Prevalence of low-grade inflammation in depression: a systematic review and meta-analysis of CRP levels

Metabolic Status Influences Probiotic Efficacy for Depression-PRO-DEMET Randomized Clinical Trial Results

Probiotics may represent a safe and easy-to-use treatment option for depression or its metabolic comorbidities. However, it is not known whether metabolic features can influence the efficacy of probiotics treatments for depression. This trial involved a parallel-group, prospective, randomized, double-blind, controlled design. In total, 116 participants with depression received a probiotic preparation containing Lactobacillus helveticus Rosell®-52 and Bifidobacterium longum Rosell®-175 or placebo over 60 days. The psychometric data were assessed longitudinally at five time-points. Data for blood pressure, body weight, waist circumference, complete blood count, serum levels of C-reactive protein, cholesterol, triglycerides, and fasting glucose were measured at the beginning of the intervention period. There was no advantage of probiotics usage over placebo in the depression score overall (PRO vs. PLC: F(1.92) = 0.58; p = 0.45). However, we found a higher rate of minimum clinically important differences in patients supplemented with probiotics than those allocated to placebo generally (74.5 vs. 53.5%; X2(1,n = 94) = 4.53; p = 0.03; NNT = 4.03), as well as in the antidepressant-treated subgroup. Moreover, we found that the more advanced the pre-intervention metabolic abnormalities (such as overweight, excessive central adipose tissue, and liver steatosis), the lower the improvements in psychometric scores. A higher baseline stress level was correlated with better improvements. The current probiotic formulations may only be used as complementary treatments for depressive disorders. Metabolic abnormalities may require more complex treatments. ClinicalTrials.gov identifier: NCT04756544.

Omega-3 fatty acids for inflamed depression - A match/mismatch study

Despite decades of research on the pathophysiology of depression, the development of new therapeutic interventions has been slow, and no biomarkers of treatment response have been clinically implemented. Several lines of evidence suggest that the clinical and biological heterogeneity among patients with major depressive disorder (MDD) has hampered progress in this field. MDD with low-grade inflammation - "inflamed depression" - is a subtype of depression that may be associated with a superior antidepressant treatment response to anti-inflammatory compounds. Omega-3 fatty acid eicosapentaenoic acid (EPA) has anti-inflammatory properties, and preliminary data suggest that it may be particularly efficacious in inflamed depression. In this study we tested the hypothesis that add-on EPA has greater antidepressant efficacy in MDD patients with high baseline high-sensitivity C-reactive protein (hs-CRP) compared to MDD patients with low hs-CRP. All subjects received 2.2 g EPA, 400 mg docosahexaenoic acid and 800 mg of other fatty acids daily for 8 weeks, added to stable ongoing antidepressant treatment. The primary outcome was change in the 17-item Hamilton Depression Rating Scale (HAMD-17). Patients and raters were blind to baseline hs-CRP status. In an intention-to-treat analysis including all subjects with at least one post baseline visit (n = 101), ahs-CRPcut-off of ≥1 mg/L, but not ≥3 mg/L, was associated with a greater improvement in HAMD-17 total score. In addition to a general antidepressant effect among patients with hs-CRP ≥ 1 mg/L, adjuvant EPA treatment improved symptoms putatively related to inflamed depression such as fatigue and sleep difficulties. This adds to the mounting evidence that delineation of MDD subgroups based on inflammation may be clinically relevant to predict treatment response to anti-inflammatory interventions.

Lifestyle factors and BMI attenuate relationships between biomarkers of inflammation and depressive symptoms and well-being: A cross-sectional study

Background

Mental disorders are a growing public health concern and evidence has linked chronic low-grade inflammation with depression and well-being. Research also suggests that certain modifiable lifestyle factors such as smoking, alcohol use, physical activity, diet quality and BMI are related to psychological health. These may modulate the relationship between low-grade inflammation and mental health conditions. In this study we examined inflammatory biomarker associations with two psychological health scores and investigated whether relationships are influenced by lifestyle factors and BMI.

Methods

This was a cross-sectional study of 1824 middle-to older-aged men and women randomly selected from a large primary care centre. Depressive symptoms and well-being were assessed using the 20-item Centre for Epidemiologic Studies Depression (CES-D) Scale and the World Health Organization-Five (WHO-5) Well-Being Index. Linear regression analyses were performed to examine depression and well-being score relationships with six inflammatory biomarkers, and a composite inflammatory biomarker score, adjusting for demographic characteristics, health conditions, lifestyle factors and BMI.

Results

Depression and well-being score associations with complement component 3 (CES-D only) c-reactive protein, interleukin 6, leptin, white blood cell counts, neutrophils and the inflammatory biomarker score were observed. These relationships survived adjustment for demographic variables and health conditions but were attenuated in models which included lifestyle factors and BMI. In final models, only leptin (β = 0.566, p = 0.018) and inflammatory score (β = 0.137, p = 0.004) associations with the CES-D score remained.

Conclusions

These findings suggest that the relationship between systemic low-grade inflammation and depressive symptoms and well-being may be largely explained by lifestyle factors and adiposity, highlighting the potential importance of promoting a healthy lifestyle in the treatment of depressive disorders.

Assessing causality between chronic obstructive pulmonary disease with depression: A bidirectional Mendelian randomization study

PURPOSE

Our investigation utilized a two-sample Mendelian randomization approach to explore the ambiguous bidirectional relationship between Chronic Obstructive Pulmonary Disease (COPD) and depression, furthering insights from existing observational studies.

METHODS

In this study, we conducted a bidirectional Mendelian randomization using genome-wide association studies (GWAS) datasets. We initially analyzed depression data from the Psychiatric Genomics Consortium and the UK Biobank (n = 500,199), alongside COPD data from the FinnGen Consortium (n = 329,552). The second phase involved comparing depression data from FinnGen (n = 372,472) with COPD data from the UK Biobank (n = 361,194). Our Mendelian analysis employs various methods to guarantee a comprehensive and rigorous investigation.

RESULTS

In the initial analytic phase utilizing the inverse variance weighted (IVW) method, COPD does not significantly contribute to the incidence of depression (IVW odds ratio (OR) = 0.989, 95 % confidence interval (CI) = 0.895 to 1.092, P = 0.824). Conversely, the data suggested a statistically significant association where depression may precipitate the development of COPD, with a notable increase in risk (IVW OR = 1.421, 95 % CI = 1.149 to 1.756, P = 0.001). Subsequent validation through a second-step analysis reinforced the hypothesis that depression elevates the likelihood of COPD onset (IVW OR = 1.002, 95 % CI = 1.0003 to 1.0046, P = 0.028).

CONCLUSION

Our study, utilizing Mendelian randomization analysis, determined that COPD does not escalate the risk of depression. Conversely, our analysis suggests that depression may elevate the risk of developing COPD. This insight underscores the importance of enhancing prevention, screening, and treatment strategies for COPD in individuals with depression.

A multisite feasibility randomized clinical trial of mindfulness-based resilience training for aggression, stress, and health in law enforcement officers

BACKGROUND

Law enforcement officers (LEOs) are exposed to significant stressors that can impact their mental health, increasing risk of posttraumatic stress disorder, burnout, at-risk alcohol use, depression, and suicidality. Compromised LEO health can subsequently lead to aggression and excessive use of force. Mindfulness training is a promising approach for high-stress populations and has been shown to be effective in increasing resilience and improving mental health issues common among LEOs.

METHODS

This multi-site, randomized, single-blind clinical feasibility trial was intended to establish optimal protocols and procedures for a future full-scale, multi-site trial assessing effects of mindfulness-based resilience training (MBRT) versus an attention control (stress management education [SME]) and a no-intervention control, on physiological, attentional, and psychological indices of stress and mental health. The current study was designed to enhance efficiency of recruitment, engagement and retention; optimize assessment, intervention training and outcome measures; and ensure fidelity to intervention protocols. Responsiveness to change over time was examined to identify the most responsive potential proximate and longer-term assessments of targeted outcomes.

RESULTS

We observed high feasibility of recruitment and retention, acceptability of MBRT, fidelity to assessment and intervention protocols, and responsiveness to change for a variety of putative physiological and self-report mechanism and outcome measures.

CONCLUSIONS

Results of this multi-site feasibility trial set the stage for a full-scale, multi-site trial testing the efficacy of MBRT on increasing LEO health and resilience, and on decreasing more distal outcomes of aggression and excessive use of force that would have significant downstream benefits for communities they serve.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03784846 . Registered on December 24th, 2018.

