Neurohormonal and inflammatory hyper-responsiveness to acute mental stress in depression

Analysis of hair cortisol level in first-episodic and recurrent female patients with depression compared to healthy controls

BACKGROUND

Although accumulating evidence has shown increased cortisol levels in serum, saliva, or 24-h urine samples in depression, a number of studies did not find the association between cortisol levels and depression. Hair cortisol levels reflect long-term and historical information of cortisol and hair cortisol analysis has been applied in the research of psychiatric diseases. The aim of this study is to compare the hair cortisol levels between patients with depression and healthy controls.

METHODS

Hair cortisol levels of 22 first-episodic and 13 recurrent female patients with depression and 30 healthy controls were measured and compared using the electrochemiluminescence immunoassay. The relationship between hair cortisol levels and Hamilton depression scale (HAMD) or Hamilton anxiety scale (HAMA) scores were also examined.

RESULTS

Before disease episode, no significant differences were observed among healthy controls, first-episodic patients and recurrent patients. In disease episode, the hair cortisol level in first-episodic patients was significantly higher than that in healthy controls or recurrent patients, while no significant difference was observed between recurrent patients and healthy controls. No significant correlation was found between HAMD or HAMA scores and hair cortisol levels in patients.

LIMITATIONS

First, long-term effects of antidepressants on the results cannot be excluded without detailed medication information of the recurrent patients. Second, sample sizes might be relatively small.

CONCLUSIONS

Our results indicate that hair cortisol levels increased in disease episode in first-episodic, but not recurrent patients with depression, which may suggest that episodes of disease have influence on cortisol levels.

Osteopathic manipulative therapy induces early plasma cytokine release and mobilization of a population of blood dendritic cells

It has been claimed that osteopathic manipulative treatment (OMT) is able to enhance the immune response of individuals. In particular, it has been reported that OMT has the capability to increase antibody titers, enhance the efficacy of vaccination, and upregulate the numbers of circulating leukocytes. Recently, it has been shown in human patients suffering chronic low back pain, that OMT is able to modify the levels of cytokines such as IL-6 and TNF-α in blood upon repeated treatment. Further, experimental animal models show that lymphatic pump techniques can induce a transient increase of cytokines in the lymphatic circulation. Taking into account all these data, we decided to investigate in healthy individuals the capacity of OMT to induce a rapid modification of the levels of cytokines and leukocytes in circulation. Human volunteers were subjected to a mixture of lymphatic and thoracic OMT, and shortly after the levels of several cytokines were evaluated by protein array technology and ELISA multiplex analysis, while the profile and activation status of circulating leukocytes was extensively evaluated by multicolor flow cytometry. In addition, the levels of nitric oxide and C-reactive protein (CRP) in plasma were determined. In this study, our results show that OMT was not able to induce a rapid modification in the levels of plasma nitrites or CRP or in the proportion or activation status of central memory, effector memory or naïve CD4 and CD8 T cells. A significant decrease in the proportion of a subpopulation of blood dendritic cells was detected in OMT patients. Significant differences were also detected in the levels of immune molecules such as IL-8, MCP-1, MIP-1α and most notably, G-CSF. Thus, OMT is able to induce a rapid change in the immunological profile of particular circulating cytokines and leukocytes.

Cardiorespiratory fitness does not alter plasma pentraxin 3 and cortisol reactivity to acute psychological stress and exercise

Pentraxin 3 (PTX3) has been recently identified as a biomarker of vascular inflammation in predicting cardiovascular events. The purpose of this study was to examine the effect of cardiorespiratory fitness on plasma PTX3 and cortisol responses to stress, utilizing a dual-stress model. Fourteen male subjects were classified into high-fit (HF) and low-fit (LF) groups and completed 2 counterbalanced experimental conditions. The exercise-alone condition (EAC) consisted of cycling at 60% maximal oxygen uptake for 37 min, while the dual-stress condition (DSC) included 20 min of a mental stress while cycling for 37 min. Plasma PTX3 revealed significant increases over time with a significant elevation at 37 min in both HF and LF groups in response to EAC and DSC. No difference in plasma PTX3 levels was observed between EAC and DSC. In addition, plasma cortisol revealed a significant condition by time interaction with greater levels during DSC at 37 min, whereas cardiorespiratory fitness level did not reveal different plasma cortisol responses in either the EAC or DSC. Aerobic exercise induces plasma PTX3 release, while additional acute mental stress, in a dual-stress condition, does not exacerbate or further modulate the PTX3 response. Furthermore, cardiorespiratory fitness may not affect the stress reactivity of plasma PTX3 to physical and combined physical and psychological stressors. Finally, the exacerbated cortisol responses to combined stress may provide the potential link to biological pathways that explain changes in physiological homeostasis that may be associated with an increase in the risk of cardiovascular disease.

