The relationship between subtypes of depression and cardiovascular disease: a systematic review of biological models

Partially distinct combinations of psychological, metabolic and inflammatory risk factors are prospectively associated with the onset of the subtypes of Major Depressive Disorder in midlife

BACKGROUND

Given the well known heterogeneity of Major Depressive Disorder (MDD), dividing this complex disorder into subtypes is likely to be a more promising approach to identify its determinants than to study it as a whole.

METHODS

In a prospective population-based cohort study (CoLaus|PsyCoLaus) with 5.5 years of follow-up, 1524 participants without MDD at baseline, aged 35-66 years (mean age 51.4 years, 43.4% females), participated in the physical and psychiatric baseline and the psychiatric follow-up evaluations.

RESULTS

The incidence of both atypical and melancholic MDD during the follow-up period were predicted by female sex, a lifetime history of minor depressive disorders and higher neuroticism scores. Higher baseline body mass index was associated with the onset of atypical MDD, whereas the absence of hypertension and younger age were associated with the development of melancholic MDD. Unspecified MDD was predicted by younger age, low concentrations of tumor necrosis factor-α and elevated life-event impact scores.

LIMITATIONS

The age range of our cohort restricts the identification of risk factors to MDD with onset in midlife and the recruitment in an urban area limits the generalizability of the findings.

CONCLUSIONS

Our data suggest that MDD subtypes are predicted by partially distinct combinations of baseline characteristics suggesting that these subtypes not only differ in their clinical manifestations but also in factors that contribute to their development. Subjects with minor depressive episodes, especially in combination with particular personality features, deserve close clinical attention to prevent the subsequent onset of atypical and melancholic major depression.

Anxiety and Cardiovascular Disease Risk: a Review

Unrecognized anxiety is a difficult clinical presentation in cardiology. Anxiety leads to recurring emergency department visits and the need for numerous diagnostic evaluations to rule out cardiovascular disease (CVD). This review focuses broadly on anxiety and its subtypes in relation to the onset and progression of CVD while describing helpful guidelines to better identify and treat anxiety. Potential mechanisms of cardiopathogenesis are also described. An emerging literature demonstrates that anxiety disorders increase the risk for incident CVD but a causal relationship has not been demonstrated. Anxiety portends adverse prognosis in persons with established CVD that is independent from depression. The level of clinical priority received by depression should be extended to research and clinical intervention efforts in anxiety. Anxiety holds direct relevance for uncovering mechanisms of cardiopathogenesis, developing novel therapeutic strategies, and initiating clinical interventions in the population at risk of developing heart disease, or those already diagnosed with CVD.

Prolonged hypothalamic-pituitary-adrenal axis activation after acute coronary syndrome in the GENESIS-PRAXY cohort

Background

Glucocorticoid excess has been linked with cardiovascular disease. Little is known about the long-term cortisol response in patients after acute coronary syndrome.

Design

The objective of this study was to describe the distribution of salivary cortisol in the post-acute phase of acute coronary syndrome and to describe the association of late-night salivary cortisol with cardiovascular risk factors.

Methods

We used late-night salivary cortisol measurements post-discharge to estimate hypothalamic-pituitary-adrenal axis activity in 309 patients aged 18–55 years enrolled in the GENESIS-PRAXY study from January 2009–April 2013. We evaluated hypothalamic-pituitary-adrenal axis activity and its association with hypertension, dyslipidemia, diabetes, smoking, family history, prior acute coronary syndrome, psychiatric diseases, acute coronary syndrome severity, as well as mortality and rate of rehospitalization at 12 months.

Results

Persistently elevated late-night salivary cortisol>2.92 nmol/l was seen in 99 (32.0%) patients: within the range of what may be seen in Cushing’s disease. Elevated late-night salivary cortisol was associated with previous acute coronary syndrome (13.3% vs 24.2%, p = 0.02), peripheral vascular disease (3.8% vs 13.1%, p = 0.002), and smoking (32.9% vs 46.5% p = 0.02). Elevated late-night salivary cortisol was associated with higher hemoglobin A1c values (5.6 ± 3.0 vs 6.1 ± 2.9, p = 0.008) and lower high density lipoprotein values (0.94 ± 0.53 vs 0.86 ± 0.50, p = 0.01). There were no differences in psychiatric symptom scores, acute coronary syndrome severity or mortality, and rate of rehospitalization at 12 months.

Conclusions

Many patients post-acute coronary syndrome have prolonged, marked activation of the hypothalamic-pituitary-adrenal axis. Late-night salivary cortisol co-associates with several cardiovascular risk factors. Further studies are needed to confirm the exact role of hypothalamic-pituitary-adrenal axis activity in the pathophysiology of cardiovascular disease.

Prospective associations of depression subtypes with cardio-metabolic risk factors in the general population

The mechanisms and temporal sequence underlying the association between major depressive disorder (MDD) and cardio-metabolic diseases are still poorly understood. Recent research suggests subtyping depression to study the mechanisms underlying its association with biological correlates. Accordingly, our aims were to (1) assess the prospective associations of the atypical, melancholic and unspecified subtypes of MDD with changes of fasting glucose, high-density lipoprotein-cholesterol, triglycerides, systolic blood pressure and the incidence of the metabolic syndrome, (2) determine the potential mediating role of inflammatory marker or adipokine concentrations, eating behaviors and changes in waist circumference during follow-up. Data stemmed from CoLaus|PsyCoLaus, a prospective cohort study including 35-66-year-old randomly selected residents of an urban area. Among the Caucasian participants who underwent the physical and psychiatric baseline evaluations, 2813 (87% participation rate) also accepted the physical follow-up exam (mean follow-up duration=5.5 years). Symptoms of mental disorders were elicited using a semi-structured interview. The atypical MDD subtype, and only this subtype, was prospectively associated with a higher incidence of the metabolic syndrome (OR=2.49; 95% CI 1.30-4.77), a steeper increase of waist circumference (β=2.41; 95% CI 1.19-3.63) and independently of this, with a steeper increase of the fasting glucose level (β=131; 95% CI 38-225) during follow-up. These associations were not attributable to or mediated by inflammatory marker or adipokine concentrations, eating behaviors, comorbid psychiatric disorders or lifestyle factors. Accordingly, our results further support the subtyping of MDD and highlight the particular need for prevention and treatment of metabolic consequences in patients with atypical MDD.

Cross-sectional association of exercise, strengthening activities, and cardiorespiratory fitness on generalized anxiety, panic and depressive symptoms

OBJECTIVE

Limited research has evaluated the individual and combined associations of physical activity (PA), cardiorespiratory fitness (CRF) and muscle strengthening activities (MSA) on generalized anxiety, panic and depressive symptoms. We evaluated this topic in a representative sample of young (20-39 years) adults, with considerations by sex.

METHODS

Data from the 1999-2004 National Health and Nutrition Examination Survey (N = 2088) were used. Generalized anxiety, panic and depressive symptoms were assessed via self-report as well as using the Generalized Anxiety Disorder, Panic Disorder, and Depressive Disorders modules of the automated version of the World Health Organization Composite International Diagnostic Interview (CIDI-Auto 2.1). PA and MSA were assessed via validated self-report questionnaires and CRF was determined via a submaximal treadmill-based test. An index variable was created summing the number (range = 0-3) of these parameters for each participant. For example, those meeting PA guidelines, MSA guidelines and having moderate-to-high CRF were classified as having an index score of 3.

RESULTS

MSA was not independently associated with generalized anxiety, panic and depressive symptoms, but those with higher levels of PA and CRF had a reduced odds of these symptoms (ranging from 40 to 46% reduced odds). Compared to those with an index score of 0, those with an index score of 1, 2, and 3, respectively, had a 39%, 54% and 71% reduced odds of having generalized anxiety, panic and depressive symptoms. Results were consistent across both sexes.

