Association between depression and elevated C-reactive protein

Corticostriatal contributions to dysregulated motivated behaviors in stress, depression, and substance use disorders

Coordinated network activity, particularly in circuits arising from the prefrontal cortex innervating the ventral striatum, is crucial for normal processing of reward-related information which is perturbed in several psychiatric disorders characterized by dysregulated reward-related behaviors. Stress-induced depression and substance use disorders (SUDs) both share this common underlying pathology, manifested as deficits in perceived reward in depression, and increased attribution of positive valence to drug-predictive stimuli and dysfunctional cognition in SUDs. Here we review preclinical and clinical data that support dysregulation of motivated and reward-related behaviors as a core phenotype shared between these two disorders. We posit that altered processing of reward-related stimuli arises from dysregulated control of subcortical circuits by upstream regions implicated in executive control. Although multiple circuits are directly involved in reward processing, here we focus specifically on the role of corticostriatal circuit dysregulation. Moreover, we highlight the growing body of evidence indicating that such abnormalities may be due to heightened neuroimmune signaling by microglia, and that targeting the neuroimmune system may be a viable approach to treating this shared symptom.

The inflammatory underpinning of depression: An historical perspective

Over the last thirty years, substantial evidence has accumulated in support of the hypothesis that dysregulation of inflammatory processes plays a critical role in the pathophysiology of depression. This review traces the evolution of research supporting this link, discussing key findings from several major investigative fronts: Alterations in inflammatory markers associated with depression; Mood changes following the exogenous administration of inflammatory challenges; The anti-inflammatory properties of traditional antidepressants and the promising antidepressant effects of anti-inflammatory drugs. Additionally, it explores how inflammatory processes interact with specific brain regions and neurochemical systems to drive depressive pathology. A thorough analysis of the 100 most-cited experimental studies on the topic ensures a comprehensive, transparent and unbiased collection of references. This methodological approach offers a panoramic view of the inflammation-depression nexus, shedding light on the complexity of its mechanisms and their connections to psychiatric categorizations, symptoms, demographics, and life events. Synthesizing insights from this extensive research, the review presents an integrative model of the biological foundations of inflammation-associated depression. It posits that we have reached a critical juncture where the translation of this knowledge into personalized immunomodulatory treatments for depression is not just possible, but imperative.

Analyzing the Impact of Family Structure Changes on Children's Stress Levels Using a Stress Biomarker

Changes in family structure (e.g., parental separation or stepfamily formation) are associated with a deterioration in children's well-being. Most researchers have focused on the impact of such changes on children's educational and psychosocial outcomes, whereas the effects on children's biological processes have been studied less often. We analyze the effects of changes in family structure on children's stress levels using data from the German Health Interview and Examination Survey for Children and Adolescents study (2003-2006 and 2014-2017). Our outcome variable is the biomarker c-reactive protein (CRP), which correlates with psychological distress and is collected from blood samples. Calculating first-difference estimators, we analyze whether children have higher CRP levels after changing to (1) single-parent families (n = 117) or (2) stepfamilies (n = 80). Our findings suggest that changing to a single-parent family significantly increases children's stress, whereas changing to a stepfamily does not. These observations are important because increased stress in childhood can negatively affect well-being later in life.

Recent Progress in Biosensors for Depression Monitoring-Advancing Personalized Treatment

Depression is currently a major contributor to unnatural deaths and the healthcare burden globally, and a patient's battle with depression is often a long one. Because the causes, symptoms, and effects of medications are complex and highly individualized, early identification and personalized treatment of depression are key to improving treatment outcomes. The development of wearable electronics, machine learning, and other technologies in recent years has provided more possibilities for the realization of this goal. Conducting regular monitoring through biosensing technology allows for a more comprehensive and objective analysis than previous self-evaluations. This includes identifying depressive episodes, distinguishing somatization symptoms, analyzing etiology, and evaluating the effectiveness of treatment programs. This review summarizes recent research on biosensing technologies for depression. Special attention is given to technologies that can be portable or wearable, with the potential to enable patient use outside of the hospital, for long periods.

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.

Causal associations between severe mental illness and sepsis: a Mendelian randomization study

Objective

SMI (severe mental illness) has been identified as a risk factor for sepsis in observational studies; however, the causal association between them has yet to be firmly established. We conducted MR (mendelian randomization) to unveil the causal relationship between SMI and sepsis as well as sepsis mortality.

Methods

GWAS (Genome-wide association) data for major depression and schizophrenia were selected as exposure. GWAS data for sepsis and sepsis mortality were selected as outcome. Genetic variants significantly associated with the exposure (P value<1x10-6) were selected as instruments. We primarily employed the IVW (inverse-variance weighted) method for analysis. Furthermore, we employed Cochrane's Q test to assess heterogeneity and the MR-Egger intercept test to identify horizontal pleiotropy.

Results

We selected 108 SNPs (single nucleotide polymorphism) used to predict major depression and 260 SNPs that predicted schizophrenia. Genetically predicted major depression was suggestively linked to a higher sepsis risk (OR=1.13, 95%CI 1.02-1.26, P=0.023). In contrast, MR analysis did not find an association between schizophrenia and sepsis risk (OR=1.00, 95%CI 0.97-1.04, P=0.811). Furthermore, no significant causal evidence was found for genetically predicted SMI in sepsis mortality. Moreover, no heterogeneity and horizontal pleiotropy were detected.

Conclusion

Our research revealed a suggestive association between genetically predicted major depression and an elevated risk of sepsis in individuals of European ancestry. This finding can serve as a reminder for clinicians to consider the possibility of subsequent infection and sepsis in depressive patients, which may help reduce the incidence of sepsis in individuals with depression.

The Interaction between Stress and Inflammatory Bowel Disease in Pediatric and Adult Patients

Background: Inflammatory bowel diseases (IBDs) have seen an exponential increase in incidence, particularly among pediatric patients. Psychological stress is a significant risk factor influencing the disease course. This review assesses the interaction between stress and disease progression, focusing on articles that quantified inflammatory markers in IBD patients exposed to varying degrees of psychological stress. Methods: A systematic narrative literature review was conducted, focusing on the interaction between IBD and stress among adult and pediatric patients, as well as animal subjects. The research involved searching PubMed, Scopus, Medline, and Cochrane Library databases from 2000 to December 2023. Results: The interplay between the intestinal immunity response, the nervous system, and psychological disorders, known as the gut-brain axis, plays a major role in IBD pathophysiology. Various types of stressors alter gut mucosal integrity through different pathways, increasing gut mucosa permeability and promoting bacterial translocation. A denser microbial load in the gut wall emphasizes cytokine production, worsening the disease course. The risk of developing depression and anxiety is higher in IBD patients compared with the general population, and stress is a significant trigger for inducing acute flares of the disease. Conclusions: Further large studies should be conducted to assess the relationship between stressors, psychological disorders, and their impact on the course of IBD. Clinicians involved in the medical care of IBD patients should aim to implement stress reduction practices in addition to pharmacological therapies.

