Depression and C-reactive protein: population-based Health 2000 Study

Sex Differences in Depression: Insights from Multimodal Gray Matter Morphology and Peripheral Inflammatory Factors

Major depressive disorder (MDD) exhibits notable sex differences in prevalence and clinical and neurobiological manifestations. Though the relationship between peripheral inflammation and MDD-related brain changes is well studied, the role of sex as a modifying factor is underexplored. This study aims to assess how sex influences brain and inflammatory markers in MDD. We utilized voxel-based and surface-based morphometry to analyze gray matter (GM) structure, along with GM-based spatial statistics (GBSS) to examine GM microstructure among treatment-naive patients with depression (n = 174) and age-matched healthy controls (n = 133). We uncovered sex-by-diagnosis interactions in several limbic system structures, the frontoparietal operculum and temporal regions. Post hoc analyses revealed that male patients exhibit pronounced brain abnormalities, while no significant differences were noted in females despite their higher depressive scores. Additionally, heightened inflammation levels in MDD were observed in both sexes, with sex-specific effects on sex-specific brain phenotypes, particularly including a general negative correlation in males. Intriguingly, mediation analyses highlight the specific role of the parahippocampal gyrus (PHG) in mediating interleukin (IL)-8 and depression in men. The findings suggest that in clinical practice, it would be beneficial to prioritize sex-specific assessments and interventions for MDD. This includes recognizing the possibility that male patients may experience significant brain alterations, especially when identifying male patients who may underreport symptoms. Possible limitations encompass a small sample size and the cross-sectional design. In future research, the incorporation of longitudinal studies or diverse populations, while considering illness duration, will enhance our understanding of how inflammation interacts with brain changes in depression.

The Impact of Changes in Depression on Cardiovascular Outcomes in Patients With Coronary Heart Disease

Background

Depression is associated with major adverse cardiovascular events (MACE). Whether longitudinal changes in depression affect MACE in patients with coronary heart disease (CHD) remains unknown.

Objectives

The authors evaluated the hypothesis that increasing or persistent depression predicts MACE in patients with CHD.

Methods

At baseline, 3,483 Emory Cardiovascular Biobank participants (median age 65.5 years, 31.6% female) completed the Patient Health Questionnaire 8 (PHQ8) for depression evaluation. At 1 year, 2,639 of these event-free participants repeated the questionnaire. Depression was defined as a PHQ8 score >9 and change in depressive symptoms ( Δ PHQ8) was year 1 score minus baseline PHQ8 scores. We categorized participants into never depression (both PHQ8 <10), new depression (baseline PHQ8 <10; 1-year PHQ8 >9), remitted depression (baseline PHQ8 >9; year 1 PHQ8 <10), and persistent depression (both PHQ8 >9) groups. Fine-Gray models with noncardiovascular death as the competing event and adjusted for demographics, CHD, and depression related factors evaluated how changes in depression affect MACE (cardiovascular death and MI).

Results

Overall, the incidence of MACE was 14%, with 8.7% of those with follow-up PHQ8 having MACE. 2.9% had persistent depression, 4.5% had new depression, 10.8% had remitted depression, and 81.8% never had depression. Increasing depressive symptoms independently predicted MACE ( Δ PHQ8 subdistribution HR: 1.06 [95% CI: 1.02-1.09], P < 0.001). Correspondingly, the incidence of MACE was higher in those with persistent (20.8%) or new depression (11.9%) than in those with remitted (9.4%) or never depression (8%) (P < 0.001). Compared to never depression, persistent depression independently predicted MACE (subdistribution HR: 2.78 [95% CI: 1.2-6.5], P = 0.017).

Conclusions

Increasing or persistent depression predicts MACE in individuals with CHD.

Association of Biomarkers with the Severity of Depression

Background

The pathogenesis of depression remains elusive and uncertain. The literature suggests that low-grade systemic inflammation might contribute to the etiology of depression. Other markers that are studied are serum magnesium and serum cortisol. The association between these factors might help understand the etiology.

Methods

This was a cross-sectional study conducted on a sample of 40 participants. Socio-demographic data was noted, and the Hamilton depression rating scale was applied to rate the severity of depression. Blood samples were drawn at 8 a.m. to record a complete blood picture (to derive the neutrophil-lymphocyte ratio (NLR)), C-reactive protein, serum magnesium, and serum cortisol.

Results

In this study, conducted on a sample size of 40, inflammatory markers such as C-reactive protein (CRP: mg/dl) and NLR were significantly increased to 15.52 ± 13.10 and 6.46 ± 2.92, respectively, showing an underlying inflammatory pathology. Serum cortisol (µg/dl) was also raised to 22.30 ± 5.46, and there was a fall in serum magnesium. Also, it is noteworthy that all these markers were significantly associated with the severity of depression, as the Pearson correlation between the Hamilton depression rating scale-21 item (HAM-D-21) score and CRP, NLR, and serum cortisol was positive and statistically significant (r = 0.55, p < .01; r = 0.51, p = .01; r = 0.46, p = .002). The Pearson correlation between the HAM-D score and serum magnesium was negative and statistically significant (r = -0.82, p < .01).

Conclusion

There is a state of systemic inflammation, hypercortisolemia, and hypomagnesemia in depressive disorders.

A Potential Role for MAGI-1 in the Bi-Directional Relationship Between Major Depressive Disorder and Cardiovascular Disease

PURPOSE OF REVIEW

Major Depressive Disorder (MDD) is characterized by persistent symptoms such as fatigue, loss of interest in activities, feelings of sadness and worthlessness. MDD often coexist with cardiovascular disease (CVD), yet the precise link between these conditions remains unclear. This review explores factors underlying the development of MDD and CVD, including genetic, epigenetic, platelet activation, inflammation, hypothalamic-pituitary-adrenal (HPA) axis activation, endothelial cell (EC) dysfunction, and blood-brain barrier (BBB) disruption.

RECENT FINDINGS

Single nucleotide polymorphisms (SNPs) in the membrane-associated guanylate kinase WW and PDZ domain-containing protein 1 (MAGI-1) are associated with neuroticism and psychiatric disorders including MDD. SNPs in MAGI-1 are also linked to chronic inflammatory disorders such as spontaneous glomerulosclerosis, celiac disease, ulcerative colitis, and Crohn's disease. Increased MAGI-1 expression has been observed in colonic epithelial samples from Crohn's disease and ulcerative colitis patients. MAGI-1 also plays a role in regulating EC activation and atherogenesis in mice and is essential for Influenza A virus (IAV) infection, endoplasmic reticulum stress-induced EC apoptosis, and thrombin-induced EC permeability. Despite being understudied in human disease; evidence suggests that MAGI-1 may play a role in linking CVD and MDD. Therefore, further investigation of MAG-1 could be warranted to elucidate its potential involvement in these conditions.

C-Reactive Protein Does Not Predict Future Depression Onset in Adolescents: Preliminary Findings from a Longitudinal Study

Introduction: Neuroinflammatory processes have been extensively implicated in the underlying neurobiology of numerous neuropsychiatric disorders. Elevated C-reactive protein (CRP), an indicator of nonspecific inflammation commonly utilized in clinical practice, has been associated with depression in adults. In adolescents, our group previously found CRP to be associated with altered neural reward function but not with mood and anxiety symptoms assessed cross-sectionally. We hypothesized that the distinct CRP findings in adolescent versus adult depression may be due to chronicity, with neuroinflammatory effects on psychiatric disorders gradually accumulating over time. Here, we conducted a longitudinal study to evaluate if CRP levels predicted future onset or progression of depression in adolescents. Methods: Participants were 53 adolescents (age = 14.74 ± 1.92 years, 35 female), 40 with psychiatric symptoms and 13 healthy controls. At baseline, participants completed semistructured diagnostic evaluations; dimensional assessments for anxiety, depression, anhedonia, and suicidality severity; and bloodwork to quantify CRP levels. Clinical assessments were repeated at longitudinal follow-up after ∼1.5 years. Spearman's correlation between CRP levels and follow-up symptom severity were controlled for body mass index, age, sex, and follow-up interval and considered significant at the two-tailed, Bonferroni-adjusted p < 0.05 level. Results: After correction for multiple comparisons, no relationships were identified between baseline CRP levels and follow-up symptom severity. Conclusion: CRP levels were not significantly associated with future psychiatric symptoms in adolescents in this preliminary analysis. This may suggest that CRP is not a useful biomarker for adolescent depression and anxiety. However, future longitudinal studies with larger sample sizes and incorporating additional indicators of neuroinflammation are needed.

Correlation of Sociodemographic Factors, Characteristics of Burns, and Neutrophil-to-Lymphocyte Ratio with the Level of Depression in Patients with Burn injuries

Background

The most common psychological impact experienced by patients with burn injuries is depression. Several significant risk factors influence depression, including sociodemographic factors (gender, employment status, socioeconomic status, and marital status) and burn characteristics (burn depth, burn area, and total burn surface area). Neutrophil-to-lymphocyte ratio (NLR) was discovered as a new biomarker for depression detection. The purpose of this study was to investigate the correlation of sociodemographic factors, burn characteristics, and NLR with the severity of depression in patients with burn injuries.

Methods

This analytic descriptive study was conducted at Dr. Hasan Sadikin General Hospital from June 2022 to April 2023. Samples were assessed by a psychiatrist using the Hamilton Depression Rating Scale instrument, and a differential white blood count was calculated to obtain the NLR value.

