Elevation of plasma concentration of adhesion molecules in late-life depression

Differentiating Stages of Bipolar and Unipolar Depression-The Possible Role of sICAM-1 and sVCAM-1

Increased immune-inflammatory activation has been repeatedly linked to etiopathogenesis and the progression of both major depressive disorder (MDD) and bipolar depression (BD). We explore the role of soluble intercellular cell adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) in diagnostic differentiation and disorder progression in patients with MDD and BD. Serum levels of sICAM-1 and sVCAM-1 were measured in 137 patients (MDD = 93 and BD = 44) and compared with 73 healthy controls. The severity of psychopathology was assessed using the Hamilton Depression Rating Scale and Clinical Global Impression Scale. After adjustment for multiple confounders, we noticed significant downregulation of sVCAM-1 and upregulation of sICAM-1 levels in both patient groups. Decreased sVCAM-1 levels were detected in patients with acute episodes of BD when compared to MDD. Immune mediators were related to indicators of progression in both mood disorders. They also followed different post-treatment normalization patterns in MDD and BD and in relation to the stage of each disorder. Adhesion molecules could potentially be useful in discriminating between patients with MDD and BD and determining the possible progression of the disorders. Future nosological methods should include time-dependent pathoplasticity and biological correlates, at least for affective disorders.

Immune-Regulatory and Molecular Effects of Antidepressants on the Inflamed Human Keratinocyte HaCaT Cell Line

Allergic contact dermatitis (ACD) is a T cell-mediated type of skin inflammation resulting from contact hypersensitivity (CHS) to antigens. There is strong comorbidity between ACD and major depression. Keratinocytes release immunomodulatory mediators including pro-inflammatory cytokines and chemokines, which modulate skin inflammation and are crucial cell type for the development of CHS. Our previous studies showed that fluoxetine and desipramine were effective in suppressing CHS in different mouse strains. However, the immune and molecular mechanisms underlying this effect remain to be explored. The aim of the current study was to determine the immune and molecular mechanisms of action of antidepressant drugs engaged in the inhibition of CHS response in the stimulated keratinocyte HaCaT cell line. The results show that LPS, TNF-α/IFN-γ, and DNFB stimulate HaCaT cells to produce large amounts of pro-inflammatory factors including IL-1β, IL-6, CCL2, and CXCL8. HaCaT stimulation was associated with increased expression of ICAM-1, a cell adhesion molecule, and decreased expression of E-cadherin. Imipramine, desipramine, and fluoxetine suppress the production of IL-1β, CCL2, as well as the expression of ICAM-1. LPS and TNF-α/IFN-γ activate p-38 kinase, but antidepressants do not regulate this pathway. LPS decreases E-cadherin protein expression and fluoxetine normalizes these effects. In summary, the antidepressant drugs examined in this study attenuate the stimulated secretion of pro-inflammatory cytokines, chemokines, and modulate adhesion molecule expression by the HaCaT cell line. Therefore, antidepressants may have some clinical efficacy in patients with ACD and patients with comorbid depression and contact allergy.

Association between plasma monocyte trafficking-related molecules and future risk of depression in older adults

BACKGROUND

The recruitment of monocytes to the brain plays an important role in the development of depression. However, the association between plasma biomarkers of monocyte trafficking and depression is unclear. This study is aimed to examine the effects of plasma monocyte chemoattractant protein-1 (MCP-1), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) on the risk of depression.

METHODS

Data were acquired from an ongoing prospective cohort study involving randomly sampled, community-dwelling Korean older adults, which has been followed every two years. We included 1,539 euthymic older adults (age = 68.2 [5.6] years; 51.7% were women) without a history of major psychiatric disorders, and dementia and neurological diseases. Geriatric psychiatrists diagnosed incident depression through a structured interview using the Korean version of the Mini International Neuropsychiatric Interview.

RESULTS

Depression had developed in 134 (8.7 %) participants during the follow-up period of 5.7 (0.8) years. The high plasma MCP-1 tertile group showed two-fold higher risk of depression than the low plasma MCP-1 tertile group (hazards ratio [HR] = 2.00, 95% confidence intervals [CI] = 1.27 - 3.13, p = 0.003). The association between high levels of plasma MCP-1 and future risk of depression was significant in the middle plasma ICAM-1 and VCAM-1 tertile groups; the high plasma MCP-1 tertile group showed about four-fold higher risk of depression than the low plasma MCP-1 tertile group.

CONCLUSIONS

Molecules involved in monocyte trafficking may be good candidates as diagnostic biomarkers and/or therapeutic targets for late life depression.

Inflammation-driven brain and gut barrier dysfunction in stress and mood disorders

Regulation of emotions is generally associated exclusively with the brain. However, there is evidence that peripheral systems are also involved in mood, stress vulnerability vs. resilience, and emotion‐related memory encoding. Prevalence of stress and mood disorders such as major depression, bipolar disorder, and post‐traumatic stress disorder is increasing in our modern societies. Unfortunately, 30%–50% of individuals respond poorly to currently available treatments highlighting the need to further investigate emotion‐related biology to gain mechanistic insights that could lead to innovative therapies. Here, we provide an overview of inflammation‐related mechanisms involved in mood regulation and stress responses discovered using animal models. If clinical studies are available, we discuss translational value of these findings including limitations. Neuroimmune mechanisms of depression and maladaptive stress responses have been receiving increasing attention, and thus, the first part is centered on inflammation and dysregulation of brain and circulating cytokines in stress and mood disorders. Next, recent studies supporting a role for inflammation‐driven leakiness of the blood–brain and gut barriers in emotion regulation and mood are highlighted. Stress‐induced exacerbated inflammation fragilizes these barriers which become hyperpermeable through loss of integrity and altered biology. At the gut level, this could be associated with dysbiosis, an imbalance in microbial communities, and alteration of the gut–brain axis which is central to production of mood‐related neurotransmitter serotonin. Novel therapeutic approaches such as anti‐inflammatory drugs, the fast‐acting antidepressant ketamine, and probiotics could directly act on the mechanisms described here improving mood disorder‐associated symptomatology. Discovery of biomarkers has been a challenging quest in psychiatry, and we end by listing promising targets worth further investigation.

Development and Internal Validation of a Novel Model to Identify Inflammatory Biomarkers of a Response to Escitalopram in Patients With Major Depressive Disorder

Objective: The aim of our study was to identify immune- and inflammation-related factors with clinical utility to predict the clinical efficacy of treatment for depression. Study Design: This was a follow-up study. Participants who met the entry criteria were administered with escitalopram (5-10 mg/day) as an initial treatment. Self-evaluation and observer valuations were arranged at the end of weeks 0, 4, 8, and 12, with blood samples collected at baseline and during weeks 2 and 12. Multivariable logistic regression analysis was then carried out by incorporating three cytokines selected by the Least Absolute Shrinkage and Selection Operator (LASSO) regression model. Internal validation was estimated using the bootstrap method with 1,000 repetitions. Results: A total of 85 patients with Major Depressive Disorder (MDD), including 62 responders and 23 non-responders, were analyzed. Monocyte chemoattractant protein-1 (MCP-1), vascular cell adhesion molecule-1 (VCAM-1), and lipocalin-2 were selected by the LASSO regression model. The area under the curve (AUC) from the logistic model was 0.811 and was confirmed as 0.7887 following bootstrapping validation. Conclusions: We established and validated a good prediction model to facilitate the individualized prediction of escitalopram treatment for MDD and created a personalized approach to treatment for patients with depression.

