.034), but no difference in depression severity after 6 weeks. DNA-methylation based cell-type profiles may be valuable in the immunological characterization and stratification of patients with MDD. Future models should consider the inclusion of more cell-types and cytokines for better a prediction of treatment outcomes.

The triangular relationship of physical activity, depression, and inflammatory markers: A large cross-sectional analysis with NHANES data

Depression is a major public health problem worldwide and is closely related with systemic inflammatory responses. Additionly, physical activity (PA) is thought to be associated with lower levels of depression and inflammatory markers. This study aimed to elucidate the complex interactions between PA, depression, and inflammatory markers. Based on the National Health and Nutrition Examination Survey (NHANES), various logistic regression were applied to analyze the pairwise correlations among the three. Restrictive cubic splines were constructed to explore the nonlinear relationship between PA and depression. Mediation models were used to identify the mediating role of inflammatory markers. The findings revealed a positive link between depression and inflammatory marker, whereas PA was inversely correlated with both inflammatory marker and depression. Particularly, we noticed the greatest reduction in the risk of depression when the level of PA was between 1200 and 1722 MET-min/week. Besides, we demonstrated that inflammatory markers mediate the potential effects of physical inactivity on depression, ranging from 1.72 % to 6.25 %. In conclusion, PA appear to protect against depression, in which inflammatory markers may play a mediating role. Moreover, we determined the optimal dosage of PA to minimize the likelihood of depression, thereby offering valuable guidance for managing depression.

C-reactive protein (CRP) level in depressed patients with suicidal behavior: A systematic review and meta-analysis

INTRODUCTION

Suicidal behavior necessitates prompt diagnosis due to its severe consequences. C-reactive protein (CRP) levels may offer insights into its pathophysiology and aid in risk assessment, potentially enhancing preventive interventions and treatment strategies. The aim of this study is to assess the CRP levels in depressed patients with and without suicidal behavior.

METHODS

Our systematic review was registered in Prospero (#CRD42024518477). We searched five databases (PubMed, Scopus, PsycINFO, Web of Science, and CINAHL Complete) for records in English from inception to February 2024. We included observational studies that measured CRP in depressed patients with and without suicidal behavior. We used the Newcastle-Ottawa Scale (NOS) to assess the quality of the included studies. We employed a random-effects model, and the statistical analysis was conducted using Stata software version 17.

RESULTS

Initial 632 articles narrowed to 15 for systematic review. Fifteen studies with 3652 participants included. Fourteen studies involving 3387 depressed patients, 1269 with suicidal behavior, analyzed CRP levels. Suicidal patients exhibited higher CRP levels (SMD: 0.80 [0.37, 1.23]). Analysis of seven studies with 465 participants, including 200 depressed patients with suicidal behavior and 265 healthy controls, showed higher CRP levels in depressed patients (SMD: 1.58 [0.97, 2.19]).

CONCLUSION

In summary, our systematic review and meta-analysis of CRP levels in suicidal patients revealed that those with suicidal behavior exhibited higher CRP levels, suggesting possible implications for treatment approaches.

Independent and joint influence of depression and advanced lung cancer inflammation index on mortality among individuals with chronic kidney disease

Background

The combined effect of depression and nutritional-inflammatory status on mortality in the chronic kidney disease (CKD) population is unclear.

Methods

We prospectively analyzed 3,934 (weighted population: 22,611,423) CKD participants from the National Health and Nutrition Examination Survey (2007-2018). Depression and nutritional-inflammatory status were assessed with Patient Health Questionnaire 9 (PHQ-9) and Advanced Lung Cancer Inflammation Index (ALI), respectively. Weighted multivariate COX regression models, restricted cubic splines (RCS) models, and stratified analyses were used to investigate the association of PHQ-9 scores and ALI with all-cause mortality.

Results

During a median follow-up of 5.8 years (interquartile range 3.4-8.6 years), a total of 985 patients died (25.0%). Each point increase in a patient's PHQ-9 score increased the risk of all-cause mortality by 4% (HR, 1.04; 95% CI, 1.02-1.06; p < 0.001), in the full adjusted model. However, an increase in ALI levels was associated with a decreased risk. HRs (95% CI) of 0.76 (0.65-0.90), 0.70 (0.57-0.86), and 0.51 (0.41-0.64) in the Q2, Q3, and Q4 of ALI compared with the Q1 of ALI, respectively. In addition, the joint analysis showed that CKD patients without depression and with higher ALI were associated with a reduced risk of all-cause mortality. Namely, patients in the highest ALI group (Q4) without depression had the lowest risk (HR, 0.32; 95% CI, 0.21-0.48). Furthermore, this combined effect was consistent across all subgroups, and no significant interaction was found (p > 0.05 for interaction).

Conclusion

In a nationally representative sample of US patients with CKD, coexisting depression and poorer nutrition-inflammation were associated with a significantly increased risk of all-cause mortality.

Considering the role of estradiol in the psychoneuroimmunology of perimenopausal depression

In recent years, a burgeoning field of research has focused on women's mental health and psychiatric conditions associated with perinatal and postpartum periods. An emerging trend points to the link between hormone fluctuations during pregnancy and postpartum that have immunologic consequences in cases of perinatal depression and postpartum psychosis. The transition to menopause (or "perimenopause") has garnered comparatively less attention, but existing studies point to the influential interaction of hormonal and immune pathways. Moreover, the role of this cross talk in perturbing neural networks has been implicated in risk for cognitive decline, but relatively less work has focused on the depressed brain during perimenopause. This brief review brings a psychoneuroimmunology lens to depression during the perimenopausal period by providing an overview of existing knowledge and suggestions for future research to intertwine these bodies of work.

Ketogenic diets in clinical psychology: examining the evidence and implications for practice

Introduction

The application of ketogenic dietary interventions to mental health treatments is increasingly acknowledged within medical and psychiatric fields, yet its exploration in clinical psychology remains limited. This article discusses the potential implications of ketogenic diets, traditionally utilized for neurological disorders, within broader mental health practices.

Methods

This article presents a perspective based on existing ketogenic diet research on historical use, biological mechanisms, and therapeutic benefits. It examines the potential application of these diets in mental health treatment and their relevance to clinical psychology research and practice.

Results

The review informs psychologists of the therapeutic benefits of ketogenic diets and introduces to the psychology literature the underlying biological mechanisms involved, such as modulation of neurotransmitters, reduction of inflammation, and stabilization of brain energy metabolism, demonstrating their potential relevance to biopsychosocial practice in clinical psychology.

Conclusion

By considering metabolic therapies, clinical psychologists can broaden their scope of biopsychosocial clinical psychology practice. This integration provides a care model that incorporates knowledge of the ketogenic diet as a treatment option in psychiatric care. The article emphasizes the need for further research and training for clinical psychologists to support the effective implementation of this metabolic psychiatry intervention.

The correlation of inflammation, tryptophan-kynurenine pathway, and suicide risk in adolescent depression

Accumulating evidence suggests a role for the tryptophan-kynurenine pathway (TKP) in the psychopathology of major depressive disorder (MDD). Abnormal inflammatory profile and production of TKP neurotoxic metabolites appear more pronounced in MDD with suicidality. Progress in understanding the neurobiology of MDD in adolescents lags significantly behind that in adults due to limited empirical evidence. Aims of this study was to investigate the association between inflammation, TKP, and suicidality in adolescent depression. Seventy-three adolescents with MDD were assessed for serum levels of interleukin (IL)-1β, IL-6, IL-18, IL-10, tumor necrosis factor-α (TNF-α), tryptophan (TRP), kynurenine (KYN), 3-hydroxykynurenine (3-HK), and kynurenine acid (KA). Correlations between cytokines and TKP measures were examined. Patients were divided into high- (n = 42) and non-high-suicide-risk groups (n = 31), and serum levels of cytokines and TKP metabolites were compared. Significant negative correlations were found between TRP and IL-8 (r =  - 0.27, P < 0.05) and IL-10 (r =  - 0.23, P < 0.05), while a significant positive correlation was observed between 3-HK and IL-8 (r = 0.39, P < 0.01) in depressed adolescents. The KYN/TPR (index of indoleamine 2,3-dioxygenase, IDO) was positively correlated with IL-1β (r = 0.34), IL-6 (r = 0.32), IL-10 (r = 0.38) and TNF-α (r = 0.35) levels (P < 0.01); and 3-HK/KYN (index of kynurenine3-monooxidase, KMO) was positively correlated with IL-8 level (r = 0.31, P < 0.01). Depressed adolescents at high suicide risk exhibited significantly higher levels of IL-1β (Z = 2.726, P < 0.05), IL-10 (Z = 2.444, P < 0.05), and TNF-α (Z = 2.167, P < 0.05) and lower levels of 3-HK (Z = 2.126, P < 0.05) compared to their non-high suicide risk counterparts. Our findings indicated that serum inflammatory cytokines were robustly associated with IDO and KMO activity, along with significantly decreased serum level of TRP, increased level of 3-HK, and higher suicide risk in adolescent depression.

Revealing genetic causality between blood-based biomarkers and major depression in east Asian ancestry

Introduction

Major Depression (MD) is a common mental disorder. In East Asian ancestry, the association, causality, and shared genetic basis between blood-based biomarkers and MD remain unclear.

Methods

We investigated the relationships between blood-based biomarkers and MD through a cross-sectional study and Mendelian randomization (MR) analysis. Cross-trait analysis and enrichment analyses were used to highlight the shared genetic determinants and biological pathways. We conducted summary data-based MR to identify shared genes, which were then validated using a transcriptome dataset from drug-naïve patients with MD.

Results

In the cross-sectional study, C-Reactive Protein showed the significantly positive correlation with depressive symptoms, while hematocrit, hemoglobin, and uric acid exhibited significantly negative correlations. In MR analysis, basophil count (BASO) and low-density lipoprotein cholesterol (LDLc) had a significant causal effect on MD. The enrichment analysis indicated a significant role of inflammatory cytokines and oxidative stress. The shared genes MFN2, FAM55C, GCC2, and SCAPER were validated, with MFN2 identified as a pleiotropic gene involved in MD, BASO, and LDLc.