CONCLUSION

PA and CRF, but not MSA, were independently associated with generalized anxiety, panic and depressive symptoms. There was evidence of an additive association between PA, CRF, and MSA on these symptoms.

Biomarkers for depression: recent insights, current challenges and future prospects

A plethora of research has implicated hundreds of putative biomarkers for depression, but has not yet fully elucidated their roles in depressive illness or established what is abnormal in which patients and how biologic information can be used to enhance diagnosis, treatment and prognosis. This lack of progress is partially due to the nature and heterogeneity of depression, in conjunction with methodological heterogeneity within the research literature and the large array of biomarkers with potential, the expression of which often varies according to many factors. We review the available literature, which indicates that markers involved in inflammatory, neurotrophic and metabolic processes, as well as neurotransmitter and neuroendocrine system components, represent highly promising candidates. These may be measured through genetic and epigenetic, transcriptomic and proteomic, metabolomic and neuroimaging assessments. The use of novel approaches and systematic research programs is now required to determine whether, and which, biomarkers can be used to predict response to treatment, stratify patients to specific treatments and develop targets for new interventions. We conclude that there is much promise for reducing the burden of depression through further developing and expanding these research avenues.

Interaction between smoking and depressive symptoms with subclinical heart disease in the Coronary Artery Risk Development in Young Adults (CARDIA) study

OBJECTIVE

Evaluate whether smoking exposure and depressive symptoms accumulated over 25 years are synergistically associated with subclinical heart disease, measured by coronary artery calcification (CAC).

METHOD

Participants (baseline: 54.5% women; 51.5% Black; age range = 18-30 years) were followed prospectively from 1985 to 2010 in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Smoking status was queried yearly from Year 0 to Year 25 to compute packyears of smoking exposure. Depressive symptoms were measured on the Center for Epidemiologic Studies Depression (CES-D) scale every 5 years to compute cumulative scores from Year 5 to Year 25. A three-level multinomial logistic regression was used to evaluate the association between cumulative smoking, cumulative depressive symptoms, and their interaction with moderate-risk CAC (score 1-99) and higher-risk CAC (score ≥100) compared with no CAC (score = 0) at Year 25. Models were adjusted for sociodemographic, clinical, and behavioral covariates.

RESULTS

Among 3,189 adults, the cumulative Smoking × Depressive Symptoms interaction was not significant for moderate-risk CAC (p = .057), but was significant for higher-risk CAC (p = .001). For adults with a 30-packyear smoking history, average CES-D scores 2, 10, and 16 were, respectively, associated with odds ratios (95% confidence intervals) 3.40 (2.36-4.90), 4.82 (3.03-7.66), and 6.25 (3.31-11.83) for higher-risk CAC (all ps < .05).

CONCLUSION

Cumulative smoking exposure and cumulative depressive symptoms have a synergistic association with subclinical heart disease, where higher lifetime smoking exposure and depressive symptoms are associated with greater odds of CAC. (PsycINFO Database Record

Association of the Interaction Between Smoking and Depressive Symptom Clusters With Coronary Artery Calcification: The CARDIA Study

OBJECTIVE

Depressive symptom clusters are differentially associated with prognosis among patients with cardiovascular disease (CVD). Few studies have prospectively evaluated the association between depressive symptom clusters and risk of CVD. Previously, we observed that smoking and global depressive symptoms were synergistically associated with coronary artery calcification (CAC). The purpose of this study was to determine whether the smoking by depressive symptoms interaction, measured cumulatively over 25 years, differed by depressive symptom cluster (negative affect, anhedonia, and somatic symptoms) in association with CAC.

METHODS

Participants (N = 3,189: 54.5% female; 51.5% Black; average age = 50.1 years) were followed from 1985-1986 through 2010-2011 in the Coronary Artery Risk Development in Young Adults (CARDIA) study. Smoking exposure was measured by cumulative cigarette pack-years (cigarette packs smoked per day × number of years smoking; year 0 through year 25). Depressive symptoms were measured using a 14-item, 3-factor (negative affect, anhedonia, somatic symptoms) model of the Center for Epidemiologic Studies Depression (CES-D) Scale (years 5, 10, 15, 20, and 25). CAC was assessed at year 25. Logistic regression models were used to evaluate the association between the smoking by depressive symptom clusters interactions with CAC ( = 0 vs. > 0), adjusted for CVD-related sociodemographic, behavioral, and clinical covariates.

RESULTS

907 participants (28% of the sample) had CAC > 0 at year 25. The depressive symptom clusters did not differ significantly between the two groups. Only the cumulative somatic symptom cluster by cumulative smoking exposure interaction was significantly associated with CAC > 0 at year 25 (p = .028). Specifically, adults with elevated somatic symptoms (score 9 out of 18) who had 10, 20, or 30 pack-years of smoking exposure had respective odds ratios (95% confidence intervals) of 2.06 [1.08, 3.93], 3.71 [1.81, 7.57], and 6.68 [2.87, 15.53], ps < .05. Negative affect and anhedonia did not significantly interact with smoking exposure associated with CAC >0, ps > .05.

CONCLUSIONS

Somatic symptoms appear to be a particularly relevant cluster of depressive symptomatology in the relationship between smoking and CVD 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.

Seasonal variations in mood and behavior associate with common chronic diseases and symptoms in a population-based study

The purpose of this study was to assess how seasonality is associated with some of the most common non-communicable diseases (NCDs) in the general Finnish population. The global seasonality score (GSS) was used to measure the magnitude of seasonality in 4689 participants, in addition to which they reported the extent to which the seasonal variations in mood and behavior were experienced as a problem. Regression models and the odds ratios were adopted to analyze the associations adjusted for a range of covariates. Seventy percent of the participants had seasonal variations in sleep duration, social activity, mood, or energy level, and forty percent those in weight and appetite. Angina pectoris and depression were significantly associated with seasonality throughout the analysis. Hypertension, high cholesterol levels, diabetes, other (than rheumatoid) joint diseases and other (than depressive) psychological illnesses were significantly associated with experiencing a problem due to the seasonal variations, with an increase in the GSS, and with seasonal affective disorder and its subsyndromal form. The co-occurrence of the seasonal variations in mood and behavior with certain common NCDs warrants future research to have insights into the etiology and potentially shared pathways and mechanisms of action.

Cross-species evidence for the role of interleukin-33 in depression risk

Extensive evidence highlights the role of inflammatory processes in major depressive disorder (MDD). However, most studies have examined a consistent set of inflammatory cytokines and there is evidence that other immune-derived products may play a role in MDD. In this article, we present data from 3 complimentary studies that support the role of a novel cytokine, interleukin-33 (IL-33), in depression risk. First, we show that a 2-SNP haplotype in the IL-33 gene (rs11792633 and rs7044343) moderated the link between women's history of childhood abuse and their history of recurrent MDD (rMDD), such that the link between childhood abuse and rMDD was stronger among women with fewer copies of the protective IL-33 CT haplotype. Second, linking these findings to differences in circulating cytokine levels, we show in a separate sample that those with a history of rMDD had higher peripheral levels of IL-33 and IL-1β compared with women with a single MDD episode or no history of MDD. Third, providing initial evidence of brain regions underlying these effects using archival rat brain tissue, we show that an acute stressor increased IL-33 expression in the paraventricular nucleus of the hypothalamus and, to a lesser extent, the prefrontal cortex, key brain regions underlying stress response and emotion regulation. These findings provide converging support for the potential role of IL-33 in risk for recurrent MDD. (PsycINFO Database Record

Modulatory Effects of Antidepressant Classes on the Innate and Adaptive Immune System in Depression

Current reviews exploring for unique immune-modulatory profiles of antidepressant classes are limited by focusing mainly on cytokine modulation only and neglecting other aspects of the innate and adaptive immune system. These reviews also do not include recent comparative clinical trials, immune-genetic studies and therapeutics with unique neurotransmitter profiles (e. g., agomelatine). This systematic review extends the established literature by comprehensively reviewing the effects of antidepressants classes on both the innate and adaptive immune system. Antidepressants appear, in general, to reduce pro-inflammatory factor levels, particularly C-reactive protein (CRP), tumour necrosis factor (TNF)-α, interleukin (IL)-1β and IL-6. We caution against conclusions as to which antidepressant possesses the greater anti-inflammatory effect, given the methodological heterogeneity among studies and the small number of comparative studies. The effects of antidepressant classes on adaptive immune factors are complex and poorly understood, and few studies have been conducted. Methodological heterogeneity is high among these studies (e. g., length of study, cohort characteristics, dosage used and immune marker analysis). We recommend larger, comparative studies - in clinical and pre-clinical populations.