Results

The study sample consisted of 32 patients, including 27 males and 6 females. There was no correlation of sociodemographic factors and burn wound characteristics with the level of depression. NLR in patients with burn injuries who had no depression, mild depression, and moderate depression was 5.78 ± 2.23, 7.4 ± 1.77, and 13.04 ± 6.25, respectively. NLR was statistically significantly associated with the level of depression in patients with burn injuries (p = 0.001).

Conclusion

There was no correlation of sociodemographic factors and burn characteristics with the level of depression. There was a significant correlation between NLR and the level of depression in patients with burn injuries at Dr. Hasan Sadikin General Hospital.

The relationship between physical performance and alcohol consumption levels in Russian adults

Investigating the relationship between alcohol consumption and physical performance, we used data from the 2015-2018 Know Your Heart study on 4215 adults aged 35-69 from Arkhangelsk and Novosibirsk, Russia. We classified participants' drinking status into non-drinking, non-problem drinking, hazardous drinking, and harmful drinking based on their self-reported drinking behaviors. To evaluate physical performance, we developed a Composite Physical Performance Scale (CPPS), which combined the results of three functional tests: grip strength (GS), closed-eyes balance, and chair rises (CR). We applied multivariable linear regression to assess the relationship between alcohol consumption and CPPS score, and ordinal logistic regression to explore the associations between alcohol consumption and the three functional tests separately. The results showed that harmful drinking was associated with lower CPPS scores compared to non-problem drinking. Among harmful drinking men, the decrease in CPPS scores was explained by all three tests equally and exceptionally by GS among women. Non-drinking was also associated with decreased CPPS, linked to lower GS and CR scores in men, and only lower GS scores in women. The study revealed a reduced physical performance in the non-drinking and harmful drinking groups compared to non-problem drinking.

Combined influence of depressive symptoms and systemic inflammation on cardiovascular diseases in China

OBJECTIVE

Previous studies had reported a significant association between depressive symptoms and inflammation. The aim of present study was to evaluate the combined effect of depressive symptoms and inflammation level on the risk of cardiovascular disease (CVD).

METHODS

A total of 9647 participants from the China Health and Retirement Longitudinal Study were included. Multivariate Cox proportional hazards regression model was used to evaluate the associations between depressive symptoms, inflammation level and new-onset CVD, stroke and cardiac events.

RESULTS

There were 1731 respondents experienced CVD (including 560 stroke and 1306 cardiac events) during the follow-up period. Compared to individuals without depressive symptoms and low hsCRP level, the adjusted hazard ratios (95% confidence intervals) were 1.23(1.09-1.38), 1.41(1.21-1.63) and 1.61(1.40-1.87) for those with high hsCRP level alone, with depressive symptoms alone, with both depressive symptoms and high hsCRP, respectively. There were additive and multiplicative effect of depressive symptoms and inflammation on the risk of CVD, stroke and cardiac events (as categorical variables). Furthermore, we found significant additive and multiplicative interactions of depressive symptoms and inflammation with CVD (as continuous variables).

CONCLUSION

Our findings indicated that there was a multiplicative effect of depressive symptoms and inflammation on the risk of CVD. Larger-sample prospective cohort studies are still required to test the potential application of combination of depressive symptoms and inflammation as a screening method to identify individuals at risk of CVD.

C-reactive protein does not predict future depression onset in adolescents: preliminary findings from a longitudinal study

Introduction

Neuroinflammatory processes have been extensively implicated in the underlying neurobiology of numerous neuropsychiatric disorders. Elevated C-reactive protein (CRP), an indicator of non-specific inflammation commonly utilized in clinical practice, has been associated with depression in adults. In adolescents, our group previously found CRP to be associated with altered neural reward function but not with mood and anxiety symptoms assessed cross-sectionally. We hypothesized that the distinct CRP findings in adolescent vs. adult depression may be due to chronicity, with neuroinflammatory effects on psychiatric disorders gradually accumulating over time. Here, we conducted a longitudinal study to evaluate if CRP levels predicted future onset or progression of depression in adolescents.

Methods

Participants were 53 adolescents (ages 14.74 ± 1.92, 35 female), 40 with psychiatric symptoms and 13 healthy controls. At baseline, participants completed semi-structured diagnostic evaluations; dimensional assessments for anxiety, depression, anhedonia, and suicidality severity; and bloodwork to quantify CRP levels. Clinical assessments were repeated at longitudinal follow-up after approximately 1.5 years. Spearman's correlation between CRP levels and follow-up symptom severity were controlled for BMI, age, sex, and follow-up interval and considered significant at the two-tailed, Bonferroni-adjusted p < 0.05 level.

Results

After correction for multiple comparisons, no relationships were identified between baseline CRP levels and follow-up symptom severity.

Conclusion

CRP levels were not significantly associated with future psychiatric symptoms in adolescents in this preliminary analysis. This may suggest that CRP is not a useful biomarker for adolescent depression and anxiety. However, future longitudinal studies with larger sample sizes and incorporating additional indicators of neuroinflammation are needed.

Red cell distribution width and depressive symptoms: A failed replication in female adolescents

OBJECTIVES

Despite the increasingly high prevalence and serious consequences of depression in adolescents, there is a lack of economical and reliable biomarkers to aid the diagnostic process. Recent findings suggest that red blood cell distribution width (RDW) is an easily obtainable biomarker of depression in adults. Here, we aimed to replicate the finding of increased RDW in clinically depressed adolescents.

METHODS

Data from depressed adolescent female patients (n = 93) and healthy controls (HC) (n = 43) aged 12-17 years from the AtR!Sk-bio cohort study were retrospectively analysed. We compared RDW between groups and tested whether there was an association between RDW and depression severity and global (psychiatric) symptom severity. We also examined the influence of age on RDW.

RESULTS

There was no significant difference between depressed patients and healthy controls and no association between RDW and depression severity. However, higher RDW values were associated with greater global symptom severity. Regardless of group, there was a positive association between RDW and age.

CONCLUSIONS

RDW appears to be unfit as an aid for clinical diagnosis of depression in adolescents, but may be useful in assessing global psychiatric symptom burden.

The Relationship between Depressive Symptoms, Quality of Life and miRNAs 8 Years after Bariatric Surgery

(1) Background: There are conflicting results on whether weight loss after bariatric surgery (BS) might be associated with quality of life (QoL)/depressive symptomatology. We aim to determine whether BS outcomes are associated with QoL/depressive symptomatology in studied patients at the 8-year follow-up after BS, as well as their relationship with different serum proteins and miRNAs. (2) Methods: A total of 53 patients with class III obesity who underwent BS, and then classified into "good responders" and "non-responders" depending on the percentage of excess weight lost (%EWL) 8 years after BS (%EWL ≥ 50% and %EWL < 50%, respectively), were included. Basal serum miRNAs and different proteins were analysed, and patients completed tests to evaluate QoL/depressive symptomatology at 8 years after BS. (3) Results: The good responders group showed higher scores on SF-36 scales of physical functioning, role functioning-physical, role functioning-emotional, body pain and global general health compared with the non-responders. The expression of hsa-miR-101-3p, hsa-miR-15a-5p, hsa-miR-29c-3p, hsa-miR-144-3p and hsa-miR-19b-3p were lower in non-responders. Hsa-miR-19b-3p was the variable associated with the response to BS in a logistic regression model. (4) Conclusions: The mental health of patients after BS is limited by the success of the intervention. In addition, the expression of basal serum miRNAs related to depression/anxiety could predict the success of BS.

Machine Learning for the Prediction of Depression Progression from Inflammation Markers

Major depressive disorder is one of the major contributors to disability worldwide with an estimated prevalence of 4%. Depression is a heterogeneous disease often characterized by an undefined pathogenesis and multifactorial phenotype that complicate diagnosis and follow-up. Translational research and identification of objective biomarkers including inflammation can assist clinicians in diagnosing depression and disease progression. Investigating inflammation markers using machine learning methods combines recent understanding of the pathogenesis of depression associated with inflammatory changes as part of chronic disease progression that aims to highlight complex interactions. In this paper, 721 patients attending a diabetes health screening clinic (DiabHealth) were classified into no depression (none) to minimal depression (none-minimal), mild depression, and moderate to severe depression (moderate-severe) based on the Patient Health Questionnaire (PHQ-9). Logistic Regression, K-nearest Neighbors, Support Vector Machine, Random Forest, Multi-layer Perceptron, and Extreme Gradient Boosting were applied and compared to predict depression level from inflammatory marker data that included C-reactive protein (CRP), Interleukin (IL)-6, IL-1β, IL-10, Complement Component 5a (C5a), D-Dimer, Monocyte Chemoattractant Protein (MCP)-1, and Insulin-like Growth Factor (IGF)-1. MCP-1 and IL-1β were the most significant inflammatory markers for the classification performance of depression level. Extreme Gradient Boosting outperformed the models achieving the highest accuracy and Area Under the Receiver Operator Curve (AUC) of 0.89 and 0.95, respectively.Clinical Relevance- The findings of this study show the potential of machine learning models to aid in clinical practice, leading to a more objective assessment of depression level based on the involvement of MCP-1 and IL-1β inflammatory markers with disease progression.

Association between testosterone levels and mood disorders: A minireview

BACKGROUND

Although many studies reported the neuropsychiatric involvement of testosterone (T) levels in the development of mood disorders, its role in this disabling disorder is still not well understood. Therefore, in this review, we aim to summarize the current literature exploring serum testosterone levels in both major depressive disorder (MDD) and bipolar disorder (BD), with particular attention given to the possible causal relationship between pathological mood alterations and T levels.

