The longitudinal associations of inflammatory biomarkers and depression revisited: systematic review, meta-analysis, and meta-regression

Role of inflammation in depressive and anxiety disorders, affect, and cognition: genetic and non-genetic findings in the lifelines cohort study

Inflammation is associated with a range of neuropsychiatric symptoms, but the issue of causality remains unclear. We used complementary non-genetic, genetic risk score (GRS), and Mendelian randomization (MR) analyses to examine whether inflammatory markers are associated with affect, depressive and anxiety disorders, and cognition. We tested in ≈55,098 (59% female) individuals from the Dutch Lifelines cohort the concurrent/prospective associations of C-reactive protein (CRP) with: depressive and anxiety disorders; positive/negative affect; and attention, psychomotor speed, episodic memory, and executive functioning at baseline and a follow-up assessment occurring 3.91 years later (SD = 1.21). Additionally, we examined the association between inflammatory GRSs (CRP, interleukin-6 [IL-6], IL-6 receptor [IL-6R and soluble IL-6R (sIL-6R)], glycoprotein acetyls [GlycA]) on these same outcomes (Nmin = 35,300; Nmax = 57,946), followed by MR analysis examining evidence of causality of CRP on outcomes (Nmin=22,154; Nmax = 23,268). In non-genetic analyses, higher CRP was associated with depressive disorder, lower positive/higher negative affect, and worse executive function, attention, and psychomotor speed after adjusting for potential confounders. In genetic analyses, CRPGRS was associated with any anxiety disorder (β = 0.002, p = 0.037) whereas GlycAGRS was associated with major depressive disorder (β = 0.001, p = 0.036). Both CRPGRS (β = 0.006, p = 0.035) and GlycAGRS (β = 0.006, p = 0.049) were associated with greater negative affect. Inflammatory GRSs were not associated with cognition, except sIL-6RGRS which was associated with poorer memory (β = -0.009, p = 0.018). There was a non-significant CRP-anxiety association using MR (β = 0.12; p = 0.054). Genetic and non-genetic analyses provide consistent evidence for an association between CRP and negative affect. These results suggest that inflammation may impact a broad range of trans-diagnostic affective symptoms.

Advancing an Inflammatory Subtype of Major Depression

Chronic inflammation plays a prominent role in multiple medical disorders, including psychiatric diseases such as major depression. Exposure to inflammatory stimuli leads to changes in neurotransmitter systems and neurocircuits in the brain that are associated with depressive symptoms. Blockade of inflammatory cytokines can reduce depressive symptoms in medically ill and medically healthy individuals with depression. Increased levels of biomarkers of inflammation are associated with an overrepresentation of neurovegetative symptoms, including anhedonia, fatigue, and psychomotor slowing, and can predict response to antidepressant treatments. Importantly, however, increased inflammatory biomarkers occur in only a subgroup of individuals with depression. Thus, there appears to be a subset of patients with depression with a unique symptom presentation and treatment response whose disease is primarily driven by inflammation. Further identifying and characterizing this inflammatory subtype of depression can foster the development of treatments targeting the immune system and its effects on the brain. Moreover, by using this mechanism-based approach to parsing the heterogeneity of depression, we can refine our diagnostic nosology and model a strategy for precision medicine and targeted therapeutics in psychiatry.

Cellular immune phenotype of major depressive disorder - findings from the EMBARC study

OBJECTIVES

Major depressive disorder (MDD) is associated with immune dysfunction. This study aimed to characterize the cellular immunophenotypes that may underpin immune dysregulation in MDD.

METHODS

Peripheral blood mononuclear cell (PBMC) samples at baseline from participants with MDD from the Establishing Moderators and Biosignatures of Antidepressant Response in Clinical Care (EMBARC) study were included. A panel of 33 antibodies was analyzed using mass cytometry to compare the immune cell abundance and marker expression profiles between participants with mild and moderate/severe depression. Mass cytometry data were investigated using (1) Uniform Manifold Approximation and Projection for Dimension Reduction (UMAP), (2) FlowSOM (self-organizing maps) for clustering, and (3) Significance Analysis of Microarrays (SAM) for statistical analyzes.

RESULTS

FlowSOM identified 8 clusters of distinct cell types. The abundance of cytotoxic T, NK, NK T, and Naïve B cells was significantly lower in participants with moderate/severe depression compared to mild depression. NKT cells had significantly lower CD56 and CD16 expression in patients with moderate/severe depression compared to patients with mild depression.

CONCLUSION

Our observations provide evidence for alterations in B, NKT, and NK cell abundance and their cell surface markers in moderate/severe depression. Further investigations into immune cell dysfunction in moderate/severe depression are necessary.

Hierarchical Phenotyping of Psychopathology: Implications and Opportunities for Precision Psychiatry when Biology Could be Associated with both Symptoms and Syndromes

As psychiatry increasingly embraces precision medicine principles, there has been increasing efforts to characterize the specificity of biology-psychopathology associations (e.g., is biology associated with syndromes or symptoms?). Unfortunately, the vast majority of research selects to test syndromes (e.g., case-control, symptom total/average scores) or individual symptoms a priori based on untested assumptions. Alternatively, most studies that attempt to empirically compare these options test biology as a predictor of a) syndromes and b) symptoms in separate models that are unable to directly falsify the specificity of observed associations because these options are not directly competing for the same variance. In this review, we will (i) discuss the historical tension between symptom- and syndrome-focused psychiatry; (ii) introduce hierarchical phenotyping as an approach to determining the specificity of biology-psychopathology associations; (iii) highlight how hierarchical phenotyping approaches are complementary to leading nosological movements in psychopathology research; (iv) illustrate how a hierarchical phenotyping lens can generate promising future directions for precision psychiatry using immunopsychiatric, genetic, and neurophysiological examples (1); (v) highlight clinical implications of hierarchical phenotyping approaches to psychiatry; (vi) discuss methodological implications of hierarchical phenotyping for best practices in measuring and modeling psychopathology; and (vii) introduce methodological resources for readers interested in investigating hierarchical phenotyping in their own work. In doing so, this review seeks to build the case for hierarchical phenotyping approaches while simultaneously preparing motivated readers to use these methods in their own work to advance precision psychopathology research.

Differential associations of serum globulin and albumin-globulin ratio with depression in cancer and non-cancer populations: a cross-sectional study

Objective

The association of globulin and albumin-globulin ratio (AGR) with depression in cancer and non-cancer populations remains understudied. Therefore, this study aims to investigate this association and potential differences, with a focus on cancer-specific pathophysiology.

Methods

This study utilized data from the National Health and Nutrition Examination Survey (NHANES) conducted from 2005 to 2016. The participants were divided into three tertiles of globulin and AGR to explore more detailed associations. Logistic regression, restricted cubic spline (RCS) curves, and subgroup analyses were conducted to assess the associations. Finally, receiver operating characteristic (ROC) curves were applied to evaluate the predictive performance of globulin and AGR for depression.

Results

After adjusting for covariates, higher globulin levels were significantly associated with an increased incidence of depression in cancer patients (OR=2.53, 95% CI: 1.69-3.80), while a higher AGR was associated with a reduced incidence (OR=0.28, 95% CI: 0.14-0.58). In the non-cancer group, a similar but weaker association was observed: higher globulin levels (OR=1.16, 95% CI: 1.00-1.35) and lower AGR (OR=0.80, 95% CI: 0.62-1.05) were associated with depression. Subgroup analyses suggested that the associations were more stable in cancer populations, while in non-cancer populations, these associations might be influenced by drinking. AUC values indicated that the biomarkers demonstrated good predictive performance.

Conclusion

This study identifies globulin and AGR as novel, cost-effective biomarkers that integrate inflammation and nutrition, providing a convenient and robust means to predict depression, particularly in cancer patients. These findings also offer new perspectives for future dual clinical interventions targeting inflammation and nutrition, as well as experimental research on depression.

Microglia Sing the Prelude of Neuroinflammation-Associated Depression

Major depressive disorder (MDD) is a psychiatric condition characterized by sadness and anhedonia and is closely linked to chronic low-grade neuroinflammation, which is primarily induced by microglia. Nonetheless, the mechanisms by which microglia elicit depressive symptoms remain uncertain. This review focuses on the mechanism linking microglia and depression encompassing the breakdown of the blood-brain barrier, the hypothalamic-pituitary-adrenal axis, the gut-brain axis, the vagus and sympathetic nervous systems, and the susceptibility influenced by epigenetic modifications on microglia. These pathways may lead to the alterations of microglia in cytokine levels, as well as increased oxidative stress. Simultaneously, many antidepressant treatments can alter the immune phenotype of microglia, while anti-inflammatory treatments can also have antidepressant effects. This framework linking microglia, neuroinflammation, and depression could serve as a reference for targeting microglia to treat depression.