Evaluating lifestyle and health-related characteristics of older adults with co-occurring depressive symptoms and cardiometabolic abnormalities

OBJECTIVE

Comorbid depression and cardiometabolic abnormalities might represent an important subgroup of depression. The aim of the present study was to evaluate lifestyle and health-related characteristics of individuals with both depressive symptoms and cardiometabolic abnormalities.

METHODS

Data were from the English Longitudinal Study of Ageing. The sample was comprised of 5365 adults aged 50-80 years. High depressive symptoms were based on the eight-item Center for Epidemiologic Studies - Depression scale. Cardiometabolic abnormalities were defined as having ≥3 cardiometabolic risk factors (hypertension, impaired glycemic control, systemic inflammation, low high-density lipoprotein cholesterol, hypertriglyceridemia, and central obesity). Four groups were created based on Center for Epidemiologic Studies - Depression scores and cardiometabolic abnormalities: those with (i) comorbid depressive symptoms and cardiometabolic abnormalities (DCM); (ii) depressive symptoms only (DnoCM); (iii) cardiometabolic abnormalities only; and (iv) neither depressive symptoms nor cardiometabolic abnormalities. Lifestyle and health-related characteristics of the four groups were compared using chi-square tests. A modified Poisson regression analysis was performed to compare the DCM and the DnoCM groups with respect to lifestyle and health-related characteristics.

RESULTS

Those in the DCM group were significantly less physically active (p = 0.003), had poorer self-rated health (p < 0.001), had lower income (p = 0.001), and were more likely to be retired (p < 0.001) than those in the DnoCM group. The pattern of results remained after controlling for other lifestyle and health-related factors.

CONCLUSION

These results provide support for a cardiometabolic subgroup of depression that is associated with physical inactivity, poorer self-rated health, lower income, and retirement. Copyright © 2015 John Wiley & Sons, Ltd.

An Unpredictable Chronic Mild Stress Protocol for Instigating Depressive Symptoms, Behavioral Changes and Negative Health Outcomes in Rodents

Chronic, unresolved stress is a major risk factor for the development of clinical depression. While many preclinical models of stress-induced depression have been reported, the unpredictable chronic mild stress (UCMS) protocol is an established translationally-relevant model for inducing behavioral symptoms commonly associated with clinical depression, such as anhedonia, altered grooming behavior, and learned helplessness in rodents. The UCMS protocol also induces physiological (e.g., hypercortisolemia, hypertension) and neurological (e.g., anhedonia, learned helplessness) changes that are clinically associated with depression. Importantly, UCMS-induced depressive symptoms can be ameliorated through chronic, but not acute, treatment with common SSRIs. As such, the UCMS protocol offers many advantages over acute stress protocols or protocols that utilize more extreme stressors. Our protocol involves randomized, daily exposures to 7 distinct stressors: damp bedding, removal of bedding, cage tilt, alteration of light/dark cycles, social stresses, shallow water bath, and predator sounds/smells. By subjecting rodents 3-4 hr daily to these mild stressors for 8 weeks, we demonstrate both significant behavioral changes and poor health outcomes to the cardiovascular system. This approach allows for in-depth interrogation of the neurological, behavioral, and physiological alterations associated with chronic stress-induced depression, as well as for testing of new potential therapeutic agents or intervention strategies.

Genetic variation in IL-1β, IL-2, IL-6, TSPO and BDNF and response to duloxetine or placebo treatment in major depressive disorder

AIM

This study investigated polymorphisms of five inflammatory-related genes for association with duloxetine and placebo response in patients with major depression.

PATIENTS & METHODS

Twenty SNPs in IL-1β, IL-2, IL-6, TSPO and BDNF were genotyped in major depressive disorder patients treated with either duloxetine (n = 215) or placebo (n = 235) for up to 8 weeks. Treatment response was measured with the Montgomery-Åsberg Depression Rating Scale.

RESULTS

IL-6 variants rs2066992 and rs10242595 were nominally associated with response to duloxetine (p = 0.047 and p = 0.028, respectively). Notably, the variant rs2066992 was also associated with placebo response (p = 0.026). However, none of our results remained significant after correction for multiple testing.

CONCLUSION

Our findings tentatively suggest that IL-6 variants play a role in duloxetine and placebo response, which warrants further investigation.

Acute coronary syndrome and depression: A review of shared pathophysiological pathways

OBJECTIVE

To examine the evidence for shared pathophysiological pathways in acute coronary syndrome and major depression and to conceptualise the dynamic interplay of biological systems and signalling pathways that link acute coronary syndrome and depression within a framework of neuro-visceral integration.

METHODS

Relevant articles were sourced via a search of published literature from MEDLINE, EMBASE and PubMed using a variety of search terms relating to biological connections between acute coronary syndrome and depression. Additional articles from bibliographies of retrieved papers were assessed and included where relevant.

RESULTS

Despite considerable research efforts, a clear understanding of the biological processes connecting acute coronary syndrome and depression has not been achieved. Shared abnormalities are evident across the immune, platelet/endothelial and autonomic/stress-response systems. From the available evidence, it seems unlikely that a single explanatory model could account for the complex interactions of biological pathways driving the pathophysiology of these disorders and their comorbidity.

CONCLUSION

A broader conceptual framework of mind-body or neuro-visceral integration that can incorporate the existence of several causative scenarios may be more useful in directing future research and treatment approaches for acute coronary syndrome-associated depression.

Acute coronary syndrome-associated depression: the salience of a sickness response analogy?

Depression emerging in conjunction with acute coronary syndrome (ACS) is thought to constitute a distinct high-risk phenotype with inflammatory determinants. This review critically examines the notion put forward in the literature that ACS-associated depression constitutes a meaningful subtype that is qualitatively different from depressive syndromes observed in psychiatric patients; and evaluates the salience of an analogy to the acute sickness response to infection or injury as an explanatory model. Specific features differentiating ACS-associated depression from other phenotypes are discussed, including differences in depression symptom profiles, timing of the depressive episode in relation to ACS, severity of the cardiac event, and associated immune activation. While an acute sickness response analogy offers a plausible conceptual framework, concrete evidence is lacking for inflammatory activity as the triggering mechanism. It is likely that ACS-associated depression encompasses several causative scenarios.

Somatic concerns, depressive traits, atherosclerosis and the incidence of cardiovascular disease in ageing Finnish men

OBJECTIVE

To examine the impact of somatic concerns and depressive traits on carotid artery intima-media thickness (IMT) and on the incidence of cardiovascular disease (CVD).

METHODS

In the cross-sectional study of 2682 Finnish men aged 42 to 61years, a subsample of 1333 men had their carotid artery IMT recorded. In the prospective part of the study participants (n=1453) were followed up for an average of 20years. Data on incident CVD (n=766) were obtained from the National Population Register. For both subsamples, the Minnesota Multiphasic Personality Inventory (MMPI) was used to measure depressive traits and somatic concerns. In addition, composite scales of general ill-being, sleep and pain problems, psychological well-being, energy level, and cheerfulness were formed.