Sleep deprivation-induced anxiety-like behaviors are associated with alterations in the gut microbiota and metabolites

The present study aimed to characterize the gut microbiota and serum metabolome changes associated with sleep deprivation (SD) as well as to explore the potential benefits of multi-probiotic supplementation in alleviating SD-related mental health disorders. Rats were subjected to 7 days of SD, followed by 14 days of multi-probiotics or saline administration. Open-field tests were conducted at baseline, end of SD (day 7), and after 14 days of saline or multi-probiotic gavage (day 21). Metagenomic sequencing was conducted on fecal samples, and serum metabolites were measured by untargeted liquid chromatography tandem-mass spectrometry. At day 7, anxiety-like behaviors, including significant decreases in total movement distance (P = 0.0002) and staying time in the central zone (P = 0.021), were observed. In addition, increased levels of lipopolysaccharide (LPS; P = 0.028) and decreased levels of uridine (P = 0.018) and tryptophan (P = 0.01) were detected in rats after 7 days of SD. After SD, the richness of the gut bacterial community increased, and the levels of Akkermansia muciniphila, Muribaculum intestinale, and Bacteroides caecimuris decreased. The changes in the host metabolism and gut microbiota composition were strongly associated with the anxiety-like behaviors caused by SD. In addition, multi-probiotic supplementation for 14 days modestly improved the anxiety-like behaviors in SD rats but significantly reduced the serum level of LPS (P = 0.045). In conclusion, SD induces changes in the gut microbiota and serum metabolites, which may contribute to the development of chronic inflammatory responses and affect the gut-brain axis, causing anxiety-like behaviors. Probiotic supplementation significantly reduces serum LPS, which may alleviate the influence of chronic inflammation.

IMPORTANCE

The disturbance in the gut microbiome and serum metabolome induced by SD may be involved in anxiety-like behaviors. Probiotic supplementation decreases serum levels of LPS, but this reduction may be insufficient for alleviating SD-induced anxiety-like behaviors.

Annual Research Review: Neuroimmune network model of depression: a developmental perspective

Depression is a serious public health problem, and adolescence is an 'age of risk' for the onset of Major Depressive Disorder. Recently, we and others have proposed neuroimmune network models that highlight bidirectional communication between the brain and the immune system in both mental and physical health, including depression. These models draw on research indicating that the cellular actors (particularly monocytes) and signaling molecules (particularly cytokines) that orchestrate inflammation in the periphery can directly modulate the structure and function of the brain. In the brain, inflammatory activity heightens sensitivity to threats in the cortico-amygdala circuit, lowers sensitivity to rewards in the cortico-striatal circuit, and alters executive control and emotion regulation in the prefrontal cortex. When dysregulated, and particularly under conditions of chronic stress, inflammation can generate feelings of dysphoria, distress, and anhedonia. This is proposed to initiate unhealthy, self-medicating behaviors (e.g. substance use, poor diet) to manage the dysphoria, which further heighten inflammation. Over time, dysregulation in these brain circuits and the inflammatory response may compound each other to form a positive feedback loop, whereby dysregulation in one organ system exacerbates the other. We and others suggest that this neuroimmune dysregulation is a dynamic joint vulnerability for depression, particularly during adolescence. We have three goals for the present paper. First, we extend neuroimmune network models of mental and physical health to generate a developmental framework of risk for the onset of depression during adolescence. Second, we examine how a neuroimmune network perspective can help explain the high rates of comorbidity between depression and other psychiatric disorders across development, and multimorbidity between depression and stress-related medical illnesses. Finally, we consider how identifying neuroimmune pathways to depression can facilitate a 'next generation' of behavioral and biological interventions that target neuroimmune signaling to treat, and ideally prevent, depression in youth and adolescents.

Depressed, stressed, and inflamed: C-reactive protein linked with depression symptoms in midlife women with both childhood and current life stress

To determine whether the relationship between inflammatory factors and clinically significant depression symptoms is moderated by high exposure to adverse childhood experiences and current life stressors in a longitudinal community cohort of midlife women. Methods: Participants from the Penn Ovarian Ageing Study community cohort (age at baseline: M = 45.3 [SD = 3.8]) were included in analyses if they had a blood sample measuring basal inflammatory markers during at least one visit where depression symptom severity and current stressful life events were also assessed (N = 142, average number of visits per participant = 1.75 [SD = 0.92]). Approximately annually over the course of 16 years, participants self-reported depression symptom severity using the Centre for Epidemiologic Studies Depression (CESD) Scale, provided menstrual diaries to determine menopause stage, and contributed blood samples. Residual blood samples were assayed for interleukin (IL)-6, IL 1-beta (IL-1β), tumour necrosis factor alpha (TNF-α), and high sensitivity C-reactive protein (hsCRP). Early life stress was quantified using the Adverse Childhood Experiences questionnaire (low [0-1 experience(s)] versus high [≥ 2 experiences]). Current stressful life events were assessed using a structured interview (low [0-1 events] vs. high [≥ 2 events]). Generalised estimating equation models were used to model associations with the outcome of interest-clinically significant depression symptoms (CESD ≥16)-and risk factors: inflammatory marker levels (log transformed), adverse childhood experiences group, and current life stressors group. Covariates included menopause stage, age at study baseline, body mass index, race, and smoking status. We found a significant three-way interaction between log hsCRP levels, adverse childhood experiences group, and current life stressors group on likelihood of experiencing clinically significant depression symptoms (OR: 4.33; 95% CI: 1.22, 15.46; p = 0.024) after adjusting for covariates. Solely for women with high adverse childhood experiences and with high current life stressors, higher hsCRP was associated with higher odds of having clinically significant depression symptoms (OR: 1.46; 95% CI 1.07, 1.98; p = 0.016). This three-way interaction was not significant for IL-6, IL-1β, or TNF-α. For women in midlife with exposure to high adverse childhood experiences and multiple current life stressors, elevated levels of CRP were uniquely associated with clinically significant depression symptoms. Early life adversity and current life stressors represent identifiable individual risk factors whose negative impact may be curtailed with inventions to target inflammation in midlife women.

Association between hs-CRP and depressive symptoms: a cross-sectional study

Background and aim

High-sensitivity C-reactive protein (hs-CRP) is a sensitive measure of low-grade inflammation and appears superior to conventional blood tests in assessing cardiovascular disease. The purpose of this investigation was to explore the link between high-sensitivity CRP and depressive symptoms among adults.

Methods and results

Multiple logistic regression and smoothed curve fitting were used to investigate the association between hs-CRP and depressive symptoms based on data from the, 2017-2020 National Health and Nutrition Examination Survey (NHANES). Subgroup analyses and interaction tests were used to assess the stability of this relationship across populations. The study comprised 6,293 non-clinical participants, which included 549 individuals with depressive symptoms. The prevalence of depressive symptoms was found to increase with increasing levels of hs-CRP. This trend persisted even after quartetting hs-CRP levels. In the fully adjusted model, each unit increase in hs-CRP was associated with a 10% increase in the odds of depressive symptoms (OR=1.10,95%CI:1.01-1.21). Participants in the highest quartile of hs-CRP had a 39% higher prevalence of depressive symptoms compared to those in the lowest quartile (OR=1.39,95%CI:1.01-1.92). Additionally, this positive correlation was more pronounced in men.

Conclusions

In adult Americans, there exists a positive association between elevated hs-CRP levels and depressive symptoms, with a more prominent manifestation of this association observed in males.

Neural, Anti-Inflammatory, and Clinical Effects of Transauricular Vagus Nerve Stimulation in Major Depressive Disorder: A Systematic Review

BACKGROUND

The discovery of effective treatments for major depressive disorder (MDD) may help target different brain pathways. Invasive vagus nerve stimulation (VNS) is an effective neuromodulation technique for the treatment of MDD; however, the effectiveness of the noninvasive technique, transauricular VNS (taVNS), remains unknown. Moreover, a mechanistic understanding of the neural effects behind its biological and therapeutic effects is lacking. This review aimed to evaluate the clinical evidence and the neural and anti-inflammatory effects of taVNS in MDD.

METHODS

Two searches were conducted using a systematic search strategy reviewed the clinical efficacy and neural connectivity of taVNS in MDD in humans and evaluated the changes in inflammatory markers after taVNS in humans or animal models of depression. A risk of bias assessment was performed in all human studies.

RESULTS

Only 5 studies evaluated the effects of taVNS in patients with depression. Although the studies demonstrated the efficacy of taVNS in treating depression, they used heterogeneous methodologies and limited data, thus preventing the conduct of pooled quantitative analyses. Pooled analysis could not be performed for studies that investigated the modulation of connectivity between brain areas; of the 6 publications, 5 were based on the same experiment. The animal studies that analyzed the presence of inflammatory markers showed a reduction in the level of pro-inflammatory cytokines or receptor expression.

CONCLUSIONS

Data on the clinical efficacy of taVNS in the treatment of MDD are limited. Although these studies showed positive results, no conclusions can be drawn regarding this topic considering the heterogeneity of these studies, as in the case of functional connectivity studies. Based on animal studies, the application of taVNS causes a decrease in the level of inflammatory factors in different parts of the brain, which also regulate the immune system. Therefore, further studies are needed to understand the effects of taVNS in patients with MDD.

Features of immunometabolic depression as predictors of antidepressant treatment outcomes: pooled analysis of four clinical trials

BACKGROUND

Profiling patients on a proposed 'immunometabolic depression' (IMD) dimension, described as a cluster of atypical depressive symptoms related to energy regulation and immunometabolic dysregulations, may optimise personalised treatment.

AIMS

To test the hypothesis that baseline IMD features predict poorer treatment outcomes with antidepressants.