The Association Between Vascular Inflammation and Depressive Disorder. Causality, Biomarkers and Targeted Treatment

Diabetes, obesity, atherosclerosis, and myocardial infarction are frequently co-morbid with major depressive disorder. In the current review, it is argued that vascular inflammation is a factor that is common to all disorders and that an endothelial dysfunction of the blood-brain barrier could be involved in the induction of depression symptoms. Biomarkers for vascular inflammation include a high plasma level of C-reactive protein, soluble cell-adhesion molecules, von Willebrand factor, aldosterone, and proinflammatory cytokines like interleukin-6 or tumor necrosis factor α. A further possible biomarker is flow-mediated dilation of the brachial artery. Treatment of vascular inflammation is expected to prevent or to reduce symptoms of depression. Several tentative treatments for this form of depression can be envisioned: eicosapentaenoic acid (EPA), valproate, Vagus-nerve stimulation, nicotinic α7 agonists, and agonists of the cannabinoid CB₂-receptor.

Depression as an Immunometabolic Disorder: Exploring Shared Pharmacotherapeutics with Cardiovascular Disease

Modern times have seen depression and cardiovascular disease (CVD) become notorious public health concerns, corresponding to alarming proportions of morbidity, mortality, decreased quality of life, and economic costs. Expanding comprehension of the pathogenesis of depression as an immunometabolic disorder has identified numerous pathophysiologic phenomena in common with CVD, including chronic inflammation, insulin resistance, and oxidative stress. These shared components could be exploited to offer improved alternatives in the joint management of these conditions. Abundant preclinical and clinical data on the impact of established treatments for CVD in the management of depression have allowed for potential candidates to be proposed for the joint management of depression and CVD as immunometabolic disorders. However, a large proportion of the clinical investigation currently available exhibits marked methodological flaws which preclude the formulation of concrete recommendations in many cases. This situation may be a reflection of pervasive problems present in clinical research in psychiatry, especially pertaining to study homogeneity. Therefore, further high-quality research is essential in the future in this regard.

Exploring Brain Derived Neurotrophic Factor and Cell Adhesion Molecules as Biomarkers for the Transdiagnostic Symptom Anhedonia in Alcohol Use Disorder and Comorbid Depression

BACKGROUND

Alcohol Use Disorder (AUD) and depressive disorder often co-exist and have a shared heritability. This study aimed to investigate Brain-Derived Neurotrophic Factor (BDNF) and three Cell Adhesion Molecules (CAMs) as transdiagnostic biomarkers in AUD and depression co-morbidity.

METHODS

In a cross-sectional study, patients with AUD (n=22), AUD and depression (n=19), and healthy controls (n=20) were examined. Depression and anxiety severity were assessed using the Hamilton Depression Rating Scale and the Hamilton Anxiety Rating Scale. Anhedonia, alcohol use and dependence, craving, and social adaptation were assessed through self-report questionnaires. BDNF and CAM concentrations in peripheral serum were measured after overnight fasting using a Luminex assay. After controlling for age and gender, biomarker levels were compared across groups. The association between biomarker concentrations and symptom severity scales were explored using correlation and multiple regression analyses.

RESULTS

BDNF and Neuronal CAM were lower in patients with AUD with and without depression compared to healthy controls. No differences were observed for Vascular CAM-1 and Interstitial CAM-1. BDNF correlated negatively with anhedonia levels. BDNF, age and gender together explained 21% of variability in anhedonia levels.

CONCLUSION

This pilot study suggests that peripheral levels of BDNF and NCAM might be reduced in AUD with and without comorbid mood disorder. Since low BDNF levels were associated with self- reported anhedonia across these conditions, BDNF and anhedonia might reflect transdiagnostic aspects involved in AUD and depression.

The Role of Intercellular Adhesion Molecule-1 in the Pathogenesis of Psychiatric Disorders

Intercellular adhesion molecule-1 (ICAM-1) is a transmembrane glycoprotein that is overexpressed in many pathological states. Although, like many other immune molecules, ICAM-1 plays only a limited role in the abundant concert of the immune response, it may be more important than we realize. In the central nervous system (CNS), ICAM-1 is expressed in microglial cells and astrocytes and in endothelial cells in the white and gray matter of the human forebrain. It is of particular interest in psychiatric disorders for two reasons: It has a key function for the blood-brain barrier, which plays an important role in the biology of psychiatric disorders, and it is a marker for inflammation. Although the blood level of soluble ICAM-1 (sICAM-1) might be lower in acute unmedicated schizophrenia, it has been reported to be increased in many other psychiatric conditions, such as major depression, bipolar disorder, and dementia. In bipolar disorder, high sICAM levels were found during both the depressed and the manic states and also during the euthymic phase (the free interval), possibly indicating that sICAM is a trait marker. High sICAM-1 blood levels have also been found in depression comorbid to a somatic disease state. Interestingly, sICAM-1 levels also increase during aging. Some studies investigated sICAM-1 levels in the cerebrospinal fluid of psychiatric disorders and ICAM-1 expression in postmortem CNS tissue of psychiatric patients and found that the overall duration and duration of the chronic phase of the psychiatric disorder seem to play a role in both. Moreover, confounders, such as antipsychotic and antidepressive medication, have to be considered. sICAM-1 levels seem to be associated with hypopermeability or hyperpermeability of the blood-brain barrier and thus to influence the communication between the CNS immune system, represented by glia cells, and the peripheral immune system. The balance between the influx and efflux of immune molecules into and out of the CNS may be one of the pinpoints in psychiatric disorders, in particular in the chronic phase, e.g., in schizophrenia. This aspect, however, needs further intense research, in particular to enable researchers to develop therapeutic principles based on an immune/inflammatory approach.

Neuroimmune nexus of depression and dementia: Shared mechanisms and therapeutic targets

Dysfunctional immune activity is a physiological component of both Alzheimer's disease (AD) and major depressive disorder (MDD). The extent to which altered immune activity influences the development of their respective cognitive symptoms and neuropathologies remains under investigation. It is evident, however, that immune activity affects neuronal function and circuit integrity. In both disorders, alterations are present in similar immune networks and neuroendocrine signalling pathways, immune responses persist in overlapping neuroanatomical locations, and morphological and structural irregularities are noted in similar domains. Epidemiological studies have also linked the two disorders, and their genetic and environmental risk factors intersect along immune-activating pathways and can be synonymous with one another. While each of these disorders individually contains a large degree of heterogeneity, their shared immunological components may link distinct phenotypes within each disorder. This review will therefore highlight the shared immune pathways of AD and MDD, their overlapping neuroanatomical features, and previously applied, as well as novel, approaches to pharmacologically manipulate immune pathways, in each neurological condition. LINKED ARTICLES: This article is part of a themed section on Therapeutics for Dementia and Alzheimer's Disease: New Directions for Precision Medicine. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.18/issuetoc.