RESULTS

In the final corrected models there were no significant associations between somatic concerns or depressive traits and IMT. Both somatic concerns and depressive traits predicted a higher CVD incidence after adjustments for age and risk factors. The association between depressive traits and CVD incidence was highest among the subgroup of men with the highest levels of hsCRP, but this result did not reach statistical significance. Of the composite scales, general ill-being predicted a higher CVD incidence in the fully adjusted model, even when all the composite scales were entered into the model simultaneously.

CONCLUSION

Somatic concerns and depressive traits predict a higher CVD incidence. In particular, general ill-being contributes to this association. The association between depressive traits and CVD may be moderated by low-grade inflammation.

The associations of depression and hypertension with brain volumes: Independent or interactive?

Independent studies on major depressive disorder (MDD) and hypertension, suggest overlapping abnormalities in brain regions associated with emotional and autonomic processing. However, the unique and interactive effects of MDD and hypertension have never been studied in a single sample. Brain volume in these areas may be an explanatory link in the comorbidity between MDD and hypertension. Voxel-based morphometry was used to test for main effects of MDD (N = 152) and hypertension (N = 82) and their interactions on gray and white matter volumes. Voxel-wise results are reported at p < .05 FWE corrected for the spatial extent of the whole brain and a-priori regions of interest (ROIs: hippocampus, anterior cingulate cortex (ACC) and inferior frontal gyrus (IFG)). In addition, analyses on the extracted total volumes of our ROIs were performed. Interactive effects in the mid-cingulate cortex (MCC) (p FWE = .01), cerebellum (p FWE = .01) and in the ACC total ROI volume (p = .02) were found. MDD in the presence, but not in the absence of hypertension was associated with lower volumes in the ACC and MCC, and with a trend towards larger gray matter volume in the cerebellum. No associations with white matter volumes were observed. Results suggest that the combination of MDD and hypertension has a unique effect on brain volumes in areas implicated in the regulation of emotional and autonomic functions. Brain volume in these regulatory areas may be an explanatory link in the comorbidity between hypertension and MDD.

Associations between depression subtypes, depression severity and diet quality: cross-sectional findings from the BiDirect Study

BACKGROUND

Depression is supposed to be associated with an unhealthy lifestyle including poor diet. The objective of this study was to investigate differences in diet quality between patients with a clinical diagnosis of depression and population-based controls. Additionally, we aimed to examine effects of specific depression characteristics on diet by analyzing if diet quality varies between patients with distinct depression subtypes, and if depression severity is associated with diet quality.

METHODS

The study included 1660 participants from the BiDirect Study (n = 840 patients with depression, n = 820 population-based controls). The psychiatric assessment was based on clinical interviews and a combination of depression scales in order to provide the classification of depression subtypes and severity. Diet quality scores, reflecting the adherence to a healthy dietary pattern, were calculated on the basis of an 18-item food frequency questionnaire. Using analysis of covariance, we calculated adjusted means of diet quality scores and tested differences between groups (adjusted for socio-demographic, lifestyle-, and health-related factors).

RESULTS

We found no differences in diet quality between controls and patients with depression if depression was considered as one entity. However, we did find differences between patients with distinct subtypes of depression. Patients with melancholic depression reported the highest diet quality scores, whereas patients with atypical depression reported the lowest scores. Depression severity was not associated with diet quality.

CONCLUSIONS

Previous literature has commonly treated depression as a homogeneous entity. However, subtypes of depression may be associated with diet quality in different ways. Further studies are needed to enlighten the diet-depression relationship and the role of distinct depression subtypes.

Platelet activating factors are associated with depressive symptoms in coronary artery disease patients: a hypothesis-generating study

INTRODUCTION

Depression is a frequent complication of coronary artery disease (CAD) with an unknown etiology. Platelet activating factor (PAF) lipids, which are associated with CAD, have recently been linked with novel proposed etiopathological mechanisms for depression such as inflammation, oxidative/nitrosative stress, and vascular endothelial dysfunction.

METHODS AND RESULTS

This hypothesis-generating study investigated the relationships between various PAF species and depressive symptoms in 26 CAD patients (age: 60.6±9.2 years, 69% male, mean Hamilton Depression Rating Scale [HAM-D] score: 11.8±5.2, HAM-D range: 3-20). Plasma PAF analyses were performed using high performance liquid chromatography electrospray ionization mass spectrometry in precursor ion scan. Significant associations between depressive symptom severity (HAM-D score) and a greater plasma abundance of the PAFs phosphocholine (PC) PC(O-12:0/2:0) (r=0.49, P=0.01), PC(O-14:1/2:0) (r=0.43, P=0.03), PC(O-17:3/2:0) (r=0.44, P=0.04), and PC(O-18:3/2:0) (r=0.50, P=0.01) were observed. Associations between those PAFs and HAM-D score persisted after adjusting for age and sex.

CONCLUSION

These preliminary findings support the exploration of the PAF lipidome for depressive symptom biomarkers in CAD patients. Patients were recruited as part of the following clinical trial: NCT00981383.

Psychosocial stress as a risk factor for sepsis: a population-based cohort study

OBJECTIVE

To characterize the relationship between stress and future risk of sepsis. We also evaluated the role of depression in this relationship.

METHODS

We used population-based data on 30,183 participants in the Reasons for Geographic and Racial Differences in Stroke cohort, characterizing stress using the Perceived Stress Scale (PSS) and depressive symptoms using the Center for Epidemiologic Studies Depression Scale (CES-D). We identified incident sepsis events as hospitalizations for a serious infection with the presence of at least two systemic inflammatory response syndrome criteria. We assessed associations between PSS and incidence of sepsis for 1 and 10 years of follow-up, adjusting for demographics and chronic medical conditions and assessing the role of health behaviors and CES-D in these relationships.

RESULTS

In 2003 to 2012, 1500 participants experienced an episode of sepsis. Mean PSS and CES-D scores were 3.2 (2.9) and 1.2 (2.1). PSS was associated with increased 1-year adjusted incidence of sepsis (hazard ratio [HR] = 1.21 per PSS standard deviation, 95% confidence interval = 1.06-1.38); multivariable adjustment for health behaviors and CES-D did not change this association (1.20, 1.03-1.39). PSS was also associated with increased 10-year adjusted incidence of sepsis (HR = 1.07 per PSS standard deviation; 95% confidence interval = 1.02-1.13). Multivariable adjustment showed that health behaviors did not affect this long-term association, whereas the addition of CES-D reduced the association between PSS and sepsis during 10-year follow-up (HR = 1.04, 0.98-1.11).

CONCLUSIONS

Increased stress was associated with higher 1-year adjusted incidence of sepsis, even after accounting for depressive symptoms. The association between stress and 10-year adjusted incidence of sepsis was also significant, but this association was reduced when adjusting for depressive symptoms. Reduction of stress may limit short-term sepsis risk.

Anhedonic depression, history of depression, and anxiety as gender-specific risk factors of myocardial infarction in healthy men and women: The HUNT study

This prospective study examines gender-specific psychological risk factors of myocardial infarction. Out of 41,248 participants free of coronary heart disease at baseline, 822 cases of myocardial infarction were identified in the Nord-Trøndelag Health Study or the mortality register. The participants completed the Hospital Anxiety and Depression Scale. Cholesterol, blood pressure, and waist–hip ratio were measured by medical staff. Smoking, diabetes, non-fatal myocardial infarction, and history of depressive episode were self-reported. Anhedonic depression (Hospital Anxiety and Depression Scale-D ≥8) was a significant predictor of myocardial infarction in women but not in men. Gender difference in risk estimate based on Hospital Anxiety and Depression Scale-D was significant (p < .01). History of depressive episode was a significant predictor of myocardial infarction in men. Symptoms of anxiety (Hospital Anxiety and Depression Scale-A ≥8) reduced the risk of having a myocardial infarction.