METHOD

Data on 2551 individuals with depression across the iSPOT-D (n = 967), CO-MED (n = 665), GENDEP (n = 773) and EMBARC (n = 146) clinical trials were used. Predictors included baseline severity of atypical energy-related symptoms (AES), body mass index (BMI) and C-reactive protein levels (CRP, three trials only) separately and aggregated into an IMD index. Mixed models on the primary outcome (change in depressive symptom severity) and logistic regressions on secondary outcomes (response and remission) were conducted for the individual trial data-sets and pooled using random-effects meta-analyses.

RESULTS

Although AES severity and BMI did not predict changes in depressive symptom severity, higher baseline CRP predicted smaller reductions in depressive symptoms (n = 376, βpooled = 0.06, P = 0.049, 95% CI 0.0001-0.12, I2 = 3.61%); this was also found for an IMD index combining these features (n = 372, βpooled = 0.12, s.e. = 0.12, P = 0.031, 95% CI 0.01-0.22, I2= 23.91%), with a higher - but still small - effect size compared with CRP. Confining analyses to selective serotonin reuptake inhibitor users indicated larger effects of CRP (βpooled = 0.16) and the IMD index (βpooled = 0.20). Baseline IMD features, both separately and combined, did not predict response or remission.

CONCLUSIONS

Depressive symptoms of people with more IMD features improved less when treated with antidepressants. However, clinical relevance is limited owing to small effect sizes in inconsistent associations. Whether these patients would benefit more from treatments targeting immunometabolic pathways remains to be investigated.

Personality predictors of dementia diagnosis and neuropathological burden: An individual participant data meta-analysis

INTRODUCTION

The extent to which the Big Five personality traits and subjective well-being (SWB) are discriminatory predictors of clinical manifestation of dementia versus dementia-related neuropathology is unclear.

METHODS

Using data from eight independent studies (Ntotal = 44,531; Ndementia = 1703; baseline Mage = 49 to 81 years, 26 to 61% female; Mfollow-up range = 3.53 to 21.00 years), Bayesian multilevel models tested whether personality traits and SWB differentially predicted neuropsychological and neuropathological characteristics of dementia.

RESULTS

Synthesized and individual study results indicate that high neuroticism and negative affect and low conscientiousness, extraversion, and positive affect were associated with increased risk of long-term dementia diagnosis. There were no consistent associations with neuropathology.

DISCUSSION

This multistudy project provides robust, conceptually replicated and extended evidence that psychosocial factors are strong predictors of dementia diagnosis but not consistently associated with neuropathology at autopsy.

HIGHLIGHTS

N(+), C(-), E(-), PA(-), and NA(+) were associated with incident diagnosis. Results were consistent despite self-report versus clinical diagnosis of dementia. Psychological factors were not associated with neuropathology at autopsy. Individuals with higher conscientiousness and no diagnosis had less neuropathology. High C individuals may withstand neuropathology for longer before death.

The therapeutic effects of saikosaponins on depression through the modulation of neuroplasticity: From molecular mechanisms to potential clinical applications

Depression is a major global health issue that urgently requires innovative and precise treatment options. In this context, saikosaponin has emerged as a promising candidate, offering a variety of therapeutic benefits that may be effective in combating depression. This review delves into the multifaceted potential of saikosaponins in alleviating depressive symptoms. We summarized the effects of saikosaponins on structural and functional neuroplasticity, elaborated the regulatory mechanism of saikosaponins in modulating key factors that affect neuroplasticity, such as inflammation, the hypothalamic-pituitary-adrenal (HPA) axis, oxidative stress, and the brain-gut axis. Moreover, this paper highlights existing gaps in current researches and outlines directions for future studies. A detailed plan is provided for the future clinical application of saikosaponins, advocating for more targeted researches to speed up its transition from preclinical trials to clinical practice.

Role of Inflammatory Mechanisms in Major Depressive Disorder: From Etiology to Potential Pharmacological Targets

The involvement of central and peripheral inflammation in the pathogenesis and prognosis of major depressive disorder (MDD) has been demonstrated. The increase of pro-inflammatory cytokines (interleukin (IL)-1β, IL-6, IL-18, and TNF-α) in individuals with depression may elicit neuroinflammatory processes and peripheral inflammation, mechanisms that, in turn, can contribute to gut microbiota dysbiosis. Together, neuroinflammation and gut dysbiosis induce alterations in tryptophan metabolism, culminating in decreased serotonin synthesis, impairments in neuroplasticity-related mechanisms, and glutamate-mediated excitotoxicity. This review aims to highlight the inflammatory mechanisms (neuroinflammation, peripheral inflammation, and gut dysbiosis) involved in the pathophysiology of MDD and to explore novel anti-inflammatory therapeutic approaches for this psychiatric disturbance. Several lines of evidence have indicated that in addition to antidepressants, physical exercise, probiotics, and nutraceuticals (agmatine, ascorbic acid, and vitamin D) possess anti-inflammatory effects that may contribute to their antidepressant properties. Further studies are necessary to explore the therapeutic benefits of these alternative therapies for MDD.

Childhood Maltreatment and Immune Cell Gene Regulation during Adolescence: Transcriptomics Highlight Non-Classical Monocytes

Childhood maltreatment has been repeatedly linked to a higher incidence of health conditions with an underlying proinflammatory component, such as asthma, chronic obstructive pulmonary disease, stroke, and cardiovascular disease. Childhood maltreatment has also been linked to elevated systemic inflammation prior to the onset of disease. However, childhood maltreatment is highly comorbid with other risk factors which have also been linked to inflammation, namely major depression. The present analysis addresses this issue by assessing the association of maltreatment with genome-wide transcriptional profiling of immune cells collected from four orthogonal groups of adolescents (aged 13-17): maltreated and not maltreated in childhood, with and without major depressive disorder. Maltreatment and psychiatric history were determined using semi-structured clinical interviews and cross-validated using self-report questionnaires. Dried whole blood spots were collected from each participant (n = 133) and assayed to determine the extent to which maltreatment in childhood was associated with a higher prevalence of transcriptional activity among differentially expressed genes, specific immune cell subtypes, and up- or down-regulation of genes involved in immune function after accounting for current major depression. Maltreatment was associated with increased interferon regulatory factor (IRF) transcriptional activity (p = 0.03), as well as nuclear factor erythroid-2 related factor 1 (NRF1; p = 0.002) and MAF (p = 0.01) among up-regulated genes, and increased activity of nuclear factor kappa beta (NF-κB) among down-regulated genes (p = 0.01). Non-classical CD16+ monocytes were implicated in both the up- and down-regulated genes among maltreated adolescents. These data provide convergent evidence supporting the role of maltreatment in altering intracellular and molecular markers of immune function, as well as implicate monocyte/macrophage functions as mechanisms through which childhood maltreatment may shape lifelong immune development and function.

Inflammation as an aetiological trigger for depressive symptoms in a prospective cohort of patients with inflammatory bowel disease

OBJECTIVE

Inflammatory bowel disease (IBD) is often comorbid with mood disorders and depressive symptoms. The aetiology of depressive symptoms in IBD, however, remains largely unknown. Consistent with the inflammatory hypothesis of depression, the aim of this study was to explore the prospective associations between inflammatory biomarkers and depressive symptoms in a cohort of IBD patients with and without a previous clinical diagnosis of mood disorder.

METHOD

IBD clinical activity was determined using the Harvey-Bradshaw Index for CD and the Partial Mayo score for UC; serum C-reactive protein (CRP) and faecal calprotectin (fCAL) were used as biomarkers of systemic and intestinal inflammation, respectively. Participants were administered the Hospital Anxiety and Depression Scale-depression (HADS-D) at baseline and 1-year follow-up.

RESULTS

Eighty-four participants (50 ± 16 years; 75% UC and 25% CD) were included in the main analyses. Longitudinal moderated regression models showed that baseline CRP significantly predicted follow-up HADS-D scores among individuals with a previous mood disorder diagnosis (β = 0.843, p < .001), but not among individuals without (β = -0.013, p = .896), after controlling for baseline HADS-D scores, body mass index, IBD phenotype, sex, and perceived stress. Likely due to lower power, results on FCAL (n = 31) were not statistically significant.

CONCLUSION

This study suggests that IBD patients with previous diagnosis of mood disorder may be at higher risk of inflammation-related 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.

C-Reactive Protein (CRP) is Associated With Chronic Pain Independently of Biopsychosocial Factors

Inflammation is linked with chronic pain but the extent to which this relationship is associated with biopsychosocial factors is not known. We investigated relationships between blood C-reactive protein (CRP) and regional chronic pain conditions adjusting for a large range and number of potential confounders. We performed cross-sectional analyses using the UK Biobank (N = 415,567) comparing CRP in people reporting any of 9 types of regional chronic pain with pain-free controls. Using logistic regression modelling, we explored relationships between CRP and the presence of chronic pain, with demographic, socioeconomic, psychological/lifestyle factors, and medical comorbidities as covariates. CRP was higher in chronic pain at any site compared with controls (Females: median [interquartile range] 1.60 mg/L [2.74] vs 1.17 mg/L [1.87], P < .001; Males: 1.44 mg/L [2.12] vs 1.15 mg/L [1.65], P < .001). In males, associations between CRP and all types of chronic pain were attenuated but remained significant after adjustment for biopsychosocial covariates (OR range 1.08-1.49, P ≤ .001). For females, adjusted associations between CRP and pain remained significant for most chronic pain types (OR range 1.07-1.34, P < .001) except for facial pain (OR 1.04, P = .17) and headache (OR 1.02, P = .07)-although these non-significant findings may reflect reduced sample size. The significant association between CRP and chronic pain after adjustment for key biopsychosocial confounders implicates an independent underlying biological mechanism of inflammation in chronic pain. The presence of yet unknown or unmeasured confounding factors cannot be ruled out. Our findings may inform better-targeted treatments for chronic pain. PERSPECTIVE: Using a large-scale dataset, this article investigates associations between chronic pain conditions and blood C-reactive protein (CRP), to evaluate the confounding effects of a range of biopsychosocial factors. CRP levels were higher in those with chronic pain versus controls after adjusting for confounders-suggesting a possible independent biological mechanism.