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.

Combined influence of depression and low-grade inflammation on mortality in peritoneal dialysis patients

BACKGROUND

The relationship between depression and systemic inflammation as risk factors for mortality is not well understood and requires further investigation.

METHODS

Patients undergoing continuous ambulatory peritoneal dialysis (CAPD) between July 01, 2015 to December 31, 2019, were analyzed and followed up until December 31, 2020. According to their status of depression (PHQ-9 score ≥ 5) and low-grade inflammation (hs-CRP level ≥ 3 mg/L), patients were divided into four groups (G1, without depression, nor inflammation; G2, with depression, without inflammation; G3, with inflammation, without depression; G4, with both depression and inflammation). We performed Kaplan-Meier and multivariable Cox proportional analyses of mortality for the combined influence of depression and systemic inflammation in this cohort.

RESULTS

During the mean follow-up of 36.3 ± 14.8 months, 73 deaths were recorded in 358 participants. Compared with patients in group G1, patients in group G2 and G3 carried 137% {hazard ratio (HR): 2.37, 95% confidence interval (CI): 1.06-5.23, p = 0.035} and 140% (HR: 2.40, 95% CI: 1.01-5.69, p = 0.048) higher risk of mortality. Patients in group G4 (with both depression and inflammation) showed the highest risks of all-cause mortality with 276% higher mortality risk (HR: 3.76, 95% CI: 1.73-8.15, p = 0.001), respectively.

CONCLUSION

The combined of depression and inflammation is associated with all-cause mortality in peritoneal dialysis patients, suggesting a need for further study of depression and low-grade inflammation in PD patients and potential relationship between them.

Treatment-resistant depression and risk of autoimmune diseases: evidence from a population-based cohort and nested case-control study

Recent literature indicates that patients with depression had increased immune activation. We hypothesised that treatment-resistant depression (TRD), an indicator of non-responsive depression with long-term dysregulated inflammation, could be an independent risk factor for subsequent autoimmune diseases. We performed a cohort study and a nested case-control study to examine the association between TRD and risk of autoimmune diseases, and to explore potential sex-specific difference. Using electronic medical records in Hong Kong, we identified 24,576 patients with incident depression between 2014 and 2016 without autoimmune history and followed up from diagnosis to death or December 2020 to identify TRD status and autoimmune incidence. TRD was defined as having at least two antidepressant regimens and the third regimen to confirm previous treatment failures. Based on age, sex and year of depression, we matched TRD patients 1:4 to the non-TRD in the cohort analysis using nearest-neighbour matching, and matched cases and controls 1:10 using incidence density sampling in the nested case-control analysis. We conducted survival analyses and conditional logistic regression respectively for risk estimation, adjusting for medical history. Across the study period, 4349 patients without autoimmune history (17.7%) developed TRD. With 71,163 person-years of follow-up, the cumulative incidence of 22 types of autoimmune diseases among the TRD patients was generally higher than the non-TRD (21.5 vs. 14.4 per 10,000 person-years). Cox model suggested a non-significant association (HR:1.48, 95% CI: 0.99-2.24, p = 0.059), whereas conditional logistic model showed a significant association (OR: 1.67, 95% CI: 1.10-2.53, p = 0.017) between TRD status and autoimmune diseases. Subgroup analysis showed that the association was significant in organ-specific diseases but not in systemic diseases. Risk magnitudes were generally higher among men compared to women. In conclusion, our findings provide evidence for an increased risk of autoimmune diseases in patients with TRD. Controlling chronic inflammation in hard-to-treat depression might play a role in preventing subsequent autoimmunity.

Living alone and cardiovascular outcomes: a meta-analysis of 11 cohort studies

To explore whether living alone could increase the risk of cardiovascular outcomes. We searched PubMed, EMBASE, and Web of Science from their inception to 5 October 2020. Cohort studies evaluating the relationship between living alone and cardiovascular outcomes were included. Subgroup analyses were conducted to explore which characteristics would affect the relationship. A total of 13 effect sizes obtained from 11 studies were included and spanned from 1993 to 2019, with 424,286 participants. This study found that living alone increased the risk of cardiovascular outcomes (HR = 1.22, 95% CI: 1.10-1.36, I² = 80.3%, P = 0.000). In subgroup analyses, living alone increased the risk of cardiovascular outcomes in patients from Europe (HR = 1.37, 95% CI: 1.17-1.61, I² = 76.2%, P = 0.000), but not increased in Asia (HR = 1.17, 95% CI: 0.83-1.66, I² = 76.2%, P = 0.000) and multiple regions (HR = 1.02, 95% CI: 0.96-1.08, I² = 0.0%, P = 0.738). For different cardiovascular outcomes, living alone has statistical significance in increasing the risk of cardiovascular mortality (HR = 1.23, 95% CI: 1.05-1.46, I² = 84.0%, P = 0.000) and myocardial infarction (HR = 1.11, 95% CI: 1.02-1.21, I² = 29.6%, P = 0.213). The risk of cardiovascular mortality in men was higher than women (HR = 1.52, 95% CI: 1.24-1.86 vs HR = 1.01, 95% CI: 0.85-1.20; P < 0.05 for interaction). Sensitivity analysis suggested that the results of the meta-analysis were robust. In conclusion, living alone could increase the risk of cardiovascular outcomes and men were more prone to cardiovascular mortality and myocardial infarction.

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.

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.

Prevalence and risk factors for chalazion in an older veteran population

BACKGROUND

Chalazia are common inflammatory eyelid lesions, but their epidemiology remains understudied. This retrospective case-control study examined the prevalence, risk factors and geographic distribution of chalazia in a large veteran population.

METHODS

Data on all individuals seen at a Veterans Affairs (VA) clinic between October 2010 and October 2015 were extracted from the VA health database. Subjects were grouped based on International Classification of Diseases, Ninth Revision (ICD-9) code for chalazion. Univariable logistic regression modelling was used to identify clinical and demographic factors associated with chalazion presence, followed by multivariable modelling to examine which factors predicted risk concomitantly. All cases were mapped across the continental US using geographic information systems modelling to examine how prevalence rates varied geographically.