Discussion

This study highlighted that BASO and LDLc have a causal effect on MD in East Asian ancestry. The pathological mechanisms of MD are related not only to inflammatory cytokines and oxidative stress but also to down regulation of MFN2 expression and mitochondrial dysfunction.

Navigating the Neuroimmunomodulation Frontier: Pioneering Approaches and Promising Horizons-A Comprehensive Review

The research in neuroimmunomodulation aims to shed light on the complex relationships that exist between the immune and neurological systems and how they affect the human body. This multidisciplinary field focuses on the way immune responses are influenced by brain activity and how neural function is impacted by immunological signaling. This provides important insights into a range of medical disorders. Targeting both brain and immunological pathways, neuroimmunomodulatory approaches are used in clinical pain management to address chronic pain. Pharmacological therapies aim to modulate neuroimmune interactions and reduce inflammation. Furthermore, bioelectronic techniques like vagus nerve stimulation offer non-invasive control of these systems, while neuromodulation techniques like transcranial magnetic stimulation modify immunological and neuronal responses to reduce pain. Within the context of aging, neuroimmunomodulation analyzes the ways in which immunological and neurological alterations brought on by aging contribute to cognitive decline and neurodegenerative illnesses. Restoring neuroimmune homeostasis through strategies shows promise in reducing age-related cognitive decline. Research into mood disorders focuses on how immunological dysregulation relates to illnesses including anxiety and depression. Immune system fluctuations are increasingly recognized for their impact on brain function, leading to novel treatments that target these interactions. This review emphasizes how interdisciplinary cooperation and continuous research are necessary to better understand the complex relationship between the neurological and immune systems.

Exploring the correlation between childhood trauma experiences, inflammation, and brain activity in first-episode, drug-naive major depressive disorder

BACKGROUND

Childhood trauma experiences and inflammation are pivotal factors in the onset and perpetuation of major depressive disorder (MDD). However, research on brain mechanisms linking childhood trauma experiences and inflammation to depression remains insufficient and inconclusive.

METHODS

Resting-state fMRI scans were performed on fifty-six first-episode, drug-naive MDD patients and sixty healthy controls (HCs). A whole-brain functional network was constructed by thresholding 246 brain regions, and connectivity and network properties were calculated. Plasma interleukin-6 (IL-6) levels were assessed using enzyme-linked immunosorbent assays in MDD patients, and childhood trauma experiences were evaluated through the Childhood Trauma Questionnaire (CTQ).

RESULTS

Negative correlations were observed between CTQ total (r = -0.28, p = 0.047), emotional neglect (r = -0.286, p = 0.042) scores, as well as plasma IL-6 levels (r = -0.294, p = 0.036), with mean decreased functional connectivity (FC) in MDD patients. Additionally, physical abuse exhibited a positive correlation with the nodal clustering coefficient of the left thalamus in patients (r = 0.306, p = 0.029). Exploratory analysis indicated negative correlations between CTQ total and emotional neglect scores and mean decreased FC in MDD patients with lower plasma IL-6 levels (n = 28), while these correlations were nonsignificant in MDD patients with higher plasma IL-6 levels (n = 28).

CONCLUSIONS

This finding enhances our understanding of the correlation between childhood trauma experiences, inflammation, and brain activity in MDD, suggesting potential variations in their underlying pathophysiological mechanisms.

Omega-3 alleviates behavioral and molecular changes in a mouse model of stress-induced juvenile depression

Introduction

Depression is increasingly diagnosed in adolescence, necessitating specific prevention and treatment methods. However, there is a lack of animal models mimicking juvenile depression. This study explores a novel model using ultrasound (US) stress in juvenile mice.

Methods

We employed the US stress model in one-month-old C57/BL6 mice, exposing them to alternating ultrasound frequencies (20-25 kHz and 25-45 kHz) for three weeks. These frequencies correspond to negative and neutral emotional states in rodents and can induce a depressive-like syndrome. Concurrently, mice received either an omega-3 food supplement (FS) containing eicosapentaenoic acid (EPA; 0.55 mg/kg/day) and docosahexaenoic acid (DHA; 0.55 mg/kg/day) or a vehicle. Post-stress, we evaluated anxiety- and depressive-like behaviors, blood corticosterone levels, brain expression of pro-inflammatory cytokines, and conducted metabolome analysis of brain, liver and blood plasma.

Results

US-exposed mice treated with vehicle exhibited decreased sucrose preference, a sign of anhedonia, a key feature of depression, increased anxiety-like behavior, elevated corticosterone levels, and enhanced TNF and IL-1β gene expression in the brain. In contrast, US-FS mice did not display these changes. Omega-3 supplementation also reduced anxiety-like behavior in non-stressed mice. Metabolomic analysis revealed US-induced changes in brain energy metabolism, with FS increasing brain sphingomyelin. Liver metabolism was affected by both US and FS, while plasma metabolome changes were exclusive to FS. Brain glucose levels correlated positively with activity in anxiety tests.

Conclusion

Chronic omega-3 intake counteracted depressive- and anxiety-like behaviors in a US model of juvenile depression in mice. These effects likely stem from the anti-inflammatory properties of the supplement, suggesting potential therapeutic applications in juvenile depression.

Cognition and gut microbiota in schizophrenia spectrum and mood disorders: A systematic review

FRILEUX, M., BOLTRI M. and al. Cognition and Gut microbiota in schizophrenia spectrum and mood disorders: a Systematic Review. NEUROSCI BIOBEHAV REV (1) 2024 Schizophrenia spectrum disorders and major mood disorders are associated with cognitive impairments. Recent studies suggest a link between gut microbiota composition and cognitive functioning. Here, we review the relationship between gut microbiota and cognition in these disorders. To do this, we conducted a systematic review, searching Cochrane Central Register of Controlled Trials, EBSCOhost, Embase, Pubmed, Scopus, and Web of Science. Studies were included if they investigated the relationship between gut microbiota composition and cognitive function through neuropsychological assessments in patients with bipolar, depressive, schizophrenia spectrum, and other psychotic disorders. Ten studies were identified. Findings underscore a link between gut dysbiosis and cognitive impairment. This relationship identified specific taxa (Haemophilus, Bacteroides, and Alistipes) as potential contributors to bolstered cognitive performance. Conversely, Candida albicans, Toxoplasma gondii, Streptococcus and Deinococcus were associated with diminished performance on cognitive assessments. Prebiotics and probiotics interventions were associated with cognitive enhancements, particularly executive functions. These results emphasize the role of gut microbiota in cognition, prompting further exploration of the underlying mechanisms paving the way toward precision psychiatry.

Bovine colostrum supplementation as a new perspective in depression and substance use disorder treatment: a randomized placebo-controlled study

Introduction

This randomized, placebo-controlled, double-blind, parallel study aimed to evaluate the effect of 3-month supplementation of bovine colostrum (BOV-COL; 8x400 mg per day) on the outcomes of depression treatment in hospitalized patients with substance use disorder (SUD). The hypothesis is that BOV-COL supplementation as an add-on treatment results in favorable alternations in selected blood inflammatory markers or neurotransmitters, leading to better depression treatment outcomes compared with placebo (PLA).

Methods

Patients with a Minnesota Multiphasic Personality Inventory-2 score ≥60 points were enrolled. Twenty-nine participants (n=18 in the BOV-COL group and n=11 in the PLA group) completed the protocol.

Results

The mean Beck Depression Inventory-II score was significantly reduced after supplementation in both groups. However, the mean 17-point Hamilton Depression Rating Scale score was decreased in the BOV-COL group, but not in the PLA group. In the BOV-COL group, there was a reduction in interleukin (IL)-1, IL-6, IL-10, the IL-6:IL-10 ratio, IL-17, and tumor necrosis factor alpha (TNF-α), while in the PLA group only IL-6 decreased. Favorable alternations in the total count and differentials of white blood cell subsets were more pronounced in the BOV-COL. There were no changes in neurotransmitter concentrations.

Conclusions

BOV-COL supplementation is a promising add-on therapy in patients with depression and SUD.

Inflammation and immune system pathways as biological signatures of adolescent depression-the IDEA-RiSCo study

The biological mechanisms underlying the onset of major depressive disorder (MDD) have predominantly been studied in adult populations from high-income countries, despite the onset of depression typically occurring in adolescence and the majority of the world's adolescents living in low- and middle-income countries (LMIC). Taking advantage of a unique adolescent sample in an LMIC (Brazil), this study aimed to identify biological pathways characterizing the presence and increased risk of depression in adolescence, and sex-specific differences in such biological signatures. We collected blood samples from a risk-stratified cohort of 150 Brazilian adolescents (aged 14-16 years old) comprising 50 adolescents with MDD, 50 adolescents at high risk of developing MDD but without current MDD, and 50 adolescents at low risk of developing MDD and without MDD (25 females and 25 males in each group). We conducted RNA-Seq and pathway analysis on whole blood. Inflammatory-related biological pathways, such as role of hypercytokinemia/hyperchemokinemia in the pathogenesis of influenza (z-score = 3.464, p < 0.001), interferon signaling (z-score = 2.464, p < 0.001), interferon alpha/beta signaling (z-score = 3.873, p < 0.001), and complement signaling (z-score = 2, p = 0.002) were upregulated in adolescents with MDD compared with adolescents without MDD independently from their level of risk. The up-regulation of such inflammation-related pathways was observed in females but not in males. Inflammatory-related pathways involved in the production of cytokines and in interferon and complement signaling were identified as key indicators of adolescent depression, and this effect was present only in females.

