Where there is depression, there is inflammation... sometimes!

Biopsychosocial factors in oral and systemic diseases: a scoping review

Background

The association between chronic oral diseases and other major systemic health conditions, commonly referred to as the oral-systemic health connection, has been previously studied with several underlying common risk factors and pathways linking both groups of diseases. Psychosocial factors contribute to an increased susceptibility to chronic oral and non-oral diseases. The aim of this review is to summarize the current state of knowledge on the role of psychosocial stress in chronic oral and systemic diseases.

Methods

A search strategy was built and a literature search was conducted using four databases (CINAHL, Embase, Medline, PsycINFO). A combination of search terms related to psychosocial stress, systemic disease, and oral conditions were used. Studies were eligible for inclusion if they included human adults (aged 18 years and older), included psychosocial factors as an exposure measure, and outcome measures of both an oral and systemic condition. Only English-language articles were considered. Pilot testing of the data extraction form and calibration were conducted and data were extracted independently by one researcher.

Results

A total of fifteen articles out of eighty full-text articles screened were determined to be eligible for inclusion in this review. Periodontal disease was the most commonly studied oral disease, measured in 53% of included articles, with the most commonly studied systemic diseases being of mental health conditions (40%) and diabetes (47%). Psychosocial stress was measured using a range of psychometric indicators and/or biomarkers, including perceived stress, individual behaviours, childhood adversity, and cortisol. In total, fourteen studies found a positive association between measures of psychosocial stress and oral-systemic health.

Conclusion

Psychosocial stress may be a common contributor to both chronic oral and non-oral diseases.

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

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

Cutaneous neuropeptides: the missing link between psychological stress and chronic inflammatory skin disease?

A "brain-skin" connection has been long been observed between chronic stress and chronic inflammatory skin disease including urticaria, psoriasis, atopic dermatitis, and prurigo nodularis. The relationship appears to be bidirectional. Chronic psychological stress has been shown to sustain hyperactivity of the sympathetic branch of the autonomic nervous system. Chronic stress is proinflammatory and in the context of several dermatologic disorders may be associated with an increase in dermal nerve fiber density, mast cells, nerve growth factor and calcitonin-gene-related peptide (CGRP). Furthermore, CGRP elicits a TH2-polarized T-cell response that is a hallmark of chronic pruritic conditions such as atopic dermatitis and prurigo nodularis. This TH2 response contributes directly to acute pruritus as well as the sensitization of cutaneous sensory neurons that are critical for chronic pruritus. Prurigo nodularis is a debilitating skin disorder featuring prominent nerve structural, neuropeptide, and TH2 cytokine aberrations that is a model deserving of future study.

Trauma History Predicts Decoupling of C-Reactive Protein and Somatic Symptoms: Results From a Cohort Study of Sexual and Gender Minority Youth

OBJECTIVE

Systemic inflammation can induce somatic symptoms (e.g., pain, nausea, fatigue) through neuroimmune signaling pathways. Previous research suggests that early-life adversity amplifies signaling between peripheral inflammation and the brain. We therefore hypothesized that greater lifetime trauma exposure at baseline would predict stronger associations between systemic inflammation and somatic symptoms at 2.5-year follow-up in a cohort study of sexual and gender minority youth assigned male at birth ( n = 694).

METHODS

We measured prior trauma exposure (lifetime count of traumatic event types reported at baseline), somatic symptoms (Brief Symptom Inventory somatization score), and systemic inflammation (C-reactive protein, interleukin 6, interleukin 1β, and tumor necrosis factor α). All models included age, gender, education, recent trauma exposure, substance use, body mass index, and HIV status as covariates.

RESULTS

Higher C-reactive protein concentrations were associated with greater somatic symptoms in the main effects model ( β = 0.019, 95% confidence interval [CI] = 0.006 to 0.031). Contrary to our hypothesis, we observed a negative interaction between prior trauma exposure and C-reactive protein levels in predicting somatic symptoms ( β = -0.017, 95% CI = -0.030 to -0.004). Higher C-reactive protein was associated with greater somatic symptoms only in participants without prior trauma exposure at baseline ( β = 0.044, 95% CI = 0.026 to 0.062). Specificity analyses revealed similar patterns when nonsomatic depressive symptoms were used as the outcome variable.

CONCLUSIONS

These results suggest that sexual and gender minority youth assigned male at birth who have a history of prior trauma exposure may experience decoupling of systemic inflammation and somatic symptoms. The absence of inflammation-related symptoms may prevent individuals from seeking necessary medical care by reducing interoceptive awareness of pathological states.

Evidence for skin-deep resilience using a co-twin control design: Effects on low-grade inflammation in a longitudinal study of youth

This study tested the skin-deep resilience hypothesis - that low socioeconomic status (SES) youth who are working hard to succeed in life experience good psychological and educational outcomes but at a cost to their physical health - in a sample of monozygotic (MZ) twins. The National Longitudinal Study of Adolescent Health (Add Health) contained a sample of 226 MZ twin pairs at Wave 1 (M age = 16 years), of whom 141 pairs completed the Wave 4 assessment 13 years later (M age = 29 years). Family SES was measured at Wave 1 via income, education, and occupation. Conscientiousness was measured at Wave 4 as an indicator of those who were working hard to succeed in life. Outcomes measured at Wave 4 included low-grade inflammation (C-reactive protein, CRP), mental health (depression, problematic alcohol use), and academic success (educational attainment). A co-twin control design was utilized which directly compared within-twin differences in the association between conscientiousness and life outcomes. Main effects of between-twin conscientiousness were found such that higher levels of conscientiousness were associated with higher educational attainment, fewer symptoms of depression, and less problematic alcohol use, across all SES groups. An interaction between family SES and within-twin difference in conscientiousness was found for CRP, such that, among twins growing up in lower SES households, the twin with higher levels of conscientiousness had higher levels of CRP. These patterns provide support for the phenomenon of skin-deep resilience using a twin methodology that reduces the possibility of confounding by shared genetic and environmental factors.