Inflammatory profiles of severe treatment-resistant depression

BACKGROUND

Treatment-resistant depression (TRD) contributes substantially to the burden of mood disorders and is undoubtedly an important subpopulation in whom there are clear unmet treatment needs. Despite a paucity of research focusing specifically on TRD, recent studies indicate that inflammatory activity may be particularly elevated in these patients.

METHODS

36 patients with TRD were investigated longitudinally before and after undertaking a specialist inpatient treatment program. 27 inflammatory proteins were compared between patients and a matched sample of non-depressed controls, as well as between treatment responders and non-responders. Treatment outcomes were calculated from depression severity scores before and after admission, and at a long-term follow-up 3-12 months after discharge.

RESULTS

TRD patients had higher levels of numerous inflammatory proteins than controls, and elevated interleukins 6 and 8, tumour necrosis factor, c-reactive protein and macrophage inflammatory protein-1 were associated with poorer treatment outcomes. A separate set of proteins (either anti-inflammatory in nature or attenuated at baseline) showed increases during treatment, regardless of clinical response. Participants with the greatest elevations in inflammation tended to be older, more cognitively impaired and more treatment-resistant at baseline.

LIMITATIONS

The small sample and large number of comparisons examined in this study must be taken into account when interpreting these results.

CONCLUSIONS

However, this study provides empirical support for theories that more severe, chronic or treatment-resistant depressive disorders are associated with dysregulated inflammatory activity. If a predictor or predictors of response in TRD are established, improved and targeted care might be more reliably provided to this vulnerable population.

Abnormal levels of vascular endothelial biomarkers in schizophrenia

Schizophrenia is associated with chronic low-grade inflammation, which has been linked to increased vascular risk and rates of cardiovascular disease. Levels of vascular endothelial growth factor (VEGF), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) have been related to aging and neurodegeneration, but their role in schizophrenia remains uncertain. Using a cross-sectional, case-control design, this study included 99 outpatients with schizophrenia and 99 healthy comparison subjects (HCs). Sociodemographic and clinical data were collected, and plasma levels of VEGF, ICAM-1, and VCAM-1 were assayed. A "vascular endothelial index" (VEI) was computed using logistic regression to create a composite measure that maximally differed between groups. General linear models were conducted to examine the possible role of demographic, physical, and lifestyle factors. A linear combination of ICAM-1 and VCAM-1 levels best distinguished the groups, with significantly higher levels of this composite VEI in persons with schizophrenia than HCs. Group differences in the VEI persisted after adjustment for BMI and cigarette smoking. Neither age nor gender was significantly related to the VEI. Schizophrenia patients with higher VEI had earlier age of disease onset, higher systolic and diastolic blood pressure, lower high-density lipoprotein cholesterol, higher insulin resistance, lower levels of mental well-being, and higher Framingham Coronary Heart Disease Risk scores. Schizophrenia is characterized by an elevation of vascular endothelial biomarkers, specifically cell adhesion molecules poised at the intersection between inflammatory response and vascular risk. Interventions aimed at reducing vascular risk may help reduce vascular endothelial abnormalities and prevent cardiovascular morbidity and mortality in schizophrenia.

Abnormal levels of vascular endothelial biomarkers in schizophrenia

Schizophrenia is associated with chronic low-grade inflammation, which has been linked to increased vascular risk and rates of cardiovascular disease. Levels of vascular endothelial growth factor (VEGF), intercellular adhesion molecule-1 (ICAM-1), and vascular cell adhesion molecule-1 (VCAM-1) have been related to aging and neurodegeneration, but their role in schizophrenia remains uncertain. Using a cross-sectional, case-control design, this study included 99 outpatients with schizophrenia and 99 healthy comparison subjects (HCs). Sociodemographic and clinical data were collected, and plasma levels of VEGF, ICAM-1, and VCAM-1 were assayed. A "vascular endothelial index" (VEI) was computed using logistic regression to create a composite measure that maximally differed between groups. General linear models were conducted to examine the possible role of demographic, physical, and lifestyle factors. A linear combination of ICAM-1 and VCAM-1 levels best distinguished the groups, with significantly higher levels of this composite VEI in persons with schizophrenia than HCs. Group differences in the VEI persisted after adjustment for BMI and cigarette smoking. Neither age nor gender was significantly related to the VEI. Schizophrenia patients with higher VEI had earlier age of disease onset, higher systolic and diastolic blood pressure, lower high-density lipoprotein cholesterol, higher insulin resistance, lower levels of mental well-being, and higher Framingham Coronary Heart Disease Risk scores. Schizophrenia is characterized by an elevation of vascular endothelial biomarkers, specifically cell adhesion molecules poised at the intersection between inflammatory response and vascular risk. Interventions aimed at reducing vascular risk may help reduce vascular endothelial abnormalities and prevent cardiovascular morbidity and mortality in schizophrenia.

The Molecular Intersection Between Senescence and Major Depression in the Elderly

Major depressive disorder in the elderly-or late-life depression (LLD)-is one of the most common mental illnesses in the aging population. LLD has several negative effects on health and well-being. Individuals with LLD have an elevated risk of chronic and persistent depressive symptoms as well as high rates of treatment resistance. They also have a higher risk of developing cognitive impairment with progression to dementia and higher rates of medical comorbidity, frailty, and mortality. The mechanisms linking LLD to these adverse health outcomes are not well understood. In this article, we review the evidence that individuals with LLD present with, i.e., enhanced molecular and cellular senescent changes, focusing on the senescence-associated secretory phenotype (SASP). We then propose a mechanistic model linking SASP to the greater risk of negative health outcomes in this population. We finally provide evidence that SASP-and cellular senescence in general-can be a therapeutic target for mitigating the risk of these negative outcomes in LLD.

The role of neuroinflammation and neurovascular dysfunction in major depressive disorder

Although depression has generally been explained with monoamine theory, it is far more multifactorial, and therapies that address the disease’s pathway have not been developed. In this context, an understanding of neuroinflammation and neurovascular dysfunction would enable a more comprehensive approach to depression. Inflammation is in a sense a type of allostatic load involving the immune, endocrine, and nervous systems. Neuroinflammation is involved in the pathophysiology of depression by increasing proinflammatory cytokines, activating the hypothalamus–pituitary–adrenal axis, increasing glucocorticoid resistance, and affecting serotonin synthesis and metabolism, neuronal apoptosis and neurogenesis, and neuroplasticity. In future, identifying the subtypes of depression with increased vulnerability to inflammation and testing the effects of inflammatory modulating agents in these patient groups through clinical trials will lead to more concrete conclusions on the matter. The vascular depression hypothesis is supported by evidence for the association between vascular disease and late-onset depression and between ischemic brain lesions and distinctive depressive symptoms. Vascular depression may be the entity most suitable for studies of the mechanisms of depression. Pharmacotherapies used in the prevention and treatment of cerebrovascular disease may help prevent vascular depression. In future, developments in structural and functional imaging, electrophysiology, chronobiology, and genetics will reveal the association between depression and brain lesions. This article aims to give a general review of the existing issues examined in the literature pertaining to depression-related neuroinflammatory and vascular functions, related pathophysiology, applicability to depression treatment, and directions for future research.