The mediating effects of sleep quality in the relationship between loneliness and depression among middle-aged and older adults

Loneliness has long been recognized as a key predictor of depression in older adults, and both are related to sleep quality. However, to this day, less is known about whether sleep quality mediates their relationship. This study aimed to examine the relationship between loneliness, sleep quality, and depressive symptoms, and to further explore whether sleep quality mediates the relationship between loneliness and depressive symptoms. Using the random cluster sampling method, 1016 permanent residents aged 45 and above in Ankang City, Shaanxi Province were selected. The relationship between loneliness, sleep quality, and depressive symptoms was analyzed using binary logistic regression, and the mediating role of sleep quality between loneliness and depressive symptoms was analyzed using the PROCESS macro in SPSS 25.0 software. The average age of the participants in this study was 60.39 ± 8.50. Regression analyses showed that individuals with loneliness (OR 7.161, 95%CI: 4.889-10.490, P < 0.001) and those with poor sleep quality (OR 4.777, 95%CI: 3.301-6.913, P < 0.001) were more likely to experience depressive symptoms than individuals without loneliness and with good sleep quality. This study also found a significant mediating effect of sleep quality between loneliness and depressive symptoms [effect value = 0.066, bootstrap 95% CI: (0.037, 0.093)] with an effect size of 13.31%. Loneliness may lead to reduced sleep quality in individuals, which in turn may lead to or exacerbate depressive symptoms. Therefore, this study highlights the importance of assessing and improving sleep quality in lonely people.

Relationship between weight-to-waist index and post-stroke depression

BACKGROUND

The weight-to-waist index (WWI) serves as an innovative metric specifically designed to assess central obesity. However, the relationship between WWI and the prevalence of post-stroke depression (PSD) remains inadequately explored in the literature.

AIM

To elucidate the relationship between WWI and PSD.

METHODS

Data from the National Health and Nutrition Examination Survey 2005 to 2018 were analyzed. Multivariable logistic regression models and propensity score matching were utilized to investigate the association between WWI and PSD, with adjustments for potential confounders. The restricted cubic spline statistical method was applied to explore non-linear associations.

RESULTS

Participants with elevated WWI values had a significantly greater risk of developing PSD. Specifically, individuals in the higher WWI range exhibited more than twice the likelihood of developing PSD compared to those with lower WWI values (odds ratio = 2.21, 95% confidence interval: 1.84-2.66, P < 0.0001). After propensity score matching, the risk of PSD remained significantly elevated (odds ratio = 1.43, 95%confidence interval: 1.09-1.88, P = 0.01). Tertile analysis revealed that participants in the highest WWI tertile faced a significantly higher risk of PSD compared to those in the lowest tertile. Restricted cubic spline analysis further revealed a non-linear association, with the risk of PSD plateauing at higher WWI values.

CONCLUSION

There is a significant association between elevated WWI and increased risk of PSD. Thus, regular depression screening should be implemented in stroke patients with elevated WWI to enhance patient outcomes.

C-reactive protein as a possible indicator of PTSD prognosis and comorbid anhedonia

Posttraumatic stress disorder (PTSD) is often chronic, which is costly to the individual and society. Easy-to-measure prognostic indicators can help to ensure that those with the greatest symptoms receive treatment. Inflammatory biomarkers may precede and predict depression chronicity and worsening, as well as PTSD. Yet, it is unknown if inflammatory biomarkers predict changes in symptoms among those who have already developed PTSD. Among 82 US military veterans (82 % male) diagnosed with PTSD, we measured C-reactive protein (CRP) and conducted clinical diagnostic interviews assessing PTSD and major depression at two visits, an average of five years apart. Cross-lagged models revealed that CRP at Time 1 was positively associated with PTSD symptom severity (p = 0.017), depression diagnosis (p < 0.001), depressive symptom count (p=.001), and anhedonia (p < 0.001) but not low mood (p = 0.183) at Time 2, covarying for baseline levels of these outcomes as autoregressive effects and for potential confounds. Results suggest that elevated CRP may be a risk factor for more chronic and severe PTSD symptoms, perhaps with comorbid anhedonic depression. Further exploration of CRP as a prognostic indicator of PTSD is warranted.

Blood cytokines in major depressive disorder in drug-naïve adolescents: A systematic review and meta-analysis

BACKGROUND

Major depressive disorder (MDD) is the most common mental health problem worldwide. Increased levels of inflammation are associated with MDD, though this relationship has been suggested to be bidirectional. The first incidence of a depressive episode usually occurs during adolescence. Hence, examining depressed, drug-naïve adolescents is important to understand the role of inflammation in the pathophysiology of MDD. Cytokines might play a crucial role in inflammation associated with MDD. Therefore, this article aims to investigate the changes in the levels of peripheral blood cytokines in adolescents with MDD.

METHODS

We conducted a systematic review and meta-analysis to assess the changes in peripheral blood cytokines in drug-naïve adolescents (10-18 years) with MDD. A comprehensive search across four databases was performed to identify original research articles. Studies in which the diagnosis of MDD was set by semi-structured interview were included.

RESULTS

Of 2291 articles, 12 met the inclusion criteria for the review, with seven suitable for meta-analysis & including up to five studies per cytokine. The meta-analysis revealed significant associations between tumor necrosis factor (TNF)-α (n = 222, Hedge's g = 0.51, p <0.01) and MDD in adolescents compared to healthy individuals. However, other blood cytokines, including interleukin (IL)-1β, IL-4, IL-6, IL-8, and interferon (IFN)-γ, did not significantly correlate with MDD in adolescents.

CONCLUSION

TNF-α was significantly elevated in drug-naïve adolescents with MDD. To further understand the role of TNF-α in MDD, a thorough investigation is required, taking into account the diversity, subtypes, chronicity, and severity of MDD.

Decoding and reconstructing disease relations between dry eye and depression: a multimodal investigation comprising meta-analysis, genetic pathways and Mendelian randomization

INTRODUCTION

The clinical presentations of dry eye disease (DED) and depression (DEP) often comanifest. However, the robustness and the mechanisms underlying this association were undetermined.

OBJECTIVES

To this end, we set up a three-segment study that employed multimodality results (meta-analysis, genome-wide association study [GWAS] and Mendelian randomization [MR]) to elucidate the association, common pathways and causality between DED and DEP.

METHODS

A meta-analysis comprising 26 case-control studies was first conducted to confirm the DED-DEP association. Next, we performed a linkage disequilibrium (LD)-adjusted GWAS and targeted phenotype association study (PheWAS) in East Asian TW Biobank (TWB) and European UK Biobank (UKB) populations. Single-nucleotide polymorphisms (SNPs) were further screened for molecular interactions and common pathways at the functional gene level. To further elucidate the activated pathways in DED and DEP, a systemic transcriptome review was conducted on RNA sequencing samples from the Gene Expression Omnibus. Finally, 48 MR experiments were implemented to examine the bidirectional causation between DED and DEP.

RESULTS

Our meta-analysis showed that DED patients are associated with an increased DEP prevalence (OR = 1.83), while DEP patients have a concurrent higher risk of DED (OR = 2.34). Notably, cross-disease GWAS analysis revealed that similar genetic architecture (rG = 0.19) and pleiotropic functional genes contributed to phenotypes in both diseases. Through protein-protein interaction and ontology convergence, we summarized the pleiotropic functional genes under the ontology of immune activation, which was further validated by a transcriptome systemic review. Importantly, the inverse variance-weighted (IVW)-MR experiments in both TWB and UKB populations (p value <0.001) supported the bidirectional exposure-outcome causation for DED-to-DEP and DEP-to-DED. Despite stringent LD-corrected instrumental variable re-selection, the bidirectional causation between DED and DEP remained.

CONCLUSION

With the multi-modal evidence combined, we consolidated the association and causation between DED and DEP.

Physical inactivity, depressive symptoms, and progression to sarcopenia in older adults: a 4-year longitudinal study

OBJECTIVES

To examine the combined association of physical inactivity and depressive symptoms with the progression to sarcopenia in community-dwelling older adults.

DESIGN

A 4-year follow-up longitudinal study.

SETTING

Community-dwelling older adults living in Japan, who were not sarcopenic at baseline.

PARTICIPANTS

The participants were 2,538 community-dwelling older adults and with a mean age of 70.9 ± 4.6 years, of whom 1,327 (52.3%) were women.

MEASUREMENTS

Sarcopenia, defined according to the European Working Group on Sarcopenia in Older People 2, was assessed at baseline and at the 4-year follow-up. Participants were divided into four groups according to their inactivity and depressive symptoms. Physical inactivity was assessed using two face-to-face questions regarding the frequency of regular exercise, sports, and light exercise per week. Depressive symptoms were defined as a score of six or higher on the Geriatric Depression Scale 15-item version. Logistic regression analysis was used to determine whether inactivity and depressive symptoms were associated with progression to sarcopenia 4 years later. For participants who could not be followed and participants with missing data in the follow-up assessment, the data at the follow-up assessment were imputed using the multiple imputations.

RESULTS

After 4 years, 518 participants (20.4%) with complete data progressed to sarcopenia. The rate of progression to sarcopenia after multiple imputations was 23.4%. Logistic regression analysis after multiple imputations showed that the group with both factors was significantly associated with the progression to sarcopenia [Odds ratio, 1.64 (95% Confidence interval 1.11-2.44), p = 0.014]. By contrast, no significant association was found for either inactivity or depressive symptoms alone.

CONCLUSION

This study indicates that the coexistence of physical inactivity and depressive symptoms may contribute to the progression of sarcopenia. Addressing both physical and mental factors, rather than limiting the problem to a single factor, may be essential for preventing sarcopenia.