Genetic link between depression and musculoskeletal disorders: insights from Mendelian randomization analysis

Background

The association between depression and musculoskeletal diseases has long been a subject of contentious debate. However, the causal relationship between the two remains uncertain. This study employs a two-sample Mendelian randomization (MR) analysis to investigate the causality between depression and six musculoskeletal diseases.

Methods

In this study, we performed MR analysis to systematically explore the causal relationship between depression and six musculoskeletal disorders. Single nucleotide polymorphisms (SNPs) that are linked to depression were employed as instrumental variables. To ensure robust and reliable conclusions, multiple analytical approaches were utilized, including inverse variance weighting(IVW), weighted median, and MR-Egger regression. Additionally, sensitivity analysis methods such as the MR-Egger intercept test, Cochran's Q test, leave-one-out analysis, and funnel plot were employed.

Results

Our MR analysis revealed a significant association between depression and cervical spondylosis (depression: OR 1.003, 95% CI 1.002-1.005, P = 8.32E-05; major depressive disorder: OR 1.003, 95% CI 1.001-1.005, P = 0.0052). Furthermore, a strong correlation was noted between major depressive disorder (MDD) and knee osteoarthritis (KOA) (OR 1.299, 95% CI 1.154-1.463, P = 1.50E-5). Sensitivity analysis confirmed the robustness of these findings. Our independent validation study also corroborated these results.

Conclusion

The MR analysis conducted in this study provides evidence supporting a genetic link between depression and cervical spondylosis, as well as KOA. Targeted interventions to manage depression in susceptible populations may contribute to lowering the risk of cervical spondylosis and KOA in these cohorts.

Clinical effects of nonconvulsive electrotherapy combined with mindfulness-based stress reduction and changes of serum inflammatory factors in depression

BACKGROUND

Depression is a common and serious psychological condition, which seriously affects individual well-being and functional ability. Traditional treatment methods include drug therapy and psychological counseling; however, these methods have different degrees of side effects and limitations. In recent years, nonconvulsive electrotherapy (NET) has attracted increasing attention as a noninvasive treatment method. However, the clinical efficacy and potential mechanism of NET on depression are still unclear. We hypothesized that NET has a positive clinical effect in the treatment of depression, and may have a regulatory effect on serum inflammatory factors during treatment.

AIM

To assess the effects of NET on depression and analyze changes in serum inflammatory factors.

METHODS

This retrospective study enrolled 140 patients undergoing treatment for depression between May 2017 and June 2022, the observation group that received a combination of mindfulness-based stress reduction (MBSR) and NET treatment (n = 70) and the control group that only received MBSR therapy (n = 70). The clinical effectiveness of the treatment was evaluated by assessing various factors, including the Hamilton Depression Scale (HAMD)-17, self-rating idea of suicide scale (SSIOS), Pittsburgh Sleep Quality Index (PSQI), and levels of serum inflammatory factors before and after 8 wk of treatment. The quality of life scores between the two groups were compared. Comparisons were made using t and χ2 tests.

RESULTS

After 8 wk of treatment, the observation group exhibited a 91.43% overall effectiveness rate which was higher than that of the control group which was 74.29% (64 vs 52, χ2 = 7.241; P < 0.05). The HAMD, SSIOS, and PSQI scores showed a significant decrease in both groups. Moreover, the observation group had lower scores than the control group (10.37 ± 2.04 vs 14.02 ± 2.16, t = 10.280; 1.67 ±0.28 vs 0.87 ± 0.12, t = 21.970; 5.29 ± 1.33 vs 7.94 ± 1.35, t = 11.700; P both < 0.001). Additionally, there was a notable decrease in the IL-2, IL-1β, and IL-6 in both groups after treatment. Furthermore, the observation group exhibited superior serum inflammatory factors compared to the control group (70.12 ± 10.32 vs 102.24 ± 20.21, t = 11.840; 19.35 ± 2.46 vs 22.27 ± 2.13, t = 7.508; 32.25 ± 4.6 vs 39.42 ± 4.23, t = 9.565; P both < 0.001). Moreover, the observation group exhibited significantly improved quality of life scores compared to the control group (Social function: 19.25 ± 2.76 vs 16.23 ± 2.34; Emotions: 18.54 ± 2.83 vs 12.28 ± 2.16; Environment: 18.49 ± 2.48 vs 16.56 ± 3.44; Physical health: 19.53 ± 2.39 vs 16.62 ± 3.46; P both < 0.001) after treatment.

CONCLUSION

MBSR combined with NET effectively alleviates depression, lowers inflammation (IL-2, IL-1β, and IL-6), reduces suicidal thoughts, enhances sleep, and improves the quality of life of individuals with depression.

Pro-inflammatory cytokines in stress-induced depression: Novel insights into mechanisms and promising therapeutic strategies

Stress-mediated depression is one of the common psychiatric disorders with a high prevalence and suicide rate, there is a lack of effective treatment. Accordingly, effective treatments with few adverse effects are urgently needed. Pro-inflammatory cytokines (PICs) may play a key role in stress-mediated depression. Thereupon, both preclinical and clinical studies have found higher levels of IL-1β, TNF-α and IL-6 in peripheral blood and brain tissue of patients with depression. Recent studies have found PICs cause depression by affecting neuroinflammation, monoamine neurotransmitters, hypothalamic pituitary adrenal axis and neuroplasticity. Moreover, they play an important role in the symptom, development and progression of depression, maybe a potential diagnostic and therapeutic marker of depression. In addition, well-established antidepressant therapies have some relief on high levels of PICs. Importantly, anti-inflammatory drugs relieve depressive symptoms by reducing levels of PICs. Collectively, reducing PICs may represent a promising therapeutic strategy for depression.

Systemic Inflammation in Asthma: What Are the Risks and Impacts Outside the Airway?

Airway inflammation in asthma has been well recognized for several decades, with general agreement on its role in asthma pathogenesis, symptoms, propensity toward exacerbation, and decline in lung function. This has led to universal recommendation in asthma management guidelines to incorporate the use of inhaled corticosteroid as an anti-inflammatory therapy for all patients with persistent asthma symptoms. However, there has been limited attention paid to the presence and potential impact of systemic inflammation in asthma. Accumulating evidence from epidemiological observations and cohort studies points to a host of downstream organ dysfunction in asthma especially among patients with longstanding or more severe disease, frequent exacerbations, and underlying risk factors for organ dysfunction. Most studies to date have focused on cognitive impairment, depression/anxiety, metabolic syndrome, and cardiovascular abnormalities. In this review, we summarize some of the evidence demonstrating these abnormalities and highlight the proposed mechanisms and potential benefits of treatment in limiting these extrapulmonary abnormalities in patients with asthma. The goal of this commentary is to raise awareness of the importance of recognizing potential extrapulmonary conditions associated with systemic inflammation of asthma. This area of treatment of patients with asthma is a large unmet need.

Perceived Control and Inflammation: Mediating and Moderating Effects in the Relationship Between Cumulative Trauma and Depression

OBJECTIVE

The effects of trauma exposure on depression risk and severity are well established, but psychosocial and biological factors that impact or explain those relationships remain poorly understood. This study examined the moderating and mediating effects of perceived control and inflammation in the relationship between trauma and depression.

METHODS

Moderation analyses and longitudinal mediation analyses were conducted on data from 945 adults who completed all three waves (spanning around 19 years) of the Midlife Development in the United States (MIDUS) study and the MIDUS Biomarker Study. Data were collected during a phone interview, self-report surveys distributed in the mail, and an in-person blood draw. Two dimensions of perceived control-mastery and constraints-were examined separately in all analyses.

RESULTS

Perceived control did not significantly moderate the relationship between trauma and depression severity at MIDUS 2 ( b = 0.03, SE = .02, p = .091). Constraints significantly mediated the relationship between trauma and MIDUS 3 depression (indirect effect = 0.03, SE = 0.01, p = .016) but not after accounting for MIDUS 2 depression. Perceived control did not have a significant moderating effect in the relationships between trauma and inflammation or inflammation and depression.

CONCLUSIONS

Findings from this study revealed that perceived control may be better characterized as an explanatory factor rather than a buffer in trauma-associated depression. Perceived constraints in particular may be a useful treatment target for trauma-associated depression. Further research is needed to examine whether these results generalize to populations other than among mostly non-Hispanic White adults in the United States.

The interaction effect of depressive symptoms and inflammation on the occurrence of cardiovascular diseases

BACKGROUND

Whether there was an interaction effect between depressive symptoms and inflammation on the occurrence of cardiovascular diseases (CVDs) was unclear.

METHODS

In this cross-sectional study, 3346 participants in the National Health and Nutrition Examination Survey (NHANES) were included. Multivariable regression analysis was performed to explore the associations of depressive symptoms or inflammation with CVDs. The attributable proportion of interaction (API), and synergy index (SI) were applied for evaluating the statistical significance of the interaction effect.

RESULTS

Depressive symptoms were associated with 2.31-fold risk of CVDs [odds ratio (OR) = 2.31, 95 % confidence interval (CI): 1.47-3.62). The increased risk of CVDs was observed in people with neutrophil to lymphocyte ratio (NLR) ≥1.88 group (OR = 1.36, 95%CI: 1.01-1.85) and neutrophil/[white blood cell (WBC)-neutrophil] ≥1.35 (OR = 1.52, 95%CI: 1.12-2.07) after adjusting for confounders. The interaction effect of depressive symptoms and high NLR on the risk of CVDs was statistically significant with an OR value of 2.60 (95%CI: 1.43-4.70) compared to low NLR and no depressive symptoms group after adjusting for confounders. The API was 0.66 (95%CI: 0.44-0.89) and SI was 4.23 (95%CI: 2.08-8.59). The interaction effect of depressive symptoms and high neutrophil/(WBC-neutrophil) was associated with the risk of CVDs compared to low neutrophil/(WBC-neutrophil) and no depressive symptoms group (OR = 3.59, 95%CI: 2.00-6.45). The API was 0.78 (95%CI: 0.63-0.93) and SI was 6.75 (95%CI: 3.55-12.82).