Dissociative symptoms reflect levels of tumor necrosis factor alpha in patients with unipolar depression

Recent evidence indicates that the nature of interactions between the nervous system and immune system is important in the pathogenesis of depression. Specifically, alterations in pro-inflammatory cytokines have been related to the development of several psychological and neurobiological manifestations of depressive disorder, as well as to stress exposure. A number of findings point to tumor necrosis factor alpha (TNF-α) as one of the central factors in these processes. Accordingly, in the present study, we test the hypothesis that specific influences of chronic stressors related to traumatic stress and dissociation are related to alterations in TNF-α levels. We performed psychometric measurement of depression (Beck Depression Inventory [BDI]-II), traumatic stress symptoms (Trauma Symptom Checklist [TSC]-40), and psychological and somatoform dissociation (Dissociative Experiences Scale [DES] and Somatoform Dissociation Questionnaire [SDQ]-20, respectively), and immunochemical measure of serum TNF-α in 66 inpatients with unipolar depression (mean age 43.1 ± 7.3 years). The results show that TNF-α is significantly related to DES (Spearman R=-0.42, P<0.01), SDQ-20 (Spearman R=-0.38, P<0.01), and TSC-40 (Spearman R=-0.41, P<0.01), but not to BDI-II. Results of the present study suggest that TNF-α levels are related to dissociative symptoms and stress exposure in depressed patients.

Leukocyte ß-adrenergic receptor sensitivity and depression severity in patients with heart failure

OBJECTIVES

Clinical outcomes are worse for patients with heart failure (HF) and elevated depression symptoms. Depression-related sympathoimmune dysregulation may be one mechanism leading to poorer HF prognosis. Sympathetically mediated adrenergic activity is known to regulate immune activity via β-adrenergic receptors (β-ARs). However, studies show conflicting relationships between leukocyte β-AR sensitivity and depression symptoms. The aim of this study was to determine in patients with HF the relationship of leukocyte β-AR sensitivity with two diverse measures of depression, self-report questionnaire versus clinical diagnostic interview.

METHODS

Patients with HF (N = 73, mean [standard deviation] age = 56.3 [13.0]) completed the Beck Depression Inventory-1A and a modified Structured Clinical Interview for the DSM-IV. Leukocyte β-AR sensitivity was determined from isoproterenol-stimulated cyclic adenosine monophosphate levels; plasma norepinephrine and epinephrine were also assessed.

RESULTS

Patients with major depression determined by Structured Clinical Interview for the DSM-IV had significantly higher β-AR sensitivity than did nondepressed patients (F(6,72) = 9.27, p = .003, η = 0.12). The Beck Depression Inventory-1A revealed a more complex relationship. Minimal, mild, and moderate-to-severe depression symptom groups had significant differences in β-AR sensitivity (F(7,72) = 7.03, p = .002, η = 0.18); mild symptoms were associated with reduced β-AR sensitivity and moderate-to-severe symptoms with higher β-AR sensitivity compared with patients with minimal depressive symptoms.

CONCLUSIONS

Clinical depression was associated with elevated β-AR sensitivity in patients with HF. By deconstructing depression measurements, a greater depth of information may be garnered to potentially reveal subtypes of depression symptoms and their relation to β-AR sensitivity.

Effects of Buddhism walking meditation on depression, functional fitness, and endothelium-dependent vasodilation in depressed elderly

OBJECTIVES

The objectives of this study were to determine the effects of the novel Buddhism-based walking meditation (BWM) and the traditional walking exercise (TWE) on depression, functional fitness, and vascular reactivity.

DESIGN

This was a randomized exercise intervention study.

SETTINGS/LOCATION

The study was conducted in a university hospital setting.