Induced mild systemic inflammation is associated with impaired ability to improve cognitive task performance by practice

Elevated inflammatory levels are linked to poorer cognition, but experimental confirmation is lacking. This report examined associations between cognitive performance and inflammation induced by exercise and vaccination. Thirty-six (exercise N = 18, vaccination N = 18) healthy males completed a paced auditory serial addition test (PASAT), which is a multifaceted measure of cognitive function. The task was completed in placebo and elevated inflammation states. Improvements in PASAT performance were related to inflammation. In the exercise study, IL-6 during the first PASAT negatively correlated with PASAT improvement (p = .022). In the vaccination study, increases in C-reactive protein between PASATs correlated with reduced PASAT improvement (p < .001). Inflammation was linked to reduced improvements in cognitive performance. Further research should identify the specific cognitive functions affects and the underlying mechanisms.

Associations between mood, anxiety or substance use disorders and inflammatory markers after adjustment for multiple covariates in a population-based study

Inflammation is one possible mechanism underlying the associations between mental disorders and cardiovascular diseases (CVD). However, studies on mental disorders and inflammation have yielded inconsistent results and the majority did not adjust for potential confounding factors. We examined the associations of several pro-inflammatory cytokines (IL-1β, IL-6 and TNF-α) and high sensitive C-reactive protein (hsCRP) with lifetime and current mood, anxiety and substance use disorders (SUD), while adjusting for multiple covariates. The sample included 3719 subjects, randomly selected from the general population, who underwent thorough somatic and psychiatric evaluations. Psychiatric diagnoses were made with a semi-structured interview. Major depressive disorder was subtyped into "atypical", "melancholic", "combined atypical-melancholic" and "unspecified". Associations between inflammatory markers and psychiatric diagnoses were assessed using multiple linear and logistic regression models. Lifetime bipolar disorders and atypical depression were associated with increased levels of hsCRP, but not after multivariate adjustment. After multivariate adjustment, SUD remained associated with increased hsCRP levels in men (β = 0.13 (95% CI: 0.03,0.23)) but not in women. After multivariate adjustment, lifetime combined and unspecified depression were associated with decreased levels of IL-6 (β = -0.27 (-0.51,-0.02); β = -0.19 (-0.34,-0.05), respectively) and TNF-α (β = -0.16 (-0.30,-0.01); β = -0.10 (-0.19,-0.02), respectively), whereas current combined and unspecified depression were associated with decreased levels of hsCRP (β = -0.20 (-0.39,-0.02); β = -0.12 (-0.24,-0.01), respectively). Our data suggest that the significant associations between increased hsCRP levels and mood disorders are mainly attributable to the effects of comorbid disorders, medication as well as behavioral and physical CVRFs.

A phase-specific neuroimmune model of clinical depression

Immune dysfunction and pro-inflammatory states in particular have been implicated in the aetiology and pathogenesis of depression. Whilst the onset of an episode and certain symptoms of depression appear well explained by this inflammatory model, the underpinnings of the episodic and progressive nature, as well as relapse and remission status in depression require attention. In this review it is suggested that additional immune factors beyond pro- and anti-inflammatory cytokines may effectively contribute to the understanding of the neurobiology of clinical depression. Considering neurobiological effects of immunomodulatory factors such as T cells, macrophages, microglia and astrocytes relevant to depression, we suggest a neuroimmune model of depression underpinned by dynamic immunomodulatory processes. This perspective paper then outlines a neuroimmune model of clinical phases of depression in an attempt to more adequately explain depression-like behaviours in pre-clinical models and the dynamic nature of depression in clinical populations. Finally, the implications for immunomodulatory treatments of depression are considered.

Depressive symptoms and carotid intima-media thickness in South American Hispanics: results from the PREVENCION study

This study aimed to: (1) examine the relationship between depressive symptoms and subclinical atherosclerosis, measured by carotid intima-media thickness (IMT); and, (2) Determine the moderating effect of gender in this relationship among South American Hispanics. We studied 496 adults enrolled in the population-based PREVENCION study. Carotid IMT was measured with high-resolution ultrasonography. Depressive symptoms were assessed using the Hospital Anxiety and Depression Scale. Mean carotid IMT was 0.66 mm. (SD = 0.17) and mean depression score was 5.6 (SD = 3.5). Depressive symptoms were not associated with carotid IMT (β = 0.04, p = 0.222) in multivariate analyses. A significant moderating effect of gender was found (β for interaction = 0.10, p = 0.030), resulting from a significant association between depressive symptoms and carotid IMT in men but not women. Depressive symptoms were associated with subclinical atherosclerosis in South American Hispanic men but not women after controlling for demographic characteristics and traditional cardiovascular risk factors.

Perfusion deficits, inflammation and aging precipitate depressive behaviour

Major depressive disorder (MDD) is a severe psychiatric illness that is associated with significant morbidity and mortality. Despite advances in the treatment of major depression, one-third of depressed patients fail to respond to conventional antidepressant medication. One pathophysiologic mechanism hypothesized to contribute to treatment resistance in depression is inflammation. Inflammation has been linked to depression by a number of putative mechanisms involving perfusion deficits that can trigger microglial activation and subsequent neuroinflammation in the elderly. However, the pathophysiological mechanisms remain to be further elucidated. This review focusses on recent studies addressing the complex relationships between depression, aging, inflammation and perfusion deficits in the elderly. We expect that a better understanding of neuroinflammatory mechanisms associated with age-related diseases may lead to the discovery of new biomarkers of MDD and development of new therapeutic interventions.

Platelet-activating factors are associated with cognitive deficits in depressed coronary artery disease patients: a hypothesis-generating study

Background

Patients with coronary artery disease (CAD) are at risk of accelerated cognitive decline, particularly those with major depression. Mechanisms for cognitive deficits associated with CAD, and the effects of depression, remain poorly understood. However, CAD is associated with inflammatory processes that have been linked to neurodegeneration, may contribute to cognitive decline, and are elevated in depression. Platelet-activating factors (PAFs) are emerging as key lipid mediators that may be central to those processes and highly relevant to cognitive decline in CAD.

Methods

This cross-sectional study investigated relationships between various PAFs and cognitive performance in 24 patients with CAD (age, 60.3 ± 9.4; 70.8% male). Analyses were repeated in a subgroup of 15 patients with CAD with major depression (DSM-IV). Cognitive performance was assessed using a standardized battery and summary z scores were calculated based on age, sex, and education norms. Global cognitive performance was the average of domain-specific z scores. Plasma PAF analyses were performed using electrospray ionization mass spectrometry (precursor ion scan).

Results

A greater abundance of PAF PC(O-18:0/2:0) was associated with poorer global cognitive performance in patients with CAD (r = -0.45, P = 0.03). In the major depressed subgroup, PAF PC(O-18:0/2:0) (r = -0.59, P = 0.02) as well as PC(O-16:0/2:0) (r = -0.52, P = 0.04), and lyso-PAF PC(O-16:0/0:0) (r = -0.53, P = 0.04) were associated with poorer global cognitive performance. A greater abundance of PAF PC(O-19:5/2:0) was associated with better global cognitive performance (r = 0.55, P = 0.03), suggesting a possible compensatory species.

Conclusions

This study suggests that certain PAFs might be associated with global cognitive performance in patients with CAD, with stronger relationships observed in those with major depression. Confirmation of these preliminary findings is warranted.

Establishing the bidirectional relationship between depression and subclinical arteriosclerosis--rationale, design, and characteristics of the BiDirect Study

BACKGROUND

Depression and cardiovascular diseases due to arteriosclerosis are both frequent and impairing conditions. Depression and (subclinical) arteriosclerosis appear to be related in a bidirectional way, and it is plausible to assume a partly joint causal relationship. However, the biological mechanisms and the behavioral pathways that lead from depression to arteriosclerosis and vice versa remain to be exactly determined.