Non-pharmacological therapeutic paradigms in stress-induced depression: from novel therapeutic perspective with focus on cell-based strategies

Major depressive disorder (MDD) is considered a psychiatric disorder and have a relationship with stressful events. Although the common therapeutic approaches against MDD are diverse, a large number of patients do not present an adequate response to antidepressant treatments. On the other hand, effective non-pharmacological treatments for MDD and their tolerability are addressed. Several affective treatments for MDD are used but non-pharmacological strategies for decreasing the common depression-related drugs side effects have been focused recently. However, the potential of extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs), microRNAs (miRNAs) as cell-based therapeutic paradigms, besides other non-pharmacological strategies including mitochondrial transfer, plasma, transcranial direct current stimulation (tDCS), transcranial magnetic stimulation (TMS), and exercise therapy needs to further study. This review explores the therapeutic potential of cell-based therapeutic non-pharmacological paradigms for MDD treatment. In addition, plasma therapy, mitotherapy, and exercise therapy in several in vitro and in vivo conditions in experimental disease models along with tDCS and TMS will be discussed as novel non-pharmacological promising therapeutic approaches.

Plasma levels of matrix metalloproteinases in early psychosis, anxiety and depression: Evidence from the ALSPAC cohort

BACKGROUND

Converging evidence supports the role of Matrix Metalloproteinases (MMPs) in psychiatric disorders. Originally identified as regulators of the extracellular matrix (ECM), MMPs' functions span multiple processes, including inflammation, synaptic plasticity, neuronal migration, and blood-brain barrier maintenance. Tissue Inhibitors of Metalloproteinases (TIMPs) are major regulators of MMPs. In the present study we examined the associations of plasma MMPs and TIMPs with mental disorders in young adults aged 24 years in the Avon Longitudinal Study of Parents and Children (ALSPAC).

METHODS

The present study was a nested case control study within the Avon Longitudinal Study of Parents and Children and comprised 374 participants who met criteria for psychiatric disorders (35 met the criteria for psychotic disorder, 201 for mild/moderate depressive disorder, and 266 for generalised anxiety disorder) and 401 controls. All cases and controls had were selected from the group of 4019 participants who had attended at age 24 years, completed psychiatric assessments and provided plasma samples. Plasma concentrations of MMP2, MMP3, MMP9 and TIMP-4 were quantified using proximity extension assays available on Olink® Cardiovascular Panel III. Logistic regression analysis compared standardised MMPs and TIMPs levels in cases and controls. Models were adjusted for sex, body mass index, and cigarette smoking.

RESULTS

There was evidence for an association between MMP3 and depressive disorder (Odds ratio [OR] 1.35, 95 % confidence interval [CI] 1.06-1.73). There was evidence for an association between TIMP4 and depressive disorder (OR 1.51, 95 % CI 1.22-1.88) and generalised anxiety disorder (OR 1.43, 95 % CI 1.19-1.72). There was no evidence for an association between MMPs and psychotic disorders.

CONCLUSIONS

The study revealed that 24-year-olds with depressive and anxiety disorders exhibited elevated plasma concentrations of TIMP-4 compared to controls. There was evidence for an association between MMP3 and depressive disorder. These findings provide further support for the involvement of metalloproteinases as biomarkers in the pathophysiology of mental disorders during early adulthood.

Habituation of the biological response to repeated psychosocial stress: a systematic review and meta-analysis

Recurrent psychosocial stress poses a significant health challenge, prompting research into mechanisms of successful adaptation. Physiological habituation, defined as decreased reactivity to repeated stressors, is pivotal in protecting the organism from allostatic load. Here, we systematically review and meta-analyze data from studies investigating the capacity of central stress systems to habituate when repeatedly exposed to a standardized psychosocial stressor, the Trier Social Stress Test (k = 47). For a comprehensive overview of biological stress systems, we examine multiple markers of the hypothalamic-pituitary-adrenal (HPA) axis, the autonomic nervous system (ANS), and the immune system. Our findings indicate that habituation patterns vary substantially between different stress systems. While most studies provide robust evidence for rapid and substantial HPA-axis habituation, ANS and immune marker responses to repeated stress are less uniform. We further integrate existing knowledge on personal and environmental influences contributing to individual differences in habituation capacity. Additionally, we discuss the implications of stress habituation patterns for health outcomes and the design of longitudinal stress studies and highlight potential avenues for future research.

Associations Between Growth Differentiation Factor 15 and Anxiety and Depression in the General Population: The Akershus Cardiac Examination 1950 Study

OBJECTIVE

Several studies suggest a bidirectional association between inflammation, and anxiety and depression. Elevated inflammatory cytokines generate and aggravate neuroinflammation, which may play a part in developing psychological symptoms. Growth differentiation factor 15 (GDF-15) is a novel biomarker possibly reflecting fibrosis and inflammation. The aim of the current study was to investigate the associations between levels of GDF-15 and symptoms of anxiety and depression in the general population.

METHODS

We measured GDF-15 in middle-aged persons participating in the Akershus Cardiac Examination 1950 Study. Symptoms of anxiety and depression were assessed using the Hospital Anxiety and Depression Scale (HADS), with HADS ≥8 denoting significant symptoms. We used multivariable regression analysis to assess the associations between GDF-15 and HADS, adjusting for levels of C-reactive protein (CRP), demographics, and comorbidities.

RESULTS

A total of 3638 participants had valid assessment of HADS and measurements of GDF-15 and CRP. The mean age was 63.9 (SD 0.65) years, and 48.8% were women. In adjusted models, levels of GDF-15 were associated with the continuous HADS-D score (β = 0.27, 95% confidence interval [CI] = 0.12 to 0.43) and HADS-D score ≥8 (odds ratio = 1.41, 95% CI = 1.12 to 1.78), but not with the continuous HADS-A score (β = 0.06, 95% CI = -0.12 to 0.24) or HADS-A score ≥8 (odds ratio = 1.06, 95% CI = 0.88 to 1.27).

CONCLUSIONS

Levels of GDF-15 are independently associated with symptoms of depression in the general population. Our results reinforce the notion that inflammation may be a contributing factor for the development of clinical depression.

REGISTRATION

ClinicalTrials.gov identifier NCT01555411 (Akershus Cardiac Examination [ACE] 1950 Study), https://clinicaltrials.gov/study/NCT01555411.

Resting-state functional connectivity is correlated with peripheral inflammatory markers in patients with major depressive disorder and healthy controls

BACKGROUND

Recent studies have highlighted the significant role of inflammation in the development and progression of major depressive disorder (MDD). Elevated levels of proinflammatory cytokines have consistently been observed in MDD, and these markers are shown to be linked to disruptions in brain networks. Therefore, we aimed to explore the relationship between inflammatory markers and resting-state functional connectivity (RSFC) in patients with MDD.

METHODS

This study included 76 patients with MDD and 92 healthy controls (HCs). Seed-to-voxel RSFC analysis was performed using brain regions that have been identified in previous studies on the neural networks implicated in MDD. These regions served as key hubs in the default mode, salience, cognitive control, and frontostriatal networks and were used as seed regions.

RESULTS

Compared with HCs, patients with MDD exhibited elevated levels of interleukin (IL)-6 and IL-8. The MDD group showed significant alterations of the RSFC between the prefrontal cortex (PFC), anterior cingulate cortex, visual cortex, postcentral gyrus, and striatal regions compared to the HC group. Additionally, within the MDD group, a positive correlation was observed between tumor necrosis factor (TNF)-α levels and the RSFC of the right dorsolateral prefrontal cortex (dlPFC) and visual cortex. Conversely, in the HC group, TNF-α levels were negatively correlated with the RSFC between the right dlPFC and bilateral dorsomedial prefrontal cortex, while positive correlations were noted between the RSFC of the right dlPFC with occipital regions and the levels of both IL-8 and TNF-α.

CONCLUSIONS

The present study confirmed that cytokine levels are linked to alterations in the RSFC, particularly in the prefrontal regions. Our findings suggest that systemic inflammation may contribute to functional disruptions in the brain networks involved in emotion regulation and cognitive control in MDD.

Meta analysis of resting frontal alpha asymmetry as a biomarker of depression

This meta-analysis investigated resting frontal alpha asymmetry (FAA) as a potential biomarker for major depressive disorder (MDD). Studies included articles utilizing FAA measure involving EEG electrodes (F3/F4, F7/F8, or Fp1/Fp2) and covering both MDD and controls. Hedges' d was calculated from FAA means and standard deviations (SDs). A systematic search of PubMed through July 2023 identified 23 studies involving 1928 MDD participants and 2604 controls. The analysis revealed a small but significant grand mean effect size (ES) for FAA (F4 - F3), suggesting limited diagnostic value of FAA in MDD. Despite the presence of high heterogeneity across studies, subgroup analyses did not identify significant differences based on calculation formula, reference montage, age, or depression severity. The findings indicate that FAA may have limited standalone diagnostic utility but could complement existing clinical assessments for MDD, highlighting the need for a multifaceted approach to depression diagnosis and prognosis.