Dietary inflammatory index and neuropsychiatric disorders

Neuropsychiatric disorders (NPDs) are considered a potential threat to mental health. Inflammation predominantly plays a role in the pathophysiology of NPDs. Dietary patterns are widely postulated to be involved in the physiological response to inflammation. This review aims to discuss the literature on how dietary inflammatory index (DII) is related to inflammation and, consequently, NPDs. After comprehensive scrutiny in different databases, the articles that investigated the relation of DII score and various NPDs and psychological circumstances were included. The association between dietary patterns and mental disorders comprising depression, anxiety, and stress proved the role of a proinflammatory diet in these conditions' exacerbation. Aging is another condition closely associated with DII. The impact of proinflammatory and anti-inflammatory diet on sleep quality indicated related disorders like sleep latency and day dysfunctions among the different populations are in relation with the high DII score. The potential effects of genetic backgrounds, dietary patterns, and the gut microbiome on DII are discussed as well. To plan preventive or therapeutic interventions considering the DII, these factors, especially genetic variations, should be considered as there is a growing body of literature indicating the role of personalized medicine in different NPDs. To the best of our knowledge, there is a limited number of RCTs on this subject, so future research should evaluate the causality via RCTs and look for therapeutic interventions with an eye on personalized medicine using information about DII in NPDs.

Distinct genomic signatures and modifiable risk factors underly the comorbidity between major depressive disorder and cardiovascular disease

Major depressive disorder (MDD) and cardiovascular disease (CVD) are often comorbid, resulting in excess morbidity and mortality. Using genomic data, this study elucidates biological mechanisms, key risk factors, and causal pathways underlying their comorbidity. We show that CVDs share a large proportion of their genetic risk factors with MDD. Multivariate genome-wide association analysis of the shared genetic liability between MDD and atherosclerotic CVD (ASCVD) revealed seven novel loci and distinct patterns of tissue and brain cell-type enrichments, suggesting a role for the thalamus. Part of the genetic overlap was explained by shared inflammatory, metabolic, and psychosocial/lifestyle risk factors. Finally, we found support for causal effects of genetic liability to MDD on CVD risk, but not from most CVDs to MDD, and demonstrated that the causal effects were partly explained by metabolic and psychosocial/lifestyle factors. The distinct signature of MDD-ASCVD comorbidity aligns with the idea of an immunometabolic sub-type of MDD more strongly associated with CVD than overall MDD. In summary, we identify plausible biological mechanisms underlying MDD-CVD comorbidity, as well as key modifiable risk factors for prevention of CVD in individuals with MDD.

Association of hemoglobin-to-red blood cell distribution width ratio and depression in older adults: A cross sectional study

BACKGROUND

The association between hemoglobin-to-red blood cell distribution width ratio (HRR) and the depression in old adults was not clear.

METHODS

We extracted data on depression, general characteristics, lifestyle, medical history, drug use, and blood indicators from the National Health and Nutrition Examination Survey 2005-2018 to investigate the relationship between HRR and depression.

RESULTS

A total of 4141 individuals were evaluated, among whom 266 (6.4 %) were identified as having depression. HRR was significantly lower in the low depression group, and Spearman correlation analysis revealed an inverse association between HRR and depression scores (r = -0.148, P < 0.001). Multiple linear regression showed that HRR was associated with depression after adjusted for general characteristics, life style, medical history, drug use and blood indicators (P = 0.010). ROC analysis demonstrated that in participants with depression, the area under the curve (AUC) for HRR was 0.612, surpassing both Hb(0.586) and RDW(0.401). These findings were statistically significant (P < 0.05).

LIMITATIONS

Only participants aged 65-79 years are selected for this study and this was a cross-sectional study that can only represent an association between HRR and depression, but not a cause-and-effect relationship.

CONCLUSIONS

HRR, being more potent than Hb or RDW, emerges as an independent risk factor for depression. It has the potential to facilitate early depression detection, aiding in the prevention of clinical deterioration or relapses, and could also serve as a viable treatment target.

NLRP3 inflammatory pathway. Can we unlock depression?

Depression holds the title of the largest contributor to worldwide disability, with the numbers expected to continue growing. Currently, there are neither reliable biomarkers for the diagnosis of the disease nor are the current medications sufficient for a lasting response in nearly half of patients. In this comprehensive review, we analyze the previously established pathophysiological models of the disease and how the interplay between NLRP3 inflammasome activation and depression might offer a unifying perspective. Adopting this inflammatory theory, we explain how NLRP3 inflammasome activation emerges as a pivotal contributor to depressive inflammation, substantiated by compelling evidence from both human studies and animal models. This inflammation is found in the central nervous system (CNS) neurons, astrocytes, and microglial cells. Remarkably, dysregulation of the NLRP3 inflammasome extends beyond the CNS boundaries and permeates into the enteric and peripheral immune systems, thereby altering the microbiota-gut-brain axis. The integrity of the brain blood barrier (BBB) and intestinal epithelial barrier (IEB) is also compromised by this inflammation. By emphasizing the central role of NLRP3 inflammasome activation in depression and its far-reaching implications, we go over each area with potential modulating mechanisms within the inflammasome pathway in hopes of finding new targets for more effective management of this debilitating condition.

Peripheral inflammatory markers in melancholic versus non-melancholic depression

BACKGROUND

Peripheral inflammation has been associated with major depression, however there is a paucity of studies examining whether inflammatory profiles differ across depressive subtypes. The current study sought to compare peripheral inflammatory markers in patients with melancholic versus non-melancholic depression and with healthy controls.

METHOD

Eighty outpatients with a current major depressive episode (MDE) were assigned as having a melancholic or a non-melancholic depressive subtype based on clinician diagnosis and the Sydney Melancholic Prototypic Index (SMPI). Participants provided peripheral venous blood from which plasma levels of cytokines and other inflammatory markers (C-reactive protein (CRP), neutrophil/lymphocyte ratio, plasma cytokines) were compared across the two patient groups and also to a group of 81 age-matched healthy controls.

RESULTS

Patients with melancholic and non-melancholic depression demonstrated increased CRP and decreased interferon-gamma (IFN-γ) levels compared to controls. Using clinician diagnosis of subtype, interleukin-12 (IL-12) and interleukin-10 (IL-10) levels were elevated in melancholic patients versus non-melancholic and control groups, with no differences found for the other measured markers of inflammation.

CONCLUSION

Study findings demonstrate shared inflammatory changes across certain inflammatory markers (CRP and IFN-γ) and increases in IL-12 and IL-10 levels specific to melancholic depression. While generally supportive of previous work, our peripheral inflammation findings in melancholic depression are relatively novel and suggest this subgroup may benefit from anti-inflammatory therapies. Further studies are required to replicate these findings.

Microglia and Microbiome-Gut-Brain Axis

The mammalian gut contains a community of microorganisms called gut microbiome. The gut microbiome is integrated into mammalian physiology, contributing to metabolism, production of metabolites, and promoting immunomodulatory actions. Microglia, the brain's resident innate immune cells, play an essential role in homeostatic neurogenesis, synaptic remodeling, and glial maturation. Microglial dysfunction has been implicated in the pathogenesis of several neuropsychiatric disorders. Recent findings indicate that microglia are influenced by the gut microbiome and their derived metabolites throughout life. The pathways by which microbiota regulate microglia have only started to be understood, but this discovery has the potential to provide valuable insights into the pathogenesis of brain disorders associated with an altered microbiome. Here, we discuss the recent literature on the role of the gut microbiome in modulating microglia during development and adulthood and summarize the key findings on this bidirectional crosstalk in selected examples of neuropsychiatric and neurodegenerative disorders. We also highlight some current caveats and perspectives for the field.

Pharmacological anti-inflammatory treatment in children and adolescents with depressive symptoms: A systematic-review and meta-analysis

Growing evidence suggests an association between inflammatory processes and depressive disorders (DD). DD typically emerge during adolescence. Treatment effects of agents with anti-inflammatory properties in youth DD have not been systematically reviewed. Here, the existing evidence on the use of anti-inflammatory drugs (including polyunsaturated fatty acids, nonsteroidal anti-inflammatory drugs, cytokine inhibitors, statins, pioglitazone, corticosteroids, and minocycline or modafinil) in children and adolescents with DD was synthesized using meta-analysis. The PROSPERO preregistered search yielded 22 records meeting search criteria. Of these, data from 19 primary studies (n = 1366 subjects) were subjected to meta-analysis. A significant but small effect in favor of anti-inflammatory agents in reducing depressive symptoms in youth with DD was found (SMD = -0.29, 95 % CI = -0.514; -0.063, p = 0.01). Post-hoc analyzes of drug subclasses found a significant effect of omega-3 fatty acids in reducing depressive symptoms. Results underline the importance to consider inflammatory pathways in the supplemental treatment of youth with DD. Further research is warranted, to clarify if anti-inflammatory agents are only effective in a subpopulation of patients (inflammatory biotype of depression in youth) and/or to alleviate specific symptom domains of depression (e.g., cognitive symptoms).