METHODS/DESIGN

This study protocol describes the rationale and design of the prospective BiDirect Study that aims at investigating the mutual relationship between depression and (subclinical) arteriosclerosis. BiDirect is scheduled to follow-up three distinct cohorts of individuals ((i) patients with acute depression (N = 999), (ii) patients after an acute cardiac event (N = 347), and (iii) reference subjects from the general population (N = 912)). Over the course of 12 years, four personal examinations are planned to be conducted. The core examination program, which will remain identical across follow-ups, comprises a personal interview (e.g. medical diagnoses, health care utilization, lifestyle and risk behavior), a battery of self-administered questionnaires (e.g. depressive symptoms, readiness to change health behavior, perceived health-related quality of life), sensory (e.g. olfaction, pain) and neuropsychological (e.g. memory, executive functions, emotional processing, manual dexterity) assessments, anthropometry, body impedance measurement, a clinical work-up regarding the vascular status (e.g. electrocardiogram, blood pressure, intima media thickness), the taking of blood samples (serum and plasma, DNA), and structural and functional resonance imaging of the brain (e.g. diffusion tensor imaging, resting-state, emotional faces processing). The present report includes BiDirect-Baseline, the first data collection wave.

DISCUSSION

Due to its prospective character, the integration of three distinct cohorts, the long follow-up time window, the diligent diagnosis of depression taking depression subtypes into account, the consideration of relevant comorbidities and risk factors, the assessment of indicators of (subclinical) arteriosclerosis in different vascular territories, and the structural and functional brain imaging that is performed for a large number of participants, the BiDirect Study represents an innovative approach that combines population-based cohorts with sophisticated clinical work-up methods and that holds the potential to overcome many of the drawbacks characterizing earlier investigations.

Dietary patterns and the risk of depression in adults: a systematic review of observational studies

PURPOSE

Diet, a modifiable lifestyle factor, may influence the development of depression. We performed a systematic review of observational studies examining the relationship between dietary patterns and depression in healthy adults.

METHODS

A literature research was conducted searching various electronic databases up to May 2013. Study selection was based on predefined inclusion and exclusion criteria. Included studies were reviewed, and relevant data were extracted by two independent researchers. Due to a high level of heterogeneity, no meta-analysis was conducted. Therefore, main results are presented in a descriptive way.

RESULTS

In total, 16 studies met the inclusion criteria and are part of this review. Dietary patterns most commonly found were traditional/healthy patterns, Western/unhealthy patterns and Mediterranean patterns. The available literature suggests a protective effect of healthy and Mediterranean patterns, as well as a potential positive association of Western patterns and depression. However, comparison of the included studies was difficult, due to differences in relevant study characteristics and methodological limitations.

CONCLUSIONS

There are indications that dietary patterns may have influence on the onset of depression, but no firm conclusion can be drawn at this point. Further research is needed to clarify the diet-depression relationship, preferably in the form of methodological strong prospective studies using more homogeneous methods.

Comorbid anxiety disorders alter the association between cardiovascular diseases and depression: the German National Health Interview and Examination Survey

PURPOSE

This study aims to examine whether specific anxiety disorder comorbidity alters the purported association between depression and specific cardiovascular diseases (CVDs).

METHODS

In 4,181 representative German participants of the general population, 12-month prevalence of psychiatric disorders was assessed through the Composite International Diagnostic Interview and CVDs by physician verified diagnosis. Adjusting for conventional risk factors logistic regression analyzed the association between CVDs (peripheral vascular disease (PVD), hypertension, cerebrovascular disease and heart disease) and combinations of comorbidity between depression and anxiety disorder types (panic disorder, specific phobia, social phobia and generalized anxiety).

RESULTS

There were 770 cases of hypertension (18.4 %), 763 cases of cerebrovascular disease (18.2 %), 748 cases of PVD (17.9 %), and 1,087 cases of CVD (26.0 %). In adjusted analyses phobia comorbid with depression was associated with cerebrovascular disease (odds ratio (OR) 1.61; 95 % confidence interval (CI) 1.04-2.50) as was panic disorder (OR 2.89; 95 % CI 1.47-5.69). PVD was significantly associated with panic disorder (adjusted OR 2.97; 95 % CI 1.55-5.69). Panic disorder was associated with CVDs (adjusted OR 2.28; 95 % CI 1.09-4.77) as was phobia (adjusted OR 1.35; 95 % CI 1.04-1.78).

CONCLUSIONS

Classification of anxiety and depression according to comorbidity groups showed discrete effects for panic disorder and specific phobia with CVDs, independent from covariates and depression.

Platelet serotonin transporter function predicts default-mode network activity

Background

The serotonin transporter (5-HTT) is abundantly expressed in humans by the serotonin transporter gene SLC6A4 and removes serotonin (5-HT) from extracellular space. A blood-brain relationship between platelet and synaptosomal 5-HT reuptake has been suggested, but it is unknown today, if platelet 5-HT uptake can predict neural activation of human brain networks that are known to be under serotonergic influence.

Methods

A functional magnetic resonance study was performed in 48 healthy subjects and maximal 5-HT uptake velocity (V_max) was assessed in blood platelets. We used a mixed-effects multilevel analysis technique (MEMA) to test for linear relationships between whole-brain, blood-oxygen-level dependent (BOLD) activity and platelet V_max.

Results

The present study demonstrates that increases in platelet V_max significantly predict default-mode network (DMN) suppression in healthy subjects independent of genetic variation within SLC6A4. Furthermore, functional connectivity analyses indicate that platelet V_max is related to global DMN activation and not intrinsic DMN connectivity.

Conclusion

This study provides evidence that platelet V_max predicts global DMN activation changes in healthy subjects. Given previous reports on platelet-synaptosomal V_max coupling, results further suggest an important role of neuronal 5-HT reuptake in DMN regulation.

Chemokines and chemokine receptors in mood disorders, schizophrenia, and cognitive impairment: a systematic review of biomarker studies

The search for immune biomarkers in psychiatric disorders has primarily focused on pro-inflammatory cytokines. Other immune proteins including chemokines have been relatively neglected in such studies. Recent evidence has implicated chemokines in many neurobiological processes potentially relevant to psychiatric disorders, beyond their classical chemotactic functions. These may include neuromodulator effects, neurotransmitter-like effects, and direct/indirect regulation of neurogenesis. This systematic review presents the existing early evidence which supports an association of many chemokines with the psychiatric disorders: depression, bipolar disorder, schizophrenia, mild cognitive impairment and Alzheimer's disease. The non-specific association of chemokines including CXCL8 (IL-8), CCL2 (MCP-1), CCL3 (MIP-1α) and CCL5 (RANTES) with these disorders across diagnostic categories implies a generalised involvement of many chemokine systemic with psychiatric disease. Additional chemokines with great mechanistic relevance including CXCL12 (SDF-1) and CX3CL1 (fractalkine) have been rarely reported in the existing human literature and should be included in future clinical studies. The potential utility of these proteins as pathologically relevant biomarkers or therapeutic targets should be considered by future clinical and translational research.

Mental disorders across the adult life course and future coronary heart disease: evidence for general susceptibility

BACKGROUND

Depression, anxiety, and psychotic disorders have been associated with an increased risk of coronary heart disease (CHD). It is unclear whether this association between mental health and CHD is present across a wider range of mental disorders.