Association of Microvascular Dysfunction With Late-Life Depression: A Systematic Review and Meta-analysis

Importance

The etiologic factors of late-life depression are still poorly understood. Recent evidence suggests that microvascular dysfunction is associated with depression, which may have implications for prevention and treatment. However, this association has not been systematically reviewed.

Objective

To examine the associations of peripheral and cerebral microvascular dysfunction with late-life depression.

Data Sources

A systematic literature search was conducted in MEDLINE and EMBASE for and longitudinal studies published since inception to October 16, 2016, that assessed the associations between microvascular dysfunction and depression.

Study Selection

Three independent researchers performed the study selection based on consensus. Inclusion criteria were a study population 40 years of age or older, a validated method of detecting depression, and validated measures of microvascular function.

Data Extraction and Synthesis

This systematic review and meta-analysis has been registered at PROSPERO (CRD42016049158) and is reported in accordance with the PRISMA and MOOSE guidelines. Data extraction was performed by an independent researcher.

Main Outcomes and Measures

The following 5 estimates of microvascular dysfunction were considered in participants with or without depression: plasma markers of endothelial function, albuminuria, measurements of skin and muscle microcirculation, retinal arteriolar and venular diameter, and markers for cerebral small vessel disease. Data are reported as pooled odds ratios (ORs) by use of the generic inverse variance method with the use of random-effects models.

Results

A total of 712 studies were identified; 48 were included in the meta-analysis, of which 8 described longitudinal data. Data from 43 600 participants, 9203 individuals with depression, and 72 441 person-years (mean follow-up, 3.7 years) were available. Higher levels of plasma endothelial biomarkers (soluble intercellular adhesion molecule-1: OR, 1.58; 95% CI, 1.28-1.96), white matter hyperintensities (OR, 1.29; 95% CI, 1.19-1.39), cerebral microbleeds (OR, 1.18; 95% CI, 1.03-1.34), and cerebral (micro)infarctions (OR, 1.30; 95% CI, 1.21-1.39) were associated with depression. Among the studies available, no significant associations of albuminuria and retinal vessel diameters with depression were reported. Longitudinal data showed a significant association of white matter hyperintensities with incident depression (OR, 1.19; 95% CI, 1.09-1.30).

Conclusions and Relevance

This meta-analysis shows that both the peripheral and cerebral forms of microvascular dysfunction are associated with higher odds of (incident) late-life depression. This finding may have clinical implications because microvascular dysfunction might provide a potential target for the prevention and treatment of depression.

A narrative literature review of depression following traumatic brain injury: prevalence, impact, and management challenges

Depression is one of the most common conditions to emerge after traumatic brain injury (TBI), and despite its potentially serious consequences it remains undertreated. Treatment for post-traumatic depression (PTD) is complicated due to the multifactorial etiology of PTD, ranging from biological pathways to psychosocial adjustment. Identifying the unique, personalized factors contributing to the development of PTD could improve long-term treatment and management for individuals with TBI. The purpose of this narrative literature review was to summarize the prevalence and impact of PTD among those with moderate to severe TBI and to discuss current challenges in its management. Overall, PTD has an estimated point prevalence of 30%, with 50% of individuals with moderate to severe TBI experiencing an episode of PTD in the first year after injury alone. PTD has significant implications for health, leading to more hospitalizations and greater caregiver burden, for participation, reducing rates of return to work and affecting social relationships, and for quality of life. PTD may develop directly or indirectly as a result of biological changes after injury, most notably post-injury inflammation, or through psychological and psychosocial factors, including pre injury personal characteristics and post-injury adjustment to disability. Current evidence for effective treatments is limited, although the strongest evidence supports antidepressants and cognitive behavioral interventions. More personalized approaches to treatment and further research into unique therapy combinations may improve the management of PTD and improve the health, functioning, and quality of life for individuals with TBI.

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.

Associations Between Psychological Constructs and Cardiac Biomarkers After Acute Coronary Syndrome

OBJECTIVE

Psychological constructs are associated with cardiovascular health, but the biological mechanisms mediating these relationships are unknown. We examined relationships between psychological constructs and markers of inflammation, endothelial function, and myocardial strain in a cohort of post-acute coronary syndrome (ACS) patients.

METHODS

Participants (N = 164) attended study visits 2 weeks and 6 months after ACS. During these visits, they completed self-report measures of depressive symptoms, anxiety, optimism, and gratitude; and blood samples were collected for measurement of biomarkers reflecting inflammation, endothelial function, and myocardial strain. Generalized estimating equations and linear regression analyses were performed to examine concurrent and prospective relationships between psychological constructs and biomarkers.

RESULTS

In concurrent analyses, depressive symptoms were associated with elevated markers of inflammation (interleukin-17: β = .047; 95% confidence interval [CI] = .010-.083]), endothelial dysfunction (endothelin-1: β = .020; 95% [CI] = .004-.037]), and myocardial strain (N-terminal pro-B-type natriuretic peptide: β = .045; 95% [CI] = .008-.083]), independent of age, sex, medical variables, and anxiety, whereas anxiety was not associated with these markers in multivariable adjusted models. Optimism and gratitude were associated with lower levels of markers of endothelial dysfunction (endothelin-1: gratitude: β = -.009; 95% [CI] = -.017 to - .001]; optimism: β = -.009; 95% [CI] = -.016 to - .001]; soluble intercellular adhesion molecule-1: gratitude: β = -.007; 95% [CI] = -.014 to - .000]), independent of depressive and anxiety symptoms. Psychological constructs at 2 weeks were not prospectively associated with biomarkers at 6 months.

CONCLUSIONS

Depressive symptoms were associated with more inflammation, myocardial strain, and endothelial dysfunction in the 6 months after ACS, whereas positive psychological constructs were linked to better endothelial function. Larger prospective studies may clarify the directionality of these relationships.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov identifier NCT01709669.