SUBJECTS

Forty-five elderly participants aged 60-90 years with mild-to-moderate depressive symptoms were randomly allocated to the sedentary control, TWE, and BWM groups.

INTERVENTIONS

The BWM program was based on aerobic walking exercise incorporating the Buddhist meditations performed 3 times/week for 12 weeks.

OUTCOME MEASURES

Depression score, functional fitness, and endothelium-dependent vasodilation as measured by the flow-mediated dilation (FMD) were the outcome measures used.

RESULTS

Muscle strength, flexibility, agility, dynamic balance, and cardiorespiratory endurance increased in both exercise groups (p<0.05). Depression score decreased (p<0.05) only in the BWM group. FMD improved (p<0.05) in both exercise groups. Significant reduction in plasma cholesterol, triglyceride, high-density lipoprotein cholesterol, and C-reactive protein were found in both exercise groups, whereas low-density lipoprotein cholesterol, cortisol, and interleukin-6 concentrations decreased only in the BWM group.

CONCLUSIONS

Buddhist walking meditation was effective in reducing depression, improving functional fitness and vascular reactivity, and appears to confer greater overall improvements than the traditional walking program.

Altered cytokine and BDNF levels in autism spectrum disorder

The contribution of neuroimmune functioning and brain-derived neurotrophic factor (BDNF) to functional dysregulation in autism spectrum disorder was assessed in 29 patients under treatment in two specialized centers of Basilicata (Chiaromonte and Matera), Southern Italy, through analysis of serum levels of cytokines and BDNF. Elevated levels of the pro-inflammatory cytokine, including interleukin-1, interleukin-6, interleukin-12, interleukin-23, tumor necrosis factor-α and BDNF were observed, regardless of age and gender. Comparisons were made with age- and gender-related healthy controls. The present findings reinforce current notions regarding immunoexcitotoxic mechanisms contributing to the pathophysiology of autistic disorder.

Serotonin transporter in lymphocytes of rats exposed to physical restraint stress

OBJECTIVES

Glucocorticoids and stress cause transcriptional and functional changes on the serotonin transporter (SERT) in the central nervous system. Stress can produce specific modifications of SERT in lymphocytes, which could be associated with alterations in immune response. The aim of this study was to evaluate the effect of a physical restraint stress protocol on (1) rat lymphocyte proliferation in the presence of the selective serotonin reuptake inhibitor fluoxetine and (2) SERT kinetic parameters, i.e. binding capacity (Bmax), affinity (Kd) and Hill coefficient (nH).

METHODS

Male adult Sprague-Dawley rats were placed in Plexiglass boxes (5 h daily for 5 days), and blood was obtained by cardiac puncture on day 6. Serum corticosterone was quantitated by an immunoenzymatic assay. Lymphocytes were isolated by density gradients and adhesion to plastic, of which there was sufficient material for further experiments, then cultured with or without the mitogen concanavalin A (Con A, 2 μg/ml) and fluoxetine (1-50 μM). Cell proliferation was measured with tetrazolium salts, and [(3)H]paroxetine was used as a SERT-specific ligand for binding assays.

RESULTS

Restraint produced a significant increase in serum corticosterone of stressed rats. The proliferative response to Con A was similar in the controls and stressed animals. Fluoxetine reduced cell proliferation with and without Con A. Restraint diminished the inhibitory effect of fluoxetine on proliferation. Restraint also increased Bmax and Kd, but decreased nH. Treatment of rats with actinomycin D, a transcription inhibitor, reduced Bmax in stressed animals.

CONCLUSIONS

Restraint stress modulated the effect of fluoxetine on cell proliferation, probably through the modification of the presence and the function of SERT.

Sleep disturbance and older adults' inflammatory responses to acute stress

OBJECTIVES

Poor sleep diminishes mental and physical health. The objective of this study was to examine associations between sleep disturbance and interleukin-6 (IL-6) responses to acute mental stress in older adults.

DESIGN

Observational study of community-dwelling, healthy older adults.

SETTING

Participants completed the study in a clinical research laboratory of a mid-sized university.

PARTICIPANTS

Generally healthy, community-dwelling men and women age 50 and older.