Depressive symptoms and immune transcriptional profiles in late adolescents

BACKGROUND

Rates of depression increase and peak during late adolescence and alterations in immune processes are thought to be both a risk factor and outcome of depression. However, few studies have examined depression-immune dynamics among adolescents. Using a functional genomics approach, the current study examined whether depressive symptoms were associated with activation of a gene expression profile, characterized by upregulated expression of pro-inflammatory-related genes and downregulated expression of antiviral-related genes in a sample of older adolescents (M_age = 18.37, SD = 0.51).

METHOD

Participants (n = 87) reported on their depressive symptoms during the past week using the CES-D, and provided blood samples for genome-wide transcriptional profiling of mRNA.

RESULTS

Adolescents with clinically-significant levels of depressive symptoms (CES-D ≥ 16) exhibited upregulated expression of inflammation-related genes and downregulated expression of antiviral-related genes compared to their peers with lower levels of depressive symptoms (CES-D < 16). Bioinformatics analyses suggested that this pattern of differential gene expression was mediated by greater activity of the pro-inflammatory transcription factor, nuclear factor-kappa B (NF-κB), and reduced activity of glucocorticoid receptors (GRs) and interferon response factors (IRFs). Additional analyses implicated monocytes, B cells, and dendritic cells as primary cellular sources of the observed gene expression patterns associated with depressive symptoms.

CONCLUSION

Results are consistent with past work demonstrating links between depression and altered immunity. They provide a molecular basis for these associations and suggest that the underlying molecular signature may emerge as early as late adolescence when rates of depression tend to increase.

A preliminary investigation of attachment style and inflammation in African-American young adults

Individuals' social experiences are associated with their mental health, physical health, and even mortality. Over the last 30 years, researchers have examined the ways in which these social experiences might be associated with chronic inflammation - a component underlying many of the chronic diseases of aging. Little research, however, has examined the role of adults' attachment style as a specific social component that might be associated with inflammation. In the present study, we utilized data from a sample of 59 African-American adults from the Maryland Adolescent Development in Context Study (MADICS) to examine the links between attachment avoidance and attachment anxiety and C-reactive protein (CRP) and interleukin (IL)-6. After controlling for demographic characteristics, body mass index, and depressive symptoms, attachment avoidance and anxiety were associated with IL-6 but not CRP. This study adds to the growing body of research identifying the wide range of social experiences associated with inflammation and further suggests that attachment relationship experiences may have implications for biological processes relevant to many chronic diseases of aging.

When inflammation and depression go together: The longitudinal effects of parent-child relationships

Parent-child relationships have long-term effects on health, particularly later inflammation and depression. We hypothesized that these effects would be mediated by later romantic partner relationships and elevated stressors in young adulthood, helping promote chronic, low grade, inflammation as well as depressive symptoms, and driving their covariation. It has been proposed recently that youth experiencing harsher parenting may also develop a stronger association between inflammation and depressive symptoms in adulthood and altered effects of stressors on outcomes. In the current investigation, we test these ideas using an 18-year longitudinal study of N = 413 African American youth that provides assessment of the parent-child relationship (at age 10), pro-inflammatory cytokine profile and depressive symptoms (at age 28), and potential mediators in early young adulthood (assessed at ages 21 and 24). As predicted, the effect of harsher parent-child relationships (age 10) on pro-inflammatory state and increased depressive symptoms at age 28 were fully mediated through young adult stress and romantic partner relationships. In addition, beyond these mediated effects, parent-child relationships at age 10 moderated the concurrent association between inflammation and depressive symptoms, as well as the prospective association between romantic partner relationships and inflammation, and resulted in substantially different patterns of indirect effects from young adult mediators to outcomes. The results support theorizing that the association of depression and inflammation in young adulthood is conditional on earlier parenting, and suggest incorporating this perspective into models predicting long-term health outcomes.

Understanding the pathophysiology of depression: From monoamines to the neurogenesis hypothesis model - are we there yet?

A number of factors (biogenic amine deficiency, genetic, environmental, immunologic, endocrine factors and neurogenesis) have been identified as mechanisms which provide unitary explanations for the pathophysiology of depression. Rather than a unitary construct, the combination and linkage of these factors have been implicated in the pathogenesis of depression. That is, environmental stressors and heritable genetic factors acting through immunologic and endocrine responses initiate structural and functional changes in many brain regions, resulting in dysfunctional neurogenesis and neurotransmission which then manifest as a constellation of symptoms which present as depression.

The relationships of current suicidal ideation with inflammatory markers and heart rate variability in unmedicated patients with major depressive disorder

Studies investigating inflammatory status and autonomic functioning simultaneously in depressed patients with current suicidal ideation (SI) are lacking. We recruited 58 unmedicated depressed patients with current SI but without lifetime history of suicidal behavior, as well as 61 equally depressed patients without lifetime history of SI or suicidal behavior. We measured serum cortisol, high-sensitivity C-reactive protein (hs-CRP), erythrocyte sedimentation rate (ESR), and autonomic functioning evaluated by frequency-domain measures of heart rate variability (HRV). The intensity of current SI was rated with the Columbia Suicide Severity Rating Scale. Chronic psychological stress was assessed using the Chinese version of the Perceived Stress Scale (PSS). Patients with current SI showed higher hs-CRP and ESR but lower variance (total HRV), low frequency (LF), and high frequency (HF) HRV than those without lifetime history of SI. We found no differences in cortisol levels and PSS scores. The intensity of current SI was negatively correlated with variance, LF, and HF but positively correlated with hs-CRP. Our results help improve the understanding of the relationships among current SI, inflammation, and autonomic functioning in depressed patients. The combined use of inflammatory markers and HRV indices may one day be applied in predicting and monitoring patients' suicide risk.