CONCLUSION

There was an interaction effect of depressive symptoms and inflammation on the occurrence of CVDs.

Genetics, epigenetics, and neurobiology of childhood-onset depression: an umbrella review

Depression is a serious and persistent psychiatric disorder that commonly first manifests during childhood. Depression that starts in childhood is increasing in frequency, likely due both to evolutionary trends and to increased recognition of the disorder. In this umbrella review, we systematically searched the extant literature for genetic, epigenetic, and neurobiological factors that contribute to a childhood onset of depression. We searched PubMed, EMBASE, OVID/PsychInfo, and Google Scholar with the following inclusion criteria: (1) systematic review or meta-analysis from a peer-reviewed journal; (2) inclusion of a measure assessing early age of onset of depression; and (3) assessment of neurobiological, genetic, environmental, and epigenetic predictors of early onset depression. Findings from 89 systematic reviews of moderate to high quality suggest that childhood-onset depressive disorders have neurobiological, genetic, environmental, and epigenetic roots consistent with a diathesis-stress theory of depression. This review identified key putative markers that may be targeted for personalized clinical decision-making and provide important insights concerning candidate mechanisms that might underpin the early onset of depression.

Metabolites and depressive symptoms: Network- and longitudinal analyses from the Finnish Depression and Metabolic Syndrome in Adults (FDMSA) Study

BACKGROUND

Depression is associated with metabolic abnormalities linked to metabolic syndrome and tissue inflammation, but the interplay between metabolic markers and their association with subsequent depression is unknown. Therefore, we aimed to describe the network of metabolites and their prospective association with depressive symptoms.

METHODS

The Finnish Depression and Metabolic Syndrome in Adults (FDMSA) cohort, originally a prospective case-control study, comprised a group with Beck Depression Inventory (BDI)-I scores ≥10 at baseline, and controls (n = 319, BDI-I < 10); mean (sd) follow-up time: 7.4 (0.7) years. Serum metabolic biomarkers were determined by proton nuclear magnetic resonance (NMR), and depressive symptoms sum-score by using the BDI-I. We examined the prospective associations between metabolites at baseline and BDI score at follow-up utilizing multivariate linear regression, parsimonious predictions models and network analysis.

RESULTS

Some metabolites tended to be either negatively (e.g. histidine) or positively associated (e.g. glycoprotein acetylation, creatinine and triglycerides in very large high density lipoproteins [XL-HDL-TG]) with depressive symptoms. None of the associations were significant after correction for multiple testing. The network analysis suggested high correlation among the metabolites, but that none of the metabolites directly influenced subsequent depressive symptoms.

LIMITATIONS

Although the sample size may be considered satisfactory in a prospective context, we cannot exclude the possibility that our study was underpowered.

CONCLUSIONS

Our results suggest that the investigated metabolic biomarkers are not a driving force in the development of depressive symptoms. These findings should be confirmed in studies with larger samples and studies that account for the heterogeneity of depressive disorders.

Genome-wide association study implicates the role of TBXAS1 in the pathogenesis of depressive symptoms among the Korean population

Although depression is an emerging disorder affecting many people worldwide, most genetic studies have been performed in European descent populations. Herein, a genome-wide association study (GWAS) was conducted in Korean population to elucidate the genomic loci associated with depressive symptoms. Two independent cohorts were used as discovery datasets, which consisted of 6474 (1484 cases and 4990 controls) and 1654 (557 cases and 1097 controls) Korean participants, respectively. The participants were divided into case and control groups based on the Beck Depression Inventory (BDI). Meta-analysis using the two cohorts revealed that rs6945590 was significantly associated with the risk of depressive symptoms [P = 2.83 × 10-8; odds ratio (OR) = 1.23; 95% confidence interval (CI): 1.15-1.33]. This association was validated in other independent cohorts which were another Korean cohort (258 cases and 1757 controls) and the East Asian study of the Psychiatric Genomics Consortium (PGC) (12,455 cases and 85,548 controls). The predicted expression levels of thromboxane A synthase 1 gene (TBXAS1), which encodes the enzyme thromboxane A synthase 1 and participates in the arachidonic acid (AA) cascade, was significantly decreased in the whole blood tissues of the participants with depressive symptoms. Furthermore, Mendelian randomization (MR) analysis showed a causal association between TBXAS1 expression and the risk of depressive symptoms. In conclusion, as the number of risk alleles (A) of rs6945590 increased, TBXAS1 expression decreased, which subsequently caused an increase in the risk of depressive symptoms.

Cross-sectional analysis of depressive symptom profiles and serum C-reactive protein levels: data from the Northern Finland 1966 birth cohort

PURPOSE

Individuals with depression exhibit significantly higher levels of systemic inflammation than those without depression, particularly among those with atypical depression. However, this association has been less convincing at the population level among individuals without a formal depression diagnosis but with suggestive symptoms. Our aim was to clarify this association.

MATERIALS AND METHODS

In a large birth cohort sample of the Finnish general population, we examined the cross-sectional association between high-sensitivity C-reactive protein (hsCRP) levels in venous blood samples and atypical/non-atypical depressive symptoms using the Beck Depression Inventory-II to screen 5443 middle-aged participants.

RESULTS

As expected, depressive symptoms associated to elevated hsCRP-levels compared to non-depressed. Participants with the atypical subtype of depressive symptoms (n = 84) had an odds ratio (OR) of 2.59 (95% CI 1.40-4.81) for elevated hsCRP levels compared to the non-depressed group. Similarly, our findings indicate that participants with non-atypical symptoms (n = 440) also showed an OR of 1.42 (95% CI 1.05-1.92) when compared to the non-depressed group (n = 4919).

CONCLUSIONS

These results provide additional support for previous research linking depression and inflammation and add to the field with a unique and sizeable study population. Furthermore, the current results support the notion that different types of depressive symptoms may be associated with inflammatory markers in slightly different ways.

Peripheral inflammation associated with depression and reduced weight loss: a longitudinal study of bariatric patients

BACKGROUND

Research implicates inflammation in the vicious cycle between depression and obesity, yet few longitudinal studies exist. The rapid weight loss induced by bariatric surgery is known to improve depressive symptoms dramatically, but preoperative depression diagnosis may also increase the risk for poor weight loss. Therefore, we investigated longitudinal associations between depression and inflammatory markers and their effect on weight loss and clinical outcomes in bariatric patients.

METHODS

This longitudinal observational study of 85 patients with obesity undergoing bariatric surgery included 41 cases with depression and 44 controls. Before and 6 months after surgery, we assessed depression by clinical interview and measured serum high-sensitivity C-reactive protein (hsCRP) and inflammatory cytokines, including interleukin (IL)-6 and IL-10.

RESULTS

Before surgery, depression diagnosis was associated with significantly higher serum hsCRP, IL-6, and IL-6/10 ratio levels after controlling for confounders. Six months after surgery, patients with pre-existing depression still had significantly higher inflammation despite demonstrating similar weight loss to controls. Hierarchical regression showed higher baseline hsCRP levels predicted poorer weight loss (β = -0.28, p = 0.01) but had no effect on depression severity at follow-up (β = -0.02, p = 0.9). Instead, more severe baseline depressive symptoms and childhood emotional abuse predicted greater depression severity after surgery (β = 0.81, p < 0.001; and β = 0.31, p = 0.001, respectively).

CONCLUSIONS

Depression was significantly associated with higher inflammation beyond the effect of obesity and other confounders. Higher inflammation at baseline predicted poorer weight loss 6 months after surgery, regardless of depression diagnosis. Increased inflammation, rather than depression, may drive poor weight loss outcomes among bariatric patients.

Assessing myocardial indices and inflammatory factors to determine anxiety and depression severity in patients with chronic heart failure

BACKGROUND

Patients with chronic heart failure (CHF) have a progressive disease that is associated with poor quality of life and high mortality. Many patients experience anxiety and depression (A&D) symptoms, which can further accelerate disease progression. We hypothesized that indicators of myocardial function and inflammatory stress may reflect the severity of A&D symptoms in patients with CHF. Changes in these biomarkers could potentially predict whether A&D symptoms will deteriorate further in these individuals.

AIM

To measure changes in cardiac and inflammatory markers in patients with CHF to determine A&D severity and predict outcomes.

METHODS

We retrospectively analyzed 233 patients with CHF treated at the Jingzhou Hospital, Yangtze University between 2018-2022 and grouped them according to Self-Rating Anxiety Scale (SAS) and Self-Rating Depression Scale (SDS) scores. We compared clinical data in the no-A&D, mild-A&D, moderate-A&D, and severe-A&D groups, the SAS and SDS scores with the New York Heart Association (NYHA) functional classification, and cardiac markers and inflammatory factors between the no/mild-A&D and moderate/severe-A&D groups. Regression analysis was performed on the markers with P < 0.05 to determine their ability to predict A&D severity in patients and the area under the receiver operating characteristic curve (AUROC) was used to evaluate their accuracy.

RESULTS

In the inter-group comparison, the following variables had an effect on A&D severity in patients with CHF: NYHA class, left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter, N-terminal pro-brain natriuretic peptide (NT-proBNP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (P < 0.05). Other variables did not differ significantly between the A&D groups (P > 0.05). In addition, we found that higher NYHA classes were associated with higher the SAS and SDS scores (P < 0.05). Regression analysis showed that LVEF, NT-proBNP, and IL-6 were independent risk factors for A&D severity (P < 0.05). Among them, NT-proBNP had the best predictive ability as a single indicator (AUROC = 0.781). Furthermore, the combination of these three indicators exhibited a good predictive effect toward discriminating the extent of A&D severity among patients (AUROC = 0.875).

CONCLUSION

Cardiac and inflammatory biomarkers, such as LVEF, NT-proBNP, and IL-6, are correlated with A&D severity in patients with CHF and have predictive value.