METHODS

We selected 9 original studies from a bibliographic search on PubMed, excluding studies on hormonal therapy and other psychiatric disorders other than mood disorders.

RESULTS

The results reported by the reviewed studies were conflicting especially with regards to the presence of dysfunctional levels of T in patients with BD. Specifically, while MDD was found to be associated with low levels of T compared to healthy controls (HC), in BD the results were highly heterogeneous, with a mixed picture of reduced, increased or no difference in T levels in BD patients compared to HC.

LIMITATIONS

Studies were highly heterogeneous in terms of samples employed, psychometric scales used for assessing depressive symptoms, T assay methods and therapeutic regimens.

CONCLUSIONS

Overall, T levels were shown to be reduced in both MDD and BD patients, ultimately suggesting that T could be useful as a biomarker in mood disorders and provide guidance for future research.

Lack of bidirectional association between C-reactive protein and depressive symptoms in middle-aged and older adults: Results from a nationally representative prospective cohort study

Depression is associated with low quality of life and increased health burdens for middle-aged and older adults in resource-limited settings. Although inflammation plays an etiological role in the development and progression of depression, the directionality of the inflammation-depression relationship is unclear, especially in non-Western populations. To examine this relationship among community-dwelling Chinese middle-aged and older adults, we obtained data from the 2011, 2013, and 2015 China Health and Retirement Longitudinal Study (CHARLS). The participants were aged 45 years or above at baseline in 2011 and completed the follow-up survey in 2013 and 2015. Depressive symptoms were measured using the 10-item Center for Epidemiologic Studies Depression Scale (CESD-10), and the C-reactive protein (CRP) level was used to measure individual inflammation levels. Cross-lagged regression analyses examined the inflammation-depression relationship. Cross-group analyses were performed to test for model invariance across the sexes. Pearson's correlations revealed no concurrent correlations between depression and CRP for both 2011 and 2015 (ps > 0.05, ranging 0.07-0.36) studies. Cross-lagged regression path analyses revealed that the paths from baseline CRP to depression in 2013 (ß_std  = -0.01, p = 0.80), from baseline CRP to depression in 2015 (ß_std  = 0.02, p = 0.47), from baseline depression to CRP in 2015 (ß_std  = -0.02, p = 0.40), and from depression at 2013 to CRP in 2015 (ß_std  = 0.03, p = 0.31) were not statistically significant. Additionally, the autoregressive model did not vary across the sexes (△χ ² = 78.75, df = 54, p = 0.02, △ comparative fit index (CFI) <0.01). We failed to find a bidirectional association between the CRP levels and depressive symptoms in our sample.

Hierarchical Inflammatory Phenotypes of Depression: A Novel Approach Across Five Independent Samples and 27,730 Adults

BACKGROUND

Although characterizing associations between inflammation and depression may prove critical for informing theory, research, and treatment decisions, extant research has been limited by ignoring the possibility that inflammation may be simultaneously associated with depression broadly and with a subset of symptoms. This lack of direct comparison has hampered attempts to understand inflammatory phenotypes of depression and critically fails to consider that inflammation might be uniquely associated with both depression broadly and individual symptoms.

METHODS

We used moderated nonlinear factor analysis in 5 NHANES (National Health and Nutrition Examination Survey) cohorts (N = 27,730, 51% female, mean age = 46 years).

RESULTS

C-reactive protein (CRP) is simultaneously associated with latent depression, appetite, and fatigue. Specifically, CRP was associated with latent depression in all 5 samples (rs: 0.044-0.089; ps: < .001-.002) and was associated with both appetite (significant rs: 0.031-0.049, significant ps: .001-.007) and fatigue (significant rs: 0.030-0.054, significant ps: < .001-.029) in 4 samples. These results were largely robust to covariates.

CONCLUSIONS

Methodologically, these models indicate that the Patient Health Questionnaire-9 is scalar noninvariant as a function of CRP (i.e., identical Patient Health Questionnaire-9 scores may represent different constructs in those with high vs. low CRP levels). Therefore, mean comparisons of depression total scores and CRP might be misleading without accounting for symptom-specific associations. Conceptually, these findings indicate that studies investigating inflammatory phenotypes of depression should examine how inflammation is simultaneously related both to depression broadly and to specific symptoms, and whether these relations function via different mechanisms. This has the potential to yield new theoretical insights and may lead to the development of novel therapies for reducing inflammation-related symptoms of depression.

Mortality of asthma, COPD, and asthma-COPD overlap during an 18-year follow up

BACKGROUND

We studied asthma, COPD, and asthma-COPD overlap (ACO) to predict mortality in a cohort of Finnish adults with an 18-year follow up.

METHODS

A national health examination survey representing Finnish adults aged ≥30 years was performed in 2000-2001. The study cohort included 5922 participants (73.8% of the sample) with all relevant data, including a comprehensive clinical examination and spirometry. These participants were followed continuously from baseline until end of 2018 for total, cardiovascular, cancer, and respiratory mortality through a record linkage. Asthma, COPD, and ACO were defined based on the survey data, including spirometry and register data. There were three separate groups of obstructive subjects (one definition excluding the others).

RESULTS

Asthma and COPD were significantly associated with higher total mortality in Cox's model adjusted for sex, age, smoking, education level, BMI, leisure time physical activity, cardiovascular disease, diabetes, and hypertension. Hazard ratios (HR) (95% confidence interval [CI]) for asthma, COPD, and ACO were 1.29 (1.05-1.58), 1.50 (1.20-1.88), and 1.26 (0.97-1.65), respectively. Additionally, asthma (HR 1.47, 95% CI 1.09-1.97) and COPD (HR 1.53, 95% CI 1.08-2.16) were associated with cardiovascular mortality. Although ACO did not predict mortality in the whole cohort, there was a significant association with mortality risk among those with hs-CRP 1-2.99 mg/l.

CONCLUSIONS

Asthma or COPD predicts higher total mortality and premature death from cardiovascular diseases.

C-Reactive Protein and Specific Depression Symptoms Among Older Adults: An Exploratory Investigation of Multi-Plane Networks Using Cross-Sectional Data From NHANES (2017-2020)

INTRODUCTION

Studies investigating the association between C-reactive protein (CRP) and depression among older adults have yielded inconsistent results. We suspect that this may be due to varying associations between CRP and particular depression symptom criteria, and we addressed this challenge using network analysis.

METHODS

We used cross-sectional data from prepandemic National Health and Nutrition Examination Survey questionnaires (2017-2020) and included a sample of 1698 adults aged 65 years or older. Depression symptoms were assessed using the Patient Health Questionnaire-9. Unregularized Mixed Graphical Models were estimated using the R package mgm before and after adjusting for relevant sociodemographic, clinical, and lifestyle covariates.

RESULTS

In the model with no covariates, the only symptom criterion associated with CRP was "appetite problems." This association remained robust after controlling for all covariates. Although not associated with CRP, other criteria such as "fatigue" and "concentration difficulty" showed associations with important covariates for older adults such as white blood cell count or hemoglobin, respectively.

DISCUSSION

The CRP-related variability in the depression symptom network that we have demonstrated may help explain the reported inconsistencies. The present study stands as exploratory, and future research should focus on applying longitudinal designs and including several other inflammatory proteins and covariates that were not measured in the current network model.

Is depression the missing link between inflammatory mediators and cancer?

Patients with cancer are at greater risk of developing depression in comparison to the general population and this is associated with serious adverse effects, such as poorer quality of life, worse prognosis and higher mortality. Although the relationship between depression and cancer is now well established, a common underlying pathophysiological mechanism between the two conditions is yet to be elucidated. Existing theories of depression, based on monoamine neurotransmitter system dysfunction, are insufficient as explanations of the disorder. Recent advances have implicated neuroinflammatory mechanisms in the etiology of depression and it has been demonstrated that inflammation at a peripheral level may be mirrored centrally in astrocytes and microglia serving to promote chronic levels of inflammation in the brain. Three major routes to depression in cancer in which proinflammatory mediators are implicated, seem likely. Activation of the kynurenine pathway involving cytokines, increases tryptophan catabolism, resulting in diminished levels of serotonin which is widely acknowledged as being the hallmark of depression. It also results in neurotoxic effects on brain regions thought to be involved in the evolution of major depression. Proinflammatory mediators also play a crucial role in impairing regulatory glucocorticoid mediated feedback of the hypothalamic-pituitary-adrenal axis, which is activated by stress and considered to be involved in both depression and cancer. The third route is via the glutamatergic pathway, whereby glutamate excitotoxicity may lead to depression associated with cancer. A better understanding of the mechanisms underlying these dysregulated and other newly emerging pathways may provide a rationale for therapeutic targeting, serving to improve the care of cancer patients.

Inflammatory markers and incident depression: Evidence in a population-based prospective study

The association between pro-inflammatory cytokines and depression is widely acknowledged. However, longitudinal data that show they lead to depression are few. In a community-based sample of older individuals (n = 2761, ages = 55-98 y) in the Singapore Longitudinal Ageing Study (SLAS), we analyzed the associations between inflammatory markers (CRP, IL6, TNFα, and inflammation risk score) and depression (defined as the presence of depressive symptoms, depression history or treatment). Cross-sectional analysis showed that CRP, IL-6 and TNFα were significantly associated with depression at baseline. Longitudinal analysis controlling for a host of potentially confounding risk factors and initial depression revealed that IL-6, TNFα, and inflammation risk score were associated with elevated risk of depression at follow-ups. However, there was no significant association between CRP and subsequent depression after adjusting for sociodemographic, lifestyles and inflammatory medical condition variables. In summary, this prospective study shows that inflammation predicts depression in older adults, and suggests that the heterogeneous findings among studies may be due to differences in study population characteristics, depression, inflammatory markers, and the extent of adjusting for confounders.