Alteration of immune markers in a group of melancholic depressed patients and their response to electroconvulsive therapy

BACKGROUND

Immune system dysfunction is implicated in the pathophysiology of major depression, and is hypothesized to normalize with successful treatment. We aimed to investigate immune dysfunction in melancholic depression and its response to ECT.

METHODS

55 melancholic depressed patients and 26 controls participated. 33 patients (60%) were referred for ECT. Blood samples were taken at baseline, one hour after the first ECT session, and 48h after ECT series completion.

RESULTS

At baseline, melancholic depressed patients had significantly higher levels of the pro-inflammatory cytokine IL-6, and lower levels of the regulatory cytokine TGF-β than controls. A significant surge in IL-6 levels was observed one hour after the first ECT session, but neither IL-6 nor TGF-β levels normalized after completion of ECT series. Seventy per cent (n=23) of ECT recipients showed clinical response and 42% (n=10) reached remission. Neither IL-6 nor TGF-β changes correlated with clinical improvement following ECT. No significant changes in IL-10, TNF-α and CRP levels were found in relation to melancholia or response to ECT.

LIMITATIONS

As a naturalistic study, some potential confounders could not be eliminated or controlled, including medication use.

CONCLUSIONS

Melancholic depressed patients demonstrated a peripheral increase in IL-6 and reduction in TGF-β, which did not normalize despite clinical response to ECT. These findings may be consistent with emerging hypotheses of the role of inflammation in mediating neurotrophin expression. The implications of chronic inflammation in the melancholic depressed population for future medical health, particularly cardiovascular risk, are largely unknown and warrant further investigation.

Gingival crevicular fluid and saliva stress hormone levels in patients with chronic and aggressive periodontitis

AIM

This cross-sectional study aims to analyse cortisol and dehydroepiandrosterone (DHEA) levels in gingival crevicular fluid (GCF) and saliva in generalized aggressive periodontitis (GAP) and generalized chronic periodontitis (GCP) patients, as well as in periodontally healthy individuals (C).

MATERIAL AND METHODS

A total of 92 patients (31 C, 34 GCP and 27 GAP) were included in the study. Clinical parameters including plaque index, gingival index, bleeding on probing, probing depth and clinical attachment level; psychosocial measurements including Beck depression inventory and state-trait anxiety inventory; and hormone levels in GCF and saliva including cortisol and DHEA were evaluated.

RESULTS

Gingival crevicular fluid cortisol and GCF/saliva DHEA values were significantly higher in the GAP group when compared to the other two groups (p < 0.05). The lowest values were in the C group and the difference between the GCP and GAP groups was statistically significant (p < 0.05). Salivary cortisol levels were comparable for the GAP and GCP groups (p > 0.05), and the C group had the lowest values in comparison with the other two groups (p < 0.05).

CONCLUSIONS

Within the limits of this study, salivary/GCF cortisol and DHEA levels were suggested to be related with more severe and aggressive forms of periodontal disease.

Psychosocial distress and inflammation: Which way does causality flow?

OBJECTIVES

This study queried causal direction in linkages of inflammation with psychosocial distress.

METHODS

Data were from the 2005-2006 and 2010-2011 waves of the U.S. National Social Life, Health, and Aging Project. Inflammation was indicated by C-reactive protein, and distress by depression, anxiety, as well as stress. Autoregressive cross-lagged panel models were used to examine causal direction.

RESULTS

Rather than being an outcome of psychosocial distress, inflammation was a predictor of it. Linkages were gender differentiated, with inflammation seeming to induce depression among men but stress among women.

DISCUSSION

Contrary to previous literature, inflammation may not be a mechanism through which psychosocial distress gets "under the skin" to cause cardiovascular and metabolic issues. Rather, it may be a node through which social pathologies and life events influence both mental health and physiological problems.

Association of serum interleukin-6 with mental health problems in children exposed to perinatal complications and social disadvantage

There is consistent evidence that inflammation is involved in mental disorders pathogenesis. Herein, using data from the High Risk Cohort Study for Psychiatric Disorders, we investigated the relationship between parental mood disorders (PMD), environmental factors, serum interleukin-6 (IL6) and mental health problems in children aged 6-12. We measured the serum levels of IL6 in 567 children. Information related to socio-demographic characteristics, mental health problems and multiple risk factors, as well as parent's psychiatric diagnosis, was captured. We evaluated two groups of environmental risk factors (i.e. perinatal complications and social disadvantage) using a cumulative risk model. Results showed that higher serum levels of IL6 were associated with PMD (RR=1.072, p=0.001), perinatal complications (RR=1.022, p=0.013) and social disadvantage (RR=1.024, p=0.021). There was an interaction between PMD and social disadvantage (RR=1.141, p=0.021), as the effect of PMD on IL6 was significantly higher in children exposed to higher levels of social disadvantage. Moreover, there was a positive correlation between IL6 and mental health problems (RR=1.099, p=0.026), which was moderated by exposure to perinatal complications or social disadvantage (RR=1.273, p=0.015 and RR=1.179, p=0.048, respectively). In conclusions, there is evidence of a differential inflammatory activation in children with PMD and exposure to environmental risk factors, when compared to matched peers. Systemic inflammation may be involved in the pathway linking familial risk and mental health problems.