MEASUREMENTS

IL-6 and negative affect at rest and following a series of challenging cognitive tests; sleep quality; depressive symptoms; perceived stress; loneliness.

RESULTS

Participants categorized as poor sleepers on the basis of Pittsburgh Sleep Quality Index scores had significantly larger IL-6 responses to the cognitive stressors than good sleepers. The association between poor sleep and heightened IL-6 response to acute stress was not explained by other psychosocial factors previously linked to immune dysregulation, including depressive symptoms, perceived stress, and loneliness.

CONCLUSIONS

Findings add to the growing evidence for poor sleep as an independent risk factor for poor mental and physical health. Older adults may be particularly vulnerable to effects of sleep disturbance due to significant age-related changes in both sleep and inflammatory regulation.

Immune system inflammation in cocaine dependent individuals: implications for medications development

OBJECTIVES

Cocaine dependence is a chronic stress state. Furthermore, both stress and substance abuse have robust and reciprocal effects on immune system cytokines, which are known to be powerful modulators of mood. We therefore examine basal and provoked changes in peripheral cytokines in cocaine dependent individuals to better understand their role in the negative reinforcing effects of cocaine.

METHODS

Twenty-eight (16 F/12 M) treatment-seeking cocaine dependent individuals and 27 (14 F/13 M) social drinkers were exposed to three 5-min guided imagery conditions (stress, drug cue, relaxing) presented randomly across consecutive days. Measures of salivary cortisol, tumor necrosis factor alpha (TNFα), interleukin-10 (IL-10), and interleukin-1 receptor antagonist (IL-1ra) were collected at baseline and various post-imagery time-points.

RESULTS

Cocaine abusers demonstrated decreased basal IL-10 compared with social drinkers. They also showed significant elevations in pro-inflammatory TNFα when exposed to stress compared with when they were exposed to relaxing imagery. This was not observed in the social drinkers. Conversely, social drinkers demonstrated increases in the anti-inflammatory markers, IL-10 and IL-1ra, following exposure to cue, which were not seen in the dependent individuals.

CONCLUSIONS

Cocaine dependent individuals demonstrate an elevated inflammatory state both at baseline and following exposure to the stress imagery condition. Cytokines may reflect potentially novel biomarkers in addicted populations for treatment development.

To live alone and to be depressed, an alarming combination for the renin-angiotensin-aldosterone-system (RAAS)

INTRODUCTION

The renin-angiotensin-aldosterone-system (RAAS) is one of the most important systems involved in the pathogenesis of cardiovascular diseases. Its role in stress response has been generally neglected, although the progression of cardiovascular disease is considerably increased in the presence of stress and especially in the presence of depression risk. With the present analysis we aimed to evaluate whether the activity of the RAAS correlates with depressive symptomatology and with chronic stress. Moreover, we aimed to analyse whether stress response is altered in the presence of depressed symptomatology. We chose "living alone" to be our paradigm of chronic stress.

METHODS AND RESULTS

Aldosterone and renin levels were assessed in 1743 (829 men, 914 women) from the population-based KORA study (Cooperative Health Research in the Region of Augsburg). The relationship between aldosterone, renin levels and the different combinations of living alone and depressive symptomatology was examined in three different multiple linear regression models adjusted for age, sex, creatinine levels, potassium levels, body mass index (BMI) and bio-behavioural factors. Neither "living alone" nor depressive symptomatology alone were associated with an activation of the RAAS, but the combination of living alone and depressive symptomatology yielded a highly significant increase in the aldosterone (p<0.01) and renin level (p=0.03).

CONCLUSION

Our findings show that depressive symptomatology is associated with a hyper-responsiveness to chronic stress. Under the condition of chronic stress depressed individuals have an activated RAAS. Activation of the RAAS might explain the known increased risk of negative cardiovascular disease outcomes in this group.

What do plasma beta-endorphin levels reveal about endogenous opioid analgesic function?