RESULTS

Overall, 208 720 of 3 453 944 (6.04%) subjects were diagnosed with chalazion during the study period. Prevalence was highest in coastal regions. The mean age of the population was 69.32±13.9 years and most patients were male (93.47%), white (77.13%) and non-Hispanic (93.72%). Factors associated with chalazion risk included smoking (OR=1.12, p<0.0005), conditions of the tear film (blepharitis (OR=4.84, p<0.0005), conjunctivitis (OR=2.78, p<0.0005), dry eye (OR=3.0, p<0.0005)), conditions affecting periocular skin (eyelid dermatitis (OR=2.95, p<0.0005), rosacea (OR=2.50, p<0.0005)), allergic conditions (history of allergies (OR=1.56, p<0.0005)) and systemic disorders (gastritis (OR=1.54, p<0.0005), irritable bowel syndrome (OR=1.45, p<0.0005), depression (OR=1.35, p<0.0005), anxiety (OR=1.31, p<0.0005)). These factors remained associated with chalazion risk when examined concomitantly.

CONCLUSION

Periocular skin, eyelid margin and tear film abnormalities were most strongly associated with risk for chalazion. The impact of environmental conditions on risk for chalazion represents an area in need of further study.

Depression duration and risk of incident cardiovascular disease: A population-based six-year cohort study

BACKGROUND

Depression symptoms are significantly associated with an increased risk of cardiovascular disease (CVD). However, understanding of the magnitude of the association between depression duration and risk of CVD is limited. Therefore, we aimed to assess whether a longer duration of exposure to depression is associated with a higher risk of new-onset CVD.

METHODS

We conducted a territory-wide retrospective cohort study among patients (≥ 10 years old) with depression diagnosed between January and December 2014 in Hong Kong. The observation period spanned January 1, 2014, to December 31, 2019, and all participants had no CVD at baseline. Incidence of CVD was calculated. We used Cox proportional hazard regression to adjust confounders and estimate hazard ratios of CVD risk.

RESULTS

Among 11,651 participants with depression, 1306 (11.2%) individuals developed CVD. Multi-adjusted models showed individuals with depression duration of 2-5 years (Hazard Ratios [HRs]: 1.38 [95% confidence interval (CI): 1.19-1.60]) and ≥6 years (1.45 [1.25-1.68]) had a significantly escalated risk of developing CVD, compared to those with depression within one year. Stratified analyses indicated that the association was prominent in women and those under 65 years old.

LIMITATIONS

Lack of depression severity information and the small sample size in some subgroup analyses.

CONCLUSIONS

Longer exposure to depression is associated with significant increased risk of CVD. The interplay between mental and vascular health emphasizes the need for CVD prevention in patients with long-term depression.

Lower Life Satisfaction and Inflammation in African American Adults: Body Adiposity Mediation and Sex Moderation

Both lower life satisfaction (LLS) and chronic inflammation are underlying conditions for numerous diseases. We investigated their associations in African American adults, within the context of three hypotheses: (a) perceived LLS will be positively associated with inflammation measured by serum C-reactive protein (CRP); (b) this association will be mediated by body adiposity; and (c) these associations will be moderated by sex. Participants (n = 83; >45 years; 59% women) were a subsample of a larger church-based intervention to reduce cardiovascular risks and were assessed at baseline and after 6 months. Body adiposity (BMI/hip/waist circumferences) was measured by standardized methods and CRP with ELISA. LLS was self-reported. The analyses were conducted in the structural equation modeling (SEM) framework. The direct relationship between LLS and CRP was significant for all participants but was mediated by BMI/hip/waist circumferences. Multi-group SEM analysis provided evidence for sex moderation by showing that the mediating pathway from LLS to CRP through BMI, and to a lesser extent through hip/waist circumferences, was significant only in women. In conclusion, perceived LLS was positively associated with the level of inflammation mediated by BMI/hip/waist circumference, with the association between LLS and CRP being stronger in women. These findings contribute to the current literature untangling mediation/moderation processes in which perceived LLS may contribute to adiposity-related inflammation. They also add to precision medicine development, suggesting that stress and inflammation-reducing interventions should focus on African Americans, particularly women.

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.

Sexual minorities are at elevated risk of cardiovascular disease from a younger age than heterosexuals

Cardiovascular disease is the leading cause of death worldwide. In this study, we assessed factors related to cardiovascular disease risk and outcomes among sexual minorities (SM). Data from multiple waves of the PATH study were used in this analysis. Multivariable regression models were used to assess the association between sexual identity and: tobacco or e-cigarette use, adverse cardiovascular events, and age at first diagnosis of adverse cardiovascular disease events. In our sample (N = 23,205), 1,660 (7.15%) participants identified as SM. SM men, relative to heterosexual men, are more likely to be diagnosed with high blood pressure (aRR = 1.27; 95% CI 1.10, 1.47), high cholesterol (aRR = 1.32; 95% CI: 1.12, 1.55), congestive heart failure (aRR = 2.29; 95% CI 1.13, 4.65), stroke (aRR = 2.39; 95% CI: 1.14, 5.04), heart attack (aRR = 2.40; 95% CI 1.42, 4.04), and other heart conditions (aRR = 1.52; 95% CI: 1.06, 2.18). Although no simple differences were observed among SM women compared to heterosexual women, SM women were more likely to be diagnosed at a younger age for high blood pressure (aRR = -0.69; 95% CI - 1.08, - 0.29), high cholesterol (aRR = -0.77; 95% CI - 1.15, - 0.38), stroke (aRR =  - 1.04; 95% CI - 1.94, - 0.13), and heart attack (aRR =  - 1.26; 95% CI - 2.42, - 0.10). SM men were only diagnosed at a younger age for stroke (aRR =  - 1.18; 95% CI - 2.06, - 0.30). Compared to heterosexuals, sexual minorities are at higher risk for cardiovascular disease, more likely to develop cardiovascular disease at an earlier age, and more likely to use tobacco products. Future research should focus on decreasing cardiovascular risk among sexual minorities including reducing tobacco use and stress. Screening recommendations for sexual minority populations should also be reviewed in light of a growing body of literature suggesting elevated risk from a young age.