Plasma cytokine and growth factor response to acute psychosocial stress in major depressive disorder

BACKGROUND

Pro-inflammatory cytokines such as interleukin (IL)-6 and tumor necrosis factor (TNF)-α are elevated in response to psychosocial stress; however, less is known about other inflammatory markers.

METHODS

We explored response to the Trier Social Stress Test (TSST) of 16 cytokines and growth factors in patients with major depressive disorder (MDD, n = 12) vs. healthy volunteers (HV, n = 16). Outcomes were baseline and post-stress levels estimated by area under the curve (AUCi) and peak change over 3 timepoints. We also explored correlations between biomarkers and clinical characteristics.

RESULTS

Baseline concentrations were higher in MDD for platelet-derived growth factor (PDGF)-AB/BB (p = 0.037, d = 0.70), granulocyte-macrophage colony-stimulating factor (GM-CSF, p = 0.033, d = 0.52), and IL-8 (p = 0.046, d = 0.74). After TSST, AUCi was higher in MDD for GM-CSF (p = 0.003, d = 1.21), IL-5 (p = 0.014, d = 1.62), and IL-27 (p = 0.041, d = 0.74). In MDD, depression severity correlated positively with soluble CD40L (sCD40L) for AUCi (Spearman's ρ = 0.76, p = 0.004) and with baseline vascular endothelial growth factor A (VEGFA, r = 0.85, p < 0.001), but negatively with baseline monokine induced by gamma interferon (MIG, aka CXCL9; r = -0.77, p = 0.003).

CONCLUSIONS

Effect sizes were robust in this exploratory study, although interpretation of the results must be cautious, given small sample size and multiple comparisons. Differential study of stress-induced biomarkers may have important ramifications for MDD treatment.

Inflammation in Posttraumatic Stress Disorder: Dysregulation or Recalibration?

Despite ample experimental data indicating a role of inflammatory mediators in the behavioral and neurobiological manifestations elicited by exposure to physical and psychologic stressors, causative associations between systemic low-grade inflammation and central nervous system inflammatory processes in posttraumatic stress disorder (PTSD) patients remain largely conceptual. As in other stress-related disorders, pro-inflammatory activity may play an equivocal role in PTSD pathophysiology, one that renders indiscriminate employment of anti-inflammatory agents of questionable relevance. In fact, as several pieces of preclinical and clinical research convergingly suggest, timely and targeted potentiation rather than inhibition of inflammatory responses may actually be beneficial in patients who are characterized by suppressed microglia function in the face of systemic low-grade inflammation. The deleterious impact of chronic stress-associated inflammation on the systemic level may, thus, need to be held in context with the - often not readily apparent - adaptive payoffs of low-grade inflammation at the tissue level.

Endocrinological Treatment Targets for Depressive Disorder

Depressive disorder exhibits heterogeneity in clinical presentation, progression, and treatment outcomes. While conventional antidepressants based on the monoamine hypothesis benefit many patients, a significant proportion remains unresponsive or fails to fully recover. An individualized integrative treatment approach, considering diverse pathophysiologies, holds promise for these individuals. The endocrine system, governing physiological regulation and organ homeostasis, plays a pivotal role in central nervous system functions. Dysregulations in endocrine system are major cause of depressive disorder due to other medical conditions. Subtle endocrine abnormalities, such as subclinical hypothyroidism, are associated with depression. Conversely, depressive disorder correlates with endocrine-related biomarkers. Fluctuations in sex hormone levels related to female reproduction, elevate depression risk in susceptible subjects. Consequently, extensive research has explored treatment strategies involving the endocrine system. Treatment guidelines recommend tri-iodothyronine augmentation for resistant depression, while allopregnanolone analogs have gained approval for postpartum depression, with ongoing investigations for broader depressive disorders. This book chapter will introduce the relationship between the endocrine system and depressive disorders, presenting clinical findings on neuroendocrinological treatments for depression.

Association between psychosocial factors and C-reactive protein across income, race, and sex

OBJECTIVE

A health disparity is a health difference that adversely affects disadvantaged populations, and thus could plausibly be due to social factors. Biopsychosocial processes that contribute to health disparities are not well-understood. Establishing whether candidate biomarkers are similarly associated with biologically relevant psychosocial constructs across health disparity groups is a current gap in our understanding.

METHOD

This study examined associations between perceived stress, depressive symptoms, and social support with C-reactive protein (CRP) and whether associations varied by race, sex, or income in 24,395 Black and White adults aged 45 years or older from the REGARDS population-based national cohort.

RESULTS

The association between depressive symptoms and CRP was slightly larger at higher (vs. lower) income levels and larger for men (vs. women) but did not vary by race. Associations between stress and CRP and social support and CRP were not moderated by income, race, or sex. An interaction between race and income, evidenced that higher income was more strongly associated with lower CRP in White participants compared to Black participants, consistent with the idea of "diminishing returns" of income for the health of Black Americans.

CONCLUSIONS

Basic associations between these psychosocial factors and CRP are small and generally similar across income, race, and sex. Black and lower-income Americans likely evidence higher CRP due to greater exposure to psychosocial risk factors rather than increased biological vulnerability to these exposures. Additionally, given small associations, CRP should not be used as a proxy for the construct of psychosocial stress. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Association between psoriasis and dementia: A systematic review

INTRODUCTION

Risk factors for dementia include genetic factors, aging, environmental factors, certain diseases, and unhealthy lifestyle; most types of dementia share a common chronic systemic inflammatory phenotype. Psoriasis is also considered to be a chronic systemic inflammatory disease. It has been suggested that psoriasis may also contribute to the risk of dementia. The aim of this study was to systematically review the literature on the association between psoriasis and dementia.

DEVELOPMENT

Articles were selected according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We searched the PubMed and Web of Science databases to identify articles published in peer-reviewed journals and studying the association between psoriasis and dementia. Studies meeting the inclusion criteria were reviewed. We used the Newcastle-Ottawa Scale to assess the quality of each study. After applying the inclusion and exclusion criteria, we included 8 studies for review, 3 of which were found to present a higher risk of bias. Six of the 8 studies supported the hypothesis that prior diagnosis of psoriasis increases the risk of dementia; one study including only a few cases reported that psoriasis decreased the risk of dementia, and one study including relatively young patients found no significant association between psoriasis and the risk of dementia.

CONCLUSION

Most studies included in this review supported the hypothesis that psoriasis constitutes a risk factor for dementia. However, well-designed stratified cohort studies assessing both psoriasis severity and treatment status are still required to determine the real effect of psoriasis on the risk of dementia and its subtypes.

Navigating the Intersection of Technology and Depression Precision Medicine

This chapter primarily focuses on the progress in depression precision medicine with specific emphasis on the integrative approaches that include artificial intelligence and other data, tools, and technologies. After the description of the concept of precision medicine and a comparative introduction to depression precision medicine with cancer and epilepsy, new avenues of depression precision medicine derived from integrated artificial intelligence and other sources will be presented. Additionally, less advanced areas, such as comorbidity between depression and cancer, will be examined.

Association between coffee consumption and high C-reactive protein levels in Korean adults

The findings of studies investigating the relationship between coffee consumption and C-reactive protein (CRP) levels have been inconsistent, and few researchers considered the type of coffee. We examined the association between coffee consumption and high CRP levels, using data from the Korea National Health and Nutrition Examination Survey, 2016-2018, with 9337 adults aged 19-64 years. A 24-h diet recall was used to assess diet, including the amount and type of coffee consumed. We classified coffee into black coffee and coffee with sugar and/or cream (non-drinkers, or ≤ 1, 2-3, > 3 cups/d) and used multivariable logistic regression models with high CRP levels (≥ 2·2 mg/l). After the adjustment for potential confounders, 2-3 cups/d of coffee consumption were inversely associated with high CRP levels, compared with no consumption (OR = 0·83, 95 % CI 0·69, 0·99). By type of coffee, the inverse association was stronger in subjects consuming black coffee (OR = 0·61, 95 % CI 0·45, 0·84), while the inverse association was much weaker in those consuming coffee with sugar and/or cream (OR = 0·92, 95 % CI 0·74, 1·14). By sex, the inverse association of 2-3 cups of black coffee was found both in men (OR = 0·65, 95 % CI 0·41, 1·03) and women (OR = 0·55, 95 % CI 0·36, 0·83). More than three cups/d of heavy coffee consumption were not significantly associated with high CRP levels. Our findings indicate that moderate black coffee consumption of 2-3 cups/d is inversely associated with high CRP levels in Korean adults. Further prospective studies are warranted to provide definitive evidence.