Depression, daily stressors and inflammatory responses to high-fat meals: when stress overrides healthier food choices

Depression, stress and diet can all alter inflammation. This double-blind, randomized crossover study addressed the impact of daily stressors and a history of major depressive disorder (MDD) on inflammatory responses to high-fat meals. During two separate 9.5 h admissions, 58 healthy women (38 breast cancer survivors and 20 demographically similar controls), mean age 53.1 years, received either a high saturated fat meal or a high oleic sunflower oil meal. The Daily Inventory of Stressful Events assessed prior day stressors and the Structured Clinical Interview for DSM-IV evaluated MDD. As expected, for a woman with no prior day stressors, C-reactive protein (CRP), serum amyloid A (SAA), intercellular adhesion molecule-1 (sICAM-1) and vascular cell adhesion molecule-1 (sVCAM-1) were higher following the saturated fat meal than the high oleic sunflower oil meal after controlling for pre-meal measures, age, trunk fat and physical activity. But if a woman had prior day stressors, these meal-related differences disappeared-because the stressors heightened CRP, SAA, sICAM-1 and sVCAM-1 responses to the sunflower oil meal, making it look more like the responses to the saturated fat meal. In addition, women with an MDD history had higher post-meal blood pressure responses than those without a similar history. These data show how recent stressors and an MDD history can reverberate through metabolic alterations, promoting inflammatory and atherogenic responses.

Soluble Intracellular Adhesion Molecule-1 in Patients with Unipolar or Bipolar Affective Disorders: Results from a Pilot Trial

BACKGROUND

Immunological and vascular markers may play a role in the pathophysiology of mood disorders and mood changes.

AIM

To test whether the cell adhesion molecule soluble intracellular adhesion molecule-1 (sICAM-1) may serve as a biomarker for patients with unipolar or bipolar affective disorders when compared to a healthy control group, and whether sICAM-1 blood levels change during different mood states.

METHODS

sICAM-1 serum concentrations were compared between 20 healthy controls and 48 patients with affective disorders (unipolar, bipolar II and bipolar I disorder) during different mood states (euthymic mood state, depression or mania).

RESULTS

When compared to healthy controls, patients with affective disorders had significantly higher sICAM-1 levels during the euthymic state (p = 0.015). Differences became more pronounced during depression (p = 0.013). When unipolar and bipolar patients were analyzed separately, unipolar patients significantly differed from controls during the euthymic and depressive mood state, while bipolar II patients showed a trend towards higher sICAM-1 levels during depression. Patients with bipolar I disorders had significantly higher sICAM-1 levels during manic states when compared to controls (p = 0.007).

CONCLUSIONS

sICAM-1 elevation in unipolar and bipolar patients, independent of mood changes, might support the hypothesis of chronic immune activation and endothelial dysfunction in patients with affective disorders.

Predictive value of sICAM-1 and sVCAM-1 as biomarkers of affective temperaments in healthy young adults

BACKGROUND

Affective temperaments are intermediate phenotypes for major affective disorders and are reported to have a neuroimmune etiopathogenesis. Here we investigated the role of soluble intercellular cell adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) in affective temperaments and mood symptoms in healthy adults.

METHODS

Healthy adults (n=94) were screened for psychiatric disorders using the nonpatient version of the Structured Clinical Interview for DSM-IV-I and II. Subjects with medical conditions associated with changes in inflammatory response were excluded, deriving the final sample (n=68). Affective temperaments were evaluated with Temperament Evaluation of Memphis, Pisa, Paris and San Diego-Autoquestionnaire (TEMPS-A). State mood symptoms were assessed using the Young Mania Rating Scale and Montgomery-Åsberg Depression Rating Scale. Serum sICAM-1 and sVCAM-1 levels were measured using enzyme-linked immunosorbent assay.

RESULTS

After adjusting for confounders (age, gender, BMI, and smoking habits), a high negative correlation between depressive and irritable temperament TEMPS-A scores and sVCAM-1 levels was detected. Although we identified no association between sICAM-1 levels and affective temperament scores, sICAM-1 was related to the state severity of manic symptoms. In a multiple linear regression model, sVCAM-1 remained a significant predictor of depressive but not irritable temperament scores.

LIMITATIONS

The temperaments were estimated on the basis of self-report questionnaire.

CONCLUSIONS

Our findings suggest that sVCAM-1 is related to affective temperaments, and it is a trait marker for liability to mood disorders. This relationship between alterations in cellular adhesion and affective temperament may be important for vulnerability to affective disorders.

Blood-based immune-endocrine biomarkers of treatment response in depression

Antidepressant treatment for major depressive disorder remains suboptimal with response rates of just over 50%. Although treatment guidelines, algorithms and clinical keys are available to assist the clinician, the process of finding an effective pharmacotherapy to maximise benefit for the individual patient is largely by "trial and error" and remains challenging. This highlights a clear need to identify biomarkers of treatment response to help guide personalised treatment strategies. We have carried out the largest multiplex immunoassay based longitudinal study to date, examining up to 258 serum markers involved in immune, endocrine and metabolic processes as potential biomarkers associated with treatment response in 332 depression patients recruited from four independent clinical centres. We demonstrated for the first time that circulating Apolipoprotein A-IV, Endoglin, Intercellular Adhesion Molecule 1, Tissue Inhibitor of Metalloproteinases 1, Plasminogen Activator Inhibitor 1, Thrombopoietin, Complement C3, Hepatocyte Growth Factor and Insulin-like Growth Factor-Binding Protein 2 were associated with response to different antidepressants. In addition, we showed that specific sets of immune-endocrine proteins were associated with response to Venlafaxine (serotonin-norepinephrine reuptake inhibitor), Imipramine (tricyclic antidepressant) and other antidepressant drugs. However, we were not able to reproduce the literature findings on BDNF and TNF-α, two of the most commonly reported candidate treatment response markers. Despite the need for extensive validation studies, our preliminary findings suggest that a pre-treatment immune-endocrine profile may help to determine a patient's likelihood to respond to specific antidepressant and/or alternative treatments such as anti-inflammatory drugs, providing hope for future personalised treatment approaches.

Endothelial damage in major depression patients is modulated by SSRI treatment, as demonstrated by circulating biomarkers and an in vitro cell model

There is a link between depression, cardiovascular events and inflammation. We have explored this connection through endothelial dysfunction, using in vivo and in vitro approaches. We evaluated circulating biomarkers of endothelial dysfunction in patients with major depression at their diagnosis (MD-0) and during antidepressant treatment with the selective serotonin reuptake inhibitor escitalopram, for 8 and 24 weeks (MD-8 and MD-24). Results were always compared with matched healthy controls (CON). We measured in vivo circulating endothelial cells (CECs) and endothelial progenitor cells (EPCs) in blood samples, and assessed plasma levels of soluble von Willebrand factor (VWF) and vascular cell adhesion molecule-1 (VCAM-1). CEC counts, soluble VWF and VCAM-1 were statistically elevated in MD-0 (P<0.01 versus CON) and gradually decreased during treatment. Conversely, EPC levels were lower in MD-0, tending to increase throughout treatment. In vitro studies were performed in human endothelial cells cultured in the presence of sera from each study group. Elevated expression of the inflammation marker intercellular adhesion molecule-1 and oxidative stress, with lower presence of endothelial nitric oxide synthase and higher reactive oxygen species production, were found in cells exposed to MD-0 sera (P<0.05 versus CON). These results were normalized in cells exposed to MD-24 sera. Thrombogenicity of extracellular matrices generated by these cells, measured as expression of VWF, tissue factor and platelet reactivity, showed non-significant differences. We provide a model of cultured endothelial cells reproducing endothelial dysfunction in naive patients with major depression, demonstrating endothelial damage and inflammation at diagnosis, and recovering with selective serotonin reuptake inhibitor treatment for 24 weeks.