Glucocorticoid mediated regulation of inflammation in human monocytes is associated with depressive mood and obesity

Dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis is observed in various conditions, including depression and obesity, which are also often related. Glucocorticoid (GC) resistance and desensitization of peripheral GC receptors (GRs) are often the case in HPA dysregulation seen in depression, and GC plays a critical role in regulation of inflammation. Given the growing evidence that inflammation is a central feature of some depression cases and obesity, we aimed to investigate the immune-regulatory role of GC-GR in relation to depressive mood and obesity in 35 healthy men and women. Depressive mood and level of obesity were assessed, using Beck Depression Inventory (BDI-Ia) and body mass index (BMI), respectively. We measured plasma cortisol levels via enzyme-linked immunosorbent assay and lipopolysaccharide-stimulated intracellular tumor necrosis factor (TNF) production by monocytes, using flow cytometry. Cortisol sensitivity was determined by the difference in monocytic TNF production between the conditions of 1 and 0 μM cortisol incubation ("cortisol-mediated inflammation regulation, CoMIR"). GR vs. mineralocorticoid receptor (MR) antagonism for CoMIR was examined by using mifepristone and spironolactone. A series of multiple regression analyses were performed to investigate independent contribution of depressive mood vs. obesity after controlling for age, gender, systolic blood pressure (SBP), and plasma cortisol in predicting CoMIR. CoMIR was explained by somatic subcomponents of depressive mood (BDI-S: β=-0.499, p=0.001), or BMI (β=-0.466, p<0.01) in separate models. The effects of BMI disappeared when BDI-S was controlled for in the model, while BDI-S remained a significant independent predictor for CoMIR (β=-0.369, p<0.05). However, BMI remained the only independent predictor when BDI-T or BDI-C were controlled for in the model. Mediation analyses also revealed that the relationship between BMI and CoMIR was mediated by BDI-S. The exploratory findings of the relative GR vs. MR roles in CoMIR, using GR and MR blockers, indicated that CoMIR in our cellular model was predominantly mediated by GRs at the higher cortisol dose (1 μM). There was initial indication that greater obesity and somatic depressive symptoms were associated with smaller efficacy of the blockers, which warrants further investigation. Our findings, although in a preclinical sample, signify the shared pathophysiology of immune dysregulation in depression and obesity and warrant further mechanistic investigation.

Catecholamine metabolites in urine, as chronic stress biomarkers, are associated with higher risk of chronic periodontitis in adults

BACKGROUND

The purpose of this case-control study is to investigate the association between stress and periodontitis by determining stress biomarkers in saliva and urine and to determine whether oral hygiene, gingival inflammation, and tooth loss are correlated with stress biomarkers in patients with periodontitis.

METHODS

A total of 77 patients (41 cases [with periodontitis] and 36 controls) participated in this study. Periodontal examination findings included probing depth, clinical attachment loss, bleeding on probing (BOP), plaque index (PI), and tooth loss. Secretory immunoglobulin (sIg)A and cortisol were determined in saliva. Cortisol, creatinine-adjusted cortisol, metanephrine, normetanephrine, and total metanephrines were measured in urine.

RESULTS

Urinary metanephrine (P = 0.013) and total metanephrine (P = 0.023) levels were higher in the case group. In cases, salivary cortisol was correlated with PI (r = 0.464, P <0.01), BOP (r = 0.401, P <0.05), and tooth loss (r = 0.245, P <0.05). Urinary metanephrine levels above the median were associated with a 3.4-fold higher risk of periodontitis (95% confidence interval [CI] = 1.1 to 10.2; P = 0.029), with an 82% increase in risk for each increment of 0.05 µg/24 hours. Urinary total metanephrine levels above the median were associated with a five-fold higher risk of periodontitis (95% CI = 1.6 to 15.7; P = 0.006).

CONCLUSIONS

The present results offer new evidence of the association between urinary concentrations of catecholamine metabolites (metanephrine and total metanephrines) and chronic periodontitis. Salivary IgA level showed no statistical difference between the cases and controls. Salivary cortisol levels in the patients with periodontitis were correlated with worse PI, higher gingival inflammation, and greater tooth loss.

Inflammation: depression fans the flames and feasts on the heat

Depression and inflammation fuel one another. Inflammation plays a key role in depression's pathogenesis for a subset of depressed individuals; depression also primes larger cytokine responses to stressors and pathogens that do not appear to habituate. Accordingly, treatment decisions may be informed by attention to questions of how (pathways) and for whom (predispositions) these links exist, which are the focus of this article. When combined with predisposing factors (moderators such as childhood adversity and obesity), stressors and pathogens can lead to exaggerated or prolonged inflammatory responses. The resulting sickness behaviors (e.g., pain, disturbed sleep), depressive symptoms, and negative health behaviors (e.g., poor diet, a sedentary lifestyle) may act as mediating pathways that lead to further, unrestrained inflammation and depression. Depression, childhood adversity, stressors, and diet can all influence the gut microbiome and promote intestinal permeability, another pathway to enhanced inflammatory responses. Larger, more frequent, or more prolonged inflammatory responses could have negative mental and physical health consequences. In clinical practice, inflammation provides a guide to potential targets for symptom management by signaling responsiveness to certain therapeutic strategies. For example, a theme across research with cytokine antagonists, omega-3 fatty acids, celecoxib, and exercise is that anti-inflammatory interventions have a substantially greater impact on mood in individuals with heightened inflammation. Thus, when inflammation and depression co-occur, treating them in tandem may enhance recovery and reduce the risk of recurrence. The bidirectional links between depression, inflammation, and disease suggest that effective depression treatments could have a far-reaching impact on mood, inflammation, and health.