Relationship between CRP and depression: A genetically sensitive study in Sri Lanka

BACKGROUND

Previous studies have shown associations between major depression and C-reactive protein (CRP) levels. Few studies have considered the extent to which shared genetic and environmental factors contribute to this association, nor have they considered the relationship outside of European populations. We examined the association between CRP levels and depression and their aetiology in a Sri Lankan population.

METHODS

Data were collected from 2577 twins and 899 singletons in Colombo, Sri Lanka. Depression symptoms were assessed using the revised Beck Depression Inventory (BDI-II). High-sensitive CRP blood levels were assessed using immunoturbidimetry. Linear regressions were performed to test the association between CRP and depression. The heritability of CRP levels was estimated using Structural Equation Modelling.

RESULTS

CRP was significantly associated with BMI (p < 0.01) but not depression (p > 0.05). In males, variance in CRP levels was explained by shared environment (51% 95%CIs: 13-62) and non-shared environment (45% 95%CIs: 36-54). In contrast, in females, CRP variance was explained by genetic (41% 95%CIs: 10-52) and non-shared environment (56% 95%CIs: 47-67). A genetic correlation between CRP and BMI was observed in females only.

LIMITATIONS

CRP level was based on a single data collection point, longer term data collection would give a more accurate picture of an individual's state of inflammation.

CONCLUSIONS

The lack of association between depression and CRP strengthens the hypothesis that inflammation might contribute to the development of some, but not all types of depression. CRP levels were moderated by the environment, suggesting interventions aimed at reducing CRP levels and risk for inflammatory conditions, particularly in males.

Comparing Genetic and Socioenvironmental Contributions to Ethnic Differences in C-Reactive Protein

C-reactive protein (CRP) is a routinely measured blood biomarker for inflammation. Elevated levels of circulating CRP are associated with response to infection, risk for a number of complex common diseases, and psychosocial stress. The objective of this study was to compare the contributions of genetic ancestry, socioenvironmental factors, and inflammation-related health conditions to ethnic differences in C-reactive protein levels. We used multivariable regression to compare CRP blood serum levels between Black and White ethnic groups from the United Kingdom Biobank (UKBB) prospective cohort study. CRP serum levels are significantly associated with ethnicity in an age and sex adjusted model. Study participants who identify as Black have higher average CRP than those who identify as White, CRP increases with age, and females have higher average CRP than males. Ethnicity and sex show a significant interaction effect on CRP. Black females have higher average CRP levels than White females, whereas White males have higher average CRP than Black males. Significant associations between CRP, ethnicity, and genetic ancestry are almost completely attenuated in a fully adjusted model that includes socioenvironmental factors and inflammation-related health conditions. BMI, smoking, and socioeconomic deprivation all have high relative effects on CRP. These results indicate that socioenvironmental factors contribute more to CRP ethnic differences than genetics. Differences in CRP are associated with ethnic disparities for a number of chronic diseases, including type 2 diabetes, essential hypertension, sarcoidosis, and lupus erythematosus. Our results indicate that ethnic differences in CRP are linked to both socioenvironmental factors and numerous ethnic health disparities.

Potential biomarkers of major depression diagnosis and chronicity

BACKGROUND

Molecular biomarkers are promising tools to be routinely used in clinical psychiatry. Among psychiatric diseases, major depression disorder (MDD) has gotten attention due to its growing prevalence and morbidity.

METHODS

We tested some peripheral molecular parameters such as serum mature Brain-Derived Neurotrophic Factor (mBDNF), plasma C-Reactive Protein (CRP), serum cortisol (SC), and the salivary Cortisol Awakening Response (CAR), as well as the Pittsburgh sleep quality inventory (PSQI), as part of a multibiomarker panel for potential use in MDD diagnosis and evaluation of disease's chronicity using regression models, and ROC curve.

RESULTS

For diagnosis model, two groups were analyzed: patients in the first episode of major depression (MD: n = 30) and a healthy control (CG: n = 32). None of those diagnosis models tested had greater power than Hamilton Depression Rating Scale-6. For MDD chronicity, a group of patients with treatment-resistant major depression (TRD: n = 28) was tested across the MD group. The best chronicity model (p < 0.05) that discriminated between MD and TRD included four parameters, namely PSQI, CAR, SC, and mBDNF (AUC ROC = 0.99), with 96% of sensitivity and 93% of specificity.

CONCLUSION

These results indicate that changes in specific biomarkers (CAR, SC, mBDNF and PSQI) have potential on the evaluation of MDD chronicity, but not for its diagnosis. Therefore, these findings can contribute for further studies aiming the development of a stronger model to be commercially available and used in psychiatry clinical practice.

Severity of Psychologic Stressors Reflects Course of Crohn's Disease in Two Siblings

A significant rise in Crohn's disease (CD) cases amongst first-degree relatives strongly suggests that inflammatory bowel disease (IBD) has a genetic component. Adherence to medical management is at the forefront for preventing disease relapse. However, given the role that stress places on the immune system, it is imperative to implore an individual's psychologic stressors to prevent future disease complications. This case of CD in two siblings, male and female, highlights the unique stress experienced by each patient at the time of symptom onset, the severity of their inflammatory symptoms, and their course of disease over several years. The male patient suffered from gender dysphoria and social anxiety for over a decade and had more chronic stress and severe complications of his disease. On the other hand, the stressors faced by his sister were periodic in nature and symptoms resided once stressful periods ended. For select patients, it is indicative that referral for psychotherapy should be considered as an ongoing mainstay of management. This case is intended to highlight the need for including psychotherapy in addition to medical management in order to treat IBD holistically.

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.

Inflammation is associated with future depressive symptoms among older adults

Inflammation has been reliably associated with depression. However, the directionality of this association is poorly understood, with evidence that elevated inflammation may promote and precede the development of depression, as well as arise following its expression. Using data from older adults (N ​= ​1,072, ages 60-73) who participated in the ongoing longitudinal St. Louis Personality and Aging Network (SPAN) study, we examined whether inflammatory markers (interleukin-6: IL-6, C-reactive protein: CRP, and tumor necrosis factor α: TNFα) and depression were prospectively predictive of one another. Fasting serum samples and self-reports of depressive symptoms (Beck Depression Inventory-II) were obtained from participants at 2 sessions approximately 2 years apart. Structural equation models as well as regressions that accounted for a host of potentially confounding covariates and depression at baseline revealed that baseline IL-6 and CRP, but not baseline TNFα were associated with elevated depressive symptoms at the follow-up session (IL-6: β ​= ​0.080, p ​= ​0.036; CRP: β ​= ​0.083, p ​= ​0.03; TNFα: β ​= ​0.039, p ​= ​0.314). However, there was no association between baseline depressive symptoms and follow-up inflammatory markers (βs ​= ​-0.12 to -0.006, all ps ​> ​0.05). Collectively, these data suggest that inflammation prospectively predicts depression, but depression does not predict inflammation in older age. These data add to a growing literature suggesting that inflammatory signaling may plausibly promote the development of depression.