The causal role of C-reactive protein and interleukin-6 on anxiety and depression symptoms and life satisfaction: Mendelian randomisation analyses in the HUNT study

BACKGROUND

Serum levels of C-reactive protein (CRP) and interleukin-6 (IL-6) have been associated with anxiety and depression in cross-sectional and Mendelian randomisation studies, but results regarding the effect size and direction have been mixed. A recent Mendelian Randomisation (MR) study suggested that CRP may decrease and IL-6 may increase anxiety and depression symptoms.

METHODS

Among 68 769 participants of the population-based Trøndelag Health Study (HUNT), we performed cross-sectional observational and one-sample MR analyses of serum CRP and two-sample MR analysis of serum IL-6. The main outcomes were symptoms of anxiety and depression assessed using the Hospital Anxiety and Depression Scale (HADS) and life satisfaction assessed using a seven-level ordinal questionnaire where higher scores indicate lower life satisfaction.

RESULTS

In cross-sectional observational analyses, a doubling in serum CRP level was associated with 0.27% (95% CI -0.20 to 0.75) difference in HADS depression score (HADS-D), -0.77% (95% CI -1.24 to -0.29) difference in HADS anxiety score (HADS-A) and -0.10% (95% CI -0.41 to 0.21) difference in life satisfaction score. In one-sample MR analyses, a doubling in serum CRP was associated with 2.43% (95% CI -0.11 to 5.03) higher HADS-D, 1.94% (95% CI -0.58 to 4.52) higher HADS-A, and 2.00% (95% CI 0.45 to 3.59) higher life satisfaction score. For IL-6, causal point estimates were in the opposite direction, but imprecise and far from conventional criteria for statistical significance.

CONCLUSIONS

Our results do not support a major causal role of serum CRP on anxiety and depression symptoms and life satisfaction, but provides weak evidence that serum CRP may modestly increase anxiety and depression symptoms and reduce life satisfaction. Our findings do not support the recent suggestion that serum CRP may lower anxiety and depression symptoms.

Major depressive disorder as a neuro-immune disorder: Origin, mechanisms, and therapeutic opportunities

Notwithstanding advances in understanding the pathophysiology of major depressive disorder (MDD), no single mechanism can explain all facets of this disorder. An expanding body of evidence indicates a putative role for the inflammatory response. Several meta-analyses showed an increase in systemic peripheral inflammatory markers in individuals with MDD. Numerous conditions and circumstances in the modern world may promote chronic systemic inflammation through mechanisms, including alterations in the gut microbiota. Peripheral cytokines may reach the brain and contribute to neuroinflammation through cellular, humoral, and neural pathways. On the other hand, antidepressant drugs may decrease peripheral levels of inflammatory markers. Anti-inflammatory drugs and nutritional strategies that reduce inflammation also could improve depressive symptoms. The present study provides a critical review of recent advances in the role of inflammation in the pathophysiology of MDD. Furthermore, this review discusses the role of glial cells and the main drivers of changes associated with neuroinflammation. Finally, we highlight possible novel neurotherapeutic targets for MDD that could exert antidepressant effects by modulating inflammation.

Pro-inflammatory markers are associated with response to sequential pharmacotherapy in major depressive disorder: a CAN-BIND-1 report

OBJECTIVE

There is limited literature on associations between inflammatory tone and response to sequential pharmacotherapies in major depressive disorder (MDD).

METHODS

In a 16-week open-label clinical trial, 211 participants with MDD were treated with escitalopram 10-20 mg daily for 8 weeks. Responders continued escitalopram while non-responders received adjunctive aripiprazole 2-10 mg daily for 8 weeks. Plasma levels of pro-inflammatory markers-C-reactive protein, interleukin (IL)-1β, IL-6, IL-17, interferon-gamma (IFN)-Γ, tumor necrosis factor (TNF)-α, and Chemokine C-C motif ligand-2 (CCL-2)-measured at baseline, and after 2, 8 and 16 weeks were included in logistic regression analyzes to assess associations between inflammatory markers and treatment response.

RESULTS

Pre-treatment IFN-Γ and CCL-2 levels were significantly associated with a lower of odds of response to escitalopram at 8 weeks. Increases in CCL-2 levels from weeks 8 to 16 in escitalopram non-responders were significantly associated with higher odds of non-response to adjunctive aripiprazole at week 16.

CONCLUSION

Higher pre-treatment levels of IFN-Γ and CCL-2 were associated with non-response to escitalopram. Increasing levels of these pro-inflammatory markers may be associated with non-response to adjunctive aripiprazole. These findings require validation in independent clinical populations.

Navigating the Complexities of Traumatic Encephalopathy Syndrome (TES): Current State and Future Challenges

Chronic traumatic encephalopathy (CTE) is a unique neurodegenerative disease that is associated with repetitive head impacts (RHI) in both civilian and military settings. In 2014, the research criteria for the clinical manifestation of CTE, traumatic encephalopathy syndrome (TES), were proposed to improve the clinical identification and understanding of the complex neuropathological phenomena underlying CTE. This review provides a comprehensive overview of the current understanding of the neuropathological and clinical features of CTE, proposed biomarkers of traumatic brain injury (TBI) in both research and clinical settings, and a range of treatments based on previous preclinical and clinical research studies. Due to the heterogeneity of TBI, there is no universally agreed-upon serum, CSF, or neuroimaging marker for its diagnosis. However, as our understanding of this complex disease continues to evolve, it is likely that there will be more robust, early diagnostic methods and effective clinical treatments. This is especially important given the increasing evidence of a correlation between TBI and neurodegenerative conditions, such as Alzheimer's disease and CTE. As public awareness of these conditions grows, it is imperative to prioritize both basic and clinical research, as well as the implementation of necessary safe and preventative measures.

Mendelian randomization studies of depression: evidence, opportunities, and challenges

BACKGROUND

Major depressive disorder (MDD) poses a significant social and economic burden worldwide. Identifying exposures, risk factors, and biological mechanisms that are causally connected to MDD can help build a scientific basis for disease prevention and development of novel therapeutic approaches.

METHODS

In this systematic review, we assessed the evidence for causal relationships between putative causal risk factors and MDD from Mendelian randomization (MR) studies, following PRISMA. We assessed methodological quality based on key elements of the MR design: use of a full instrumental variable analysis and validation of the three key MR assumptions.

RESULTS

We included methodological details and results from 52 articles. A causal link between lifestyle, metabolic, inflammatory biomarkers, particular pathological states and MDD is supported by MR investigations, although results for each category varied substantially.

CONCLUSIONS

While this review shows how MR can offer useful information for examining prospective treatment targets and better understanding the pathophysiology of MDD, some methodological flaws in the existing literature limit reliability of results and probably underlie their heterogeneity. We highlight perspectives and recommendations for future works on MR in psychiatry.

Integrating Metabolomics and Network Pharmacology to Explore the Mechanism of Xiao-Yao-San in the Treatment of Inflammatory Response in CUMS Mice

Depression can trigger an inflammatory response that affects the immune system, leading to the development of other diseases related to inflammation. Xiao-Yao-San (XYS) is a commonly used formula in clinical practice for treating depression. However, it remains unclear whether XYS has a modulating effect on the inflammatory response associated with depression. The objective of this study was to examine the role and mechanism of XYS in regulating the anti-inflammatory response in depression. A chronic unpredictable mild stress (CUMS) mouse model was established to evaluate the antidepressant inflammatory effects of XYS. Metabolomic assays and network pharmacology were utilized to analyze the pathways and targets associated with XYS in its antidepressant inflammatory effects. In addition, molecular docking, immunohistochemistry, Real-Time Quantitative Polymerase Chain Reaction (RT-qPCR), and Western Blot were performed to verify the expression of relevant core targets. The results showed that XYS significantly improved depressive behavior and attenuated the inflammatory response in CUMS mice. Metabolomic analysis revealed the reversible modulation of 21 differential metabolites by XYS in treating depression-related inflammation. Through the combination of liquid chromatography and network pharmacology, we identified seven active ingredients and seven key genes. Furthermore, integrating the predictions from network pharmacology and the findings from metabolomic analysis, Vascular Endothelial Growth Factor A (VEGFA) and Peroxisome Proliferator-Activated Receptor-γ (PPARG) were identified as the core targets. Molecular docking and related molecular experiments confirmed these results. The present study employed metabolomics and network pharmacology analyses to provide evidence that XYS has the ability to alleviate the inflammatory response in depression through the modulation of multiple metabolic pathways and targets.