SSRIs in the course of COVID-19 pneumonia: Evidence of effectiveness of antidepressants on acute inflammation. A retrospective study

INTRODUCTION

Relationships between inflammation and mood have been observed in terms of pro-inflammatory effects induced by depressive conditions and, in parallel, by an antidepressant-induced favorable effect on the recovery of inflammatory states. Selective serotonin reuptake inhibitor (SSRI) drugs were hypothesized to improve the prognosis of COVID-19 pneumonia, a typical acute inflammation, in terms of decreased mortality rate and pro-inflammatory cytokine serum levels.

METHODS

The medical records of COVID-19 pneumonia inpatients at Careggi University Hospital (Florence) were analyzed for prognosis and Interleukin 6 (IL-6) after admission for over a period of 22 months. Medical records of patients treated at admission and not discontinued until discharge with an SSRI or with vortioxetine were identified. Two groups, one treated with antidepressants, the other not treated, were evaluated according to the mentioned parameters. Multiple linear regression and logistic regression were performed.

RESULTS

The entire sample composed of 1236 records (recovered patients 77.1%, deceased patients 22.9%). The treated group (n = 107) had a better prognosis than the untreated group in spite of age and comorbidity both being greater than in the untreated group. Correspondingly, IL-6 levels in the treated group were significantly lower (p < 0.01) than the levels in the untreated group, in every comparison.

CONCLUSIONS

Outcomes of this study support the hypothesis of the favorable influence of some antidepressants on the prognosis of COVID-19, possibly mediated by IL-6 modulation. Reduction in acute inflammation induced by the action of antidepressants was confirmed.

Inflammatory mediation of the relationship between early adversity and major depressive disorder: A systematic review

Early adverse experience is related to psychiatric illness that occurs decades later. The mechanisms underlying this phenomenon have not been fully identified. There is a translational and clinical literature linking early adversity with Major Depressive Disorder (MDD) and inflammation. We reviewed articles that examine whether inflammation mediates this relationship.

METHODS

Literature review of PUB MED, CINAHL and APA Psycinfo articles that explicitly examine inflammation as a mediator between early adversity and depression using ((((((((((adversity) OR (trauma)) OR (maltreatment)) OR (child abuse)) AND (inflammation)) OR (inflammatory cytokines)) OR (crp)) OR (il-6)) OR (tnf)) AND (mediates)) AND (depression))))))))) as key words.

RESULTS

2842 articles were initially identified. 1338 non-human studies were excluded and 512 more were filtered out as reviews. The remaining 992 titles and, when necessary, abstracts and manuscripts were reviewed and 956 were removed as being of other non-related phenomena. Four additional studies were added by hand searching the references of remaining studies. Out of these 40, 15 explicitly examined inflammation as a mediator of the relationship between early adversity and later depression. Approximately half (8/15) showed evidence that inflammation mediated the relationship between early adversity and depression. Sensitivity analyses showed that studies taking place in clinical populations, in youth and those that used the Adverse Childhood Events Scale to measure adversity, and IL-6 and TNF-α (as opposed to CRP) to measure inflammation were most likely to show mediation.

CONCLUSIONS

There is evidence to support the model of inflammation mediating the relationship between early adversity and depression. Certain measures in clinical populations appear more likely to support this model. Further study with more standardized, robust methods will help to answer this question more definitively and may elucidate a subtype of depression related to early adversity by alterations in immune function.

Combined influence of nutritional and inflammatory status and depressive symptoms on mortality among US cancer survivors: Findings from the NHANES

BACKGROUND

Inflammation and nutrition and depression are interrelated, and both are related to changes in mortality rates. We investigated the association of nutritional and inflammation index or depressive symptoms with the risk of all-cause mortality or cause-specific mortality among cancer survivors.

METHODS

A prospective cohort of a nationally representative sample of cancer survivors, aged 40 years or older (n = 2331; weighted population, 15 248 255; 67.6 ± 11.0 years; 50.6 % males), were recruited from the US National Health and Nutrition Examination Survey (NHANES) from 2005 to 2018. Advanced lung cancer inflammation index (ALI) reflected inflammation and nutritional status and Patient Health Questionnaire 9 (PHQ-9) demonstrated depressive symptoms. The independent and joint associations of ALI and PHQ-9 score with mortality outcomes were examined among cancer survivors and Cox regression analysis based on weights was used to calculate the relative risk.

RESULTS

We identified 605 all-cause deaths (cancer, 204; non-cancer, 401) over a median of 6.2 years of follow-up (15,385 person-years; interquartile range, 3.3-9.8 years). High ALI was observed to be consistently associated with lower risks of all-cause (hazard ratio [HR], 0.516; 95 % CI, 0.400-0.667) and non-cancer (HR, 0.414; 95 % CI, 0.291-0.588) mortality compared with low ALI in a series of adjusted models. Meanwhile, lower PHQ-9 score (0-4) was associated with lower risks of all-cause (HR, 0.686; 95 % CI, 0.521-0.903) and non-cancer (HR, 0.686; 95 % CI, 0.474-0.992) mortality compared with higher PHQ-9 score (≥10). Furthermore, joint analyses showed that high ALI was associated with a decreased risk of death among cancer survivors who were not depressive. Specifically, survivors with high ALI but not depressive symptoms had the lowest overall (HR, 0.404; 95 % CI, 0.228-0.715) risks.

CONCLUSION

In this cohort study, we observed impact of nutritional and inflammatory status and depressive symptoms on mortality among cancer survivors, with the lowest risks of death from both all causes and non-cancer being noted among the combination of high level ALI with no depression.

From biological aging to functional decline: Insights into chronic inflammation and intrinsic capacity

Intrinsic capacity is the sum of an individual's physical and mental capacities, which helps determine functional ability. Intrinsic capacity decline is an important predictor of adverse health outcomes and can identify individuals at higher risk of functional decline. Aging is characterized by a decrease in physiological reserves and functional abilities. Chronic inflammation, a mechanism of aging, is associated with decreased intrinsic capacity, which may mirror the broader relationship between aging and functional ability. Therefore, it is crucial for maintaining functional ability and promoting healthy aging to study the mechanisms of intrinsic capacity decline, identify easily available markers, and make targets for intervention from the perspective of chronic inflammation. We reviewed the current research on chronic inflammation, inflammation-related markers, and intrinsic capacity. To date, there is still no inflammatory markers with high specificity and sensitivity to monitor intrinsic capacity decline. Interleukin-6, C-reactive protein, and tumor necrosis factor-alpha may potentially indicate changes in intrinsic capacity, but their results with intrinsic capacity or each intrinsic capacity domain are inconsistent. Considering the variations in individual responses to changes in inflammatory markers, it may be beneficial to explore the use of multiple analytes instead of relying on a single marker. This approach could be valuable in monitoring the decline of intrinsic capacity in the future.

Effects of elevated emotional symptoms on metabolic disease development: a 10-year follow-up study

Background

In recent decades, the relationship between emotional disorders (i.e., depression and anxiety) and alterations in physiological functions (i.e., inflammation or metabolism) have been well supported. However, studies on a symptom-based approach have provided mixed results. Our study aims to gain insight into how subclinical statuses, featured by elevated depressive and/or anxious symptoms, may influence immunometabolic alterations in the concurrent relationship; and the development of metabolic diseases at 10-year follow-up: diabetes, hypertension and hypercholesterolemia.

Methods

Data from 758 Greek adults [394 men (aged 41 ± 10 years) and 364 women (aged 37 ± 12 years)] were used. Four groups were created according to the levels of depressive and anxiety symptoms: (1) control group (CG), (2) depressive group (DG), (3) anxiety group (AG) and (4) depressive and anxiety group (DAG). Multi-indicator multi-causes (MIMIC) modeling was used to estimate metabolic function and inflammatory response scores, on a wide selection of blood biomarkers. Finally, a binary logistic regression was carried out to study the influence of symptoms on the development of the aforementioned metabolic diseases on a 10-year follow-up.

Results

Group membership was not associated with metabolic function score. Conversely, DAG membership was related with higher inflammatory response score (B = 0.20, CI95 = 0.01, 0.40), with respect to the CG (p < 0.05). Both age and sex were significant variables in the calculation of both scores. Regarding disease at 10-year follow-up effect, risk of developing diabetes, hypertension and hypercholesterolemia was associated with age and socioeconomic status. Moreover, DG membership was significant for diabetes risk (OR = 2.08, CI95 = 1.00, 4.22) and DAG for hypercholesterolemia (OR = 1.68, CI95 = 1.16, 2.43).

Limitations

Data on anti-inflammatory drugs and psychopharmacological medication were not collected in this study.

Conclusions

Elevated symptoms of depression and anxiety accounts for inflammatory alterations at concurrent relationship and a higher risk of 10-year follow-up metabolic diseases.

The needle in the haystack: Identifying and validating common genes of depression, insomnia, and inflammation

BACKGROUND

Insomnia, inflammation, and depression are often co-occurring conditions. The mechanisms underlying these conditions remain unclear.

MATERIALS AND METHODS

We collected microarray datasets of depression and insomnia from GEO and analyzed them for differentially expressed genes (DEGs). We then overlapped the DEGs with a list of inflammatory response-related genes to identify genes associated with all three conditions. We next performed analyses of enrichment analyses, KEGG mapping, and protein-protein interaction to identify hub genes. Furthermore, we established a depression rat model with inflammation and insomnia to validate the potential genes. At last, a two-sample Mendelian randomization (MR) study was conducted to confirm the association of identified target genes with depression outcomes.

RESULTS

We obtained 32 common DEGs associated with the depression, insomnia and inflammatory, and found that the PI3K-AKT signaling pathway might be involved in the inflammatory response in insomnia and depression. CREB1, CYBB, FYN, and CCR5 were identified as targets for the next validation. In model rats, the CCR5 and PI3K-AKT pathways were significantly up-regulated, while the model group exhibited significantly lower hippocampal p-CREB protein expression. The MR study suggested a potential causal relationship between CREB1 and the risk of depression (OR = 1.11, p = 0.013).