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.

Relationship Between Serum Fibrinogen Level and Depressive Symptoms in an Adult Population with Spinal Cord Injury: A Cross-Sectional Study

PURPOSE

Depression is associated with an inflammatory immune response. There are minimal data regarding the association of inflammatory markers with depression in patients with spinal cord injury (SCI). We aimed to investigate the association of inflammatory markers with depression in middle-aged and elderly SCI patients.

METHODS

Data were obtained from the Midlife in the United States (MIDUS) study, a longitudinal study of a representative sample of the adult population. We analyzed the associations of serum levels of fibrinogen, interleukin-6, tumor necrosis factor-ɑ, and C-reactive protein with depressive symptoms.

RESULTS

The median participant age was 52.5 years; 44.9% of participants were men. Multivariate linear regression analyses showed that an increased serum fibrinogen level (Sβ = 0.114, p = 0.005) was associated with higher Centre for Epidemiological Studies-Depression (CES-D) scores after adjustment for age, sex, body mass index (BMI), ethnicity, education, marital status, smoking, alcohol use, exercise, perceived stress score, and cardiovascular disease (CVD). Multivariate logistic regression analysis showed that an increased serum fibrinogen level was independently associated with a history of depression (odds ratio [OR] = 1.240, 95% confidence interval [CI] = 1.103-1.997, p = 0.012) and depressive symptoms (OR = 1.884, 95% CI = 1.165-2.499, p < 0.001; CES-D score ≥ 16) after adjustment for confounding factors. Stratified analysis revealed that the association between serum fibrinogen level and depressive symptoms was affected by antidepressant use.

CONCLUSION

Serum fibrinogen level had a significantly positive association with depressive symptoms in middle-aged and elderly patients with SCI. Future longitudinal cohort studies should evaluate the possible use of serum fibrinogen for diagnosis of depression in SCI patients.

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.

Fibrinogen Levels and the Risk of Cerebrovascular Events in Older Adults With Both Depressive Symptoms and Cognitive Impairment: A Prospective Study

Depression and cognitive impairment have been identified as risk factors for cerebrovascular events (CVE), and one of their potential etiological pathways is inflammatory status. This prospective study aims to investigate the association between inflammatory markers and the risk of CVE in a population of 2659 older adults, enrolled in the Progetto Veneto Anziani (Pro.V.A.), with depressive symptoms, cognitive impairment, or both conditions. For each individual, we assessed at baseline the presence of depressive symptoms (defined as a Geriatric Depression Scale ≥11), cognitive impairment (defined as a Mini-Mental State Examination <24), and serum levels of fibrinogen, white blood cells (WBC), and erythrocyte sedimentation rate (ESR). During a 4.4-year follow-up, 188 (7.1%) participants had CVE. Among the inflammatory markers, high fibrinogen values were associated with a 50% higher risk of CVE in the whole sample, and with a 4-fold higher risk in individuals with both depressive symptoms and cognitive impairment (hazard ratio = 4.04, 95% confidence interval: 1.45-11.23). Elevated WBC were associated with a 5% higher risk of CVE in the whole sample and in those with both conditions. No significant association was observed with the ESR. In conclusion, our study found that high fibrinogen levels may predict the risk of CVE in older people with concomitant depressive symptoms and cognitive impairment. Therefore, fibrinogen could be considered as an easily accessible aging biomarker, which might estimate the chronic inflammatory status and its potential detrimental effects on the most vulnerable older adults.

Dietary fiber and its associations with depression and inflammation

Dietary fiber is a crucial component of a healthy diet, with benefits that can be attributed to processes in the gut microbiota and the resulting by-products. Observational studies support associations between dietary fiber intake and depression and inflammation, but the potential mechanisms are poorly understood. This review examines evidence of the effects of dietary fiber on depression and inflammation and considers plausible mechanisms linking dietary fiber and depression, including microbiota-driven modification of gene expression and increased production of neurotransmitters. Additionally, inflammation may mediate the relationship between dietary fiber intake and depression. A high-fiber diet potentially lowers inflammation by modifying both the pH and the permeability of the gut. The resultant reduction in inflammatory compounds may alter neurotransmitter concentrations to reduce symptoms of depression. Further research into the link between dietary fiber intake and inflammation and depression is essential, as findings could potentially provide guidance for improvement in or prevention of inflammatory and depressive disorders.

C-reactive protein in saliva and dried blood spot as markers of stress reactivity in healthy African-Americans

Aim: Noninvasive assessments of C-reactive protein (CRP) in stress contexts have seldom been compared. This study evaluated CRP response to acute social stress as measured in saliva and dried blood spot (DBS). Materials & methods: African-Americans (N = 118; mean age = 32 years) participated in a laboratory-based social-evaluative stressor task. Six saliva samples taken before, during and after were assayed for salivary CRP. DBS measurements of CRP were taken alongside saliva at the first and last collection. Results: Salivary and DBS CRP were modestly positively associated with one another at baseline, and only salivary CRP increased in response to the stressor task. Conclusion: Noninvasive measures of CRP reactivity may be only moderately related to one another in stress reactivity contexts.

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 effect of self-rated health (SRH) on all-cause mortality and specific causes of mortality among individuals aged 50 years and older

Although different gender associations between self-rated health (SRH) and mortality have been reported, the results of the respective studies have been inconsistent and little is known about the cause-specific relation of mortality with SRH by gender. Therefore, to evaluate the gender differences in all-cause or specific causes of mortality by SRH, this retrospective cohort study was conducted using the data of 19,770 Korean adults aged 50 years and over who underwent health screening at Seoul National University Hospital between March 1995 and December 2008. SRH was surveyed using a simple questionnaire, and the all-cause mortality and cause-specific mortality were followed up from baseline screening until December 31, 2016. Results showed that the relationship between SRH and all-cause mortality differed by gender, and the differences also varied depending on the cause of death. In men, the adjusted hazard ratio (aHR) of all-cause mortality was higher in the poor SRH group than the very good SRH groups even after adjustment for socio-demographic, clinical, and behavioral risk factors (aHR:1.97, 95% CI 1.51-2.56), and these results were similar to those for cancer, cardiovascular, and respiratory disease mortalities (aHR:1.52, 95% CI 0.93-2.50; aHR: 2.11, 95% CI 1.19-3.74; aHR:10.30, 95% CI 2.39-44.44, respectively). However, in women, the association between SRH and all-cause mortality was insignificant, and inverse relationships were found for cardiovascular and respiratory disease mortalities in the poor and very good SRH groups. Cancer mortality had a positive relation with SRH (aHR: 1.14, 95% CI 0.75-1.72; aHR: 2.58, 95% CI 1.03-6.48; aHR: 0.49, 95% CI 0.24-0.98; aHR: 0.15, 95% CI 0.04-0.57: all-cause, cancer, cardiovascular, and respiratory disease mortalities, respectively). Clinicians need to take these gender differences by SRH into account when evaluating the health status of over-middle aged adults.