Depression unveiled: Insights into etiology and animal models for behavioral assessment, exploring the multifactorial nature and treatment of depression

Over the past century, significant shifts in daily living have led to an increased prevalence of mental disorders, often linked to hormonal imbalances. Among these, anxiety and depression stand out as prevalent diagnoses, particularly in industrialized nations. Depression, according to the DSM-5, is a heterogeneous condition that affects emotional, cognitive, and physical functioning, with symptoms including insomnia, sexual dysfunction, and weight changes. Cognitive theories of depression highlight its impact on judgment, decision-making, thinking, and focus. Depression's multifaceted nature means that no two patients experience identical symptoms, risk factors, or treatment responses. The COVID-19 pandemic has exacerbated mental health issues, with social isolation, restricted contact, and altered daily routines contributing to increased anxiety and depression, especially among adolescents and young adults. The pandemic's psychological toll underscores the need for effective treatment strategies for mental disorders. The physical manifestations of major depressive disorder (MDD) are associated with a heightened risk of developing various medical conditions, including metabolic disorders, cardiovascular disease, stroke, epilepsy, and dementia. This review provides a comprehensive exploration of depression and anxiety, covering their different types, epidemiology, potential causes, diagnostic criteria, and available treatment options. It delves into the role of pharmacological interventions and examines recent advancements to enhance therapeutic outcomes. Additionally, the review assesses the therapeutic potential of drugs, offering insights into their efficacy in treating these complex mental health disorders. By targeting the multifactorial etiology of depression through drug repurposing and new drug development, researchers aim to enhance treatment efficacy and achieve better outcomes for patients with depression.

Associations between biomarkers of inflammation and depressive symptoms-potential differences between diabetes types and symptom clusters of depression

Inflammation is a probable biological pathway underlying the relationship between diabetes and depression, but data on differences between diabetes types and symptom clusters of depression are scarce. Therefore, this cross-sectional study aimed to compare associations of a multimarker panel of biomarkers of inflammation with depressive symptoms and its symptom clusters between people with type 1 diabetes (T1D) and type 2 diabetes (T2D). This cross-sectional study combined data from five studies including 1260 participants (n = 706 T1D, n = 454 T2D). Depressive symptoms were assessed using the Center for Epidemiological Studies-Depression Scale (CES-D). Serum levels of 92 biomarkers of inflammation were quantified with proximity extension assay technology. After quality control, 76 biomarkers of inflammation remained for statistical analysis. Associations between biomarkers and depressive symptom scores and clusters (cognitive-affective, somatic, anhedonia) were estimated with multivariable linear regression models. Nine biomarkers were positively associated with depressive symptoms in the total sample (CCL11/eotaxin, CCL25, CDCP1, FGF-21, IL-8, IL-10RB, IL-18, MMP-10, TNFRSF9; all p < 0.05) without interaction by diabetes type. Associations differed for eight biomarkers (pinteraction < 0.05). TNFβ was inversely associated with depressive symptoms in T1D, whereas three biomarkers (GDNF, IL-18R1, LIF-R) were positively associated with depressive symptoms in T2D. For the remaining four biomarkers (CD6, CD244, FGF-5, IFNγ) associations were not significant in either subgroup. Biomarker associations were more pronounced with somatic and anhedonia than with cognitive-affective symptoms. These results indicate that different proinflammatory pathways may contribute to depression in T1D and T2D and that there may be a symptom specificity in the link between subclinical inflammation and depression.

Neurobiological mechanisms of antidepressant properties of psilocybin: A systematic review of blood biomarkers

Psilocybin represents a novel therapeutic approach for individuals with major depressive disorder (MDD) who do not respond to conventional antidepressant treatment. Investigating the influence of psilocybin on the pathophysiological processes involved in MDD could enhance our neurobiological understanding of the presumed antidepressant action mechanism. This systematic review aims to summarize the results of human studies investigating changes in blood-based biomarkers of MDD to guide future research on potentially relevant analytes that could be monitored in clinical trials. A systematic search was performed in MEDLINE, Embase, and Web of Science to retrieve studies investigating changes in serum and plasma levels of neurotrophic, immunologic, neuroendocrine, and metabolic markers. Nine studies were included, describing findings on 15 biomarkers, exclusively in healthy participants. Studies consistently reported a decrease in interleukin-6, C-reactive protein, and eosinophils, and an increase in cortisol, prolactin, oxytocin, thyroid-stimulating hormone, adrenocorticotropic hormone, brain-derived neurotrophic factor, and free fatty acids following psilocybin administration. Less consistent effects were observed on interleukin-1β, interleukin-8, tumour necrosis factor-alpha, soluble urokinase plasminogen activator receptor, and growth hormone. The results are in line with preclinical studies and provide initial support from human studies that psilocybin potentially leads to beneficial effects on biomarkers of MDD. However, given the limited number of studies, findings should be approached with caution prior to replication. Further research should include larger samples, clinical populations, longer-term assessment, rigorous experimental designs, and account for the potential confounding of psychological stress related to the psychedelic experience.

Developing a translational research framework for MDD: combining biomolecular mechanisms with a spiraling risk factor model

Objective

The global incidence and burden of Major Depressive Disorder (MDD) are increasing annually, with current antidepressant treatments proving ineffective for 30-40% of patients. Biomolecular mechanisms within the microbiota-gut-brain axis (MGBA) may significantly contribute to MDD, potentially paving the way for novel treatment approaches. However, integrating the MGBA with the psychological and environmental aspects of MDD remains challenging. This manuscript aims to: 1) investigate the underlying biomolecular mechanisms of MDD using a modeling approach, and 2) integrate this knowledge into a comprehensive 'spiraling risk factor model' to develop a biopsychosocial translational research framework for the prevention and treatment of MDD.

Methods

For the first aim, a systematic review (PROSPERO registration) was conducted using PubMed, Embase, and Scopus to query literature published between 2016-2020, with select additional sources. A narrative review was performed for the second aim.

Results

In addition to genetics and neurobiology, research consistently indicates that hyperactivation of the HPA axis and a pro-inflammatory state are interrelated components of the MGBA and likely underlying mechanisms of MDD. Dysregulation of the MGBA, along with imbalances in mental and physical conditions, lifestyle factors, and pre-existing treatments, can trigger a downward spiral of stress and anxiety, potentially leading to MDD.

Conclusions

MDD is not solely a brain disorder but a heterogeneous condition involving biomolecular, psychological, and environmental risk factors. Future interdisciplinary research can utilize the integrated biopsychosocial insights from this manuscript to develop more effective lifestyle-focused multimodal treatment interventions, enhance diagnosis, and stimulate early-stage prevention of MDD.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42020215412.

The impact of inflammatory response on psychological status of medical staff during COVID-19 pandemic

BACKGROUND

Limited research has been conducted on the relationship between inflammatory markers and psychological status in medical staff fighting COVID-19.

OBJECTIVE

This article examines the psychological and inflammatory conditions of medical personnel working on the front lines of the battle against COVID-19.

METHODS

A total of 102 clinical staff members were included in this study. All subjects received the Symptom Checklist-90 questionnaire (SCL-90) and Posttraumatic Stress Disorder Checklist-Civilian questionnaires for assessing different mental symptoms. The levels of various inflammatory markers, including IL-1β, IL-2, IL-6, IL-8, TNF-a, and IFN-γ, along with GDNF, were evaluated.

RESULTS

Spearman correlation analysis showed that the levels of IL-6 were positively associated with the anxiety score (Spearman's rho = .230, p = .021), obsessive-compulsive symptoms (Spearman's rho = .201, p = .042). The levels of IL-8 were negatively associated with the anxiety score (Spearman's rho = -.223, p = .028), obsessive-compulsive symptoms (Spearman's rho = -.252, p = .012), hyperarousal (Spearman's rho = -.221, p = .028). The levels of TNF-α were positively associated with the anxiety score (Spearman's rho = .201, p = .045), obsessive-compulsive symptoms (Spearman's rho = .222, p = .035).

CONCLUSION

Generally, our results suggested that IL-6, IL-8 and TNF-α might play a role in the development of psychological symptoms among medical staff.

Acute and chronic response of supervised band-elastic resistance exercise in systemic cytokines levels of bipolar disorders and schizophrenia individuals: A pilot study

Despite earlier research demonstrating the immunomodulatory effects of acute and chronic exercise in many medical illnesses, there is a lack of literature evaluating the acute and chronic effects of exercise on the cytokine levels in individuals with bipolar disorder (BD) or schizophrenia (SCH). This study aims to examine the acute effects of resistance exercise on cytokines and the chronic effects of resistance exercise by 10 weeks on cytokine levels, symptoms of disease, and muscular strength in individuals with BD and SCH. The included individuals (N=10) performed a single session of band-elastic resistance exercises (six exercises, 3 sets of 12-15 repetitions, 60 seconds of interval between sets). A sub-sample (N=6) of individuals performed a supervised band-elastic resistance exercise program (2 times a week, for 10 weeks, 6 exercises, 3 sets of 12-15 repetitions, 60 seconds of interval). We verified for acute effects: IL-2 (P=0.0085) and IL-4 (P=0.0253) levels increased, while IL-6 decreased (P=0.0435), and for chronic effects: increased IL-2 and IL-4 levels (significant effect size - Pre vs Post), a decrease in disease symptoms, and an increase in muscular strength. This study adds to what is already known about how resistance exercises affect people with BD and SCH in both short-term (systemic cytokines levels) and long-term (symptoms of disease, muscular strength, and systemic cytokines levels).

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.