Plasma levels of beta-endorphin (BE), an endogenous opioid analgesic, are often reported as they relate to acute and chronic pain outcomes. However, little is known about what resting plasma BE levels might reveal about functioning of the endogenous opioid antinociceptive system. This study directly examined associations between resting plasma BE and subsequent endogenous opioid analgesic responses to acute pain in 39 healthy controls and 37 individuals with chronic low back pain (LBP). Resting baseline levels of plasma BE were assessed. Next, participants received opioid blockade (8 mg naloxone i.v.) or placebo in a double-blind, randomized, crossover design. Participants then underwent two acute pain stimuli: finger pressure (FP) pain and ischaemic (ISC) forearm pain. Blockade effects (naloxone minus placebo pain ratings) were derived to index endogenous opioid analgesic function. In placebo condition analyses for both pain stimuli, higher resting BE levels were associated with subsequently greater reported pain intensity (p's < 0.05), with this effect occurring primarily in healthy controls (BE × Participant Type interactions, p's < 0.05). In blockade effect analyses across both pain tasks, higher resting plasma BE predicted less subsequent endogenous opioid analgesia (smaller blockade effects; p's < 0.05). For the ISC task, these links were significantly more prominent in LBP participants (BE × Participant Type Interactions, p's < 0.05). Results suggest that elevated resting plasma BE may be a potential biomarker for reduced endogenous opioid analgesic capacity, particularly among individuals with chronic pain. Potential clinical implications are discussed.

[Role of gastrointestinal inflammations in the development and treatment of depression]

Recent studies have revealed that inflammation, among other factors, may be involved in the pathogenesis of depression. One line of studies has shown that depression is frequently associated with manifest gastrointestinal inflammations and autoimmune diseases as well as with cardiovascular diseases, neurodegenerative diseases, type 2-diabetes and also cancer, in which chronic low-grade inflammation is a significant contributing factor. Thus depression may be a neuropsychiatric manifestation of a chronic inflammatory syndrome. Another line of studies has shown that the primary cause of inflammation may be the dysfunction of the "gut-brain axis". Although, this is a bidirectional mechanism, life style factors may primarily affect the symbiosis between host mucous membrane and the microbiota. Local inflammation through the release of cytokines, neuropeptides and eicosanoids may also influence the function of the brain and of other organs. Role of metabolic burst due to inflammation represents a new aspect in both pathophysiology and treatment of the depression. Finally, an increasing number of clinical studies have shown that treating gastrointestinal inflammations with probiotics, vitamin B, D and omega 3 fatty acids, through attenuating proinflammatory stimuli to brain, may also improve depression symptoms and quality of life. All these findings justify an assumption that treating gastrointestinal inflammations may improve the efficacy of the currently used treatment modalities of depression and related diseases. However, further studies are certainly needed to confirm these findings.

Association between social isolation and inflammatory markers in depressed and non-depressed individuals: results from the MONICA/KORA study

INTRODUCTION

Depressed individuals not only suffer from chronic low grade inflammation, but also exhibit an inflammatory hyper-responsiveness to acute stress. We investigate whether chronic stress also induces an exaggerated inflammatory response in individuals with increased depression features. As model for chronic stress, social isolation was chosen.

METHODS

Interleukin (IL)-6 and hs-CRP levels were assessed in 1547 subjects (847 men and 700 women), derived from the population-based MONICA/KORA study. Standardized questionnaires were used to assess depressed mood (depression and exhaustion subscale) and social isolation (social network index). The relationship between the two inflammatory markers, social isolation and depressed mood was examined taking into account interactions social isolation × depressed mood using multivariable linear regression models, adjusted for age, BMI, smoking, alcohol, and physical activity. Analyses were performed in men and women separately.

RESULTS

We observed a significant interaction between depressed mood and social isolation regarding IL-6 and hs-CRP, respectively in men (p-value=0.02 for IL-6 and <0.01 for hs-CRP), evidencing a substantial synergistic effect of social isolation, and depressed mood on inflammatory responses. Furthermore, depressed and socially isolated men had highly significantly elevated IL-6 levels (geometric mean: 3.76 vs. 1.92 pg/ml, p-value <0.01) and heightened hs-CRP levels (geometric mean: 2.01 vs. 1.39 mg/l, p=0.08) in comparison with non-depressed and socially integrated men. In women, no significant associations were seen.

CONCLUSION

The interaction of depressed mood and social isolation elicits a substantial synergistic impact on inflammatory markers in men, but not in depressed women.