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.

Psychological distress and C-reactive protein in a South African national survey

OBJECTIVE

To examine the association of psychological distress with serum C-reactive protein (CRP) in a South African cohort.

METHODS

Data were analysed on individuals aged ≥15 years from the South African National Health and Nutrition Examination Survey (SANHANES) of 2012. Psychological distress was evaluated using the Kessler Psychological Distress Scale. Linear regression models assessed the association of psychological distress with serum CRP, adjusting for possible confounding factors.

RESULTS

The analytic sample comprised n = 3944 individuals (mean age = 40 and sex = 36% males). Psychological distress was significantly associated with increased serum CRP levels (B = 0.31 and p = 0.001). This association was no longer significant after adjusting for demographic variables, lifestyle factors, cardiac disease, diabetes, hypertension, trauma and anti-inflammatory medication use (B = 0.15 and p = 0.062).

CONCLUSION

Psychological distress was associated with elevated levels of CRP among South African adults. However, the association was confounded by a range of factors, with demographic variables (age, sex and population group) having the largest confounding effect. These findings indicate that CRP is not a useful biomarker of psychological distress, and that additional work is needed on the underlying psychobiology of psychological distress.

Changes in inflammation with treatment for bipolar II depression: Pilot trial data on differential effects of psychotherapy and medication

OBJECTIVES

Limited prospective data, mostly focused on bipolar I disorder, suggests that pro-inflammatory cytokines are elevated in abnormal mood states. We evaluated whether treatment normalizes peripheral markers of inflammation in bipolar II disorder.

METHODS

Using data from a randomized clinical trial of Interpersonal and Social Rhythm Therapy (IPSRT) + quetiapine vs. IPSRT + placebo for bipolar II depression, we examined whether these treatments for bipolar II depression impact inflammatory cytokines and whether observed changes in cytokines are associated with changes in depressive symptomatology as measured by the Hamilton Rating Scale for Depression (HRSD-17).

RESULTS

Cytokine values were available for 33 participants who completed baseline and 20-week followup visits. After excluding those with CRP values >=10 mg/L, there were 27 patients available for analysis (IPSRT+quetiapine N=10, IPSRT+placebo N=17). Baseline measure of inflammation did not appear to moderate treatment response, nor was change in HRSD-17 score correlated with changes in cytokines. Those who received IPSRT+quetiapine had significantly greater increases in IL-6 (p=0.02) and TNF-α (p=0.04), even after adjusting for changes in body mass index, than the IPSRT alone group. Descriptively, the quetiapine group showed increases in pro-inflammatory and decreases in anti-inflammatory cytokines and the psychotherapy group showed reduced pro-inflammatory cytokines.

CONCLUSIONS

Despite both groups showing depression improvement, this small study suggests a more pro-inflammatory cytokine profile over time with quetiapine plus psychotherapy compared to psychotherapy alone. Elevated risk of cardiovascular morbidity and mortality among those with bipolar II disorder underscores the importance of delivering treatments that do not exacerbate these risk factors.

Inflammatory Bowel Disease: A Stressed "Gut/Feeling"

Inflammatory bowel disease (IBD) is a chronic and relapsing intestinal inflammatory condition, hallmarked by a disturbance in the bidirectional interaction between gut and brain. In general, the gut/brain axis involves direct and/or indirect communication via the central and enteric nervous system, host innate immune system, and particularly the gut microbiota. This complex interaction implies that IBD is a complex multifactorial disease. There is increasing evidence that stress adversely affects the gut/microbiota/brain axis by altering intestinal mucosa permeability and cytokine secretion, thereby influencing the relapse risk and disease severity of IBD. Given the recurrent nature, therapeutic strategies particularly aim at achieving and maintaining remission of the disease. Alternatively, these strategies focus on preventing permanent bowel damage and concomitant long-term complications. In this review, we discuss the gut/microbiota/brain interplay with respect to chronic inflammation of the gastrointestinal tract and particularly shed light on the role of stress. Hence, we evaluated the therapeutic impact of stress management in IBD.

Independent and joint association of obesity and metabolic syndrome with depression and inflammation

OBJECTIVE

To investigate the separate and combined associations of obesity and metabolic syndrome (MetS) with depression and the role of inflammation.

METHOD

Depression was assessed with the Patient Health Questionnaire-9 (PHQ-9) and was defined with a cutpoint of ≥10. Obesity was defined as body mass index (BMI) ≥30 kg/m2 from measured height and weight. MetS was defined based on the American Heart Association consensus definition. Participants were divided into four groups: healthy normal weight (MHN), metabolically healthy obese (MHO), metabolically unhealthy normal weight (MUN), and metabolic unhealthy obese (MUO). C-Reactive protein was assessed in a subsample.

RESULTS

A total of 18,025 subjects were included in the analysis. Participants with MUO had the highest prevalence of depression compared with the MHN group (14.8% vs. 6.8, p < .001). While both obesity and MetS were independently associated with depression, there was a significant interaction between the two (p < .001), indicating that the associations of obesity and MetS with depression were synergistic. After adjusting for baseline characteristics, compared with the MHN group, the MUO group had the highest odds of depression (odds ratio [OR] = 2.30, 95% CI [2.03, 2.61]), followed by MHO group (OR = 1.51, 95% CI [1.30, 1.74]) and the MUN group (OR = 1.39, 95% CI [1.18, 1.64]). The MUO group also showed the highest level of C-reactive protein, and the latter partially mediated the effect between MUO and depressive symptoms (20.5% of the total effect).