Major Depressive Disorder and Bipolar Disorder Predispose Youth to Accelerated Atherosclerosis and Early Cardiovascular Disease: A Scientific Statement From the American Heart Association

In the 2011 "Expert Panel on Integrated Guidelines for Cardiovascular Health and Risk Reduction in Children and Adolescents," several medical conditions among youth were identified that predispose to accelerated atherosclerosis and early cardiovascular disease (CVD), and risk stratification and management strategies for youth with these conditions were elaborated. Major depressive disorder (MDD) and bipolar disorder (BD) among youth satisfy the criteria set for, and therefore merit inclusion among, Expert Panel tier II moderate-risk conditions. The combined prevalence of MDD and BD among adolescents in the United States is ≈10%, at least 10 times greater than the prevalence of the existing moderate-risk conditions combined. The high prevalence of MDD and BD underscores the importance of positioning these diseases alongside other pediatric diseases previously identified as moderate risk for CVD. The overall objective of this statement is to increase awareness and recognition of MDD and BD among youth as moderate-risk conditions for early CVD. To achieve this objective, the primary specific aims of this statement are to (1) summarize evidence that MDD and BD are tier II moderate-risk conditions associated with accelerated atherosclerosis and early CVD and (2) position MDD and BD as tier II moderate-risk conditions that require the application of risk stratification and management strategies in accordance with Expert Panel recommendations. In this scientific statement, there is an integration of the various factors that putatively underlie the association of MDD and BD with CVD, including pathophysiological mechanisms, traditional CVD risk factors, behavioral and environmental factors, and psychiatric medications.

Trajectories of relationship stress and inflammatory processes in adolescence

Researchers have identified cross-sectional links between interpersonal stress and inflammation. Little is known, however, about how these dynamics unfold over time, what underlying immune pathways might exist, or whether moderators such as race could alter the strength of the connection between interpersonal stress and inflammatory processes. We examined whether adolescent girls whose relationship trajectories were characterized by chronic stress would exhibit a proinflammatory phenotype marked by systemic inflammation, heightened cytokine responses to bacterial challenges, and resistance to the anti-inflammatory properties of cortisol. Significant Stress × Race interactions revealed that family stress trajectories predicted glucocorticoid sensitivity and peer stress trajectories predicted cytokine production for White but not Asian girls. Relationship stress trajectories were not associated with systemic inflammation, however. These findings suggest that particular subgroups of adolescent girls who face chronic and elevated stress in their close relationships may be at risk for disruptions to the immune system.

The Association between Depressive Symptoms and Physical Diseases in Switzerland: A Cross-Sectional General Population Study

OBJECTIVE

To estimate the association between depressive symptoms and physical diseases in Switzerland, as respective findings might inform about future estimates of mental and physical health care costs.

METHODS

A population-based study, using data from the Swiss Health Survey collected by computer-assisted telephone interviews and additional written questionnaires during the year 2007 (n = 18,760) in Switzerland. The multistage stratified random sample included subjects aged 15 years and older, living in a private Swiss household with a telephone connection. Complete data were available for 14,348 subjects (51% of all subjects reached by telephone). Logistic regression analyses were used to estimate the associations between depressive symptoms and any physical disease, or a specific physical disease out of 13 non-communicable physical diseases assessed with a self-report checklist on common physical diseases. Analyses were adjusted for sex, age, education, occupation, and household income.

RESULTS

In the adjusted models, depressive symptoms were associated with arthrosis and arthritis [Odds Ratio (OR) = 1.79, 95% confidence interval (CI) = 1.28-2.50] and any physical disease (OR = 1.67, 95% CI = 1.33-2.10) after controlling for multiple testing.

CONCLUSION

Our findings contribute to a better understanding of the comorbidity of depressive symptoms and arthrosis and arthritis in Switzerland and might have implications for more precise future estimates of mental and physical health care costs.

Depression and cardiovascular disease: does antidepressant treatment improve cardiac outcome?

OBJECTIVE

The association between depression and cardiovascular disease has been well documented but the nature of this relationship continues to be defined. Given the accumulation of epidemiological evidence linking these diseases a number of interventional studies have been undertaken to assess the issue of whether antidepressant treatment in depressed patients with cardiovascular disease improves cardiac outcome. The objective of this paper is to review recent randomised controlled trials on this topic and to explore the implications that these may have for future research in this area.

METHOD

This review is derived from a MEDLINE search using the search terms 'depressive disorder' and 'cardiovascular diseases'. Only randomised controlled trials published in English with clearly defined methods and interventions are included here. Reference sections from the articles were used to identify additional relevant studies.

RESULTS

A small number of high quality trials were uncovered which indicated mixed results in terms of the treatment of depression in cardiovascular disease. None indicated a statistically significant difference in cardiac outcome.

CONCLUSIONS

It is not possible at this time to recommend treatment for depression to reduce cardiovascular risk. However depression remains prevalent in patients with cardiovascular disease and is a treatable cause of morbidity in its own right.

Suicidal ideation is associated with elevated inflammation in patients with major depressive disorder

BACKGROUND

Patients with major depressive disorder (MDD) who attempt or complete suicide have elevated inflammation compared to nonsuicidal patients with MDD. However, greater severity of depression and the medical lethality of suicide attempts could account for such elevated inflammation in suicide attempters and suicide completers.

METHODS

To clarify, we measured inflammatory markers in patients with MDD with and without high levels of suicidal ideation and in nondepressed controls (N = 124). Levels of suicidal ideation, depression severity, and recent suicide attempts were assessed by structured clinical interviews. A composite score including the inflammatory markers tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-10 (IL-10), and C-reactive protein (CRP) was used as an inflammatory index. Analysis of covariance models were used to assess group differences with adjustments for age and gender.