LIMITATIONS

The identified potential genes and pathways require further laboratory and clinical evidence verification.

CONCLUSION

We identified four potential inflammatory related-genes (CREB1, CYBB, FYN, and CCR5). CREB1 may be a potential inflammatory response-related biomarker and drug target for depression and insomnia, as validated by the followed rat model and MR study.

Proinflammatory phenotype in major depressive disorder with adulthood adversity: In line with social signal transduction theory of depression

BACKGROUND

The social signal transduction theory of depression proposes that life stress can be transformed into inflammatory signals, and ultimately lead to the development of major depressive disorder (MDD). The hypotheses of this study were: (1) The pro-inflammatory effect of life stress was only seen in patients with MDD, but not in healthy controls (HCs); (2) Inflammation can mediate the relationship between life stress and depressive symptoms.

METHODS

This study included 170 MDD patients and 196 HCs, and 13 immune-inflammatory biomarkers closely related to MDD were measured, principal component analysis (PCA) was adopted to extract the inflammatory index. Life stress was assessed by Life Event Scale (LES), a total score of >32 points on the LES was considered as adulthood adversity (AA). Path analyses were used to explore the relationship among adulthood stress, inflammatory index, and severity of depression.

RESULTS

Among MDD patients, α2M, CXCL-1, IL-1β, and TLR-1 levels were higher in patients with AA than non-AA group (all FDR-adjusted P values <0.05), meanwhile, the levels of CCL-2 and IL-18 were lower. Path analyses suggested that pro- and anti-inflammatory index could mediate the association between AA and severity of depression in MDD patients.

CONCLUSION

This study found that inflammatory signals can mediate the relationship between adulthood adversity and depression, however, the causal relationship need to be further confirmed. These findings shed light on further understanding the theory of social signal transduction in MDD and provide clues for stress management and controlling inflammation strategies in depression.

CLINICAL TRIALS

NCT02023567.

Peripheral Blood Inflammatory Cytokine Factors Expressions are Associated with Response to Acupuncture Therapy in Postpartum Depression Patients

Background

Increasing evidences demonstrate that immune dysregulation can result in depression, and it is reported that persistent inflammatory response is related to the unresponsiveness of antidepressant treatment.

Purpose

This study aimed to explore the reason why some responded but some not responded to acupuncture in treating postpartum depression (PPD), and whether it related to the levels of inflammatory cytokines.

Patients and Methods

Women diagnosed with PPD were recruited in to accept 8-week acupuncture. All subjects were assessed the 17-item Hamilton Depression Rating Scale (HDRS17) at baseline, week 1, week 2, week 4 and week 8 during the treatment. A panel of 9 cytokines was measured at baseline and 8 weeks.

Results

Of the 121 participants, 96 completed the 8-week assessment and 46 completed the blood sample collection. HDRS17 scores of 96 subjects showed significant statistical reduction since the first week (P = 0.002) and reached to 5.31 (P < 0.000) at the end of therapy. And we divided the 46 subjects into responders and non-responders according to the response rate of HDRS17 scores. Responders and non-responders did not differ significantly between-group in changes in the 9 cytokines. In responders, IL-6, IL-10 and IFN-γ levels were statistically lower (P = 0.006; P = 0.033; P = 0.024), while TGF-β1 was statistically higher after 8 weeks treatment (P < 0.000). In non-responders, the levels of IL-5, TNF-α and TGF-β1 were statistically higher (P = 0.018; P < 0.000; P < 0.000), while IFN-γ was statistically lower (P = 0.005).

Conclusion

Acupuncture could alleviate depressive symptoms of patients with PPD and might through adjusting peripheral inflammatory response by up-regulating anti-inflammatory cytokines and down-regulating pro-inflammatory cytokines.

The association between the Short Physical Performance Battery and longitudinal trajectories of depressive symptoms among Chinese older adults

BACKGROUND

In this study, the long-term trajectories of depressive symptoms in a 7-year prospective survey cohort of Chinese older adults were explored. Additionally, the study examined whether there was an independent association between scores on the Short Physical Performance Battery (SPPB) and the different trajectories of depressive symptoms.

METHODS

A total of 2177 elderly individuals had their depressive symptoms assessed based on the Center for Epidemiological Studies-Depression (CES-D) scale in the years 2011, 2013, 2015, and 2018. In addition, their demographic characteristics, chronic diseases, and lifestyle factors were also assessed. The trajectories of depressive symptoms were analysed using the group-based trajectories analysis model. Furthermore, the relationship between the objectively measured SPPB scores and the long-term trajectory of depressive symptoms was explored using multinomial logistic regression.

RESULTS

The group-based trajectory analysis model categorized the trajectories of depressive symptoms across four waves into four groups: persistent low depressive symptoms, increasing depressive symptoms, decreased depressive symptoms, and persistent high depressive symptoms. After controlling for confounding factors, it was observed that a higher baseline SPPB score was associated with an increased likelihood of persistent high depressive symptoms, OR (95% CI) = 0.724 (0.644, 0.814), for the persistent high depressive symptoms versus the persistent low depressive symptoms.

CONCLUSIONS

Low levels of SPPB score are associated with persistent high depressive symptoms in older adults. Conversely, improving physical performance as measured by the SPPB can help reduce the risk of major depressive disorder and persistent depressive disorder in the elderly.

Effects of estrogen and progesterone on neuroactive steroids and cytokines in patients with suicidality

BACKGROUND

In ovulating psychiatric patients experiencing suicidality, suicidal ideation (SI) often peaks perimenstrually. Our recent double-blind, placebo-controlled, crossover randomized clinical trial (RCT; NCT03720847) showed that perimenstrual administration of estradiol and progesterone (EP) can prevent this peak in SI and depressed mood. In this pre-registered follow-up analysis, we studied how the menstrual cycle and experimental manipulation affected two neurobiological systems associated with the menstrual cycle and suicide risk: GABAergic neuroactive steroids (NAS) and peripheral cytokines.

METHODS

In 26 psychiatric outpatients with natural menstrual cycles and past-month SI, we analyzed serum samples from three blood draws (midluteal, perimenstrual, midfollicular) per experimental condition (EP vs placebo) timed to a luteinizing hormone-surge ovulation test. Using gas chromatography/mass spectrometry (GC/MS), we measured the progesterone (P4)-derived pregnane NAS (3α,5α)- 3-hydroxypregnan20-one (3α,5α-THP), (3α,5β)- 3-hydroxypregnan-20-one (3α,5β-THP), (3α,5α)- 3,21-dihydroxypregnan-20-one (3α,5α-THDOC), (3α,5α)- 3-hydroxyandrostan-17-one (3α,5α-A), the androstane NAS (3α,5β)- 3-hydroxyandrostan-17-one (3α,5β-A), (3α,5α,17β)-androstane-3,17-diol (3α,5α-A-diol), (3α,5β,17β)-androstane-3,17-diol (3α,5β-A-diol), and their precursor pregnenolone. High sensitivity multiplex assay kits quantified peripheral cytokines IL-1β, IL-6, and TNF-α.

RESULTS

P4-derived NAS fluctuated in parallel with P4 and increased with exogenous perimenstrual administration of EP. Conversely, androstane NAS either did not fluctuate or fluctuated inversely from P4, and these NAS decreased with exogenous EP. Peripheral cytokines did not show cyclical patterns, but each significantly predicted SI, depressed mood, or anxiousness. Concomitant SSRI medication use predicted lower androstane NAS.

CONCLUSIONS

While preliminary and exploratory, our findings provide critical descriptive context for future studies. Further, our work presents menstrual cycle-related patterns for ten frequently-studied biomarkers, allowing for improved quality of comparisons involving naturally-cycling populations in research.

Weighing poor immunometabolic health in relatives for severity of affective symptoms: A study of patients with depressive and anxiety disorders and their siblings

BACKGROUND

Affective (i.e. depressive and anxiety) disorders often co-occur with immunometabolic diseases and related biological pathways. Although many large population-based and meta-analytic studies have confirmed this link in community and clinical samples, studies in at-risk samples of siblings of persons with affective disorders are lacking. Furthermore, this somatic-mental co-occurrence may be partially explained by familial clustering of the conditions. First, we examined whether the association between a wide range of immunometabolic diseases and related biomarker based risk-profiles with psychological symptoms replicates in at-risk siblings of probands with affective disorders. Second, leveraging on a sibling-pair design, we disentangled and quantified the effect of probands' immunometabolic health on siblings' psychological symptoms and on the association between immunometabolic health and these symptoms in siblings.

METHODS

The sample included 636 participants (Mage = 49.7; 62.4% female) from 256 families, each including a proband with lifetime depressive and/or anxiety disorders and at least one of their sibling(s) (N = 380 proband-sibling pairs). Immunometabolic health included cardiometabolic and inflammatory diseases, body mass index (BMI), and composite metabolic (based on the five metabolic syndrome components) and inflammatory (based on interleukin-6 and C-reactive protein) biomarker indices. Overall affective symptoms and specific atypical, energy-related depressive symptoms were derived from self-report questionnaires. Mixed-effects analyses were used to model familial clustering.

RESULTS

In siblings, inflammatory disease (γ = 0.25, p = 0.013), higher BMI (γ = 0.10, p = 0.033) and metabolic index (γ = 0.28, p < 0.001) were associated with higher affective symptoms, with stronger associations for atypical, energy-related depressive symptoms (additionally associated with cardiometabolic disease; γ = 0.56, p = 0.048). Immunometabolic health in probands was not independently associated with psychological symptoms in siblings nor did it moderate the association between immunometabolic health and psychological symptoms estimated in siblings.