Circadian cortisol, depressive symptoms and neurological impairment in early multiple sclerosis

OBJECTIVE

There is evidence for the existence of a hyperactive hypothalamus-pituitary-adrenal (HPA) axis and its potential role in disease progression in multiple sclerosis (MS). Depressive symptoms are also common in MS. At the same time, depressive symptoms are often associated with an elevated circadian cortisol secretion. So far, little is known about the interplay between depressive symptoms and circadian HPA axis abnormalities in MS.

METHODS

Here we investigated depressive symptoms, circadian HPA axis function, cortisol awakening response (CAR) and neurological impairment in 32 early stage relapsing-remitting MS (RRMS) patients and 16 age- and sex-matched controls. Saliva cortisol samples were collected in patients' home environment. Depressive symptoms were assessed by self-report measures. Neurological impairment was assessed by the Kurtzke Expanded Disability Status Scale (EDSS).

RESULTS

RRMS patients expressed a significantly higher CAR when compared to healthy controls. After patients were divided into two groups based on their depressive symptom load (Beck Depression Inventory (BDI); median-split), only RRMS patients with moderately elevated depression scores (BDI high) statistically differed in their cortisol release when compared to healthy controls. RRMS patients with low depression scores (BDI low) expressed similar circadian patterns as healthy controls. Neurological impairment (EDSS) was more pronounced in the BDI high group than in the BDI low group.

CONCLUSION

In summary, there is evidence, that a hyperactive HPA axis is primarily present in MS patients expressing moderately elevated depressive symptoms. MS patients with only few depressive symptoms do not significantly differ in CAR when compared to healthy controls. To the best of our knowledge, this is the first study showing that in early stage MS, a hyperactive HPA axis is primarily present in patients who express moderate depressive symptoms.

The effects of allostatic load on neural systems subserving motivation, mood regulation, and social affiliation

The term allostasis, which is defined as stability through change, has been invoked repeatedly by developmental psychopathologists to describe long-lasting and in some cases permanent functional alterations in limbic–hypothalamic–pituitary–adrenal axis responding following recurrent and/or prolonged exposure to stress. Increasingly, allostatic load models have also been invoked to describe psychological sequelae of abuse, neglect, and other forms of maltreatment. In contrast, neural adaptations to stress, including those incurred by monoamine systems implicated in (a) mood and emotion regulation, (b) behavioral approach, and (c) social affiliation and attachment, are usually not included in models of allostasis. Rather, structural and functional alterations in these systems, which are exquisitely sensitive to prolonged stress exposure, are usually explained as stress mediators, neural plasticity, and/or programming effects. Considering these mechanisms as distinct from allostasis is somewhat artificial given overlapping functions and intricate coregulation of monoamines and the limbic–hypothalamic–pituitary–adrenal axis. It also fractionates literatures that should be mutually informative. In this article, we describe structural and functional alterations in serotonergic, dopaminergic, and noradrenergic neural systems following both acute and prolonged exposure to stress. Through increases in behavioral impulsivity, trait anxiety, mood and emotion dysregulation, and asociality, alterations in monoamine functioning have profound effects on personality, attachment relationships, and the emergence of psychopathology.

Modulation of cortisol responses to the DEX/CRH test by polymorphisms of the interleukin-1beta gene in healthy adults

BACKGROUND

Recently, hypothalamus-pituitary-adrenal (HPA) axis function assessed with the combined dexamethasone (DEX)/corticotropin releasing hormone (CRH) test has been shown to be associated with response to antidepressant treatment. A polymorphism (rs16944) in the interleukin-1beta (IL-1β) gene has also been reported to be associated with the medication response in depression. These findings prompted us to examine the possible association between IL-1β gene polymorphisms and HPA axis function assessed with the DEX/CRH test.

METHODS

DEX/CRH test was performed in 179 healthy volunteers (45 males: mean age 40.5 ± 15.8 years; 134 females: mean age 47.1 ± 13.2 years). Five tagging single nucleotide polymorphisms (SNPs) of IL-1β gene (rs2853550, rs1143634, rs1143633, rs1143630, rs16944) were selected at an r2 threshold of 0.80 with a minor allele frequency > 0.1. Genotyping was performed by the TaqMan allelic discrimination assay. A two-way factorial analysis of variance (ANOVA) was performed with the DEX/CRH test results as the dependent variable and genotype and gender as independent variables. To account for multiple testing, P values < 0.01 were considered statistically significant for associations between the genotypes and the cortisol levels.