Sense of purpose in life and inflammation in healthy older adults: A longitudinal study

BACKGROUND

A higher sense of purpose in life has been linked with reduced risk of age-related chronic health conditions that share elevated inflammation as a key risk factor (e.g., neurodegenerative diseases, heart disease, and diabetes). While prior research has documented cross-sectional associations between higher sense of purpose and lower inflammation, few studies have examined the association between purpose and changes in inflammation over time.

OBJECTIVE

We tested if a higher sense of purpose was prospectively associated with lower likelihood of developing unhealthy C-reactive protein levels in older adults who initially had healthy CRP levels (i.e., <3 ug/mL).

METHODS

Participants were 6925 adults aged > 50 in the Health and Retirement Study who were followed for 8 years. Participants completed the purpose in life subscale of the Ryff Psychological Well-being Scales at study baseline in 2006/2008. CRP was obtained from blood spots collected at baseline and after 4 and 8 years of follow-up. Pooled logistic regression estimated discrete-time hazard ratios (HR) and 95% confidence intervals (CI) for the association between baseline purpose and onset of unhealthy CRP levels (>3 ug/mL).

RESULTS

There was no strong evidence of an association between baseline continuous purpose scores and onset of unhealthy CRP levels over time in the overall analytic sample. In sex-stratified models, higher purpose was associated with lower hazards of developing unhealthy CRP levels among men, while associations were null in women (e.g., in sociodemographics-adjusted model, men: HR=0.89, 95% CI: 0.79-0.99; women: HR=0.96, 95% CI: 0.85-1.08; interaction between continuous purpose scores and sex p = 0.15).

CONCLUSIONS

Findings suggest that a higher versus lower sense of purpose is associated with lower inflammation levels in older men. In specific populations, purpose may serve as a novel target for future interventions aimed at reducing inflammation.

Association of depression and obesity with C-reactive protein in Germany: A large nationally representative study

INTRODUCTION

Depression and obesity often occur comorbidly, and once both are present, they further increase the risk of developing other medical comorbidities, likely due to the underlying chronic low-grade inflammation. We investigated to what extent depression and obesity are associated with levels of high-sensitivity C-reactive protein (hsCRP) in a nationally representative sample of the German adult population.

METHODS

We analyzed data from the German Health Interview and Examination Survey for Adults (DEGS1, N = 7115), and its mental health module (DEGS1-MH; N = 4483). Two different depression measures were used: current depressive symptoms assessed by the self-administered German version of the Patient Health Questionnaire-9 and major depressive disorder (MDD) in the last 12 months assessed by a modified German version of the Composite International Diagnostic Interview. Obesity was defined by body mass index calculated from measured data. Associations with log(x + 1)-transformed hsCRP levels were analyzed using multivariable linear regression models.

RESULTS

Obese participants with depressive symptoms had significantly higher hsCRP compared to non-obese participants with depressive symptoms adjusted for sociodemographic and behavioral variables and medication use. In non-obese individuals, depressive symptoms were inversely associated with hsCRP, whereas MDD was not associated with hsCRP after adjustment for covariates. Additional analyses suggested symptom-specific associations of hsCRP as higher levels were linked to fatigue (β = 0.10, p <.001) while lower levels were linked to cognitive problems (β = -0.09, p <.001). Low SES, current smoking, lower levels of physical exercise, and the use of anti-inflammatory/anti-rheumatic medication and antidepressants were additional determinants of hsCRP in the fully adjusted models.

CONCLUSIONS

Our data suggest that obesity status is more strongly associated with increased inflammation than depressive symptoms or MDD. The relationship between depression and hsCRP in our population-based sample is substantially influenced by obesity status as well as other medical factors, lifestyle, and socioeconomic status. Furthermore, our findings suggest that the association between hsCRP and depression is symptom-specific rather than generalized.

Inflammatory Cytokines, but Not Dietary Patterns, Are Related to Somatic Symptoms of Depression in a Sample of Women

Background

Depression is a heterogenous disorder with both cognitive and somatic symptom dimensions that may differentially relate to systemic inflammation. Diet, which has the potential to modulate both inflammation levels and mood, is yet to be studied within the context of individual depression dimensions. This study examined the associations between inflammatory cytokines and dietary patterns with depressive symptom dimension profiles among a sample of women recruited in a non-clinical setting.

Methods

Inflammatory cytokines (IL-6 and TNF-α), inflammatory diet (Diet Inflammatory Index; DII), and depressive symptoms (Beck Depression Inventory-II; BDI-II) were measured in 136 females (M age = 22.01 ± 4.02, range 18-59 years). Multiple linear regressions were used to investigate the relationships between inflammatory cytokines and diet with self-reported cognitive, somatic, and total depressive symptoms, adjusting for demographic factors.

Results

Findings showed that increased somatic dimension scores were positively associated with IL-6 (ß = 0.273, p = 0.002) and TNF-α (ß = 0.215, p = 0.017), but not inflammatory diet (p = 0.300). Total BDI-II scores were only positively associated with IL-6 (ß = 0.221, p = 0.012), and cognitive dimension scores were not associated with any inflammation measures.

Conclusions

These findings contribute to existing evidence that inflammatory cytokines are associated with the somatic symptoms of depression. Inflammatory diet index was not associated with depression measures.

C-reactive protein is related to a distinct set of alterations in resting-state functional connectivity contributing to a differential pathophysiology of major depressive disorder

BACKGROUND

Several studies in major depressive disorder (MDD) have found inflammation, especially C-reactive protein (CRP), to be consistently associated with MDD and network dysfunction. The aim was to investigate whether CRP is linked to a distinct set of resting-state functional connectivity (RSFC) alterations.

METHODS

For this reason, we investigated the effects of diagnosis and elevated blood plasma CRP levels on the RSFC in 63 participants (40 females, mean age 31.4 years) of which were 27 patients with a primary diagnosis of MDD and 36 healthy control-subjects (HC), utilizing a seed-based approach within five well-established RSFC networks obtained using fMRI.

RESULTS

Of the ten network pairs examined, five showed increased between-network RSFC-values unambiguously connected either to a diagnosis of MDD or elevated CRP levels. For elevated CRP levels, increased RSFC between DMN and AN was found. Patients showed increased RSFC within DMN areas and between the DMN and ECN and VAN, ECN and AN and AN and DAN.

CONCLUSIONS

The results of this study show dysregulated neural circuits specifically connected to elevated plasma CRP levels and independent of other alterations of RSFC in MDD. This dysfunction in neural circuits might in turn result in a certain immune-inflammatory subtype of MDD.

C-Reactive Protein as a Biomarker for Major Depressive Disorder?

The etiopathogenesis of depression is not entirely understood. Several studies have investigated the role of inflammation in major depressive disorder. The present work aims to review the literature on the association between C-Reactive Protein (CRP) and depression. A systematic review was performed for the topics of ‘CRP’ and ‘depression’ using the PubMed database from inception to December 2021. Fifty-six studies were identified and included in the review. Evidence suggested the presence of dysregulation in the inflammation system in individuals with depression. In most studies, higher blood CRP levels were associated with greater symptom severity, a specific pattern of depressive symptoms, and a worse response to treatment. Moreover, about one-third of depressed patients showed a low-grade inflammatory state, suggesting the presence of a different major depressive disorder (MDD) subgroup with a distinct etiopathogenesis, clinical course, treatment response, and prognosis, which could benefit from monitoring of CRP levels and might potentially respond to anti-inflammatory treatments. This work provides robust evidence about the potential role of CRP and its blood levels in depressive disorders. These findings can be relevant to developing new therapeutic strategies and better understanding if CRP may be considered a valuable biomarker for depression.

Neutrophil-to-Lymphocyte Ratio, Platelet-to-Lymphocyte Ratio, and Monocyte-to-Lymphocyte Ratio in Depression: An Updated Systematic Review and Meta-Analysis

BACKGROUND

Research on neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR) in depression is still emerging and has increased 3-fold since the first meta-analysis. An updated meta-analysis with sufficient studies can provide more evidence for a potential relationship between NLR, PLR, MLR, and depression.

METHODS

We identified 18 studies from the PubMed, EMBASE, Cochrane library, and Web of Science databases. Meta-analyses were performed to generate pooled standardized mean differences (SMDs) and 95% confidence intervals (CIs) between patients with depression and controls. Sensitivity analysis, subgroup analysis, meta-regression, and publication bias were conducted.