METHODS AND RESULTS

Participants were 1 107 524 Swedish men conscripted at a mean age of 18.3 years. Mental disorders were assessed by psychiatric interview on conscription, and data on hospital admissions for mental disorder and CHD were obtained from national registers during 22.6 years of follow-up. An increased risk of incident CHD was evident across a range of mental disorders whether diagnosed at conscription or on later hospital admission. Age-adjusted hazard ratios (95% confidence intervals) according to diagnoses at conscription ranged from 1.30 (1.05, 1.62) (depressive disorders) to 1.90 (1.58, 2.38) (alcohol-related disorders). [corrected]. The equivalent figures according to diagnoses during hospital admission ranged from 1.49 (1.24-1.80) (schizophrenia) to 2.82 (2.53-3.13) (other substance use disorders). Associations were little changed by adjustment for parental socioeconomic status, or body mass index, diabetes mellitus, and blood pressure measured at conscription, but they were partially attenuated by the adjustment for smoking, alcohol intake, and intelligence measured at conscription, and for education and own socioeconomic position.

CONCLUSIONS

Increased risk of incident CHD is present across a range of mental disorders and is observable when the disorders are diagnosed at a young age.

Sex and age differences in the relation of depressive symptoms with blood pressure

BACKGROUND

Longitudinal associations between depressive symptoms and blood pressure have been inconsistent. Most studies have examined incident hypertension as an outcome, and few have examined effect modification.

METHODS

This study examined moderating influences of sex and age on coincident trajectories of depressive symptoms and blood pressure among 2,087 participants from the Baltimore Longitudinal Study of Aging (aged 19-97 years; 53% men; 74% white). Participants underwent clinical blood pressure measurement and completed the Center for Epidemiological Studies-Depression (CES-D) scale on up to 14 occasions (mean = 3.8; SD = 2.6) over up to 29 years (mean = 7.8; SD = 6.4). CES-D was log-transformed (CES-D(log)) for analyses.

RESULTS

Mixed-effects regression revealed that prospective relations of CES-D(log) to diastolic blood pressure differed by age in women (b = 0.095; P = 0.001) but not men; greater CES-D(log) attenuated the expected age-related decline in diastolic blood pressure. Across all testing sessions, greater CES-D(log) was associated significantly with higher average systolic blood pressure for women (b = 2.238; P = 0.006) but not men. Age-stratified analyses showed that greater CES-D(log) was associated significantly with higher average systolic (b = 3.348; P = 0.02) and diastolic (b = 1.730; P < 0.03) blood pressure for older adults (≥58.8 years at first visit). In the younger age cohort, sex moderated the relation of CES-D(log) to systolic blood pressure (b = -3.563; P = 0.007); greater CES-D(log) in women, but lesser CES-D(log) in men, was associated with higher systolic blood pressure.

CONCLUSIONS

Results demonstrate sex and age differences in the relation between depressive symptoms and blood pressure. Findings suggest the potential importance of preventing, detecting, and lowering depressive symptoms to prevent hypertension among women and older adults.

Sympathetic vasomotor tone is associated with depressive symptoms in young females: a potential link between depression and cardiovascular disease

BACKGROUND

Although increased sympathetic nervous system (SNS) activity is commonly associated with major depressive disorder (MDD) and cardiovascular disease (CVD), a biomarker linking these two entities remains elusive. We therefore evaluated the relationship between depressive symptoms and cardiovascular modulation by heart rate variability (HRV), brachial blood pressure (BP), ambulatory BP (ABP), and low frequency component of systolic BP variability (LFSBP), a surrogate of sympathetic vasomotor tone. We hypothesized that LFSBP would be the strongest predictor of depressive symptoms compared with HRV and BP measurements.

METHODS

Eighty young healthy female subjects (20.51 ± 2.82 years) were evaluated for depressive symptoms using the Center for Epidemiologic Studies Depression Scale (CES-D). Data collection was conducted after a 10-minute resting period. Beat-to-beat BPs were recorded for 5-minute at baseline (BASE) followed by a 3-minute cold pressor test (CPT). ABP was obtained for 24 hours.

RESULTS

Hierarchical multiple regression analyses indicated that LFSBP at BASE was a stronger predictor of CES-D variance than BP and HRV indices, with LFSBP uniquely accounting for 8.1% of variance in CES-D scores during laboratory beat-by-beat BP assessments and 44.7% in ABP assessments. Individuals with acute depression scores (n = 12; CES-D ≥ 16) had significantly higher (P < 0.001) mean LFSBP values (6.66 ± 2.54 mm Hg(2)) than the remaining sample (3.32 ± 2.2 mm Hg(2)), whereas no other significant differences were detected in any of the other cardiovascular variables. Cardiovascular responses to CPT did not predict CES-D scores.

CONCLUSIONS

These findings suggest that LFSBP could be a biomarker of neurovascular functioning with potential clinical implications for understanding the interaction between MDD and CVD.

Post-stroke depression and depression-executive dysfunction syndrome are associated with recurrence of ischaemic stroke

BACKGROUND

Depression and depression-executive dysfunction syndrome (DES) are common neuropsychiatric consequences of stroke. We hypothesized that if stroke as a cerebrovascular event causes depression, this so-called post-stroke depression will further increase the risk of recurrent stroke. The objective of the study was to investigate whether patients with post-stroke depression or DES have increased rates of stroke recurrence.

METHODS

We included 223 patients from the Helsinki Stroke Aging Memory cohort (n = 486) admitted to Helsinki University Central Hospital with a follow-up of 12 years. We included only patients with first-ever ischaemic stroke who were testable for depression and executive dysfunction. For follow-up, national register data were reviewed for all diagnosis codes of ischaemic stroke, survival data and causes of death. Neuropsychological and neuropsychiatric evaluations for depression and executive functions were performed 12-20 weeks after the index stroke. Univariate analysis was performed using χ(2), Mantel-Haenszel, ANOVA, and Kaplan-Meier log rank analyses. A Cox multivariable model with forced entry was used to adjust for stroke risk factors (age, gender, smoking, atrial fibrillation, hypertension, diabetes, peripheral arterial disease, hypercholesterolaemia).

RESULTS

The mean time to first recurrent stroke was shorter for the depressed patient group (8.15, 95% CI 7.11-9.19 vs. 9.63, 8.89-10.38 years) and even shorter for patients with DES (7.15, 5.55-8.75 vs. 9.75, 9.09-10.41 years) compared to the remaining groups, respectively. The cumulative risk for recurrent ischaemic stroke in the 12-year follow-up was higher for the depression group (log rank p = 0.04) and for the DES group (log rank p = 0.01) compared to the remaining groups, respectively. Cox multivariable analyses revealed that the older age of the patient (1.05; 1.01-1.08/year), the absence of hypercholesterolaemia (0.24; 0.09-0.59), depression (1.68; 1.07-2.63), and DES (1.95; 1.14-3.33) were all associated with recurrent stroke.

CONCLUSIONS

Depression and especially DES are associated with a shorter interval to recurrence of ischaemic stroke but executive dysfunction alone is not associated with a more rapid stroke recurrence. Diagnosis and treatment of depressive syndromes should be considered as a part of secondary prevention in patients with ischaemic stroke.

Platelet activating factors in depression and coronary artery disease: a potential biomarker related to inflammatory mechanisms and neurodegeneration

The persistence of a depressive episode in coronary artery disease (CAD) patients not only heightens the risk of acute ischemic events, but it is also associated with accelerated cognitive decline. Antidepressant interventions for depression in CAD have only modest effects and novel approaches are limited by a poor understanding of etiological mechanisms. This review proposes that the platelet activating factor (PAF) family of lipids might be associated with the persistence of a depressive episode and related neurodegenerative pathology in CAD due to their association with leading etiological mechanisms for depression in CAD such as inflammation, oxidative and nitrosative stress, vascular endothelial dysfunction, and platelet reactivity. The evidence implicating PAFs in CAD, vascular pathology, and neurodegenerative processes is also presented. We also propose future directions for the investigation of PAFs as mediators of persistent depression. In summary, PAFs are implicated in leading mechanisms associated with depression in CAD. PAFs may therefore be associated with the persistence of depression in CAD and related to neurodegenerative and cognitive sequelae.