Neural and immune interactions linking early life stress and anhedonia

Early experiences of stress and adversity are associated with blunted reward sensitivity and altered reward learning. Meanwhile, anhedonia is characterized by impairments in reward processing, including motivation, effort, and pleasure. Early life stress (ELS) and anhedonia share psychological, behavioral, and neurobiological correlates, and the system-level interactions that give rise to anhedonia have yet to be fully appreciated. The proposed framework uses a multilevel, multisystem approach to aid in understanding neural-immune interactions that link ELS and anhedonia. The interactions linking anhedonia and ELS presented here include reduced reward sensitivity, alterations in hypothalamic-pituitary-adrenal (HPA) axis response, elevated inflammatory cytokines or physiological markers of stress, and blunted reward circuitry functioning along the mesocorticolimbic pathway. The clinical implications and areas for future research are also discussed. Ultimately, this research may inform the development of more specific and individualized treatments for anhedonia.

Adverse childhood experiences and psychiatric comorbidity in multiple sclerosis, inflammatory bowel disease, and rheumatoid arthritis in the Canadian longitudinal study on aging

OBJECTIVES

Adverse childhood experiences (ACE) are associated with immune-mediated inflammatory diseases (IMID). We evaluated whether: (i) ACE associate with psychiatric comorbidity among individuals with IMID, including rheumatoid arthritis (RA), multiple sclerosis (MS), and inflammatory bowel disease (IBD); (ii) whether psychiatric disorders mediate the relationship between ACE and IMID; and (iii) whether these findings differ from those in individuals with other chronic physical disorders.

METHODS

Using data from the Canadian Longitudinal Study on Aging (CLSA) we performed a retrospective case-control study of participants aged 45-85 years recruited between 2010 and 2015. ACE were queried using questions derived from the Childhood Experiences of Violence Questionnaire-Short Form and the National Longitudinal Study of Adolescent to Adult Health Wave III questionnaire. We used multivariable logistic regression and causal mediation analysis to address our objectives.

RESULTS

We included 13,977 CLSA participants. Among the 31 % of IMID participants who reported a comorbid psychiatric disorder, 79 % reported a history of ACE. ACE associated with increased odds (OR [95 % CI]) of a psychiatric disorder (2.55 [1.02-6.35]) among participants with IMID; this did not differ across IMID. The total effect (OR [95 % CI]) of ACE on IMID was 1.11 (1.07-1.16), of which 10.60 % (8.04-17.47) was mediated by psychiatric disorders. We found similar associations among participants with other chronic physical disorders.

CONCLUSION

Our findings suggest that psychiatric disorders partially mediate the association between ACE and IMID. Most participants with IMID and comorbid psychiatric disorders report a history of ACE and may benefit from trauma-informed mental health care.

Inflammation is associated with pain and fatigue in older adults

Introduction

Increasing evidence suggests that inflammation may play a pivotal role in the development of chronic pain and fatigue in aging individuals. This study investigated the relationship between three inflammatory markers (IL-6, CRP, and TNFα) and pain and fatigue, both cross-sectionally and longitudinally, in a sample of older adults from the Saint Louis Personality and Aging (SPAN) study.

Methods

SPAN study participants provided blood samples at two in-person sessions approximately 2 years apart for the analysis of the inflammatory biomarkers IL-6, CRP, and TNFα. Pain and fatigue were assessed using the RAND-36 Health Status Inventory. Correlations (with false discovery rate correction for multiple testing) and follow-up linear regressions including potentially confounding demographic (e.g., annual household income) and health (e.g., BMI, medication use) covariates were used to estimate cross sectional and longitudinal associations. Analytic ns ranged from 533 to 815.

Results

Cross-sectional analyses revealed that higher IL-6 and CRP were associated with greater reported pain and fatigue, even after accounting for covariates (βs > .098, ps < .05). TNFα was associated with greater fatigue only (β = .100, p = .012). Longitudinally, CRP and IL-6 predicted future pain and fatigue, although only the relationship between CRP and future fatigue survived the inclusion of covariates (β = .104, p = .022). Both pain and fatigue predicted higher levels of IL-6 and CRP approximately 2 years later, although only the associations with IL-6 survived the inclusion of covariates (βs > .12, ps < .01).

Discussion

Our study adds to a growing body of literature showing that inflammation is associated with greater pain and fatigue in older adults. Our longitudinal data showing temporal bidirectional associations is consistent with evidence from non-human animal models that heightened inflammation causally contributes to fatigue and also suggests that the experience of pain and fatigue may contribute to inflammation. It will be important for future work to identify how lifestyle factors associated with pain and fatigue (e.g., physical activity) may contribute to these associations.

Splenic γδ T cells mediate antidepressant and prophylactic actions of arketamine in lipopolysaccharide-induced depression in mice

Arketamine, the (R)-enantiomer of ketamine, exhibits both therapeutic and sustained prophylactic effects in an inflammation-driven model of depression, although the precise mechanisms remain elusive. Given the involvement of γδ T cells in inflammatory processes, this study explored their role in the effects of arketamine. To assess therapeutic outcomes, mice received lipopolysaccharide (LPS:1.0 mg/kg), followed by either arketamine (10 mg/kg) or saline. For prophylactic assessment, arketamine or saline was administered six days prior to LPS exposure. A single dose of LPS (1.0 mg/kg) reduced the proportion of γδ T cells in the spleen but did not affect their levels in the blood, prefrontal cortex, or small intestine. Arketamine mitigated LPS-induced splenomegaly, counteracted the elevation of plasma interleukin-6 levels and the reduction in the proportion of splenic γδ T cells, and alleviated depression-like behavior as assessed by the forced swimming test. Notably, negative correlations were observed between the proportion of splenic γδ T cells and indicators of inflammation and depression. Furthermore, pretreatment with a γδ TCR antibody significantly countered the therapeutic and prophylactic effects of arketamine on LPS-induced changes. These findings highlight a novel role for splenic γδ T cells in inflammation-associated depression and suggest the potential of arketamine as a treatment option. Consequently, γδ T cells may represent a novel therapeutic target for inflammation-related depression. Further studies on the role of γδ T cells in depressed patients with inflammation are warranted.

Higher inflammatory proteins predict future depressive symptom severity among adolescents with lower emotional clarity

BACKGROUND

A growing body of work has implicated inflammation in the pathogenesis of depression. As not all individuals with heightened levels of peripheral inflammation develop symptoms of depression, additional work is needed to identify other factors that catalyze the relationship between inflammation and depressive symptoms. Given that elevated levels of inflammatory activity can induce a variety of emotional changes, the present study examined whether emotional clarity, the trait-like ability to identify, discern, and express one's emotions, influences the strength of the association between inflammatory signaling and concurrent and prospective symptoms of depression.

METHODS

Community adolescents (N = 225, Mage = 16.63 years), drawn from a larger longitudinal project investigating sex and racial differences in depression onset, provided blood samples to determine peripheral levels of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and C-reactive protein (CRP) at a baseline visit, along with self-report measures of emotional clarity and depressive symptom severity. Depressive symptom severity was assessed again at a follow-up visit approximately 5-months after baseline.

RESULTS

Hierarchical multiple regressions detected a significant interaction between inflammatory markers and emotional clarity on future depression severity, controlling for baseline depressive symptoms. Specifically, among adolescents with low levels of emotional clarity, higher levels of IL-6, CRP, and inflammatory composite scores were significantly associated with greater future depression severity.

CONCLUSIONS

These results indicate that low emotional clarity and high inflammatory signaling may jointly confer risk for prospective depressive symptom severity among adolescents. Therapeutic interventions that improve emotional clarity may reduce risk of depressive symptoms among adolescents with low-grade peripheral inflammation.

Acute and chronic effects of physical exercise in inflammatory biomarkers in people with depression: A systematic review with meta-analysis

People with depression have increased levels of pro-inflammatory cytokines compared to healthy subjects. Physical exercise can alleviate depressive symptoms and has anti-inflammatory properties. The aim of this study was to identify the effects of exercise on inflammatory biomarkers in people with depression. Clinical trials evaluating the acute and chronic effects of exercise on inflammatory biomarkers in adults with clinical depression were included. The search was conducted on the following databases: PubMed, Embase, Web of Science, PsycINFO, and SPORTDiscus. The risk of bias was assessed with the "Risk of bias in randomized trials" (RoB2) tool. Random effects meta-analyses estimated the acute and chronic effects of exercise for each marker separately. Heterogeneity was estimated with the l2 test. A total of 10 studies (497 participants) were included. No significant acute effects interleukins (IL)-6, IL-10, and IL-8 levels were found. Chronically, exercise increased the levels of TNF-α (Standardized Mean Difference = 0.296; 0.03-0.562, p = 0.029). No chronic effects were found for IL-6 and IL-1B. Overall, 90% of the studies had a moderate or high risk of bias. Exercise seems to promote a small increase in TNF-α, but literature is scarce and with a high risk of bias.

Luteal phase sertraline treatment of premenstrual dysphoric disorder (PMDD): Effects on markers of hypothalamic pituitary adrenal (HPA) axis activation and inflammation

RATIONALE

Premenstrual dysphoric disorder (PMDD) is characterized by severe affective symptoms during the luteal phase of the menstrual cycle. There is some evidence of altered interactions between the hypothalamic pituitary gonadal (HPG) and hypothalamic pituitary adrenal (HPA) axes in PMDD. There is also evidence that similar affective disorders such as major depression and perinatal depression are associated with dysregulation in immune factors, but this has not been characterized in PMDD.