RESULTS

A total of 18 studies including 2,264 depressed patients and 2,415 controls were included. Depressed patients had significantly higher NLR and PLR compared with controls (SMD = 0.33, 95% CI: 0.15-0.52, p < 0.001 and SMD = 0.24, 95% CI: 0.02-0.46, p < 0.05, respectively). MLR was slightly higher in depressed individuals compared to controls (SMD = 0.15, 95% CI: -0.26 to 0.55, p > 0.05), despite the absence of significance. Sensitivity analysis removing one study responsible for heterogeneity showed a higher and significant effect (SMD = 0.32, 95% CI: 0.20-0.44) of MLR. Three subgroup analyses of NLR, PLR, MLR, and depression revealed obvious differences in the inflammatory ratios between depressed patients and controls in China and the matched age and gender subgroup. Individuals with post-stroke depression (PSD) had higher NLR and MLR values as compared to non-PSD patients (SMD = 0.51, 95% CI: 0.36-0.67, p < 0.001 and SMD = 0.46, 95% CI: 0.12-0.79, p < 0.01, respectively). Meta-regression analyses showed that male proportion in the case group influenced the heterogeneity among studies that measured NLR values (p < 0.05).

CONCLUSIONS

Higher inflammatory ratios, especially NLR, were significantly associated with an increased risk of depression. In the subgroup of China and matched age and gender, NLR, PLR, and MLR were all elevated in depressed patients vs. controls. Individuals with PSD had higher NLR and MLR values as compared to non-PSD patients. Gender differences may have an effect on NLR values in patients with depression.

Inflammation in obese children and adolescents: Association with psychosocial stress variables and effects of a lifestyle intervention

Obesity in childhood and adolescence is a complex health issue that has detrimental effects on the physical and psychological health of the youngster, both in the short and long term. A characteristic of obesity is the associated chronic low-grade inflammation which can result in insulin resistance. Previous research suggested that biomarkers referring to such increased inflammation may help in understanding resistance to weight loss. Whether and how psychosocial factors are related with inflammation remains to be proven. The current study consisted of 594 children and adolescents (7-19 years), of whom 480 had follow-up data, who enrolled for a ten-month inpatient multidisciplinary obesity treatment consisting of healthy food routines, physical activities and psychological treatment. The purpose of the study was to explore (1) the relationship between inflammation and psychosocial stress variables (i.e., depressive symptoms, eating behavior, concerns about eating/shape/weight, insecure parent-child attachment) (correlational and multiple regression analysis), (2) whether a lifestyle intervention for obese youngsters results in decreased C-reactive protein (CRP) values (paired t-test) and (3) which psychosocial variables influence this CRP change as indication of treatment success (multiple regression analysis with change in BMI as control variable). Results showed that the psychosocial stress variables emotional eating, external eating and attachment anxiety are related to higher CRP values. Our data further suggested that a lifestyle intervention decreases the CRP values. This significant reduction in blood inflammatory marker was besides being influenced by weight loss also dependent on psychosocial variables, more specific on self-reported attachment avoidance, as this latter was related to less CRP decrease.

Low-grade inflammation as a potential mediator between depressive symptoms and temporomandibular pain: an 11-year follow-up study on Finnish adults

BACKGROUND

Low-grade inflammation and depressiveness have been associated with chronic pain conditions.

OBJECTIVE

To examine whether low-grade inflammation mediates the association between depressive symptoms and temporomandibular (TM) pain in Finnish adults based on the Health 2000/2011 Surveys (BRIF8901).

METHODS

The sample comprised subjects who underwent clinical TM pain examination (pain on palpation of the masticatory muscles and temporomandibular joints) in 2000 and 2011 and responded to questions on TM pain symptoms in 2011. The serum level of hs-CRP was obtained in both years, and depressiveness was assessed using the Beck Depression Inventory-21 (BDI-21) in 2000 and BDI-13 in 2011. Four subgroups were formed based on the presence of TM pain: No pain, pain in 2000-only, pain in the 2011-only, and pain in both-years. Analyses included Rao Scott's chi-square test cross-sectionally, and multinomial logistic regression longitudinally with the level of hs-CRP and BDI-21 score in 2000 as predictors. Mediation was tested using Hayes A. Processv3.5.

RESULTS

Higher BDI-21/-13 and hs-CRP levels corresponded to higher prevalences of TM pain in both years. Longitudinally, in men, higher hs-CRP level predicted TM pain in 2000-only and TM pain in both-years. Higher BDI-21 score predicted having TM pain in 2011-only. In women, higher BDI-21 score predicted TM pain in 2000-only and having TM pain in both-years. Both BDI-21 and hs-CRP had a direct effect on TM pain outcome with no mediation detected.

CONCLUSION

While depressiveness may increase the risk of chronic TM pain in women, the risk in men is increased by low-grade inflammation.

Lack of Associations Between C-Reactive Protein and Mood and Anxiety Symptoms in Adolescents

Introduction: Increased peripheral inflammation has been consistently documented in both adult and pediatric depression. However, elevated levels of C-reactive protein (CRP), a nonspecific biomarker for inflammation, have been primarily reported in adults; whether CRP plays a similar role in adolescent depression has not been conclusively established. In our prior work, we identified relationships between CRP and reward neurocircuitry in adolescents with psychiatric symptoms (N = 64) but not with depressive symptoms. Extending this work, we sought to examine CRP across the full range of mood and anxiety symptom severity in a larger, clinically diverse cohort of psychotropic medication-free adolescents and healthy controls (HCs). Methods: Subjects were adolescents (N = 127, age: 15.17 ± 2.19 years, 78 female) with psychiatric symptoms (n = 96, including previous cohort of 64) and HC (n = 31). All completed a semi-structured psychiatric evaluation and dimensional assessments for depression, anxiety, anhedonia, and suicidality. Group-comparison and correlation analyses utilized nonparametric statistics controlled for body mass index, sex, and age at p_FWE < 0.05. Results: No group differences were identified in CRP levels between the clinical cohort and HCs. In addition, correlations between CRP and clinical symptomatology were not significant in either the whole sample or the psychiatric group. Conclusions: We found that, unlike in adults, CRP was not associated with depressive symptoms. This suggests that inflammation in pediatric depression is more narrowly delimited at the onset of psychiatric symptoms and may only become systemic with chronicity.

Association between high-sensitivity C-reactive protein levels and depression: Moderation by age, sex, obesity, and aerobic physical activity

BACKGROUND

Low-grade systemic inflammation evidenced by elevated serum high-sensitivity C-reactive protein (hsCRP) levels can be a biomarker for depression. This study aimed to investigate the association between serum hsCRP levels and depressive symptoms and to explore the potential moderating effects of age, sex, body mass index (BMI), and aerobic physical activity on the association.

METHODS

Data of 10,702 adults (≥ 19 years) were obtained from the nationwide cross-sectional Korea National Health and Nutrition Examination Surveys of 2016 and 2018. Significant depressive symptoms were defined as ≥ 10 on the Patient Health Questionnaire-9, and high hsCRP level was defined as > 3.0 mg/L.

RESULTS

Adults with high hsCRP levels were more likely to have depressive symptoms (odds ratio [OR]: 1.41, 95% confidence interval [CI]: 1.07-1.84) and suicidal ideation (OR: 1.39, 95% CI: 1.07-1.80) than those with low hsCRP levels. In the age- and sex-stratified analysis, high hsCRP levels were associated with depressive symptoms in the non-geriatric population (age ≤ 64 years) alone, with a higher OR in males than females. In subgroup analyses, the association between them was observed only among obese adults and adults without aerobic physical activity.

LIMITATIONS

Causal interpretation is limited due to the cross-sectional design.

CONCLUSIONS

Our results replicate previous findings of an association between high hsCRP levels and depressive symptoms in adults using a large nationally representative sample. The association between them was more prominent in the non-geriatric population, males, obese adults, and those without aerobic physical activity.

From Heartbreak to Heart Disease: A Narrative Review on Depression as an Adjunct to Cardiovascular Disease

Patients with cardiovascular disease (CVD) commonly have subclinical depression and are often delayed in their diagnosis. Literature suggests an increased association of depression and adverse cardiovascular events like myocardial infarction and heart failure. Prevalence of depression in developed countries is approximately 16.6%, and it confers higher cardiovascular mortality even after attrition bias and confounding factors are eliminated. Pharmacological and cognitive-behavioral therapy have been extensively studied, and are generally safe and effective in alleviating depressive symptoms in patients with CVD. However, their impact on cardiovascular outcomes is still unclear. Results of randomized controlled trials have shown antidepressants, especially selective serotonin reuptake inhibitors, to be safe and effective for healing a "broken heart." This review outlines the prevalence of depression in patients with CVD, the pathophysiological mechanism causing cardiovascular events with depression, and a link between depression and CVD. There is a wealth of literature explaining the precursor of CVD in depression, and like all chronic diseases, inflammation seems to be the culprit in this case as well.

The correlation between mental health status, sleep quality, and inflammatory markers, virus negative conversion time among patients confirmed with 2019-nCoV during the COVID-19 outbreak in China: An observational study

The 2019 coronavirus disease (COVID-19) has spread to the whole world. Psychological and sleep problems among confirmed patients have drawn extensive attention which may be highly related to immune function and inflammatory responses of people. The aim of this study is to examine the correlation of mental health status, sleep quality, and inflammatory markers, virus negative conversion time (NCT) among confirmed patients during the COVID-19 outbreak.A cross-sectional survey was conducted in this study. Data from 66 patients assessed with demographic information, anxious symptom, depressive symptom, stress, and sleep quality were collected using a smartphone-based questionnaire platform and then clinical characteristics and laboratory indicators were collected using case review.Nearly 30% of the participants reported depression, anxiety, perceived pressure, and poor sleep quality. Compared with the group without depression, neutrophil count, and ratio of neutrophil count to lymphocyte count (NLR) in the depression disorder group were increased (P = .028, 0.043). There was also a significant difference in NLR and NCT between the anxiety group and the non-anxiety group (P = .021, .024). Similarly, compared with the good sleep quality group, NLR in the poor sleep quality group was increased (P = .011). Correlation analysis indicated that Self-Rating Depression Scale score was positively related to neutrophil count and NLR (r = 0.366, 0.330, P = .016, .031). The total score of Pittsburgh Sleep Quality Index (PSQI) was negatively related to lymphocyte count (r = -0.317, P = .049), and the sleep disturbance as 1 of the 7 dimensions of PSQI scale was positively correlated with NCT and NLR (r = 0.370, 0.340, P = .020, .034).In our study, confirmed patients were prone to have psychological and sleep problems. The level of inflammation in patients with psychological and sleep problems was higher than that in patients without corresponding problems. The inflammatory level increased with the increase of Self-Rating Depression Scale score, and the lymphocyte count decreased with the increase of the PSQI score. NCT was prolonged in the anxiety group and sleep disturbance was positively correlated with NCT.