The Effect of Antidepressant Treatment on Neurocognitive Functions, Redox and Inflammatory Parameters in the Context of COVID-19

Inflammation is an important component of the etiopathology of depression that uses oxidative and nitrosative stress (O&NS) and elevated inflammatory markers. SARS-CoV-2 infection is also associated with abnormal inflammatory processes, which may impair effective treatment of depression in COVID-19 survivors. In the presented study, thirty-three hospitalized patients with major depressive disorder (MDD) were started on antidepressant treatment, and twenty-one were re-evaluated after 4-6 weeks. The control group consisted of thirty healthy volunteers. All participants underwent neuropsychiatric evaluation, biochemical blood and urine analyses. The results of the research demonstrated positive correlations of the Hamilton Depression Rating Scale (HAM-D) scores with serum catalase (CAT) and urinary S-Nitrosothiols levels, and the Beck Depression Inventory (BDI) scores with serum reduced glutathione (GSH) and superoxide dismutase (SOD) levels. Depressed patients with a history of COVID-19 prior to the treatment had higher urinary nitric oxide (NO) levels and lower serum glutathione peroxidase (GPx) levels. In the control group, COVID-19 survivors had higher levels of urinary N-formylkynurenine (NFK). Our results suggest that the antidepressant treatment has a modulating effect on O&NS, reduces depressive symptoms and improves cognitive functions The present study does not indicate that clinical response to antidepressant treatment is associated with COVID-19 history and baseline SARS-CoV-2 antibody levels. Nevertheless, further research in this area is needed to systematize antidepressant treatment in COVID-19 survivors.

Emotional states predict cellular immune system activity under conditions of life as it is lived: A multivariate time-series analysis approach

The relationship between emotional states and immune system activity is characterized by bidirectional influences; however, limited information is available regarding the temporal dynamics of these effects. The goal of this investigation was to examine how these psychoimmunological interdependencies unfold over time under conditions of "life as it is lived". For this purpose, three healthy women collected their entire urine over a period of approximately two months at 12-h intervals (8 am-8 pm, 8 pm-8 am), resulting in a total of 112 to 126 consecutive measurements per subject. In addition, among other regular psychological assessments, the subjects completed the EWL-60-S, an emotional state questionnaire, each morning and evening. To assess the extent of T-helper type 1 immune activation, the neopterin per creatinine concentration was measured in the urine samples using high-pressure liquid chromatography. The dynamic relationships between the time series of the six emotional states (performance-related activity, general inactivity, extraversion/introversion, general feeling of comfort, emotional irritation, anxiety/depressiveness) and urinary neopterin levels were estimated in vector-autoregressive models and evaluated using Granger-causality tests, impulse-response functions and forecast error variance decompositions. The findings showed that emotional states explained up to 20% of the variance of urinary neopterin per creatinine levels, whereby most of the effects occurred within a period of approximately three days. Across all subjects, increases in anxiety/depressiveness and extraversion led to increases in neopterin levels, while a general feeling of comfort led to decreases in neopterin. These results emphasize the importance of the interdependencies between emotional states and immune system activity and showcase the potential that intensive longitudinal study designs offer for psychoneuroimmunology.

Associations of serum cortisol and inflammatory marker features with depression and anxiety in young women with gynecologic cancer

PURPOSE

Serum cortisol and inflammatory markers may play a role in depression and anxiety, but little is known about whether various features of serum cortisol and inflammatory markers have different associations with depression and anxiety. This study examines the associations of serum cortisol and inflammatory marker features with depression and anxiety in young women with gynecologic cancer.

METHODS

Sixty-four young women with gynecologic cancer, aged 15-39 years, were recruited in a tertiary general hospital and a tertiary hospital specializing in oncology in China from May to December 2021. The Hospital Anxiety and Depression Scale was used to evaluate depression and anxiety. Blood samples were taken at 8 am, 4 pm, and 10 pm on the same day to examine the various features (average, variability, and diurnal patterns) of serum cortisol and inflammatory markers, namely C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α).

RESULTS

Young women with gynecologic cancer who reported depression/anxiety had significantly higher average levels of serum cortisol, IL-6 and TNF-α than those who did not. The dysregulations in the diurnal patterns of serum cortisol and IL-6 were associated with depression and anxiety. Serum cortisol levels were significantly higher in the depression/anxiety group at 10 pm. Depression and anxiety were associated with elevated levels of IL-6 and TNF-α at each time point.

CONCLUSION

This study revealed various associations of serum cortisol and inflammatory marker features with depression and anxiety in young women with gynecologic cancer. Further research is needed to understand the role of serum cortisol and inflammatory marker features in the progression of depression and anxiety.

Abdominal obesity mediates the causal relationship between depression and the risk of gallstone disease: retrospective cohort study and Mendelian randomization analyses

OBJECTIVE

Our study aimed to explore the causal effect of depression on the risk of gallstone disease, and the mediation effects of metabolic traits.

METHODS

A retrospective cohort study on Chinese elderly from the Dongfeng-Tongji cohort (including 18,141 individuals) was conducted to estimate the adverse effect of probable depression on the risk of gallstone disease. Two-sample Mendelian randomization was performed in European and East-Asian ancestries, to verify the causal relationship between major depression and gallstone disease. We further applied two-step Mendelian randomization to explore the mediation effects of metabolic traits.

RESULTS

In the cohort study, probable depression was associated with an increased risk of gallstone disease within 5 years, with RR (95% CI) of 1.33 (1.12, 1.58) in multivariable regression, and 1.34 (1.11, 1.61) following propensity score weighting. Bidirectional Mendelian randomization in European ancestry revealed a positive causal effect (OR: 1.21; 95% CI: 1.07 to 1.37) of genetically predicted major depression liability on gallstone disease, based on the inverse variance weighted method. Little evidence was presented from other complementary approaches, and the analysis in East-Asian ancestry (IVW estimated OR: 1.03; 95% CI: 0.92 to 1.15). The indirect effect via waist circumference and HDL-C were 1.06 (95% CI: 1.02 to 1.10) and 1.01 (95% CI: 1.00 to 1.01) respectively, which mediated 25.8% and 3.78% of the causal relationship.

CONCLUSIONS

Our study suggested a higher risk of gallstone disease in the population with probable depression, while the two-sample Mendelian randomization provided weak evidence for the causal relationship, which was moderately mediated by abdominal obesity.

Biological markers of sex-based differences in major depressive disorder and in antidepressant response

Major depressive disorder (MDD) presents different clinical features in women and men, with women being more affected and responding differently to antidepressant treatment. Specific molecular mechanisms underlying these differences are not well studied and this narrative review aims at providing an overview of the neurobiological features underlying sex-differences in biological systems involved in MDD pathophysiology and response to antidepressant treatment, focusing on human studies. The majority of the reviewed studies were performed through candidate gene approaches, focusing on biological systems involved in MDD pathophysiology, including the stress response, inflammatory and immune, monoaminergic, neurotrophic, gamma-aminobutyric acid and glutamatergic, and oxytocin systems. The influence of the endocrine system and sex-specific hormone effects are also discussed. Genome, epigenome and transcriptome-wide approaches are less frequently performed and most of these studies do not focus on sex-specific alterations, revealing a paucity of omics studies directed to unravel sex-based differences in MDD. Few studies about sex-related differences in antidepressant treatment response have been conducted, mostly involving the inflammatory system, with less evidence on the monoaminergic system and sparse evidence in omics approaches. Our review covers the importance of accounting for sex-differences in research, optimizing patient stratification for a more precise diagnostic and individualized treatment for women and men.

Predictors of successful anti-inflammatory drug trials in patients with schizophrenia: A meta-regression and critical commentary

Given evidence pointing toward a role for immune dysregulation in the pathogenesis of schizophrenia, anti-inflammatory agents are promising adjunctive treatments that have potential to support a causal relationship for inflammation and psychopathology and lead to novel treatments for individuals. Indeed, previous meta-analyses have demonstrated small-to-medium effect sizes (ES) in favor of various anti-inflammatory agents, though there is significant heterogeneity and challenges in the interpretation of this literature. Identifying predictors, including sociodemographic variables, trial duration, and/or symptoms themselves, of successful anti-inflammatory trials may help identify which patients who might benefit from these compounds. We performed a meta-regression analysis of 63 adjunctive anti-inflammatory trial arms (2232 patients randomized to adjunctive anti-inflammatory agents and 2207 patients randomized to placebo).Potential predictors of effect size estimates for changes in psychopathology scores from baseline to endpoint included geography, trial duration, sample size, age, sex, race, smoking, body mass index, illness duration, age of onset of psychosis, study quality score and psychopathology scores (total and subscale) at baseline. Geography (β = 0.31, p = 0.011), smaller sample size (β = 0.33, p = 0.009), and higher study quality score (β = 0.44, p < 0.001) were significant predictors of larger ES estimates for change in total psychopathology in favor of anti-inflammatory agents. Smaller sample size (β = 0.37, p = 0.034) and higher study quality score (β = 0.55, p = 0.003) were significant predictors of larger ES estimates for change in negative psychopathology in favor of anti-inflammatory agents. Higher study quality score (β = 0.46, p = 0.019) was a significant predictor of larger ES estimates for change in general psychopathology in favor of anti-inflammatory agents. These findings should be interpreted with caution given concerns of publication bias regarding the geographic differences and small study effects. The lack of an association with other demographic variables should be seen as a primary limitation of the literature that needs to be considered in future studies. The association with study quality score suggests that future anti-inflammatory trials must consider demographic variables known to be associated with inflammation (e.g., BMI and smoking) and evidence of increased baseline inflammation should be incorporated in study design. Moreover, evidence of target engagement and endpoints thoughts to be associated with increased inflammation should be considered as well.

Purpose in life and markers of immunity and inflammation: Testing pathways of episodic memory

OBJECTIVE

This prospective cohort study examines whether purpose in life is associated with markers of immunity and inflammation and tests these markers as mediators between purpose and episodic memory.