AIMS

The goals of this exploratory study were to identify 1) whether HPA-HPG axis interactions and immune markers differ between PMDD patients and controls across the menstrual cycle; 2) how luteal phase sertraline treatment impacts stress and inflammatory markers.

METHODS

Participants were females age 18-50 with regular menstrual cycles, not using psychotropic or hormonal medications, and were assigned to a control group or PMDD group based on prospective daily symptom ratings and clinical interview. Blood was drawn in the follicular and luteal phases, during laboratory sessions involving a mildly stressful task. In a second luteal phase, PMDD participants received open-label sertraline (50 mg/d) from ovulation to menses. Serum cortisol and ACTH were measured via ELISA and operationalized as area under the curve with respect to ground (AUCg), and peak level following laboratory task. Serum TNF-α, IL-6, CXCL-8, and IL-1β were measured using multiplex kits. Serum allopregnanolone (ALLO) was measured by gas chromatography/mass spectroscopy. To characterize HPA-HPG axis interactions across the menstrual cycle in PMDD participants and controls, multilevel linear models predicted cortisol and ACTH from the interaction of cycle phase (controlling for sertraline treatment), ALLO, and group. To determine the effects of sertraline treatment on inflammatory markers and how groups might differ in cyclical change on each marker, multilevel linear models predicted inflammatory markers from cycle phase (controlling for sertraline treatment) and group. A final set of exploratory models tested whether inflammatory markers predict premenstrual symptom score severity.

RESULTS

The sample included n=77 participants (41 controls, 36 PMDD); 28 participants with PMDD completed sertraline treatment. Group x phase x ALLO interactions showed that higher ALLO levels predicted lower cortisol peak in the treated luteal phase (interaction between phase and ALLO, p=0.042), and there was a higher cortisol peak in the treated luteal phase than the untreated luteal phase (p=0.038). CXCL-8 was significantly associated with premenstrual symptom severity after controlling for group and cycle phase (p=0.011). There were no main effects of group, phase, or ALLO on cortisol AUCg, ACTH AUCg, IL-6, CXCL-8, IL-1β, nor TNF-α (p's>0.05).

CONCLUSION

Serum markers of HPA axis and immune function did not vary by menstrual cycle phase nor PMDD status. However, sertraline treatment in the luteal phase was associated with higher ALLO levels predicting lower cortisol peak in response to mild laboratory stress, suggesting that sertraline treatment may normalize HPG-HPA axis interactions among individuals with PMDD. Greater premenstrual symptomatology was associated with higher levels of the inflammatory marker CXCL-8, but further research is needed into the potential role of inflammation in PMDD.

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.

A follow-up study with a double-blinded, randomized controlled vitamin D supplementation trial in patients with major depressive episode (DepFuD): A study protocol and baseline characteristics

Promising initial studies on vitamin D (VD) supplementation as an adjunct treatment for major depressive disorder (MDD) require rigorously designed randomized controlled trials (RCTs). We aim to investigate the effects of augmenting standard MDD treatment with VD supplementation and examine factors influencing the treatment outcome. This article describes the study design, measures, and baseline characteristics. This multicenter RCT compares the efficacy of a six-month VD intervention at 100 micrograms/day versus 10 micrograms/day (μg/day) (4000 IU (international units)/day vs. 400 IU/day) added to a standard treatment in outpatients aged 20-61 years with MDD. The primary outcome is change in the Montgomery-Åsberg Depression Rating Scale (MADRS) score. Secondary outcomes are other indicators of mental health and functionality (BDI, SOC, 15-D, PSS10, LS-4, LOT-R, YSQ-S2-extended, CORE-OM, TAS-20, BRCS, TADS, SCL-90, DIAD, GAF), and circulating biomarkers. Intervention assessments are conducted at baseline, 3, and 6 months, and follow-ups at 18 months and 6 years post-baseline. The baseline sample had 319 subjects (74% women; median age 31 (inter-quartile range (IQR) 15), mean MADRS score 21.38 (SD 6.04)), with 281 assigned to the RCT. At present, the study continues as a follow-up study. DepFuD project will provide extensive information regarding the potential benefits of VD and enables to identify various biopsychosocial depression-associated risk factors.

Sex-specific association of peripheral blood cell indices and inflammatory markers with depressive symptoms in early adolescence

BACKGROUND

Previous studies have reported the correlation of dysregulated blood cell indices and peripheral inflammatory markers with depression in adults but limited studies have examined this correlation in early adolescents.

METHODS

This study used data from the Chinese Early Adolescents Cohort Study, which was conducted in Anhui, China. Students' depression symptoms were repeatedly measured using the Chinese version of the Center for Epidemiological Studies Depression Scale for Children. Students' blood samples were collected in September 2019 and September 2021. The peripheral blood cell counts and inflammatory marker levels were determined using routine blood tests. Multivariable regression models were used to explore the associations between blood cell indices and adolescent depressive symptoms in both the whole sample and the sex-stratified samples.

RESULTS

The white blood cell (WBC) count, neutrophil count (NC), platelet (PLT) count, neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio, and systemic immune inflammation index (SII) were positively correlated with the severity of depressive symptoms during follow-up. The mean corpuscular volume (MCV), mean hemoglobin (HGB) volume (MCH), and mean corpuscular HGB concentration (MCHC) exhibited negative temporal correlations with depressive symptoms. Additionally, several sex-specific blood cell markers were correlated with depression. Male adolescents with increased red blood cell (RBC) and female adolescents with decreased HGB levels and upregulated WBC, NC, NLR, and SII levels exhibited severe depressive symptoms at follow-up.

CONCLUSIONS

These findings suggested the potential usefulness of peripheral blood cell indices in the assessment of depression in early adolescents.

T cell activation and lowered T regulatory cell numbers are key processes in severe major depressive disorder: Effects of recurrence of illness and adverse childhood experiences

BACKGROUND

Major depressive disorder (MDD) is characterized by increased T helper (Th)1 polarization, T cell activation (e.g., CD71+ and CD40L+), and cannabinoid receptor type 2 bearing CD20+ B cells; and lower T regulatory (Treg) numbers.

AIMS

To delineate the effects of adverse childhood experiences (ACEs) and recurrence of illness (ROI) on activated T and CB2-bearing B populations, and Tregs, including FoxP3 + CD152+, FoxP3 + GARP+, and FoxP3 + CB1+ cells.

METHODS

We measured ROI, ACEs, the number of activated T cells, Tregs, and CD20 + CB2+ B cells, in 30 MDD patients and 20 healthy controls.

RESULTS

A larger part of the variance in the depression phenome (40.8 %) was explained by increased CD20 + CB2+ and activated T cells, and lowered Tregs. ROI and lifetime suicidal behaviors were significantly and positively associated with CD20 + CB2+, CD3 + CD71+, CD3 + CD40L+, CD4 + CD71+, CD4 + CD40L+, and CD4HLADR+ numbers. ROI was significantly correlated with CD8 + CD40L+ numbers. The sum of ACEs was significantly associated with CD20 + CB2+, CD3 + CD40L+, CD4 + 40 L+ numbers, T cell activation (positively) and Treg (inversely) indices. One replicable latent vector could be extracted from activated T cells, lifetime and current suicidal behaviors, number of depressive episodes, and severity of depression, and 48.8 % of its variance was explained by ACEs.

CONCLUSIONS

ACE-induced activation of T effector and cytotoxic cells and B cells with autoimmune potential, coupled with lowered Treg numbers are a key component of depression. The findings indicate that increasing ROI, the phenome of depression and suicidal behaviors, are caused by autoimmune processes, which are the consequence of ACEs and increasing sensitization of immune responses.

Role of T and B lymphocyte cannabinoid type 1 and 2 receptors in major depression and suicidal behaviours

Early flow cytometry studies revealed T cell activation in major depressive disorder (MDD). MDD is characterised by activation of the immune-inflammatory response system (IRS) and the compensatory immunoregulatory system (CIRS), including deficits in T regulatory (Treg) cells. This study examines the number of cannabinoid type 1 (CB1) and type 2 (CB2) receptor-bearing T/B lymphocytes in MDD, and the effects of in vitro cannabidiol (CBD) administration on CB1/CB2-bearing immunocytes. Using flow cytometry, we determined the percentage of CD20+CB2+, CD3+CB2+, CD4+CB2+, CD8+CB2+ and FoxP3+CB1+ cells in 19 healthy controls and 29 MDD patients in 5 conditions: baseline, stimulation with anti-CD3/CD28 with or without 0.1 µg/mL, 1.0 µg/mL, or 10.0 µg/mL CBD. CB2+ was significantly higher in CD20+ than CD3+ and CD4+ and CD 8+ cells. Stimulation with anti-CD3/CD8 increases the number of CB2-bearing CD3+, CD4+ and CD8+ cells, as well as CB1-bearing FoxP3+ cells. There was an inverse association between the number of reduced CD4+ CB2+ and IRS profiles, including M1 macrophage, T helper-(Th)-1 and Th-17 phenotypes. MDD is characterised by lowered basal FoxP3+ CB1+% and higher CD20+ CB2+%. 33.2% of the variance in the depression phenome (including severity of depression, anxiety and current suicidal behaviours) is explained by CD20+ CB2+ % (positively) and CD3+ CB2+% (inversely). All five immune cell populations were significantly increased by 10 µg/mL of CBD administration. Reductions in FoxP3+ CB1+% and CD3+ /CD4+ CB2+% contribute to deficits in immune homoeostasis in MDD, while increased CD20+CB2+% may contribute to the pathophysiology of MDD by activating T-independent humoral immunity.