Sex hormones and immune system: A possible interplay in affective disorders? A systematic review

BACKGROUND

Sex hormones and the immune system may play a key role in sex differences in affective disorders. The understanding of their interplay may lead to the detection of new sex-specific tailored therapeutic approaches. The aim of this systematic review is to summarise the evidence supporting a possible association between sex hormones and inflammatory biomarkers in people with affective disorders.

METHODS

A systematic search of the literature published until January 2021 was conducted on PubMed database. The initial search identified a total of 1259 studies; 20 studies investigating inflammatory biomarkers and sex hormones in patients exhibiting depressive symptoms were included: 10 studies focused on patients with affective disorders, and 10 studies focused on women in menopause or in the post-partum period exhibiting depressive symptoms.

RESULTS

Testosterone and exogenous female sex hormones may play protective roles through their modulation of the immune system, respectively, in male patients with bipolar disorder and in peri-/post-menopausal women with depression.

LIMITATIONS

The main limitations are the paucity of studies investigating both sex hormones and immune biomarkers, the lack of statistical analyses exploring specifically the association between these two classes of biomarkers, and the great heterogeneity between the participants' samples in the studies.

CONCLUSION

This review highlights the need to investigate the interplay between sex hormones and immune system in affective disorders. The inconsistent or incomplete evidence may be improved by studies in patients with moderate-high inflammatory levels that specifically evaluate the relationship between sex hormones and the immune system.

Serum Levels of CRP are Associated with Depression in a Middle-aged and Elderly Population with Diabetes Mellitus: A Diabetes Mellitus-Stratified Analysis in a Population-Based Study

BACKGROUND

The direct relationship between inflammation and depression in patients with diabetes is still unclear. We examined the association between serum C-reactive protein (CRP) levels and the high prevalence of depression in populations (aged ≥49 years) with and without type 2 diabetes.

METHODS

Cross-sectional and longitudinal data from 3895 participants obtained from The Irish Longitudinal Study on Ageing (TILDA) were analyzed to determine the association between serum CRP levels and depression, accounting for relevant confounding factors.

RESULTS

Multivariable analyses showed a positive association between serum CRP and depression score, independent of age and gender, BMI, marital status, education, smoking status, alcohol drinking status, systolic BP, diastolic BP, physical activity, self-reported CVDs and laboratory measurements in subjects with diabetes mellitus (coefficient = 0.179, P<0.001) but not in subjects without diabetes mellitus (coefficient = 0.011, P = 0.495). Higher serum CRP levels were associated with an increased risk of depressive symptoms in subjects with diabetes mellitus (OR = 1.301, 95% CI 1.012-1.799, P = 0.011) but not in subjects without diabetes mellitus (OR = 1.004, 95% CI 0.992-1.013, P = 0.344) after adjusting for these same confounding factors. After a follow-up of 4 years, higher serum CRP levels were significantly associated with a higher possibility of depression events in subjects with diabetes mellitus.

LIMITATIONS

Time-varying confounding factors may interfere with our results.

CONCLUSION

We observed a significant positive association between serum CRP levels and the prevalence of depressive symptoms in a middle-aged and elderly population with diabetes after adjustment for a range of lifestyle factors.

Inflammation predicts new onset of depression in men, but not in women within a prospective, representative community cohort

Depression has been associated with increased inflammation. However, only few large-scale, prospective studies have evaluated whether inflammation leads to new cases of depression and whether this association can be found in men and women. Longitudinal data of N = 10,357 adult participants with no evidence of depression at baseline (based on Patient Health Questionnaire (PHQ-9), lifetime diagnoses, and current antidepressant medication) were evaluated for depression 5 years later. Multivariate logistic regression models were used to predict the onset of depression based on C-reactive protein (CRP) and white blood cell count (WBC). We used interaction terms and separate analyses in men and women to investigate gender-dependent associations. Based on both markers, inflammation was predictive of new cases of depression 5 years later, even when adjusting for sociodemographic, physical health, health behavior variables, and baseline depression symptoms. As established by interaction terms and separate analyses, inflammatory markers were predictive of depression in men, but not in women. Additional predictors of new onset of depression were younger age, loneliness, smoking (only in men), cancer and less alcohol consumption (only in women). The study indicates gender differences in the etiology of depressive disorders within the community, with a greater role of physical factors in men.

Major depressive disorder increased risk of psoriasis: A propensity score matched cohort study

BACKGROUND

Reports showed that elevated proinflammatory cytokines, as detected in patients with psoriasis, was noted in individuals with major depressive disorder (MDD). Therefore, this study aimed to clarify the association of MDD and prospective incidence of psoriasis in human using a nationwide study.

METHOD

This population-based cohort study used the data from the Taiwan National Health Insurance system. 64,486 patients were defined as MDD cohort and 64,486 propensity score matched subjects without MDD were identified as comparison cohort. Each patient was independently tracked for a 5-year study period to assure them for a psoriasis diagnosis after the index date. Stratified Cox proportional hazard models were used to calculate the hazard ratio (HRs) for 5-year psoriasis risk.

RESULTS

After adjustments, the HR of psoriasis for MDD patients was 1.32 compared with subjects without MDD. The stratified analyses present that MDD patients had approximately 1.30-fold significantly higher risk of psoriasis than comparison subjects in most subgroups. Furthermore, compared with the matched subjects without MDD, the adjusted HRs of psoriasis in the 2-, 3-, 4- and 5-year study periods were 1.33, 1.32, 1.33 and 1.32, respectively.

LIMITATIONS

Several patients with MDD or psoriasis might not include in this study, because of using a medical claims database.

CONCLUSIONS

This study provides population-based evidence that MDD is an independent risk factor of developing psoriasis, with an increased risk in the male sex. Additional investigations verifying our findings and exploring possible pathological mechanisms would be of great interest and value to the psychiatric field.

How handling extreme C-reactive protein (CRP) values and regularization influences CRP and depression criteria associations in network analyses

Increasingly, it has been recognized that analysis at the symptom, rather than diagnostic, level will drive progress in the field of immunopsychiatry. Network analysis offers a useful tool in this pursuit with the ability to identify associations between immune markers and individual symptoms, independent of all other variables modeled. However, investigation into how methodological decisions (i.e., including vs. excluding participants with C-reactive protein (CRP) >10 mg/L, regularized vs. nonregularized networks) influence results is necessary to establish best practices for the use of network analysis in immunopsychiatry. In a sample of 3,464 adult participants from the 2015-2016 National Health and Nutrition Examination Survey dataset, this study found consistent support for associations between CRP and fatigue and changes in appetite and some support for additional CRP-criterion associations. Methodologically, results consistently demonstrated that including individuals with CRP >10 mg/L and estimating nonregularized networks provided better estimates of these associations. Thus, we recommend considering the use of nonregularized networks in immunopsychiatry and inclusion of cases with CRP values >10 mg/L when testing the association between CRP and depression criteria, unless contraindicated by the research question being tested. Additionally, results most consistently suggest that CRP is uniquely related to fatigue and changes in appetite, supporting their inclusion in an immunometabolic phenotype of depression. Finally, these associations suggest that fatigue and changes in appetite might be particularly receptive to anti-inflammatory treatments. However, future research with more nuanced measures is necessary to parse out whether appetite increases or decreases drive this association. Further, longitudinal research is an important next step to test how these relationships manifest over time.

Depression and inflammation among children and adolescents: A meta-analysis

BACKGROUND

Increasing evidence suggests that youth with Major Depressive Disorder (MDD) exhibit early indicators of cardiovascular disease. A leading hypothesized mechanism of this association is via inflammatory pathways, however, results examining this direct association are mixed. Our objective was to synthesize and quantify observational studies examining the association of depression and inflammation among children and adolescents.

METHODS

Electronic searches were conducted in MEDLINE, Embase, PsycINFO, and Scopus, yielding 2,757 non-duplicate records from 1946 to 2019. The included studies measured depression or depressive symptoms and examined its association with inflammation in participants younger than 18 years. All relevant articles were reviewed and data extracted by two independent coders. Estimates were examined by using random-effects meta-analysis.

RESULTS

Twenty-two studies (20,791 participants) were included. Significant associations were observed between concurrent depression and CRP (n = 7; r = 0.12; 95% confidence interval [CI] = 0.04 to 0.19), and IL-6 (n = 7; r = 0.17; 95% CI= 0.10 to 0.24). Longitudinal analyses revealed that depression is a significant predictor of IL-6 (n = 3; r = 0.29; 95% CI= 0.04 to 0.50) and conversely, that inflammation (measured by CRP or IL-6) predicts future depression (n = 4; r = 0.04; 95% CI= 0.00 to 0.08).