RESULTS

Patients with MDD and high suicidal ideation had significantly higher inflammatory index scores than both controls, F(1,53) = 18.08, partial η(2) = .25, P < .001, and patients with MDD and lower suicidal ideation F(1,44) = 7.59, partial η(2) = .15, P = .009. In contrast, patients with lower suicidal ideation were not significantly different from controls on the inflammatory index, F(1,63) = .52, partial η(2) = .01, P = .47. Follow-up analyses indicated that differences between patients with MDD and high versus lower suicidal ideation were independent of depression severity and recent suicide attempts.

CONCLUSIONS

Suicidal ideation may be uniquely associated with inflammation in depressed patients.

Clustering of depression and inflammation in adolescents previously exposed to childhood adversity

BACKGROUND

There is mounting interest in the hypothesis that inflammation contributes to the pathogenesis of depression and underlies depressed patients' vulnerability to comorbid medical conditions. However, research on depression and inflammation has yielded conflicting findings, fostering speculation that these conditions associate only in certain subgroups, such as patients exposed to childhood adversity.

METHODS

We studied 147 female adolescents. All were in good health at baseline but at high risk for depression because of family history or cognitive vulnerability. Subjects were assessed every 6 months for 2.5 years, undergoing diagnostic interviews and venipuncture for measurement of two inflammatory biomarkers, C-reactive protein (CRP) and interleukin-6 (IL-6). Childhood adversity was indexed by parental separation, low socioeconomic status, and familial psychopathology.

RESULTS

Multilevel models indicated that childhood adversity promotes clustering of depression and inflammation. Among subjects exposed to high childhood adversity, the transition to depression was accompanied by increases in both CRP and IL-6. Higher CRP remained evident 6 months later, even after depressive symptoms had abated. These lingering effects were bidirectional, such that among subjects with childhood adversity, high IL-6 forecasted depression 6 months later, even after concurrent inflammation was considered. This coupling of depression and inflammation was not apparent in subjects without childhood adversity.

CONCLUSIONS

These findings suggest that childhood adversity promotes the formation of a neuroimmune pipeline in which inflammatory signaling between the brain and periphery is amplified. Once established, this pipeline leads to a coupling of depression and inflammation, which may contribute to later affective difficulties and biomedical complications.

Inflammation in neurological and psychiatric diseases

In recent years, compelling evidence suggests that inflammation plays a critical role in the pathology of a vast number of neurological diseases such as stroke, Parkinson's disease, Alzheimer's disease and amyotrophic lateral sclerosis as well as neuropsychiatric diseases such as major depression and schizophrenia. Despite emerging evidence in human and animal models alike, modulating inflammatory responses have yet to be proven as an effective treatment to prevent or delay the progression of these diseases. The primary focus of this special edition is to highlight some of our current findings on the complexities of targeting neuroinflammation as a novel therapy, and its role in neurological and psychiatric disorders.

C-reactive protein serum level in drug-free male Egyptian patients with schizophrenia

Despite the growing research interest in the role of immunological markers in schizophrenia, few studies, with conflicting results, have focused on the association between high sensitivity C-reactive protein (hs-CRP) levels and clinical characteristics in schizophrenia. In this cross-sectional case-control study, a sample of 200 antipsychotic-free male Egyptian schizophrenia patients was assessed by the Positive and Negative Syndrome Scale (PANSS) and compared with 200 healthy controls as regards serum hs-CRP level using an immunoturbidimetric method. CRP level for patients (geometric mean=3.3 mg/L) was significantly (P=0.000) higher than that for controls (geometric mean=1.4 mg/L). PANSS scores and patients' data, which significantly correlated with serum hs-CRP level, were entered into a stepwise multiple regression analysis. Results of this analysis showed that PANSS negative symptom score was second only to the waist circumference, with which they explained 54.7 % of the variation in serum hs-CRP. Comparable results were obtained when patients, controls and the relevant confounders were included in one multivariate analysis. We concluded that in Egyptian men, waist circumference and schizophrenia diagnosis are strong predictors of raised CRP level independent of a number of potentially confounding variables. In antipsychotic-free patients, CRP level is higher than in healthy controls and is positively correlated with the severity of the psychopathology as measured by PANSS. This relationship is especially notable in negative, but not positive symptoms.

Burnout: a fashionable diagnosis

BACKGROUND

"Burnout syndrome" is now a common reason for medical excuses from work, and thus an important topic in health-related economics. Much research is still needed, however, to establish the scientific basis for this entity, the criteria by which it might be diagnosed and classified, and how it should be treated.

METHODS

A systematic review of this topic, previously published as an HTA report, is presented here together with a selective overview of pertinent literature.

RESULTS

There currently exists neither an officially accepted definition nor a valid instrument for the differential diagnosis of burnout syndrome. Its manifestations are generally considered to lie along three dimensions: emotional exhaustion, depersonalization, and reduced performance ability and/or motivation. Most of the available studies on its epidemiology and differential diagnosis provide no more than a low level of evidence for their conclusions. There have been no controlled trials of treatments for burnout.

CONCLUSION

High-quality controlled studies on burnout syndrome are lacking. A standardized and internationally accepted diagnostic instrument with a validated rating scale should be developed. There is also a need for epidemiological and health-economic studies on the prevalence, incidence, and cost of burnout. The etiology and pathogenesis of burnout should be studied with special regard to the possible role of neurobiological factors. Treatments for it should be studied systematically so that their effects can be judged at a high level of evidence. In view of the current lack of knowledge about what is called "burnout," the term should not be used as a medical diagnosis or as a basis for decisions regarding disability or other socioeconomic matters.