Inflammatory biomarkers in depression: scoping review

BACKGROUND

Inflammation is increasingly recognised as a fundamental component of the pathophysiology of major depressive disorder (MDD), with a variety of inflammatory biomarkers playing pivotal roles. These markers are closely linked to both the severity of symptoms and the responsiveness to treatments in MDD.

AIMS

This scoping review aims to explore the scientific literature investigating the complex relationships between inflammatory biomarkers and depression, by identifying new studies and critical issues in current research.

METHOD

Following the PRISMA Extension for Scoping Reviews guidelines, we systematically searched databases including PubMed, Scopus, PsycINFO, Open Grey and Cochrane Library. Our search focused on articles published from 1 January 2020 to 1 May 2024. We included studies evaluating inflammatory biomarkers in adult patients with MDD, utilising observational and randomised controlled trial designs, and review studies.

RESULTS

Our analysis examined 44 studies on the complex interplay between inflammation and its multiple effects on MDD. Significant associations between specific inflammatory biomarkers and depression severity were found, requiring cautious interpretation. We also highlight several methodological limitations in the current studies, which warrant caution in directly applying these findings to clinical practice. However, identified methodologies show potential for using these biomarkers as diagnostic tools or therapeutic targets, including anti-inflammatory interventions.

CONCLUSIONS

The findings emphasise the need for sophisticated, integrative research to understand inflammation's role in MDD. Future studies should identify specific biomarker panels for diagnosing depression and bridging peripheral biomarker measurements with central neuroinflammatory processes, leading to better diagnostic and treatment strategies.

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.

Identification of Pyroptosis-Related Molecular Subtypes and Diagnostic Model development in Major Depressive Disorder

Major depressive disorder (MDD) is a prevalent psychological disorder associated with inflammation, with complex pathological mechanisms. Pyroptosis has been suggested to contribute to inflammation in central nervous system diseases. Little research, however, has examined what role pyroptosis played in MDD. In the present study, the differential expression pyroptosis-related genes (DE-PRGs) in MDD were identified from the GEO database (GSE98793 and GSE19738). Then, consensus clustering analysis was used to evaluate differences in MDD molecular subtypes characteristics based on PRGs. The characteristic diagnostic biomarkers for MDD were identified by Weighted Correlation Network Analysis (WGCNA) and multiple machine learning algorithms. Three intersection genes (GZMA, AKR1C3, and CD52) were obtained, which are expected to become potential biomarkers for MDD with excellent reliability and accuracy. Subsequently, the immune infiltration characteristics result indicated that the development of MDD is mediated by immune-related function, where three DE-PRGs were strongly related to the immune infiltration landscape of MDD. The biological experiments in vitro further proved that three unique PRGs are emerging as important players in MDD diagnosis. Our research aimed to provide novel ideas and biomarkers targeting MDD.

Relative value of novel systemic immune-inflammatory indices and classical hematological parameters in predicting depression, suicide attempts and treatment response

This study compared the power of the novel inflammatory markers systemic immune inflammation index (SII) and the system inflammation response index (SIRI) versus the classical hematological indices neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), and platelet counts in distinguishing between major depressive disorder (MDD) with and without suicide attempts and distinguishing the non-response to selective serotonin reuptake inhibitor (SSRI) treatment. A total of 139 young adult MDD patients and 54 healthy controls (HC) were included. We found that, in comparison to HC, baseline NLR, PLR, SII, and SIRI were significantly higher in MDD patients, but only NLR and SII had area under the ROC curve (AUC) values greater than 0.7. MDD patients with suicide attempts (SA) showed significantly higher baseline MLR and SIRI, and a tendency to increase NLR compared to those without SA. In terms of AUC, sensitivity, and specificity, NLR was better than MLR, SIRI, SII, and PLR in distinguishing SA. Non-responders to SSRI treatment showed a significant increase in baseline platelet count and PLR compared to responders with an AUC greater than 0.7. These findings highlight the potential benefit of combining novel and classical hematological indices in predicting depression, suicide attempts and treatment response.

Role of Inflammation in Depressive and Anxiety Disorders, Affect, and Cognition: Genetic and Non-Genetic Findings in the Lifelines Cohort Study

Inflammation is associated with a range of neuropsychiatric symptoms; however, the nature of the causal relationship is unclear. We used complementary non-genetic, genetic risk score (GRS), and Mendelian randomization (MR) analyses to examine whether inflammatory markers are associated with affect, depressive and anxiety disorders, and cognition. We tested in ≈ 55,098 (59% female) individuals from the Dutch Lifelines cohort the concurrent/prospective associations of C-reactive protein (CRP) with: depressive and anxiety disorders; positive/negative affect; and attention, psychomotor speed, episodic memory, and executive functioning. Additionally, we examined the association between inflammatory GRSs (CRP, interleukin-6 [IL-6], IL-6 receptor [IL-6R and soluble IL-6R (sIL-6R)], glycoprotein acetyls [GlycA]) on these same outcomes (Nmax=57,946), followed by MR analysis examining evidence of causality of CRP on outcomes (Nmax=23,268). In non-genetic analyses, higher CRP was associated with a depressive disorder, lower positive/higher negative affect, and worse executive function, attention, and psychomotor speed after adjusting for potential confounders. In genetic analyses, CRPgrs was associated with any anxiety disorder (β = 0.002, p = 0.037) whereas GlycAGRS was associated with major depressive disorder (β = 0.001, p = 0.036). Both CRPgrs (β = 0.006, p = 0.035) and GlycAGRS (β = 0.006, p = 0.049) were associated with greater negative affect. Inflammatory GRSs were not associated with cognition, except slL-6RGRS which was associated with poorer memory (β=-0.009, p = 0.018). There was weak evidence for a CRP-anxiety association using MR (β = 0.12; p = 0.054). Genetic and non-genetic analyses provide consistent evidence for an association between CRP and negative affect. These results suggest that dysregulated immune physiology may impact a broad range of trans-diagnostic affective symptoms.

Analysis of potential diagnostic markers and therapeutic targets for rheumatoid arthritis with comorbid depression immunologic indicators

OBJECTIVE

Depression can impact the severity of rheumatoid arthritis (RA). This study aimed to investigate the relationship between Th1, Th2, Th17, Treg cell subsets, and their associated cytokines (e.g., IL-2, IL-4, IL-6, IL-10, IL-17, IFN-γ, and TNF-α), and the occurrence of RA both with and without comorbid depression. The objective is to identify potential biological markers, therapeutic targets, and the therapeutic effects of RA with comorbid depression.

RESULTS

53 RA patients,46 RA with comorbid depression patients and 51 healthy subjects were included in the RA,RD and HC group from August 2021 and October 2022. Among RA patients, 46.46 % were comorbid with depression. IL-6 concentrations were significantly higher in RD group than in RA group.Comparison between the HC and RA and RD groups revealed that Th1 %, Th17 %, Th1, Th17, Th1/Th2, Th17/Treg and Th1/Treg were significantly higher in the RA and RD groups, and conversely, Th2 %, Treg%, Th2 and Treg were significantly lower than in the HC group.The RA group compared to the RD group found that Th17 %, Th17 and Th17/Treg were significantly higher in the RD group than in the RA group, however, Th1 %, Treg and Th2/Treg were significantly lower than in the RA group. The total HAMD score had a medium strength positive correlation with IL-6.

CONCLUSION

These findings suggest that elevated the autoimmunity status was overactivated in RA with or without depression activates patients, IL-6 may be a predictor of the severity of RA with comorbid depression, IL-6 concentrations and an imbalance in the Th17/Treg may underlie the comorbidity of RA and depression, offering potential targets for therapeutic intervention, prompting further evaluation of the role of indirect inflammatory markers in RA with comorbid depression, highlighting the need for additional research to clarify the complex relationship between inflammation and psychological health.

Periodontitis and Depressive Disorders: The Effects of Antidepressant Drugs on the Periodontium in Clinical and Preclinical Models: A Narrative Review

Background/Objectives: Several psychological conditions, including stress and depression, can adversely affect oral health; in fact, antidepressants, commonly used to treat depressive disorders, may have conflicting effects on the periodontal status of individuals. The aim of this review was to determine the effects of antidepressants on the periodontium. Methods: A literature search was conducted using electronic databases, Pubmed/MEDLINE, Cochrane Library, focusing on the use of antidepressants and their effects on periodontal health in animals or humans. Results: Seventeen articles have been included with the use of amitriptyline (two studies), desipramine (one study), imipramine (two studies), desvenlafaxine (one study), fluoxetine (six studies), venlafaxine (three studies) and tianeptine (two studies). One study evaluated several categories of antidepressants, such as selective serotonin reuptake inhibitors (SSRI), serotonin-norepinephrine reuptake inhibitors (SNRI), tricyclic, atypical and monoamine oxidase inhibitors (MAO). Most trials showed improvements in periodontal health, especially with fluoxetine, but also with imipramine, desipramine, desvenlafaxine and tianeptine; on the contrary, worsening of clinical periodontal indices and increased loss of alveolar bone were reported with venlafaxine. Conclusions: This review suggests that in the presence of comorbidity between periodontitis and depression, pharmacological treatment with SNRIs, SSRIs and mixed antidepressants is associated with improvement in periodontal parameters, except for venlafaxine. Healthcare professionals (especially oral and mental health professionals) should investigate proper adherence to medication therapy in patients with a history of periodontitis and depression. Further clinical trials are needed to confirm these results.