CONCLUSIONS

Our findings demonstrate that the link between later life immunometabolic health and psychological symptoms is consistently present also in adult siblings at high risk for affective disorders. Familial clustering did not appear to have a substantial impact on this association. Instead, individual lifestyle, rather than familial factors, may have a relatively higher impact in the clustering of later life immunometabolic conditions with psychological symptoms in at-risk adult individuals. Furthermore, results highlighted the importance of focusing on specific depression profiles when investigating the overlap with immunometabolic health.

Stress to inflammation and anhedonia: Mechanistic insights from preclinical and clinical models

Anhedonia, as evidenced by impaired pleasurable response to reward, reduced reward motivation, and/or deficits in reward-related learning, is a common feature of depression. Such deficits in reward processing are also an important clinical target as a risk factor for depression onset. Unfortunately, reward-related deficits remain difficult to treat. To address this gap and inform the development of effective prevention and treatment strategies, it is critical to understand the mechanisms that drive impairments in reward function. Stress-induced inflammation is a plausible mechanism of reward deficits. The purpose of this paper is to review evidence for two components of this psychobiological pathway: 1) the effects of stress on reward function; and 2) the effects of inflammation on reward function. Within these two areas, we draw upon preclinical and clinical models, distinguish between acute and chronic effects of stress and inflammation, and address specific domains of reward dysregulation. By addressing these contextual factors, the review reveals a nuanced literature which might be targeted for additional scientific inquiry to inform the development of precise interventions.

Exploring the multiverse: the impact of researchers' analytic decisions on relationships between depression and inflammatory markers

In recent years, a replication crisis in psychiatry has led to a growing focus on the impact of researchers' analytic decisions on the results from studies. Multiverse analyses involve examining results across a wide array of possible analytic decisions (e.g., log-transforming variables, number of covariates, or treatment of outliers) and identifying if study results are robust to researchers' analytic decisions. Studies have begun to use multiverse analysis for well-studied relationships that have some heterogeneity in results/conclusions across studies.We examine the well-studied relationship between peripheral inflammatory markers (PIMs; e.g., white blood cell count (WBC) and C-reactive protein (CRP)) and depression severity in the large NHANES dataset (n = 25,962). Specification curve analyses tested the impact of 9 common analytic decisions (comprising of 58,000+ possible combinations) on the association of PIMs and depression severity. Relationships of PIMs and total depression severity are robust to analytic decisions (based on tests of inference jointly examining effect sizes and p-values). However, moderate/large differences are noted in effect sizes based on analytic decisions and the majority of analyses do not result in significant findings, with the percentage of analyses with statistically significant results being 46.1% for WBC and 43.8% for CRP. For associations of PIMs with specific symptoms of depression, some associations (e.g., sleep, appetite) in males (but not females) were robust to analytic decisions. We discuss how multiverse analyses can be used to guide research and also the need for authors, reviewers, and editors to incorporate multiverse analyses to enhance replicability of research findings.

Inflammatory hypotheses of sleep disturbance - depression link: Update and research agenda

Studies in human and experimental animal models support a role of inflammation in the aetiology of depression, yet the precise role played by sleep disturbance (i.e., difficulties falling or maintaining sleep) is poorly understood. Consistent evidence from prospective epidemiological studies suggests sleep disturbance as a predictor of major depression episodes and depression recurrence. In parallel, up to 20% of individuals with sleep disturbance have low-grade peripheral inflammation (i.e., CRP>3 mg/l), and preliminary longitudinal evidence showed that sleep disturbance may even predict the levels of inflammation. Therefore, it is possible that sleep disturbance may increase inflammation, which in turn may contribute (i.e., mediate) to the onset - or worsening - of depression. Alternatively, sleep disturbance may serve as a vulnerability factor and increase the risk of developing depressive symptoms when facing an immune challenge. The aim of this review was to summarise the state of the science on the role of sleep disturbance in contributing to depression-related inflammation. A research agenda is also proposed to advance the study of sleep disturbance in the psychoneuroimmunology of depression.

Prospective network analysis of proinflammatory proteins, lipid markers, and depression components in midlife community women

BACKGROUND

Vulnerability theories propose that suboptimal levels of lipid markers and proinflammatory proteins predict future heightened depression. Scar models posit the reverse association. However, most studies that tested relationships between non-specific immune/endocrine markers and depression did not separate temporal inferences between people and within-person and how different immunometabolism markers related to unique depression symptoms. We thus used cross-lagged prospective network analyses (CLPN) to investigate this topic.

METHODS

Community midlife women (n = 2224) completed the Center for Epidemiologic Studies-Depression scale and provided biomarker samples across five time-points spanning 9 years. CLPN identified significant relations (edges) among components (nodes) of depression (depressed mood, somatic symptoms, interpersonal issues), lipid markers [insulin, fasting glucose, triglycerides, low-density lipoprotein-cholesterol (LDL), high-density lipoprotein-cholesterol (HDL)], and proinflammatory proteins [C-reactive protein (CRP), fibrinogen], within and across time-points. All models adjusted for age, estradiol, follicle-stimulating hormone, and menopausal status.

RESULTS

In within-person temporal networks, higher CRP and HDL predicted all three depression components (d = 0.131-2.112). Increased LDL preceded higher depressed mood and interpersonal issues (v. somatic symptoms) (d = 0.251-0.327). Elevated triglycerides predicted more somatic symptoms (v. depressed mood and interpersonal problems) (d = 0.131). More interpersonal problems forecasted elevated fibrinogen and LDL levels (d = 0.129-0.331), and stronger somatic symptoms preceded higher fibrinogen levels (d = 0.188).

CONCLUSIONS

Results supported both vulnerability and scar models. Long-term dysregulated immunometabolism systems, social disengagement, and related patterns are possible mechanistic accounts. Cognitive-behavioral therapies that optimize nutrition and physical activity may effectively target depression.

Immune Dysregulation in Treatment-Resistant Depression: Precision Approaches to Treatment Selection and Development of Novel Treatments

Owing to the link between immune dysfunction and treatment-resistant depression (TRD) and the overwhelming evidence that the immune dysregulation and major depressive disorder (MDD) are associated with each other, using immune profiles to identify the biological distinct subgroup may be the step forward to understanding MDD and TRD. This report aims to briefly review the role of inflammation in the pathophysiology of depression (and TRD in particular), the role of immune dysfunction to guide precision medicine, tools used to understand immune function, and novel statistical techniques.

Effect of fluvoxamine on plasma interleukin-6 in patients with major depressive disorder: a prospective follow-up study

Introduction

Major depressive disorder (MDD) is associated with low-grade inflammation, and anti-inflammatory treatment can help improve depressive symptoms. A recent study found that fluvoxamine (FLV) can reduce Interleukin-6 (IL-6) production via sigma-1 receptor in inflammation models. However, the anti- IL-6 effect of FLV in treating patients with MDD and whether it can contribute to antidepressant effects remain unclear.

Methods

A total of 65 patients with MDD and 34 healthy controls were recruited at baseline, and 50 patients completed the FLV treatment for 2 months. We assessed depression and anhedonia and collected plasma IL-6 levels at baseline, 1 month, and 2 months after baseline. This study evaluated the changes in clinical measures and IL-6 during treatment and analyzed their association. Further subgroup analyses were conducted in patients with MDD with high, medium, or low IL-6.

Results

Depression and anhedonia were significantly improved in patients with MDD, while the IL-6 did not significantly change after the FLV treatment. However, IL-6 significantly declined after the FLV treatment among patients with MDD with higher baseline IL-6. No significant associations were found between the changes in depressive symptoms and IL-6.

Conclusion

Our study provided preliminary evidence suggesting that the anti-IL-6 effect of FLV might not play a vital role in its antidepressant treatment, at least in patients with MDD with low inflammation. However, for patients with MDD with higher IL-6, FLV can help reduce IL-6 significantly in the antidepressant treatment, which may help guide the individual treatment of MDD with higher IL-6 levels.

Clinical trial registration

https://clinicaltrials.gov/ct2/show/NCT04160377, identifier NCT04160377.

Inflammation, stress and depression: An exploration of ketamine's therapeutic profile

Well-established animal models of depression have described a proximal relationship between stress and central nervous system (CNS) inflammation - a relationship mirrored in the peripheral inflammatory biomarkers of individuals with depression. Evidence also suggests that stress-induced proinflammatory states can contribute to the neurobiology of treatment-resistant depression. Interestingly, ketamine, a rapid-acting antidepressant, can partially exert its therapeutic effects via anti-inflammatory actions on the hypothalamic-pituitary adrenal (HPA) axis, the kynurenine pathway or by cytokine suppression. Further investigations into the relationship between ketamine, inflammation and stress could provide insight into ketamine's unique therapeutic mechanisms and stimulate efforts to develop rapid-acting, anti-inflammatory-based antidepressants.

Non-steroidal anti-inflammatory drug target gene associations with major depressive disorders: a Mendelian randomisation study integrating GWAS, eQTL and mQTL Data

Previous observational studies reported associations between non-steroidal anti-inflammatory drugs (NSAIDs) and major depressive disorder (MDD), however, these associations are often inconsistent and underlying biological mechanisms are still poorly understood. We conducted a two-sample Mendelian randomisation (MR) study to examine relationships between genetic variants and NSAID target gene expression or DNA methylation (DNAm) using publicly available expression, methylation quantitative trait loci (eQTL or mQTL) data and genetic variant-disease associations from genome-wide association studies (GWAS of MDD). We also assessed drug exposure using gene expression and DNAm levels of NSAID targets as proxies. Genetic variants were robustly adjusted for multiple comparisons related to gene expression, DNAm was used as MR instrumental variables and GWAS statistics of MDD as the outcome. A 1-standard deviation (SD) lower expression of NEU1 in blood was related to lower C-reactive protein (CRP) levels of -0.215 mg/L (95% confidence interval (CI): 0.128-0.426) and a decreased risk of MDD (odds ratio [OR] = 0.806; 95% CI: 0.735-0.885; p = 5.36 × 10^-6). A concordant direction of association was also observed for NEU1 DNAm levels in blood and a risk of MDD (OR = 0.886; 95% CI: 0.836-0.939; p = 4.71 × 10^-5). Further, the genetic variants associated with MDD were mediated by NEU1 expression via DNAm (β = -0.519; 95% CI: -0.717 to -0.320256; p = 3.16 × 10^-7). We did not observe causal relationships between inflammatory genetic marker estimations and MDD risk. Yet, we identified a concordant association of NEU1 messenger RNA and an adverse direction of association of higher NEU1 DNAm with MDD risk. These results warrant increased pharmacovigilance and further in vivo or in vitro studies to investigate NEU1 inhibitors or supplements for MDD.