CONCLUSION

Both obesity and MetS are associated with depression independent of each other, but when present together, these conditions have a synergistic association with depression. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Longitudinal effects of race, ethnicity, and psychosocial disadvantage on systemic inflammation

Objective

Psychosocial factors likely contribute to racial and ethnic inequalities in cardiovascular diseases (CVDs). However, precise social, psychological, and physiological pathways linking race and ethnicity to the development of CVDs are not well understood. Systemic inflammation, commonly indexed by C-reactive protein (CRP), is a biomarker for CVD risk and progression. The objective of this study was to identify mediating pathways from race and ethnicity to CRP through social, psychological, and behavioral variables.

Methods

Using data from 12,382 participants aged 51 and older in the Health and Retirement Study, structural equation models tested for direct and indirect effects of race and ethnicity on CRP measured over four years through educational disadvantage, everyday discrimination, depressive symptoms, external locus of control, and smoking.

Results

Educational disadvantage mediated Black-White and Hispanic-White disparities in baseline CRP directly, as well as indirectly through elevated depressive symptoms, higher external locus of control, and smoking. Educational disadvantage also mediated Black-White and Hispanic-White disparities in CRP change directly, as well as indirectly through higher external locus of control and smoking. Independent of education, discrimination mediated Black-White differences in baseline CRP via elevated depressive symptoms, higher external locus of control, and smoking. Discrimination also mediated Black-White disparities in CRP change via external locus of control.

Conclusions

Results from this population-based, longitudinal study support the view that racially patterned social disadvantage is prospectively associated with longitudinal inflammatory processes, and some of these effects are independently mediated by psychological and behavioral factors. Biopsychosocial pathways to health disparities also differ between minority groups.

Inflammatory and vascular correlates of mood change over 8 weeks

Background

Mood disorders have been associated with a variety of cardiovascular disease risk factors, including inflammation and large artery stiffness, particularly while depressed although longitudinal studies have been limited.

Methods

With measurements at baseline and 8 weeks, the researchers prospectively assessed mood, levels of inflammatory markers (hsCRP and TNF-α), serum lipids, and large artery stiffness in a cohort of 26 participants with a diagnosis of a mood disorder, enriched for current depression. Depressive symptoms were measured using the Montgomery-Åsberg Depression Rating Scale (MADRS) at baseline and 8 weeks. Associations between depressive symptoms and other measures were assessed using linear mixed models, unadjusted and adjusted for age and BMI.

Results

The mean age of the participants (n=26) was 41.6 (standard deviation [SD] 12.8) years, and 81% were female. During the study, there was a mean (SD) MADRS score improvement of 9.5 (9.4) from baseline to eight weeks. Reductions in the primary outcome TNF-α with improvement in depression fell short of significance (P=0.076). In secondary analyses, there was a statistically significant association between improved cholesterol ratio (P=0.038) and triglycerides (P=0.042) with depression improvement. There was no statistically significant change in large artery stiffness during the study.

Conclusion

Improved depressive symptoms were associated with improved cholesterol ratios even after adjustment, suggesting possible mechanism by which acute mood states may influence cardiovascular disease risk. Future longitudinal studies with extended and intensive follow-up investigating cardiovascular disease risk related to acute changes and persistence of mood symptoms is warranted.

Sex Difference in the Association between High-sensitivity C-reactive Protein and Depression: The 2016 Korea National Health and Nutrition Examination Survey

Elevated levels of circulating high-sensitivity C-reactive protein (hs-CRP) have been observed in depression, with the body mass index (BMI) being a major mediator of this association. However, the sex difference in the association between hs-CRP and depression remains unclear. This study aimed to investigate the sex difference in the association between hs-CRP and depression. Data from the 2016 Korea National Health and Nutritional Examination Survey were used for our study. High hs-CRP was defined as >3.0 mg/L, while depression was determined using a cut-off score of 10 in the Patient Health Questionnaire-9. The study population comprised 5,483 Korean adults. Men with high hs-CRP levels showed statistically higher prevalence of depression than those with low hs-CRP levels (8.90% vs. 3.65%, P < 0.0001). The high hs-CRP group was 1.86 times more likely to have depression after adjusting for BMI and other covariates in men (adjusted odds ratio: 1.86; 95% confidence interval: 1.07–3.25; P = 0.029). Meanwhile, no statistically significant association between hs-CRP and depression was found among women. Depression was considerably associated with hs-CRP only in men, indicating a biological difference between men and women that can independently modify the relationship between hs-CRP and depression.

Peripheral Biomarkers of Inflammation in Depression: Evidence from Animal Models and Clinical Studies

Depression is a highly prevalent psychiatric condition, with over 300 million sufferers, and is an important comorbidity for other conditions, like cardiovascular disorders or diabetes. Therapy is largely based on psychotherapy and/or pharmacological intervention, particularly aimed at altering neurotransmitter levels in the central nervous system, but inadequate response to treatment remains a significant clinical problem. Herein, evidence supporting a molecular link between inflammation and depression will be discussed, particularly the increased prevalence of depression in chronic inflammatory diseases and the evidence on the use of anti-inflammatory drugs to treat depression. Moreover, the potential for the levels of peripheral inflammatory molecules to act as depression biomarkers, in the diagnosis and monitoring of depression will be examined, considering clinical- and animal model-based evidence.

Salivary C-reactive protein among at-risk adolescents: A methods investigation of out of range immunoassay data

Inflammatory markers including C-Reactive Protein (CRP) are increasingly used within research and clinical settings. Yet, varying methodologies for cleaning immunoassay data with out of range (OOR) samples may alter characteristic levels of CRP, thereby obscuring interpretation and reliability. This study investigated the influence of eight immunoassay OOR data treatment techniques on salivary CRP (sCRP) samples from at-risk adolescents. Participants from the 'Sleep and Education: learning New Skills Early' (SENSE) Study were 86 adolescents at-risk for depression (50 female), aged 14.29 years (SD = 1.04). ANOVA results showed no statistically significant differences in average morning (F(7, 590) = 1.24, p = .28) and evening (F(7, 599)=1.29, p = .25) values produced by each OOR data cleaning technique. However, varying techniques produced differences in the magnitude of Pearson's correlations between consecutive saliva samples (r's between 0.27-0.78), and influenced the significance of a sCRP diurnal pattern; two techniques produced statistically higher morning than evening sCRP levels (t(85) = 2.70, p = .01 and t(85) = 2.67, p = .01), whereas six techniques failed to find statistical differences between morning and evening sCRP levels (p's >.05). Varying techniques also produced statistically divergent associations between sCRP and age and depressive symptoms. Results from this study provide evidence for the temporal stability of sCRP among adolescents, show winsorization as an effective OOR data management technique, and highlight the influence of methodological decisions in cleaning salivary biomarker data and the need for consistency within the field.