The Cognition and Affect after Stroke - a Prospective Evaluation of Risks (CASPER) study: rationale and design

BACKGROUND

Cognitive impairment and neuropsychiatric syndromes, like depression and apathy, are frequent residual consequences of stroke. These have a large impact on quality of life and long-term prognosis. Several factors are involved in the development of these residual syndromes, although their exact role and their interrelationships remain still rather unclear. The Cognition and Affect after Stroke: a Prospective Evaluation of Risks (CASPER) study has been primarily designed to examine whether stroke-specific (e.g. lesion location, volume, type, severity), cerebrovascular and neurodegenerative (e.g. white matter changes, atrophy, microbleeds, perivascular spaces), inflammatory, endothelial, and (epi)genetic markers are associated with cognitive impairment, post-stroke depression, and post-stroke apathy, and whether they predict their course over 12 months. The secondary aims are to investigate how the above-mentioned markers interact with each other, and to determine if patients with apathy and depression after stroke differ in pathogenesis, course, and outcome (e.g. functional outcome, neurocognitive performance, quality of life).

METHODS/DESIGN

CASPER is a 1-year prospective clinical cohort follow-up study in 250 stroke patients recruited at the neurological in- and outpatient services at Maastricht University Medical Center (MUMC+, Maastricht, The Netherlands), and Zuyderland Medical Center (Sittard and Heerlen, The Netherlands). At baseline (3 months post-stroke), a neuropsychological assessment, neuropsychiatric interview, blood sample, and brain magnetic resonance imaging (MRI) scan are conducted. Assessment of neuropsychiatric and neurocognitive status are repeated 6 and 12 months later.

DISCUSSION

The CASPER study investigates stroke-specific, vascular, neurodegenerative, inflammatory, and genetic markers of the development of vascular cognitive impairment, depression, and apathy after stroke. This creates the possibility to study not only the contribution of these individual markers but also their joint contribution, which differentiates this study from earlier stroke cohorts who lacked long-term follow-up data, a large sample size, an extensive MRI protocol, and markers from the blood. The knowledge we derive from this study might help in identifying markers that are associated with, or can predict the onset, maintenance, and progression of vascular cognitive impairment, depression, and apathy after stroke, and could provide new insights into possibilities for treatment and rehabilitation that result in better functional outcome after stroke.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02585349.

Role of sICAM-1 and sVCAM-1 as biomarkers in early and late stages of schizophrenia

Schizophrenia (SZ) is a neuroprogressive disorder presenting with biochemical, functional, and structural changes, which differ from early to late stages of the illness. We explored the differences in serum levels of soluble intercellular cell adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) between early and late stages of SZ, in regard to clinical characteristics and treatment application. Serum levels of sICAM-1 and sVCAM-1 were measured in 80 patients with SZ (40 early stage; 40 late stage), and compared with 80 healthy controls, matched by age, gender, body mass index, and smoking habits with each SZ group. Serum levels of sICAM-1 and sVCAM-1 were measured using ELISA. The severity of psychopathology was assessed using the Clinical Global Impression Scale and five-factor Positive and Negative Symptoms in Schizophrenia Scale. After adjustment for confounders, we noticed normal levels of sICAM-1 in the early stage, and elevated levels of sICAM-1 in the late stage of SZ. sVCAM-1 levels were decreased in both stages of SZ. Higher sICAM-1 levels have been related to more pronounced cognitive deficit and excitement symptoms in the early stage of SZ and to favorable characteristics of treatment application in both stages. SZ is associated with changes in the levels of adhesion molecules that vary from early to late stages of the illness. This implies that the concept of biochemical staging is applicable in SZ, at least for markers of cellular adhesion.

Blood levels of S-100 calcium-binding protein B, high-sensitivity C-reactive protein, and interleukin-6 for changes in depressive symptom severity after coronary artery bypass grafting: prospective cohort nested within a randomized, controlled trial

BACKGROUND

Cross-sectional and retrospective studies have associated major depressive disorder with glial activation and injury as well as blood-brain barrier disruption, but these associations have not been assessed prospectively. Here, we aimed to determine the relationship between changes in depressive symptom severity and in blood levels of S-100 calcium-binding protein B (S-100B), high-sensitivity C-reactive protein, and interleukin-6 following an inflammatory challenge.

METHODS

Fifty unselected participants were recruited from a randomized, controlled trial comparing coronary artery bypass grafting procedures performed with versus without cardiopulmonary bypass for the risk of neurocognitive decline. Depressive symptom severity was measured at baseline, discharge, and six-month follow-up using the Beck Depression Inventory II (BDI-II). The primary outcome of the present biomarker study was acute change in depressive symptom severity, defined as the intra-subject difference between baseline and discharge BDI-II scores. Blood biomarker levels were determined at baseline and 2 days postoperative.

RESULTS

Changes in S-100B levels correlated positively with acute changes in depressive symptom severity (Spearman ρ, 0.62; P = 0.0004) and accounted for about one-fourth of their observed variance (R2, 0.23; P = 0.0105). This association remained statistically significant after adjusting for baseline S-100B levels, age, weight, body-mass index, or β-blocker use, but not baseline BDI-II scores (P = 0.064). There was no statistically significant association between the primary outcome and baseline S-100B levels, baseline high-sensitivity C-reactive protein or interleukin-6 levels, or changes in high-sensitivity C-reactive protein or interleukin-6 levels. Among most participants, levels of all three biomarkers were normal at baseline and markedly elevated at 2 days postoperative.

CONCLUSIONS

Acute changes in depressive symptom severity were specifically associated with incremental changes in S-100B blood levels, largely independent of covariates associated with either. These findings support the hypothesis that glial activation and injury and blood-brain barrier disruption can be mechanistically linked to acute exacerbation of depressive symptoms in some individuals.

Protective effect of sex on chronic stress- and depressive behavior-induced vascular dysfunction in BALB/cJ mice

The presence of chronic, unresolvable stresses leads to negative health outcomes, including development of clinical depression/depressive disorders, with outcome severity being correlated with depressive symptom severity. One of the major outcomes associated with chronic stress and depression is the development of cardiovascular disease (CVD) and an elevated CVD risk profile. However, in epidemiological research, sex disparities are evident, with premenopausal women suffering from depressive symptoms more acutely than men, but also demonstrating a relative protection from the onset of CVD. Given this, we investigated the differential effect of sex on conduit artery and resistance arteriolar function in male and female mice following 8 wk of an unpredictable chronic mild stress (UCMS) protocol. In males, plasma cortisol and depressive symptom severity (e.g., coat status, anhedonia, delayed grooming) were elevated by UCMS. Endothelium-dependent dilation to methacholine/acetylcholine was impaired in conduit arteries and skeletal muscle arterioles, suggesting a severe loss of nitric oxide bioavailability and increased production of thromboxane A2 vs. prostaglandin I2 associated with elevated reactive oxygen species (ROS) and an increased level of systemic inflammation. Endothelium-independent dilation was intact. In females, depressive symptoms and plasma cortisol increases were more severe than in males, although alterations to vascular reactivity were blunted, including the effects of elevated ROS and inflammation on dilator responses. These results suggest that compared with males, female rats are more susceptible to chronic stress in terms of the severity of depressive behaviors, but that the subsequent development of vasculopathy is blunted owing to an improved ability to tolerate elevated ROS and systemic inflammatory stress.