The interactive association of adverse childhood experiences and polygenic susceptibility with depressive symptoms and chronic inflammation in older adults: a prospective cohort study

BACKGROUND

Adverse childhood experiences (ACEs) and genetic liability are important risk factors for depression and inflammation. However, little is known about the gene-environment (G × E) mechanisms underlying their aetiology. For the first time, we tested the independent and interactive associations of ACEs and polygenic scores of major depressive disorder (MDD-PGS) and C-reactive protein (CRP-PGS) with longitudinal trajectories of depression and chronic inflammation in older adults.

METHODS

Data were drawn from the English longitudinal study of ageing (N~3400). Retrospective information on ACEs was collected in wave3 (2006/07). We calculated a cumulative risk score of ACEs and also assessed distinct dimensions separately. Depressive symptoms were ascertained on eight occasions, from wave1 (2002/03) to wave8 (2016/17). CRP was measured in wave2 (2004/05), wave4 (2008/09), and wave6 (2012/13). The associations of the risk factors with group-based depressive-symptom trajectories and repeated exposure to high CRP (i.e. ⩾3 mg/L) were tested using multinomial and ordinal logistic regression.

RESULTS

All types of ACEs were independently associated with high depressive-symptom trajectories (OR 1.44, 95% CI 1.30-1.60) and inflammation (OR 1.08, 95% CI 1.07-1.09). The risk of high depressive-symptom trajectories (OR 1.47, 95% CI 1.28-1.70) and inflammation (OR 1.03, 95% CI 1.01-1.04) was also higher for participants with higher MDD-PGS. G×E analyses revealed that the associations between ACEs and depressive symptoms were larger among participants with higher MDD-PGS (OR 1.13, 95% CI 1.04-1.23). ACEs were also more strongly related to inflammation in participants with higher CRP-PGS (OR 1.02, 95% CI 1.01-1.03).

CONCLUSIONS

ACEs and polygenic susceptibility were independently and interactively associated with elevated depressive symptoms and chronic inflammation, highlighting the clinical importance of assessing both ACEs and genetic risk factors to design more targeted interventions.

Peripheral blood cellular immunophenotype in depression: a systematic review and meta-analysis

INTRODUCTION

Meta-analyses implicate immune dysfunction in depression confirming increased levels of circulating immune proteins (e.g., cytokines) in depression cases compared to controls. White blood cells (WBC) both produce and are influenced by cytokines, and play key roles in orchestrating innate and adaptive immune responses, but their role in depression remains unclear. Therefore, a systematic review of studies of various WBC subsets in depression is required for a greater understanding of the nature of immune dysfunction in this illness.

METHODS

We searched PubMed and PsycINFO databases (inception to 5th April 2022) and conducted a systematic review and meta-analysis of identified studies comparing absolute count and/or relative percentage of flow cytometry-derived WBC subsets between depression cases and controls. Selected studies were quality assessed. Random-effect meta-analysis was performed.

RESULTS

Thirty-three studies were included and 27 studies (n = 2277) were meta-analysed. We report an increase in mean absolute counts of WBC (seven studies; standardised mean difference [SMD] = 1.07; 95% CI, 0.61-1.53; P < 0.01; I2 = 64%), granulocytes (two studies; SMD = 2.07; 95% CI, 1.45-2.68; P < 0.01; I2 = 0%), neutrophils (four studies; SMD = 0.91; 95% CI, 0.23-1.58; P < 0.01; I2 = 82%), monocytes (seven studies; SMD = 0.60; 95% CI, 0.19-1.01; P < 0.01; I2 = 66%), CD4+ helper T cells (11 studies; SMD = 0.30; 95% CI, 0.15-0.45; P < 0.01; I2 = 0%), natural killer cells (11 studies; SMD = 1.23; 95% CI, 0.38-2.08; P < 0.01; I2 = 95%), B cells (10 studies; SMD = 0.30; 95% CI, 0.03-0.57; P = 0.03; I2 = 56%), and activated T cells (eight studies; SMD = 0.45; 95% CI, 0.24-0.66; P < 0.01; I2 = 0%) in depression, compared to controls. Fewer studies reported relative percentage, indicating increased neutrophils and decreased total lymphocytes, Th1, and Th2 cells in depression.

CONCLUSIONS

Depression is characterised by widespread alterations in circulating myeloid and lymphoid cells, consistent with dysfunction in both innate and adaptive immunity. Immune cells could be useful biomarkers for illness subtyping and patient stratification in future immunotherapy trials of depression, along with cytokines, other biomarkers, and clinical measures.

Oxidative Stress in Depression: The Link with the Stress Response, Neuroinflammation, Serotonin, Neurogenesis and Synaptic Plasticity

Depression is a prevalent, complex, and highly debilitating disease. The full comprehension of this disease is still a global challenge. Indeed, relapse, recurrency, and therapeutic resistance are serious challenges in the fight against depression. Nevertheless, abnormal functioning of the stress response, inflammatory processes, neurotransmission, neurogenesis, and synaptic plasticity are known to underlie the pathophysiology of this mental disorder. The role of oxidative stress in disease and, particularly, in depression is widely recognized, being important for both its onset and development. Indeed, excessive generation of reactive oxygen species and lack of efficient antioxidant response trigger processes such as inflammation, neurodegeneration, and neuronal death. Keeping in mind the importance of a detailed study about cellular and molecular mechanisms that are present in depression, this review focuses on the link between oxidative stress and the stress response, neuroinflammation, serotonergic pathways, neurogenesis, and synaptic plasticity's imbalances present in depression. The study of these mechanisms is important to lead to a new era of treatment and knowledge about this highly complex disease.

Quetiapine effect on depressive-like behaviors, oxidative balance, and inflammation in serum of rats submitted to chronic stress

Major depressive disorder (MDD) etiology is still not completely understood, and many individuals resist the traditional treatments. Chronic exposure to stressful events can contribute to development and progression and be involved in biological changes underlying MDD. Among the biological mechanisms involved, inflammatory changes and oxidative balance are associated with MDD pathophysiology. Quetiapine, a second-generation antipsychotic, induces a better therapeutic response in individuals refractory to traditional treatments. The main objectives of this research were as follows: to evaluate the effect of chronic mild stress (CMS) on depressive-like behaviors, oxidative stress, and inflammation in adult rats; to evaluate the possible antidepressant, antioxidant, and anti-inflammatory effects of quetiapine. The animals were submitted to CMS protocols. At the end of the CMS, the animals were submitted to a chronic treatment for 14 days with the following drugs: quetiapine (20 mg/kg), imipramine (30 mg/kg), and escitalopram (10 mg/kg). At the end of the treatments, the animals were evaluated in the open field tests, anhedonia (splash test), and forced swimming. The animals were euthanized after the behavioral tests, and serum samples were collected. Myeloperoxidase (MPO) activity and interleukin-6 (IL-6) levels were analyzed. CMS induced an increase in depressive-like behaviors, and quetiapine significantly reduced these behaviors. MPO activity and IL-6 levels increased in the serum of animals submitted to CMS. Quetiapine significantly reduced MPO activity and IL-6 levels. These results corroborate other evidence, indicating that chronic stress is a relevant phenomenon in the etiology of depression and suggesting that quetiapine induces an antidepressant effect because it reduces oxidative and inflammatory mechanisms.

Depressive symptoms predict longitudinal changes of chronic inflammation at the transition to adulthood

Background

Inflammation is closely related to poor mental and physical health, including depressive symptoms and its specific symptoms. To reveal the linear and nonlinear relationships between depressive symptoms and chronic inflammation levels, and perform further analysis of the associations between symptom-specificity of depressive symptoms and inflammation among young adults by using a prospective design.

Methods

In this longitudinal study, we examined college students recruited from two universities in China, who were examined at baseline and 2-years follow-up. Depressive symptoms were measured by applying the Patient Health Questionnaire 9 (PHQ-9) at baseline. Plasma levels of four inflammatory biomarkers, including interleukin-6 (IL-6), interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and C reactive protein (CRP) were assayed at baseline and 2-year follow-up. In addition to the conventional generalized linear models, as well as restricted cubic splines were innovatively used to analyze the cross-sectional and longitudinal nonlinear relationships between depressive symptoms and inflammatory biomarkers.

Results

Generalized linear model analysis revealed that there were no statistical associations between depressive symptoms and any inflammatory biomarker levels. The results of the restricted cubic spline demonstrated a U-shaped nonlinear association between depressive symptoms and ΔIL-1β or ΔTNF-α (changes in baseline and 2-year follow-up), but these associations disappeared after adjusting the confounders. Symptom-specificity of depressive symptoms such as sleeping problems and suicidal ideation were associated with lower IL-1β at baseline or changes in IL-1β levels. Sleeping problems and psychomotor changes at baseline were associated with higher CRP at 2-year follow-up. Suicidal ideation at baseline was associated with changes in TNF-α levels.

Conclusion

Our findings suggested that symptom-specificity of depressive symptoms was associated with inflammation during a 2-year follow-up at the transition to adulthood. Simultaneously, more research is warranted to seek the directionality of depressive symptoms and chronic inflammation.