Psychological stress in childhood and susceptibility to the chronic diseases of aging: moving toward a model of behavioral and biological mechanisms

Among people exposed to major psychological stressors in early life, there are elevated rates of morbidity and mortality from chronic diseases of aging. The most compelling data come from studies of children raised in poverty or maltreated by their parents, who show heightened vulnerability to vascular disease, autoimmune disorders, and premature mortality. These findings raise challenging theoretical questions. How does childhood stress get under the skin, at the molecular level, to affect risk for later diseases? And how does it incubate there, giving rise to diseases several decades later? Here we present a biological embedding model, which attempts to address these questions by synthesizing knowledge across several behavioral and biomedical literatures. This model maintains that childhood stress gets "programmed" into macrophages through epigenetic markings, posttranslational modifications, and tissue remodeling. As a consequence these cells are endowed with proinflammatory tendencies, manifest in exaggerated cytokine responses to challenge and decreased sensitivity to inhibitory hormonal signals. The model goes on to propose that over the life course, these proinflammatory tendencies are exacerbated by behavioral proclivities and hormonal dysregulation, themselves the products of exposure to early stress. Behaviorally, the model posits that childhood stress gives rise to excessive threat vigilance, mistrust of others, poor social relationships, impaired self-regulation, and unhealthy lifestyle choices. Hormonally, early stress confers altered patterns of endocrine and autonomic discharge. This milieu amplifies the proinflammatory environment already instantiated by macrophages. Acting in concert with other exposures and genetic liabilities, the resulting inflammation drives forward pathogenic mechanisms that ultimately foster chronic disease.

Clinical variations modulate patterns of gene expression and define blood biomarkers in major depression

The aim of the study is to compare the expression level of candidate genes between patients suffering from a severe major depressive episode (MDE) and controls, and also among patients during MDE evolution. After a comprehensive review of the biological data related to mood disorders, we initiated a hypothesis-driven exploration of candidate mRNAs. Using RT-qPCR, we analyzed peripheral blood mononuclear cells (PBMCs) mRNA obtained from a homogeneous population of 11 patients who suffered from severe melancholic MDE. To assess the evolution of MDE, we analyzed PBMC mRNAs that were collected on Day 1 and 8 weeks later. Data from these patient samples were analyzed in comparison to age- and sex-matched healthy controls. Among 40 candidate genes consistently transcribed in PBMCs, 10 were differentially expressed in at least one comparison. We found that variations of mRNA levels for NRG1, SORT1 and TPH1 were interesting state-dependent biological markers of the disease. We also observed that variations in other mRNA expression were associated with treatment efficacy or clinical improvement (CREB1, HDAC5, HSPA2, HTR1B, HTR2A, and SLC6A4/5HTT). Significantly, 5HTT exhibited a strong correlation with clinical score evolution. We also found a state-independent marker, IL10. Moreover, the analysis of 2 separate MDEs concerning a same patient revealed comparable results for the expression of CREB1, HSPA2, HTR1B, NRG1 and TPH1. Overall, our results indicate that PBMCs obtained at different time points during MDE progression represent a promising avenue to discover biological markers for depression.

More evidence that depressive symptoms predict mortality in COPD patients: is type D personality an alternative explanation?

Background/Purpose

The present study attempted to replicate our previous finding that depressive symptoms are a risk factor for mortality in stable chronic obstructive pulmonary disease (COPD), but in a different population with a different measure of depressive symptoms. We further investigated whether type D personality is associated with mortality in patients with COPD and whether it explains any relationship observed between depressive symptoms and mortality.

Methods

In 122 COPD patients, mean age 60.8 ± 10.3 years, 52% female, and mean forced expiratory volume in 1 s (FEV₁) 41.1 ± 17.6%pred, we assessed body mass index, post bronchodilator FEV₁, exercise capacity, depressive symptoms with the Hospital Anxiety and Depression Scale, and type D with the Type D Scale.

Results

In the 7 years follow-up, 48 (39%) deaths occurred. The median survival time was 5.3 years. Depressive symptoms (hazard ratio = 1.07, 95% confidence intervals = 1.00–1.14) were an independent risk factor for mortality. Type D was not associated with mortality.

Conclusions

We can rule out type D as an explanation for the relationship between depressive symptoms and mortality observed in this sample. However, ambiguity remains as to the interpretation of the value of depressive symptoms in predicting death.

Marriage protects men from clinically meaningful elevations in C-reactive protein: results from the National Social Life, Health, and Aging Project (NSHAP)

OBJECTIVE

To examine the association between marital status and C-reactive protein (CRP) levels after accounting for a range of relevant of demographic, subjective, and objective health indicators and psychological variables. Minor elevations in CRP (>3 mg/L) are a nonspecific marker of systemic inflammation and predict the future onset of cardiovascular disease.

METHODS

Data from the National Social Life, Health, and Aging Project (NSHAP), a population-based study of community-dwelling older adults in the United States, were used to study CRP elevations. Home-based interviews were conducted with the entire NSHAP sample, a subset of whom provided whole blood samples for the CRP analyses. The final sample consisted of 1715 participants (n = 838 men) with an average age of 69.51 years. Multiple and logistic regression analyses were conducted, using CRP as a continuous and dichotomous outcome variable.

RESULTS

Across the entire NSHAP sample, married men demonstrated the lowest levels of CRP. After adjusting for the competing predictors, marriage remained a unique protective factor against elevated CRP for men (odds ratio = 0.56, 95% Confidence Interval = 0.39-0.79). The absolute risk reduction (for being classified in the high-risk CRP group) associated with being a married man was roughly equivalent to that observed for adults who were normotensive, nonsmokers, and those with a normal body mass index.