Biomarkers of vascular risk, systemic inflammation, and microvascular pathology and neuropsychiatric symptoms in Alzheimer's disease

Numerous serum and plasma based biomarkers of systemic inflammation have been linked to both neuropsychiatric disorders and Alzheimer's disease (AD). The present study investigated the relationship of clinical biomarkers of cardiovascular risk (cholesterol, triglycerides, and homocysteine) and a panel of markers of systemic inflammation (CRP, TNF-α, IL1-ra, IL-7, IL-10, IL-15, IL-18) and microvascular pathology (ICAM-1, VCAM-1) to neuropsychiatric symptoms in a sample with mild AD. Biomarker data was analyzed on a sample of 194 diagnosed with mild to moderate probable AD. The sample was composed of 127 females and 67 males. The presence of neuropsychiatric symptoms was gathered from interview with caretakers/family members using the Neuropsychiatric Inventory. For the total sample, IL-15, VCAM (vascular adhesion molecule), and triglycerides were significantly and negatively related to number of neuropsychiatric symptoms, and total cholesterol and homocysteine were positively related and as a group accounted for 16.1% of the variance. When stratified by gender, different patterns of significant biomarkers were found with relationships more robust for males for both total symptoms and symptom clusters. A combination of biomarkers of systemic inflammation, microvascular pathology, and clinical biomarkers of cardiovascular risk can account for a significant portion of the variance in the occurrence of neuropsychiatric symptoms in AD supporting a vascular and inflammatory component of psychiatric disorders found in AD. Gender differences suggest distinct impact of specific risks with total cholesterol, a measure of cardiovascular risk, being the strongest marker for males and IL-15, a marker of inflammation, being the strongest for females.

The role of glia in late-life depression

Late-life depression (LLD) has a complex and multifactoral etiology. There is growing interest in elucidating how glia, acting alone or as part of a glial-neuronal network, may contribute to the pathophysiology of depression. In this paper, we explore results from neuroimaging studies showing gray-matter volume loss in key frontal and subcortical structures implicated in LLD, and present the few histological studies that have examined neuronal and glial densities in these regions. Compared to results in younger people with depression, there appear to be age-dependent differences in neuronal pathology but the changes in glial pathology may be more subtle, perhaps reflecting a longer-term compensatory gliosis to earlier damage. We then consider the mechanisms by which both astrocytes and microglia may mediate and modulate neuronal dysfunction and possible degeneration in depression. These include a critical role in the response to peripheral inflammation and central microglial activation, as well as a key role in glutamate metabolism. Advances in our understanding of glia are highlighted, including the role of microglia as "electricians" of the brain and astrocytes as key communicating cells, an integral part of the tripartite synapse. Finally, implications for clinicians are discussed, including the consideration of glia as biomarkers for LLD and incorporation of glia into future therapeutic strategies.

Microvascular pathology in late-life depression

Since the era of Gaupp who introduced the concept of atheroscletic depressive disorder, the concept of late-life depression has been correlated with cerebrovascular comorbidities, microvascular lesions, frontal cortical and subcortical gray and white matter hyperintensities. The predominant neuropsychological deficits concern the domains of planning, organization and abstraction, with executive dysfunction being the predominant finding. MRI studies reveal a higher prevalence of white matter lesions in elderly patients with depression. Molecular mechanisms underlying the disease still remain unclear. Hyperhomocysteinemia has been associated with depression through its toxicity to neurons and blood vessels. Endothelial dysfunction is another possible mechanism referring to the loss of vasodilatation capacity. Inflammatory phenomena, such as increased peripheral leucocytes, elevated CRP and cytokine levels, could play a role in endothelial dysfunction. In this review we will briefly combine findings from neurobiological, epidemiological, structural and post-mortem data. A more complex model in late-life depression combining different modalities could be an elucidating approach to the disease's etiopathogeny in the future.

Brain-derived neurotrophic factor not associated with metabolic syndrome but inversely correlated with vascular cell adhesion molecule-1 in men without diabetes

BACKGROUND

Excessive visceral fat with unbalanced adipokines is a critical pathogenic factor of metabolic syndrome (MetS), which is associated with disorders of the central nervous system and cardiovascular disease. Because brain-derived neurotrophic factor (BDNF) plays an important role in neurons, we examined the relationship of BDNF to MetS, adipose tissue and biomarkers in men.

METHODS

Thirty-four non-diabetic men with MetS and another 24 age-matched men without MetS were enrolled. In addition to fasting blood samples, the area of adipose tissue at the waist was assessed by magnetic resonance imaging (MRI).

RESULTS

There was no significant difference in serum BDNF concentrations between men with or without MetS (40.9±8.0 vs. 43.2±6.1 ng/ml, P=0.235). However, the serum concentration of soluble vascular cell adhesion molecule-1 (VCAM-1) was higher in the subjects with a lower BDNF level (737±230 vs. 628±115 ng/ml, P=0.025). An inverse correlation between VCAM-1 and BDNF was observed (r=-0.391, P=0.002). After adjusting for visceral adipose tissue, VCAM-1 was found to be independently associated with BDNF [95% confidence interval (-0.025, -0.005), P=0.004].

CONCLUSION

These data show no difference in serum BDNF levels between the men with MetS and controls. However, serum BDNF was inversely correlated with serum VCAM-1 in men without diabetes.

The interaction between cerebrovascular disease and neuroticism in late-life depression: a cross-sectional study

OBJECTIVE

Vascular disease and neuroticism are both risk factors for late-life depression. In this study we examined the interaction between vascular disease and neuroticism as determinants of clinically relevant depressive symptoms (CRDS) in late-life.

METHODS

Multivariate logistic regression in a survey of 1396 population-dwelling people aged ≥70 years. CRDS were defined as scoring ≥16 on the CES-D. Vascular disease was categorised into four levels: none, ≥2 vascular risk factors, cardiac disease or stroke.

RESULTS

Neuroticism was strongly associated with CRDS in women (OR: 1.6, 95% CI: 1.4-1.8). In men vascular disease interacted negatively but significantly with neuroticism (cardiac disease by neuroticism: OR: 0.8, 95% CI: 0.6-0.9; stroke by neuroticism: OR: 0.8, 95% CI: 0.6-0.96) when predicting CRDS.