The immune phenotype of perinatal anxiety in an anxiety-focused behavioral intervention program in Pakistan

BACKGROUND

Dysregulation of the immune system has been associated with psychiatric disorders and pregnancy-related complications, such as perinatal depression. However, the immune characteristics specific to perinatal anxiety remain poorly understood. In this study, our goal was to examine specific immune characteristics related to prenatal anxiety within the context of a randomized controlled trial designed to alleviate anxiety symptoms-the Happy Mother - Healthy Baby (HMHB) study in Rawalpindi, Pakistan.

MATERIALS AND METHODS

Pregnant women (n = 117) were followed prospectively in the 1st, 2nd, and 3rd trimesters (T1, T2, T3) and at 6 weeks postpartum (PP6). Each visit included a blood draw and anxiety evaluation (as measured by the anxiety subscale of the Hospital Anxiety and Depression Scale - HADS -using a cutoff ≥ 8). We enrolled both healthy controls and participants with anxiety alone; those with concurrent depression were excluded.

RESULTS

K-means cluster analysis revealed three anxiety clusters: Non-Anxiety, High and Consistent Anxiety, and Decreasing Anxiety. Principal components analysis revealed two distinct clusters of cytokine and chemokine activity. Women within the High and Consistent Anxiety group had significantly elevated chemokine activity across pregnancy (in trimester 1 (β = 0.364, SE = 0.178, t = 2.040, p = 0.043), in trimester 2 (β = 0.332, SE = 0.164, t = 2.020, p = 0.045), and trimester 3 (β = 0.370, SE = 0.179, t = 2.070, p = 0.040) compared to Non-Anxiety group. Elevated chemokine activity was associated with low birthweight (LBW) and small for gestational age (SGA).

CONCLUSION

Our findings reveal a unique pattern of immune dysregulation in pregnant women with anxiety in a Pakistani population and offer preliminary evidence that immune dysregulation associated with antenatal anxiety may be associated with birth outcomes. The dysregulation in this population is distinct from that in our other studies, indicating that population-level factors other than anxiety may play a substantial role in the differences found. (Clinicaltrials.gov # NCT04566861).

Maternal pre-pregnancy diet and prenatal depression: the mediating role of pre-pregnancy weight status and prenatal inflammation

Depression is a common prenatal psychological complication. We aimed to investigate if maternal pre-pregnancy diet can impact prenatal depressive symptoms and the mediating role of pre-pregnancy BMI and inflammation. We used data (N 1141) from the Alberta Pregnancy Outcomes and Nutrition cohort study. We calculated Mediterranean diet adherence (MED) and dietary inflammatory index (DII) scores using data from pre-pregnancy FFQ. In the third-trimester, we assessed depressive symptoms using Edinburgh Postpartum Depression Scale (EPDS) and inflammation through serum C-reactive protein (CRP) levels. BMI was calculated from self-reported pre-pregnancy weight. Race-stratified analyses (white and people of colour) were run. We observed no association between MED or DII tertiles and depressive symptoms. However, white participants in the MED tertile-3 had lower risk of depression (EPDS < 10) compared with tertile-1 (OR = 0·56, 95 % CI, 0·33, 0·95). White individuals in MED tertile-3 had lower BMI (MD = -1·08; 95 % CI, -1·77, -0·39) and CRP (MD = -0·53; 95 % CI, -0·95, -0·11) than tertile-1, and those in DII tertile-2 (MD = 0·44; 95 % CI, 0·03, 0·84) and tertile-3 (MD = 0·42; 95 % CI, 0·01, 0·83) had higher CRP than tertile-1. Among people of colour, neither MED nor DII was associated with BMI or CRP, but BMI was negatively associated with depressive symptoms (β = -0·25, 95 % CI, -0·43, -0·06). We found no association between diet and depressive symptoms through BMI or CRP, in either race. Pre-pregnancy diet might affect the risk of prenatal depression in a race-specific way. Further research is required to explore the racial differences in the association between maternal diet and prenatal depressive symptoms/depression risk.

Inflammation as a mediator between adverse childhood experiences and adult depression: A meta-analytic structural equation model

Exposure to adverse childhood experiences (ACEs) confers a higher risk of developing depression in adulthood, yet the mediation of inflammation remains under debate. To test this model, we conducted a systematic review and two-stage structural equation modelling meta-analysis of studies reporting correlations between ACEs before age 18, inflammatory markers and depression severity in adulthood. Scopus, Pubmed, Medline, PsycInfo, and CINAHL were searched up to 2 October 2023. Twenty-two studies reporting data on C-reactive protein (CRP, n = 12,935), interleukin-6 (IL-6, n = 4108), tumour necrosis factor-α (TNF-α, n = 2256) and composite measures of inflammation (n = 1674) were included. Unadjusted models revealed that CRP (β = 0.003, 95 % LBCI 0.0002 to 0.0068), IL-6 (β = 0.003, 95 % LBCI 0.001 to 0.006), and composite inflammation (β = 0.009, 95 % LBCI 0.004 to 0.018) significantly mediated the association between ACEs and adult depression. The mediation effects no longer survived after adjusting for BMI; however, a serial mediation model revealed that BMI and IL-6 sequentially mediated the association between ACEs and depression (β = 0.002, 95 % LBCI 0.0005 to 0.0046), accounting for 14.59 % and 9.94 % of the variance of IL-6 and depressive symptoms, respectively. Due to the cross-sectional nature of assessment of inflammation and depression findings should be approached with caution; however, results suggest that complex interactions of psychoneuroimmunological and metabolic factors underlie the association between ACEs and adulthood depression.

Multidimensional Religiousness and Spirituality Are Associated With Lower Interleukin-6 and C-Reactive Protein at Midlife: Findings From the Midlife in the United States Study

BACKGROUND

Religiousness and spirituality (R/S) are associated with lower morbidity and mortality, yet the physiological mechanisms underlying these associations are under-studied. Chronic inflammation is a plausible biological mechanism linking R/S to downstream health given the sensitivity of the immune system to the social environment and the role of inflammation in many chronic diseases.

PURPOSE

The purpose of the present study was to examine associations between multiple R/S dimensions and two markers of chronic inflammation, interleukin-6 (IL-6) and C-reactive protein (CRP).

METHODS

In this cross-sectional study, data came from biological subsamples of two cohorts from the Midlife in the United States (MIDUS) Study (combined N = 2,118). Predictors include six R/S measures (service attendance, spirituality, private religious practices, daily spiritual experiences, religious coping, and R/S-based mindfulness). Outcomes include log-transformed IL-6 and CRP. Covariates include age, gender, cohort, race, educational attainment, body mass index (BMI), smoking status, and physical activity.

RESULTS

Older adults, women (vs. men), non-White (vs. White) adults, those with higher BMIs, current smokers, and those not meeting physical activity guidelines had significantly higher IL-6 and CRP. In fully adjusted models, greater spirituality, daily spiritual experiences, religious coping, and R/S-based mindfulness were associated with lower IL-6. Higher spirituality was also associated with lower CRP.

CONCLUSIONS

Many dimensions of R/S may be health protective for adults given their associations with lower levels of chronic inflammation. Findings underscore the importance of examining multiple dimensions of R/S to understand mechanistic pathways.

Allostatic Load and Depression Symptoms in Cancer Survivors: A National Health and Nutrition Examination Survey Study

BACKGROUND

Individuals with cancer often experience stress throughout the cancer trajectory and have a high risk of experiencing depression.

OBJECTIVE

The aim of this study was to examine the relationship between allostatic load (AL), a measure of cumulative stress-related physiologic dysregulation of different body systems, and symptoms of depression in cancer survivors.

METHODS

Participants were 294 adult cancer survivors from the US National Health and Nutrition Examination Survey (NHANES 2007-2018). Allostatic load was measured using 14 indicators representing cardiometabolic risk, glucose metabolism, cardiopulmonary functioning, parasympathetic functioning, and inflammation. Depressive symptoms were measured with the Patient Health Questionnaire-9. The relationship between AL and depressive symptoms was investigated using multiple regression adjusted for diverse sociodemographic and diagnosis variables.

RESULTS

Higher AL was associated with higher depressive symptom scores. The higher risk of depression was concentrated among those survivors in the highest AL quartile, with 21% (95% confidence interval, 11%-32%) of survivors presenting a high risk of depression compared with 8% to 11% of survivors in the lower quartiles. In exploratory analyses, the relationship between AL and depressive symptoms was only significant among survivors with a lower income. In contrast, in survivors in the highest income group, depressive symptoms were lower and unrelated to AL.

CONCLUSION

High AL is associated with more depressive symptoms among cancer survivors.

IMPLICATIONS FOR PRACTICE

Nurses have an important role in identifying psychological distress in cancer patients and survivors. Further research is needed to investigate the usefulness of AL as a marker in the context of cancer follow-up care and screening for psychological distress.