LIMITATIONS

Results are limited by the small number of studies preventing examination of some moderator variables. Findings are correlational, not causal.

CONCLUSION

Depression is positively associated with concurrent and future inflammation among children and adolescents. Results suggest that bidirectional associations may exist between depression and a pro-inflammatory state.

Correlates of C-reactive protein with neural reward circuitry in adolescents with psychiatric symptoms

INTRODUCTION

Increased inflammation has been implicated in many psychiatric conditions across ages. We previously reported relationships between blood cytokine levels and anhedonia, the decreased capacity to experience pleasure, as well as with reward brain activation in adolescents with psychiatric symptoms. Here, we sought to extend this work in a larger cohort of adolescents with psychiatric symptoms and assess the relationships of C-Reactive Protein (CRP, inflammation biomarker) with clinical symptoms and reward-related brain activation.

METHODS

Subjects were 64 psychotropic-medication-free adolescents with psychiatric symptoms (ages: 15.17 ± 2.10, 44 female). All had psychiatric evaluations and dimensional assessments for anxiety, depression, anhedonia, and suicidality. Neuroimaging included the Reward Flanker fMRI Task examining brain activation during reward anticipation, attainment and positive prediction error. Both whole-brain and ROI analyses focusing on reward circuitry were performed. All analyses were controlled for BMI, age, and sex at pFWE < 0.05.

RESULTS

No relationships were identified between CRP and clinical symptom severity. CRP was positively associated with brain activation during reward attainment in regions of the visual and dorsal attention networks, as well as during positive prediction error in the cerebellum. In ROI analyses, CRP was negatively correlated with brain activation during reward anticipation in dorsal anterior cingulate cortex. When subject with high CRP was excluded, CRP was also positively correlated with positive predication error activation in nucleus accumbens.

CONCLUSION

Despite lack of associations of CRP with clinical symptomatology, our fMRI findings suggest a relationship between inflammation and brain function early course of psychiatric conditions.

Using network analysis to examine links between individual depressive symptoms, inflammatory markers, and covariates

BACKGROUND

Studies investigating the link between depressive symptoms and inflammation have yielded inconsistent results, which may be due to two factors. First, studies differed regarding the specific inflammatory markers studied and covariates accounted for. Second, specific depressive symptoms may be differentially related to inflammation. We address both challenges using network psychometrics.

METHODS

We estimated seven regularized Mixed Graphical Models in the Netherlands Study of Depression and Anxiety (NESDA) data (N = 2321) to explore shared variances among (1) depression severity, modeled via depression sum-score, nine DSM-5 symptoms, or 28 individual depressive symptoms; (2) inflammatory markers C-reactive protein (CRP), interleukin 6 (IL-6), and tumor necrosis factor α (TNF-α); (3) before and after adjusting for sex, age, body mass index (BMI), exercise, smoking, alcohol, and chronic diseases.

RESULTS

The depression sum-score was related to both IL-6 and CRP before, and only to IL-6 after covariate adjustment. When modeling the DSM-5 symptoms and CRP in a conceptual replication of Jokela et al., CRP was associated with 'sleep problems', 'energy level', and 'weight/appetite changes'; only the first two links survived covariate adjustment. In a conservative model with all 38 variables, symptoms and markers were unrelated. Following recent psychometric work, we re-estimated the full model without regularization: the depressive symptoms 'insomnia', 'hypersomnia', and 'aches and pain' showed unique positive relations to all inflammatory markers.

CONCLUSIONS

We found evidence for differential relations between markers, depressive symptoms, and covariates. Associations between symptoms and markers were attenuated after covariate adjustment; BMI and sex consistently showed strong relations with inflammatory markers.

Peripheral Markers of Depression

Major Depressive Disorder (MDD) is a leading cause of disability worldwide, creating a high medical and socioeconomic burden. There is a growing interest in the biological underpinnings of depression, which are reflected by altered levels of biological markers. Among others, enhanced inflammation has been reported in MDD, as reflected by increased concentrations of inflammatory markers-C-reactive protein, interleukin-6, tumor necrosis factor-α and soluble interleukin-2 receptor. Oxidative and nitrosative stress also plays a role in the pathophysiology of MDD. Notably, increased levels of lipid peroxidation markers are characteristic of MDD. Dysregulation of the stress axis, along with increased cortisol levels, have also been reported in MDD. Alterations in growth factors, with a significant decrease in brain-derived neurotrophic factor and an increase in fibroblast growth factor-2 and insulin-like growth factor-1 concentrations have also been found in MDD. Finally, kynurenine metabolites, increased glutamate and decreased total cholesterol also hold promise as reliable biomarkers for MDD. Research in the field of MDD biomarkers is hindered by insufficient understanding of MDD etiopathogenesis, substantial heterogeneity of the disorder, common co-morbidities and low specificity of biomarkers. The construction of biomarker panels and their evaluation with use of new technologies may have the potential to overcome the above mentioned obstacles.

Depression and Perceived Stress, but Not Anxiety, are Associated with Elevated Inflammation in an Obese Adult Population

BACKGROUND

Anxiety, depression and perceived stress are risk factors for adverse health problems. Inflammation participates in the development of chronic diseases such as psychiatric disorders. This study explored the relationships between inflammatory biomarkers and depression, anxiety and perceived stress in an obese adult population.

METHODS

The relationships between psychological scores and inflammatory markers were analyzed.

RESULTS

A higher BMI was not correlated with a higher anxiety score (P=0.152); however, BMI was positively associated with a higher depression score (P<0.001) and a higher perceived stress score (P<0.001). Multivariate linear regression analysis revealed that in participants with BMI≥30 and 25≤BMI<30, depression and perceived stress were significantly and independently associated with ICAM-1, E-selectin and CRP, but these associations were not observed in participants with BMI<25. The anxiety score was not associated with any inflammatory marker in any group of subjects, as determined by multivariate analysis.

CONCLUSION

Depression and perceived stress were strongly associated with increased serum levels of pro-inflammatory markers, including ICAM-1, E-selectin and CRP, among a general obese population from the United States. These results further suggest that depression and perceived stress might also be chronic systemic inflammatory diseases.

Does physical activity influence the association between depressive symptoms and low-grade inflammation in adults? A study of 8,048 adults

This study investigated whether physical activity (PA) influences the association between depression risk and low-grade inflammation. This was a cross-sectional study including 8,048 adults (18-59y). Depression symptoms were evaluated with the Beck depression inventory (BDI) and physical activity through the international physical activity questionnaire. Adults with infectious and inflammatory diseases were excluded. Blood samples were collected, including high sensitivity C-reactive protein (CRP), a marker of low-grade inflammation when ≥3mg/L. Additional measures of LDL-C, HDL-C, triglycerides and fasting glucose were also determined. Sex, chronological age, tobacco smoking, alcohol drinking, body mass index, dyslipidemia, high blood pressure and fasting glucose were used as covariates. Mediation models were conducted using the procedures of Karlson Holm Breen. Adults with elevated CRP (≥3mg/L) compared to those with low CRP (<3mg/L) presented with higher BDI scores [8.5%(95%CI:7.2%-10.1%) vs. 5.8%(95%CI:5.2-6.4)] as well as higher prevalence of physical inactivity 67.4% (95%CI:64.9-69.9) vs. 59.7% (95%CI:58.4-60.9). The prevalence of elevated CRP was highest in physically inactive adults with greater depression risk. Models revealed that physical activity risk explained 13% of the association between depression risk and elevated CRP (p=0.035), independently of potential confounders. Physical activity may reduce the association between depression symptoms and elevated CRP. Future longitudinal research is required to determine the directionality of the relationships observed.

Association between C reactive protein and depression in a population of healthy adults: the Cooper Center Longitudinal Study

The relationship between depression and inflammation is currently a topic of much interest. Previous studies have produced mixed results regarding the association between depression and high-sensitivity C reactive protein (hs-CRP). The aim of this report was to determine the association between hs-CRP and depression in a large sample of healthy adults. This is a cross-sectional study of 26,638 healthy adults seen for preventive medical examinations between December 2000 and August 2018 at the Cooper Clinic in Dallas, Texas. Multivariable logistic regression was used to evaluate the association between hs-CRP levels and depressive symptoms as measured by the 10-item Center for Epidemiologic Studies Depression Scale. Covariates included race, age, education, smoking history, alcohol use, menopausal status, body mass index (BMI), and medication use. The Hs-CRP level demonstrated a weakly positive association with depressive symptoms (OR 1.06 per mg/L, 95% CI 1.03 to 1.09 for women; OR 1.05 per mg/L, 95% CI 1.02 to 1.09 for men) that became insignificant when controlling for BMI in women (OR 1.02 per mg/L, 95% CI 0.98 to 1.05) and men (OR 1.02 per mg/L, 95% CI 0.98 to 1.05). Adjusting for antidepressant and statin use did not affect the association between hs-CRP and depressive symptoms in women (OR 0.99 per mg/L, 95% CI 0.96 to 1.03) or men (OR 1.01 per mg/L, 95% CI 0.97 to 1.05). Levels of hs-CRP were not associated with depression independent of BMI in a predominantly white, male population of higher socioeconomic status. This finding suggests that associations between hs-CRP and depression may be explained by obesity, which warrants further investigation into shared pathways between obesity and depression.