METHODS

Participants from the Venous Blood Study of the Health and Retirement Study reported on their purpose in life, had their blood assayed for markers of immunity and inflammation, and were administered an episodic memory task (N = 8999). Regression analyses tested the association between purpose and each marker. Prospective mediation analyses (N = 6092) tested whether these markers measured in 2016 were mediators between purpose measured in 2012/2014 and episodic memory measured in 2018.

RESULTS

Higher purpose in life was associated with lower neutrophil counts (β = -0.08, p < .001), lower ratio of neutrophils/lymphocytes (β = -0.05, p < .001), and lower systemic immune inflammation index (β = -0.04, p < .001); purpose was unrelated to monocyte, platelet, and lymphocyte counts or the ratio of platelets/lymphocytes (all ns). Purpose was associated negatively with c-reactive protein (β = -0.07, p < .001), Interleukin-6 (β = -0.08, p < .001), Interleukin-10 (β = -0.07, p < .001), Interleukin-1ra (β = -0.08, p < .001), and soluble Tumor Necrosis Factor Receptor 1 (sTNFR1; β = -0.10, p < .001); purpose was unrelated to Transforming Growth Factor beta 1. These associations were largely not moderated by age, sex, race, ethnicity, and education. Lower neutrophils, Interleukin-6, and sTNFR1 were associated prospectively with better episodic memory and mediated the association between purpose and episodic memory.

CONCLUSION

Purpose in life is associated with markers of immunity and inflammation, some of which are one mechanism in the pathway between purpose and healthier episodic memory.

Psilocybin induces acute and persisting alterations in immune status in healthy volunteers: An experimental, placebo-controlled study

Patients characterized by stress-related disorders such as depression display elevated circulating concentrations of pro-inflammatory cytokines and a hyperactive HPA axis. Psychedelics are demonstrating promising results in treatment of such disorders, however the mechanisms of their therapeutic effects are still unknown. To date the evidence of acute and persisting effects of psychedelics on immune functioning, HPA axis activity in response to stress, and associated psychological outcomes is preliminary. To address this, we conducted a placebo-controlled, parallel group design comprising of 60 healthy participants who received either placebo (n = 30) or 0.17 mg/kg psilocybin (n = 30). Blood samples were taken to assess acute and persisting (7 day) changes in immune status. Seven days' post-administration, participants in each treatment group were further subdivided: 15 underwent a stress induction protocol, and 15 underwent a control protocol. Ultra-high field (7-Tesla) magnetic resonance spectroscopy was used to assess whether acute changes in glutamate or glial activity were associated with changes in immune functioning. Finally, questionnaires assessed persisting self-report changes in mood and social behavior. Psilocybin immediately reduced concentrations of the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α), while other inflammatory markers (interleukin (IL)- 1β, IL-6, and C-reactive protein (CRP)) remained unchanged. Seven days later, TNF-α concentrations returned to baseline, while IL-6 and CRP concentrations were persistently reduced in the psilocybin group. Changes in the immune profile were related to acute neurometabolic activity as acute reductions in TNF-α were linked to lower concentrations of glutamate in the hippocampus. Additionally, the more of a reduction in IL-6 and CRP seven days after psilocybin, the more persisting positive mood and social effects participants reported. Regarding the stress response, after a psychosocial stressor, psilocybin did not significantly alter the stress response. Results are discussed in regards to the psychological and therapeutic effects of psilocybin demonstrated in ongoing patient trials.

The incidence of adhesive capsulitis and COVID-19 pandemic effect

Background

There are multiple pieces of evidence in the literature that coronavirus disease 2019 (COVID-19) has a pronounced effect on physiological health. There is little existing literature that has studied the pandemic's impact on adhesive capsulitis (AC) incidence. This study aimed to compare the incidence of primary AC before and during the pandemic.

Methods

A retrospective cohort study was done to establish the incidence of primary AC during the COVID-19 pandemic, from March 2020 to March 2021, the pandemic period, and from March 2019 to March 2020, the control period. During these periods, all patients diagnosed with primary AC were included. Patients were also categorized into three different treatment groups according to corticosteroid injection status (none, 1 injection, and 2 injections). The waiting time for the appointment was calculated as a possible confounding factor. Statistical analysis used the chi-square for categorical variables and the Student t test for continuous variables.

Results

There were 69 patients diagnosed with primary AC out of 704 new referrals during the pandemic. One year earlier, a total of 73 patients were diagnosed with primary AC out of 1148 new referrals. Representing a relative increase of 3.5% (P = .086) in the incidence of primary AC. No significant differences were found between the control and the pandemic groups in regard to the distribution of patients per treatment group (P = .13), age (P = .49), sex (P = .21), laterality (P = .54), diabetic disease (P = .45), and thyroid disease (P = .62).

Conclusion

There was a nonstatistically significant increase in the incidence of primary AC during the COVID-19 pandemic. No other significant differences were found. Further research is still needed to evaluate the relationship between the COVID-19 pandemic and AC.

Endotoxin-Induced Physiological and Psychological Sickness Responses in Healthy Humans: Insights into the Post-Acute Phase

INTRODUCTION

Experimental endotoxemia is a translational model of systemic inflammation that has contributed significantly to our current understanding of sickness behavior and inflammation-associated depression. Previous studies using this model revealed a strong association between cytokine levels, endocrine changes, and psychological sickness symptoms during the acute phase of inflammation. The objective of this randomized, double-blind, placebo-controlled crossover study was to gain insight into potential post-acute physiological and psychological consequences of endotoxin administration that may either persist or newly emerge between 24 and 72 h after injection. The main focus was on associations between serum levels of C-reactive protein (CRP) and affective symptoms as well as alterations in diurnal cortisol profile, the two key features of inflammation-associated depression.

METHODS

Healthy male volunteers (N = 18) received an injection of either endotoxin (0.8 ng/kg) or placebo on two separate but otherwise identical study days, 7 days apart. Blood and saliva samples were collected during acute and post-acute phases after injection to measure blood inflammatory markers (interleukin [IL]-6, IL-1 receptor antagonist [ra], CRP) and salivary cortisol levels. In addition, participants completed a comprehensive battery of questionnaires to assess physical and psychological sickness symptoms.

RESULTS

Endotoxin treatment induced a short-time rise in plasma IL-6 and a longer increase in IL-1ra. The increase in serum CRP was delayed compared to cytokines, peaking at 24 h and gradually decreasing until 72 h after injection. The inflammatory response was accompanied by bodily and psychological sickness symptoms which occurred only in the acute phase, whereas none of the symptoms persisted or recurred in the post-acute phase. Salivary cortisol levels were significantly increased during the acute phase and exhibited pronounced circadian changes. However, no significant differences in diurnal cortisol profiles were observed between placebo and endotoxin conditions on the days after treatment.

CONCLUSION

Our findings suggest that CRP, which is elevated in patients with inflammation-associated depression, does not appear to be responsible for depressive symptomatology. Moreover, a single inflammatory episode is not sufficient to alter diurnal cortisol profiles, as observed in inflammation-associated depression. In addition, the absence of persistent lipopolysaccharide-induced psychological and physiological changes beyond the acute phase further supports the safety of endotoxin administration in humans.

Composite Biomarkers, Behavioral Symptoms, and Comorbidities in Axial Low Back Pain: A Systematic Review

PURPOSE

Proinflammatory cytokines play a critical role in chronic inflammation and pain and contribute to behavioral symptoms (depressive symptoms, anxiety, fatigue, sleep disturbance) and comorbidities (diabetes, cardiac diseases, cancer). Evidence is lacking on the specific proinflammatory cytokines associated with these behavioral symptoms/comorbidities co-occurring with axial low back pain (aLBP). This review aimed to systematically analyze the following: (1) specific proinflammatory cytokines associated with aLBP in adults, (2) associations among proinflammatory cytokines and behavioral symptoms in aLBP, and (3) relationships among proinflammatory cytokines and comorbidities in aLBP, to develop a new clinical framework for future diagnostic and intervention targets for patients with aLBP.

METHODS

Electronic databases, including PubMed/MEDLINE, ProQuest Nursing & Allied Health Source, and CINAHL Complete (EBSCO) were searched for the period January 2012 to February 2023. Eligible studies included cross-sectional, case-control, longitudinal, and cohort studies in which proinflammatory cytokines were reported in adults above 18 years with aLBP. Intervention studies and randomized controlled trails were excluded. The Joanna Briggs Institute (JBI) criteria were used for quality evaluation.

RESULTS

Findings from 11 studies showed 3 proinflammatory cytokines associated with pain intensity in adult patients with aLBP: C-Reactive Protein (CRP), Tumor Necrosis Factor (TNF-α), and Interleukin (IL-6). Some studies assessed associations between proinflammatory cytokines and depressive symptoms; none explored the association of proinflammatory cytokines with fatigue, anxiety, sleep disturbance, or comorbidities (diabetes, cardiac diseases, and cancer) in aLBP.

CONCLUSIONS

Proinflammatory cytokines in aLBP can serve as composite biomarkers for pain, associated symptoms, and comorbidities and may serve as a target for future interventions. There is need for well-designed studies assessing associations among chronic inflammation, behavioral symptoms, and comorbidities.