CONCLUSIONS

Remaining married in late adulthood affords men unique and robust protection against elevated levels of CRP. The findings are discussed in terms of the pathways linking marital status and health outcomes among older adults.

Close relationships, inflammation, and health

Different aspects of personal relationships including social integration, social support, and social conflict have been related to inflammation. This article summarizes evidence linking the quality and quantity of relationships with gene expression, intracellular signaling mechanisms, and inflammatory biomarkers, and highlights the biological and psychological pathways through which close relationships impact inflammatory responses. Relationship conflict and lower social support can effectively modulate proinflammatory cytokine secretion both directly (via CNS/neural/endocrine/immune biobehavioral pathways), and indirectly, by promoting depression, emotional stress responses, and detrimental health behaviors. Accordingly, thorough assessments of health behaviors and attention to key methodological issues are necessary to identify the contributions of relationships to inflammation, and thus we highlight procedural issues to be considered in the design of studies. Despite some notable methodological challenges, the evidence suggests that learning more about how close relationships influence inflammation will provide important new insights into the ways that relationships impact health.

Association of major depressive disorder with serum myeloperoxidase and other markers of inflammation: a twin study

BACKGROUND

Major depressive disorder (MDD) has been linked to inflammation, but this association may be due to common precursors to both depression and inflammation. Myeloperoxidase (MPO) is an inflammatory enzyme produced by activated leukocytes that predicts risk of coronary heart disease. We sought to examine whether MPO and other markers of inflammation are associated with MDD and whether the association is confounded by genetic or other shared familial factors.

METHODS

We examined 178 monozygotic and dizygotic middle-aged male twin pairs. We assessed MDD with the Structured Clinical Interview for DSM-IV. Blood markers of inflammation included MPO, interleukin-6, white blood cell count, C-reactive protein, tumor necrosis factor (TNF)-alpha, the TNF-alpha soluble receptor II, and fibrinogen. Analyses were conducted in the overall sample and among 67 twin pairs discordant for MDD using mixed effects regression.

RESULTS

Twins with a history of MDD had 32% higher levels of MPO (p < .0001); this difference persisted after adjusting for other risk factors. Among dizygotic MDD-discordant twin pairs, twins with MDD had 77% higher MPO than their brothers without MDD, after adjusting for other factors (p < .0001). In contrast, no significant association was found in monozygotic twins (p = .13). Similar, but weaker, associations were found between MDD and other inflammatory biomarkers.

CONCLUSIONS

Myeloperoxidase is a useful biomarker of immune activation in MDD. However, the association between inflammation and MDD is largely due to common genetic liability. Our results are consistent with the hypothesis that genes promoting inflammation are involved in the pathogenesis of MDD.

Major depression as a risk factor for chronic disease incidence: longitudinal analyses in a general population cohort

OBJECTIVE

Cross-sectional studies have consistently reported associations between major depression (MD) and chronic medical conditions. Such studies cannot clarify whether medical conditions increase the risk for MD or vice versa. The latter possibility has received relatively little attention in the literature. In this study, we evaluate the incidence of several important chronic medical conditions in people with and without MD.

METHOD

The data source was the Canadian National Population Health Survey (NPHS). The NPHS included the Composite International Diagnostic Interview Short Form to assess past-year major depressive episodes. The NPHS also collected self-report data about professionally diagnosed long-term medical conditions. A longitudinal cohort was interviewed every 2 years between 1994 and 2002. Proportional hazards models were used to compare the incidence of chronic conditions in respondents with and without MD and to produce age-, sex- and covariate-adjusted estimates of the hazard ratios.

RESULTS

The adjusted hazard ratios associated with MD at baseline interview were elevated for several long-term medical conditions: heart disease (1.7), arthritis (1.9), asthma (2.1), back pain (1.4), chronic bronchitis or emphysema (2.2), hypertension (1.7) and migraines (1.9). The incidences of cataracts and glaucoma, peptic ulcers and thyroid disease were not higher in respondents with MD.

CONCLUSION

A set of conditions characterized particularly by pain, inflammation and/or autonomic reactivity has a higher incidence in people with MD.

Bacterial infection early in life protects against stressor-induced depressive-like symptoms in adult rats

Both early-life stress and immune system activation in adulthood have been linked independently to depression in a number of studies. However, the relationship between early-life infection, which may be considered a "stressor", and later-life depression has not been explored. We have reported that neonatal bacterial infection in rats leads to exaggerated brain cytokine production, as well as memory impairments, to a subsequent peripheral immune challenge in adulthood, and therefore predicted that stressor-induced depressive-like symptoms would be more severe in these rats as well. Rats treated on postnatal day 4 with PBS or Escherichia coli were as adults exposed to inescapable tailshock stress (IS), and then tested for sucrose preference, social exploration with a juvenile, and overall activity, 1, 3, 5, and 7 days following the stressor. Serum corticosterone and extracellular 5-HT within the basolateral amygdala were measured in a second group of rats in response to the IS. IS resulted in profound depressive-like behaviors in adult rats, but, surprisingly, rats that suffered a bacterial infection early in life had blunted corticosterone responses to the stressor and were remarkably protected from the depressive symptoms compared to controls. These data suggest that early-life infection should be considered within a cost/benefit perspective, in which outcomes in adulthood may be differentially protected or impaired. These data also suggest that the immune system likely plays a previously unsuspected role in "homeostatic" HPA programming and brain development, which may ultimately lend insight into the often-contradictory literature on cytokines, inflammation, and depression.