Association between C-reactive protein and mood disorder in a representative sample of the Canadian population: analysis of CHMS data 2013-2014

OBJECTIVES

The inflammatory biomarker C-reactive protein (CRP) measures systemic inflammation and has been shown to be increased in patients with mood disorders such as depression. The objective of this study was to determine the association between self-reported mood disorders with CRP levels in a representative sample of the Canadian population using the Canadian Health Measures Survey (CHMS) data 2013-2014.

METHODS

The CHMS is an ongoing national cross-sectional survey of Canadians about their general health. The current study used the data collected from Cycle 3 (2012/13) and was limited to adults aged 18 and older. Survey weights were assigned to adjust for non-response and non-random sample selection of the responding sample.

RESULTS

Data were analyzed from 5782 respondents (400 (6.9%) self-reported mood disorders and 5382 (93.1%) reported no mood disorders). The CRP level was significantly higher among those with mood disorders than among those without (3.22 (0.17) vs. 2.34 (0.04) mg/L, p = 0.003). Respondents with CRP levels > 10.00 mg/L had 2.69 greater odds of reporting a mood disorder compared with those with CRP levels ≤ 1.00 mg/L (p = 0.02). Higher proportions of respondents with mood disorders were older, had lower BMI, had secondary education, had weak sense of community, had higher proportion of asthma or arthritis, were current/past smokers, had daily consumption of 3+ drinks of alcohol, and used prescription drugs, cannabis/hashish, or other drugs compared with those without mood disorders (all p's < 0.05).

CONCLUSION

This study supported the association of CRP and mood disorder, specifically in a representative sample of the Canadian population. Targeting inflammation in depression and mood disorder warrants further study.

Gender differences in the link between depressive symptoms and ex vivo inflammatory responses are associated with markers of endotoxemia

Depressive symptoms are often linked with higher inflammation and inflammatory responses, although these associations are not always consistent. In a recent study (N = 160, 25–65 years, 67% women), our group reported gender differences relevant to this association: In men higher depressive symptoms were related to heightened ex vivo inflammatory responses to lipopolysaccharide (LPS), whereas in women higher depressive symptoms were related to attenuated inflammatory responses. In the present manuscript, we investigate markers of endotoxemia – i.e., markers of the presence of endotoxin in the blood, presumably due to bacterial translocation from the gut – as factors that elicit gender-dependent immune responses that may be associated with links between depressive symptoms and inflammation. We examined ex vivo inflammatory responses in whole blood via a composite index of LPS-stimulated cytokines. The ratio of LPS-binding protein to soluble CD14 receptor (LBP:sCD14) was quantified as an index of endotoxemia that captures the relative reliance on pro-inflammatory versus non-inflammatory pathways for bacterial clearance. Levels of endotoxemia markers in blood were found to moderate gender differences in the link between depressive symptoms and stimulated inflammation (Gender × Depressive Symptoms × Endotoxemia: B = −0.039, 95%CI [-0.068, 0.009], p = 0.010). At lower LBP:sCD14 levels, depressive symptoms and stimulated inflammation were unrelated in both men and women. However, with higher levels of LBP:sCD14, men showed an increasingly positive correlation and women showed a negative correlation between depressive symptoms and stimulated inflammation. Hence, men and women exhibited similar associations between depressive symptoms and inflammatory responses at lower endotoxin marker levels, but these associations became divergent at higher levels of endotoxin markers. This information provides a novel perspective on risk factors for depression-linked alterations in inflammation, which may help to determine susceptibility to the downstream physical consequences of depressive symptomatology.

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Depressive symptoms link to higher inflammation in men, lower inflammation in women.

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These gender differences were only apparent at moderate or higher endotoxemia.

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Men’s inflammation may be particularly sensitive to depressed mood and endotoxemia.

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Endotoxemia may be an important factor in gender, depression and inflammation links.

Inflammation and the dimensions of depression: A review

Patients with depressive disorders show a wide range of clinical manifestations including cognitive and neurovegetative symptoms. Importantly, these symptoms can differ in terms of biological etiology, and deconstructing depression into specific symptoms may provide valuable insight into the underlying neurobiology. Little research has examined inflammation in the context of depressive dimensions. Here we conduct a narrative review of the existing literature (21 studies) to elucidate whether the depression-inflammation link is symptom specific. Overall, there is evidence that an association exists between neurovegetative symptoms of depression and inflammation, independent of cognitive symptoms. The same cannot be said of cognitive symptoms and inflammation. There is also some evidence of gender differences in the directionality of the relationship between depression and inflammation. Potential explanations for these findings, limitations of the existing literature and recommendations for future research design are discussed.

Positive Association Between Serum Levels of High-Sensitivity C-Reactive Protein and Depression/Anxiety in Female, but Not Male, Patients With Type 2 Diabetes Mellitus

Purpose:

Patients with Type 2 diabetes (T2D) have increased risk of depression and anxiety. Evidence suggests that a heightened inflammatory state may contribute to this association. Females experience more depression and higher inflammation levels than males. This study compared associations of serum high-sensitivity C-reactive protein (hs-CRP) levels with symptoms of depression and anxiety between men and women with Type 2 diabetes mellitus (T2DM).

Method:

Cross-sectional data including demographic and disease characteristics, symptoms of depression and anxiety, clinical data, and laboratory values were collected from 392 patients with T2DM recruited from a general hospital in Shandong Province, China. We evaluated associations between serum hs-CRP level and symptoms of depression and anxiety in males and females separately using multiple linear regressions and χ2 tests for trend.

Results:

Sex moderated the association between serum hs-CRP level and symptoms of depression ( B = .112 [ SE = 0.049]; p = .022) and anxiety ( B = .137 [ SE = 0.053]; p = .011). Among females, hs-CRP level was positively associated with depression ( B = .034, 95% confidence interval [CI] = [.006, .061]; p = .016, false discovery rate [FDR]-adjusted p = .020) and anxiety ( B = .041, 95% CI [.011, .071], p = .007, FDR-adjusted p = .007). Positive trends indicated a higher prevalence of clinically significant symptoms of depression and anxiety in higher serum hs-CRP categories in females. No associations were found in males.

Conclusion:

Findings demonstrate that associations between serum hs-CRP level and symptoms of depression and anxiety in patients with T2D are sex-specific, with only females demonstrating a significant positive association.

Elevated hs-CRP level is associated with depression in younger adults: Results from the Korean National Health and Nutrition Examination Survey (KNHANES 2016)

INTRODUCTION

Reports on the association between the level of circulating high-sensitivity C-reactive protein (hs-CRP) and depression have been inconsistent. The aim of this study was to examine the association between hs-CRP and depression in a large sample.

METHODS

This study used data obtained from a representative Korean sample of 5447 people who participated in the first (2016) year of the seventh Korean National Health and Nutrition Examination Survey (KNHNES VII-1). Depression was identified using a cutoff of 5 on the Patient Health Questionnaire-9 (PHQ-9), and high hs-CPR level was defined as ≥ 3.0 mg/L.

FINDINGS

Participants with a high CRP levels had a significantly higher rate of depression than did those with a low hs-CRP levels (25.1% vs. 19.8%, p = 0.007). Serum hs-CRP was independently associated with the PHQ-9 total score after adjusting for potentially confounding factors (B = 0.014; 95% CI = 0.008-0.020). After controlling for body mass index (BMI), smoking, alcohol use problems, hypertension, diabetes, dyslipidemia, chronic illness related hs-CRP, and metabolic syndrome. Furthermore, elevated hs-CRP level was significantly associated with an increased risk of depression (adjusted OR = 1.44; 95% CI = 1.01-2.07) in younger adults, but no significant association was observed among older adults.

CONCLUSION

These findings suggest a significant correlation between high hs-CRP levels and depression in younger adults. Further studies are necessary to investigate the age-specific association and the biological mechanism involved.

The brain-adipocyte-gut network: Linking obesity and depression subtypes

Major depressive disorder (MDD) and obesity are dominant and inter-related health burdens. Obesity is a risk factor for MDD, and there is evidence MDD increases risk of obesity. However, description of a bidirectional relationship between obesity and MDD is misleading, as closer examination reveals distinct unidirectional relationships in MDD subtypes. MDD is frequently associated with weight loss, although obesity promotes MDD. In contrast, MDD with atypical features (MDD-AF) is characterised by subsequent weight gain and obesity. The bases of these distinct associations remain to be detailed, with conflicting findings clouding interpretation. These associations can be viewed within a systems biology framework-the psycho-immune neuroendocrine (PINE) network shared between MDD and metabolic disorders. Shared PINE subsystem perturbations may underlie increased MDD in overweight and obese people (obesity-associated depression), while obesity in MDD-AF (depression-associated obesity) involves more complex interactions between behavioural and biomolecular changes. In the former, the chronic PINE dysfunction triggering MDD is augmented by obesity-dependent dysregulation in shared networks, including inflammatory, leptin-ghrelin, neuroendocrine, and gut microbiome systems, influenced by chronic image-associated psychological stress (particularly in younger or female patients). In MDD-AF, behavioural dysregulation, including hypersensitivity to interpersonal rejection, fundamentally underpins energy imbalance (involving hyperphagia, lethargy, hypersomnia), with evolving obesity exaggerating these drivers via positive feedback (and potentially augmenting PINE disruption). In both settings, sex and age are important determinants of outcome, associated with differences in emotional versus cognitive dysregulation. A systems biology approach is recommended for further research into the pathophysiological networks underlying MDD and linking depression and obesity.