MicroRNA-132 may play a role in coexistence of depression and cardiovascular disease: a hypothesis

Different individuals have different degrees of neuroplasticity due to their different experiences. Neuroplasticity may play a role in individual differences among neuropsychiatric disease treatment efficacy. Since the nervous system monitors and coordinates internal organ function, neuroplasticity may be associated with other diseases. Cardiovascular disease (CVD) is associated with depression, which is a disorder of disrupted neuroplasticity. MicroRNA-132 (miR-132) has a roles in neuroplasticity and cardiovascular function. Thus, we hypothesize that miR-132 may play a role in coexistence of depression and CVD.

Treating depression and depression-like behavior with physical activity: an immune perspective

The increasing burden of major depressive disorder makes the search for an extended understanding of etiology, and for the development of additional treatments highly significant. Biological factors may be useful biomarkers for treatment with physical activity (PA), and neurobiological effects of PA may herald new therapeutic development in the future. This paper provides a thorough and up-to-date review of studies examining the neuroimmunomodulatory effects of PA on the brain in depression and depression-like behaviors. From a neuroimmune perspective, evidence suggests PA does enhance the beneficial and reduce the detrimental effects of the neuroimmune system. PA appears to increase the following factors: interleukin (IL)-10, IL-6 (acutely), macrophage migration inhibitory factor, central nervous system-specific autoreactive CD4+ T cells, M2 microglia, quiescent astrocytes, CX3CL1, and insulin-like growth factor-1. On the other hand, PA appears to reduce detrimental neuroimmune factors such as: Th1/Th2 balance, pro-inflammatory cytokines, C-reactive protein, M1 microglia, and reactive astrocytes. The effect of other mechanisms is unknown, such as: CD4+CD25+ T regulatory cells (T regs), CD200, chemokines, miRNA, M2-type blood-derived macrophages, and tumor necrosis factor (TNF)-α [via receptor 2 (R2)]. The beneficial effects of PA are likely to occur centrally and peripherally (e.g., in visceral fat reduction). The investigation of the neuroimmune effects of PA on depression and depression-like behavior is a rapidly developing and important field.

Sigma-1 receptor chaperone and brain-derived neurotrophic factor: emerging links between cardiovascular disease and depression

Epidemiological studies have demonstrated a close relationship between depression and cardiovascular disease (CVD). Although it is known that the central nervous system (CNS) contributes to this relationship, the detailed mechanisms involved in this process remain unclear. Recent studies suggest that the endoplasmic reticulum (ER) molecular chaperone sigma-1 receptor and brain-derived neurotrophic factor (BDNF) play a role in the pathophysiology of CVD and depression. Several meta-analysis studies have showed that levels of BDNF in the blood of patients with major depressive disorder (MDD) are lower than normal controls, indicating that blood BDNF might be a biomarker for depression. Furthermore, blood levels of BDNF in patients with CVD are also lower than normal controls. A recent study using conditional BDNF knock-out mice in animal models of myocardial infarction highlighted the role of CNS-mediated mechanisms in the cardioprotective effects of BDNF. In addition, a recent study shows that decreased levels of sigma-1 receptor in the mouse brain contribute to the association between heart failure and depression. Moreover, sigma-1 receptor agonists, including the endogenous neurosteroid dehydroepiandosterone (DHEA) and the selective serotonin reuptake inhibitor (SSRI) fluvoxamine, show potent cardioprotective and antidepressive effects in rodents, via sigma-1 receptor stimulation. Interestingly, agonist activation of sigma-1 receptors increased the secretion of mature BDNF from its precursor proBDNF via chaperone activity in the ER. Given the role of ER stress in the pathophysiology of CVD and MDD, the author will discuss the potential link between sigma-1 receptors and BDNF-TrkB pathway in the pathophysiology of these two diseases. Finally, the author will make a case for potent sigma-1 receptor agonists and TrkB agonists as new potential therapeutic drugs for depressive patients with CVD.

Major depression and first-time hospitalization with ischemic heart disease, cardiac procedures and mortality in the general population: a retrospective Danish population-based cohort study

OBJECTIVE

We investigated the association between unipolar depression and incident hospital admissions due to ischemic heart disease, invasive cardiac procedures and mortality independent of other medical illnesses.

METHODS

A population-based cohort of 4.6 million persons aged 15 years or older and born in Denmark was followed up from 1995-2009. Incidence rate ratio (IRR) and mortality rate ratio (MRR) were estimated by survival analysis, stratified by or adjusted for gender, age, severe chronic somatic comorbidity and calendar time.

RESULTS

Adjusted risks of cardiac hospital admissions and death were significantly increased by up to 15% and 68%, respectively, in persons with hospital admissions due to depression, and were most increased in 15-59 year old women (IRR: 1.64; MRR: 2.57) and men with depression (IRR: 1.39; MRR: 2.21), and during the first 180 days after being diagnosed with depression (women: IRR: 1.38; MRR: 2.35; men: IRR: 1.42; MRR: 2.67). One-year mortality after new ischemic heart disease was elevated by 34% in women and men. By contrast, overall rates of invasive cardiac procedures following cardiac hospitalizations were significantly decreased by 34% in persons with depression but were twofold increased in men recently diagnosed with depression.

CONCLUSION

Clinical depression leading to hospitalization was a risk factor for new cardiac complications independent of somatic comorbidity in the magnitude of other cardiac risk factors, particularly in individuals between 15-59 years of age and during the first weeks following psychiatric admission. Our findings support recent cardiovascular disease prevention guidelines on assessing depression among other psychosocial factors in patients at increased cardiovascular disease (CVD) risk.

Uncovering the neurobehavioural comorbidities of epilepsy over the lifespan

Epilepsy is a common neurological disorder that is complicated by psychiatric, cognitive, and social comorbidities that have become a major target of concern and investigation in view of their adverse effect on the course and quality of life. In this report we define the specific psychiatric, cognitive, and social comorbidities of paediatric and adult epilepsy, their epidemiology, and real life effects; examine the relation between epilepsy syndromes and the risk of neurobehavioural comorbidities; address the lifespan effect of epilepsy on brain neurodevelopment and brain ageing and the risk of neurobehavioural comorbidities; consider the overarching effect of broader brain disorders on both epilepsy and neurobehavioural comorbidities; examine directions of causality and the contribution of selected epilepsy-related characteristics; and outline clinic-friendly screening approaches for these problems and recommended pharmacological, behavioural, and educational interventions.

Moderators of the relationship between depression and cardiovascular disorders: a systematic review

OBJECTIVE

A bidirectional relationship between depression and cardiovascular disease (CVD) including biological mechanisms has been proposed; however, the potential role of clinical and sociodemographic moderators in this relationship remains unclear. We aim to systematically review the moderating influence of the clinical and sociodemographic variables on the observed interrelationship between depressive disorders and CVD.

METHOD

We systematically reviewed MEDLINE, The Cochrane Library and PsycINFO databases. After the exclusion of articles, 101 remained for this review.

RESULTS

Several studies suggest that clinical characteristics of depression, such as severity of depression, number of episodes and duration of depression, may moderate the relationship between depression and cardiovascular disease. Consistently, various studies support a role for marital status, education and income as moderators of this relationship. Several of these studies vary in methodology, hence yielding some inconsistent results. Longitudinal and controlled studies are required to investigate the effect sizes of these moderating factors on the depression-CVD relationship.

CONCLUSIONS

Clinical characteristics of depression and sociodemographic factors appear to be moderators in the bidirectional relationship between depression and cardiovascular disease. Further research should consider these factors in conjunction with subtypes of depression and biological markers in a comprehensive model of this interrelationship. Our findings may assist with clinical decision-making processes.