Longitudinal association of inflammation with depressive symptoms: A 7-year cross-lagged twin difference study

BACKGROUND

The direction of the association between inflammation and depressive symptoms remains inconsistent. The objective of this study was to evaluate the temporal relationship between inflammation and depressive symptoms, and to assess the role of genetic factors on this association.

METHODS

In this longitudinal cross-lagged twin difference study, we examined 166 (83 pairs) middle-aged male twins recruited from the Vietnam Era Twin Registry, who were assessed at baseline and after 7 years of follow-up. We assayed plasma levels of two inflammatory biomarkers, interleukin-6 (IL-6) and high sensitivity C-reactive protein (CRP) and measured depressive symptoms using the Beck Depression Inventory-II (BDI). To evaluate the direction of the association, we constructed multivariable mixed-effects regression models and calculated standardized beta-coefficients to compare the strength of the within-pair association for both pathways. We then conducted a stratified analysis by zygosity and assessed the associations in monozygotic and dizygotic twin pairs separately.

RESULTS

The 166 twins were 95% white and had a mean (SD) age of 54 (3) years at baseline. The cross-lagged analysis showed significant and positive associations from visit 1 IL-6 to visit 2 BDI across all models (beta-coefficients ranging from 0.18 to 0.22). However, the opposite pathway (visit 1 BDI to visit 2 IL-6) was not significant after adjusting for confounding factors. In contrast, visit 1 BDI was significantly associated with visit 2 CRP in all models (beta-coefficients ranging from 0.23 to 0.33), while the opposite pathway (visit 1 CRP to visit 2 BDI) showed no significant association. When stratifying by zygosity, significant associations from IL-6 to depression were only seen in monozygotic twins, but associations from depression to CRP were more robust in dizygotic twins, which implies that genetic factors may play a role in this association.

CONCLUSIONS

The association between inflammation and depression may be bidirectional. Elevated IL-6 levels are more likely to be a risk factor of depression rather than a consequence, while the opposite may be true for elevated CRP. The biological underpinnings of these bidirectional pathways need further evaluation.

Health, pre-disease and critical transition to disease in the psycho-immune-neuroendocrine network: Are there distinct states in the progression from health to major depressive disorder?

The psycho-immune-neuroendocrine (PINE) network is a regulatory network of interrelated physiological pathways that have been implicated in major depressive disorder (MDD). A model of disease progression for MDD is presented where the stable, healthy state of the PINE network (PINE physiome) undergoes progressive pathophysiological changes to an unstable but reversible pre-disease state (PINE pre-diseasome) with chronic stress. The PINE network may then undergo critical transition to a stable, possibly irreversible disease state of MDD (PINE pathome). Critical transition to disease is heralded by early warning signs which are detectible by biomarkers specific to the PINE network and may be used as a screening test for MDD. Critical transition to MDD may be different for each individual, as it is reliant on diathesis, which comprises genetic predisposition, intrauterine and developmental factors. Finally, we propose the PINE pre-disease state may form a "universal pre-disease state" for several non-communicable diseases (NCDs), and critical transition of the PINE network may lead to one of several frequently associated disease states (influenced by diathesis), supporting the existence of a common Chronic Illness Risk Network (CIRN). This may provide insight into both the puzzle of multifinality and the growing clinical challenge of multimorbidity.

Replication and reproducibility issues in the relationship between C-reactive protein and depression: A systematic review and focused meta-analysis

One of the most common inflammatory markers examined in depression is C-reactive protein (CRP). However, the magnitude of the association between CRP and depression when controlling for potentially confounding factors such as age, sex, socio-economic status, body mass index, medication and other substance use, and medical illness, is unclear. Inconsistencies in other methodological practices, such as sample collection, assaying, and data cleaning and transformation, may contribute to variations in results. We aggregate studies that examined the association between CRP and depression in two ways. First, a systematic review summarizes how studies of CRP and depression have reported on methodological issues. Second, a tiered meta-analysis aggregates studies that have adhered to various levels of methodological rigor. Findings from the systematic review indicate a lack of protocol detail provided. The effect between depression and CRP was small, but highly significant across all stages of the meta-analysis (p < 0.01). The effect size in the most methodologically rigorous stage of the meta-analysis, which included studies controlling for age, sex, obesity, medical conditions and substance, medication, or psychosocial factors, was small (r = 0.05). There were also only 26 articles in this stage (13% of studies from the systematic review), suggesting that more studies that consistently account for these confounding factors are needed. Additionally, an a priori quality score of methodological rigor was a significant moderator in this stage of the meta-analysis. The effect size was strikingly attenuated (r = 0.005) and non-significant in studies with higher quality scores. We describe a set of recommended guidelines for future research to consider, including sample collection and assaying procedures, data cleaning and statistical methods, and control variables to assess.

Gender differences in longitudinal relationships between depression and anxiety symptoms and inflammation in the health and retirement study

Depression and anxiety have been linked to elevated inflammation in cross-sectional and longitudinal studies. Yet, in terms of longitudinal studies, findings are inconsistent regarding whether depression predicts worsening inflammation or vice versa, and anxiety has been infrequently examined. Further, we know little about longitudinal relationships between inflammation and specific symptom profiles of depression and anxiety. The current study examined longitudinal associations between depression and anxiety symptoms and inflammation in 13,775 people (59% women, average age = 67) participating in the Health and Retirement Study - a population-based study focused on older adults. High sensitivity C-reactive protein and depression and anxiety symptoms were measured at two time-points separated by four years. We used cross-lagged panel models to examine bidirectional relationships, and tested interactions with gender. We found that depressive symptoms predicted increasing inflammation for men, but not for women, and inflammation predicted worsening depression for women, but not for men. These gender differences were driven by somatic symptoms. Specifically, somatic symptoms predicted increasing inflammation for men only and were predicted by inflammation for women only. Regardless of gender, inflammation predicted worsening dysphoric symptoms of depression, and lack of positive affect predicted increasing inflammation over time. Anxiety was not associated with inflammation longitudinally. These findings indicate bidirectional relationships between depressive symptoms and inflammation, but not between anxiety symptoms and inflammation, and that the direction of these effects may differ by gender and type of depressive symptom.