CONCLUSIONS

In men vascular disease attenuates the predictive value of neuroticism in CRDS, which might be mediated by apathy caused by cerebrovascular disease.

Altered aortic vascular reactivity in the unpredictable chronic mild stress model of depression in mice: UCMS causes relaxation impairment to ACh

Major depression is an independent risk factor for the development of cardiovascular disease. This impact of depression on vascular function seems to be mediated by the endothelial dysfunction, defined as an impairment of endothelium-dependent vasorelaxation, which represents a reliable predictor of atherosclerosis and has been regularly found to be associated with depression. This study aimed at investigating aortic vascular reactivity in mice submitted to the unpredictable chronic mild stress (UCMS) procedure, a reliable model of depression. The results confirm the effectiveness of the UCMS procedure to induce neuroendocrine, physical and behavioral depression-like alterations as well as a significant decrease of acetylcholine-induced vasorelaxation without any effect on phenylephrine-induced vasoconstriction. In this study, we reveal an altered vascular reactivity in an animal model of depression, demonstrating an endothelial dysfunction reminiscent to the one found in depressed patients.

Early and late-onset effect of chronic stress on vascular function in mice: a possible model of the impact of depression on vascular disease in aging

Depression is recognized as a predictor of increased cardiac morbidity and mortality. In addition, depressed patients exhibit an increase in the serum markers of endothelial dysfunction and platelet activation involved in the cascade of events leading to atherosclerosis. The purpose of this study was to determine the early and late-onset expression of various vascular markers in a rodent model of depression. Male DBA (an inbred strain of mice)/2J mice were exposed to either 7 weeks of controlled living conditions or unpredictable chronic mild stress (UCMS), and subsequently given daily fluoxetine (10 mg/kg) or NaCl (9%) during the last 5 weeks of the experiment. Depressive-like behavior was evaluated by using motivational and self-care behavior, including the assessment of the animal's coat state and grooming behavior. Enzyme-linked immunoassay was used to quantify matrix metalloproteinase-9 (MMP-9), vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1), and plasminogen activator inhibitor-1 (PAI-1) expression either immediately after the end of the UCMS procedure (short term condition) or 10 months later (long-term condition). Results indicate that 1) UCMS procedure induces a short-term depressive-like behavior in mice, defined as coat state deterioration, an effect that is prevented by fluoxetine treatment; 2) UCMS procedure has no effect on the short-term expression of the studied markers; however, UCMS increases expression of plasminogen activator inhibitor-1 only in the long-term group; 3) fluoxetine treatment is unable to counteract this UCMS-induced change; 4) aging induces behavioral perturbation, defined as a decrease in grooming motivation, and an increase of all the vascular markers in both control and UCMS groups and 5) pretreatment with fluoxetine has no protective effects on aging-induced behavioral and vascular alterations. Thus, in this model of depression-like behavior, UCMS appears to induce late-onset physiological changes, which are consistent with human studies indicating that depression is a risk factor for the development of heart disease.

The impact of neuroimmune dysregulation on neuroprotection and neurotoxicity in psychiatric disorders--relation to drug treatment

An inflammatory pathogenesis has been postulated for schizophrenia and major depression (MD). In schizophrenia and depression, opposing patterns oftype-1 vs type-2 immune response seem to be associated with differences in the activation of the enzyme indoleamine 2,3-dioxygenase and in the tryptophan-kynurenine metabolism, resulting in increased production of kynurenic acid in schizophrenia and decreased production of kynurenic acid in depression. These differences are associated with an imbalance in the glutamatergic neurotransmission, which may contribute to an excessive agonist action of N-methyl-D-aspartate (NMDA) in depression and of NMDA antagonism in schizophrenia. Regarding the neuroprotective function of kynurenic acid and the neurotoxic effects of quinolinic acid (QUIN), different patterns of immune activation may also lead to an imbalance between the neuroprotective and the neurotoxic effects of the tryptophanlkynurenine metabolism. The differential activation of microglia cells and astrocytes may be an additional mechanism contributing to this imbalance. The immunological imbalance results in an inflammatory state combined with increased prostaglandin E2 production and increased cyclo-oxygenase-2 (COX-2) expression. The immunological effects of many existing antipsychotics and antidepressants, however, partly correct the immune imbalance and the excess production of the neurotoxic QUIN, COX-2 inhibitors have been tested in animal models of depression and in preliminary clinical trials, pointing to favorable effects in schizophrenia and in MD.

Psychological factors in asthma

Asthma has long been considered a condition in which psychological factors have a role. As in many illnesses, psychological variables may affect outcome in asthma via their effects on treatment adherence and symptom reporting. Emerging evidence suggests that the relation between asthma and psychological factors may be more complex than that, however. Central cognitive processes may influence not only the interpretation of asthma symptoms but also the manifestation of measurable changes in immune and physiologic markers of asthma. Furthermore, asthma and major depressive disorder share several risk factors and have similar patterns of dysregulation in key biologic systems, including the neuroendocrine stress response, cytokines, and neuropeptides. Despite the evidence that depression is common in people with asthma and exerts a negative impact on outcome, few treatment studies have examined whether improving symptoms of depression do, in fact, result in better control of asthma symptoms or improved quality of life in patients with asthma.

Depression and cognition in older adults

PURPOSE OF REVIEW

Recognition that depression is associated with neurocognitive impairment and renewed recent interest in milder forms of cognitive impairment in older people (typified by the concept of mild cognitive impairment) have stimulated researchers to investigate the relationship between depression and cognitive impairment. This review identifies and clarifies recent progress in this rapidly developing research area.

RECENT FINDINGS

Neurocognitive impairment persists in most depressed older people after clinical recovery, and slowed information processing speed and possibly executive dysfunction and vascular risk factors underlie this. Most studies suggest that this neurocognitive impairment in turn leads to increased mild cognitive impairment as well as dementia. White matter disease appears to directly contribute to depression in older people and this worsens over time. Polymorphisms in the serotonin transporter gene may be a key risk factor as well, and depression worsens vascular outcome in peripheral arterial disease.

SUMMARY

Clinicians should be aware that neurocognitive deficits persist and have an adverse effect on outcome, and that vascular risk factors may contribute to these deficits.

Recent understandings in geriatric affective disorder

PURPOSE OF REVIEW

This article focuses on recent research into depression, bipolar disorder and anxiety in older people.

RECENT FINDINGS

Many physical illnesses are associated with a high prevalence of depression but overall medical burden may largely account for this. The relationship between depression and vascular disease is two way. Frontal brain dysfunction may underlie depression both in cerebrovascular disease and neurodegenerative disorders. Besides antidepressants, psychological treatments, psychosocial interventions and enhanced primary care services are effective. Longer-term outcomes are poor but preventive strategies show promise. Medical and psychiatric comorbidity are also important themes in later-life anxiety and bipolar disorders.

SUMMARY

Improving prognosis is a key concern and more research into novel pharmacological approaches (including vasoprotection), psychological interventions and prevention is needed.