RESULTS

The cortisol levels after DEX administration (DST-Cortisol) showed significant associations with the genotypes of rs16944 (P = 0.00049) and rs1143633 (P = 0.0060), with no significant gender effect or genotype × gender interaction. On the other hand, cortisol levels after CRH administration (DEX/CRH-Cortisol) were affected by gender but were not significantly influenced by the genotype of the examined SNPs, with no significant genotype × gender interaction.

CONCLUSIONS

Our results suggest that genetic variations in the IL-1β gene contribute to the HPA axis alteration assessed by DST-Cortisol in healthy subjects. On the other hand, no significant associations of the IL-1β gene polymorphisms with the DEX/CRH-Cortisol were observed. Confirmation of our findings in futures studies may add new insight into the communication between the immune system and the HPA axis.

Leukocyte telomere length in major depression: correlations with chronicity, inflammation and oxidative stress--preliminary findings

BACKGROUND

Depression is associated with an unusually high rate of aging-related illnesses and early mortality. One aspect of "accelerated aging" in depression may be shortened leukocyte telomeres. When telomeres critically shorten, as often occurs with repeated mitoses or in response to oxidation and inflammation, cells may die. Indeed, leukocyte telomere shortening predicts early mortality and medical illnesses in non-depressed populations. We sought to determine if leukocyte telomeres are shortened in Major Depressive Disorder (MDD), whether this is a function of lifetime depression exposure and whether this is related to putative mediators, oxidation and inflammation.

METHODOLOGY

Leukocyte telomere length was compared between 18 unmedicated MDD subjects and 17 controls and was correlated with lifetime depression chronicity and peripheral markers of oxidation (F2-isoprostane/Vitamin C ratio) and inflammation (IL-6). Analyses were controlled for age and sex.

PRINCIPAL FINDINGS

The depressed group, as a whole, did not differ from the controls in telomere length. However, telomere length was significantly inversely correlated with lifetime depression exposure, even after controlling for age (p<0.05). Average telomere length in the depressed subjects who were above the median of lifetime depression exposure (≥9.2 years' cumulative duration) was 281 base pairs shorter than that in controls (p<0.05), corresponding to approximately seven years of "accelerated cell aging." Telomere length was inversely correlated with oxidative stress in the depressed subjects (p<0.01) and in the controls (p<0.05) and with inflammation in the depressed subjects (p<0.05).

CONCLUSIONS

These preliminary data indicate that accelerated aging at the level of leukocyte telomeres is proportional to lifetime exposure to MDD. This might be related to cumulative exposure to oxidative stress and inflammation in MDD. This suggest that telomere shortening does not antedate depression and is not an intrinsic feature. Rather, telomere shortening may progress in proportion to lifetime depression exposure.

Depression as a potential modulator of Beta-adrenergic-associated leukocyte mobilization in heart failure patients

OBJECTIVES

the aim of this study was to determine whether depressive symptoms are related to alterations in the sensitivity of peripheral blood mononuclear cells to β-adrenergic agonists in patients with heart failure (HF) by measuring in vitro chemotaxis (CTX) to isoproterenol at rest and after acute exercise in patients with HF and controls.

BACKGROUND

clinical outcomes are worse for patients with HF presenting with symptoms of depression. Sympathetically modulated immune dysregulation associated with depression may be one mechanism leading to worse prognosis.

METHODS

seventy-seven patients with HF and 44 controls (mean age 56.4 ± 1.3 years) completed the Beck Depression Inventory and a 15-min mild-graded exercise task on a stationary bicycle. Exercise intensity was kept relative to fitness levels for all participants by gradually increasing resistance to reach a Borg scale subjective rating of 12 to 13, "somewhat hard." Plasma norepinephrine and epinephrine levels were measured before and after exercise. Chemotaxis to isoproterenol was determined by measuring in vitro peripheral blood mononuclear cell migration through a modified Boyden chamber.

RESULTS

In patients with HF, depressive symptom severity was associated with greater CTX after exercise (p = 0.001). Higher resting norepinephrine in patients with HF was also associated with increased CTX to exercise (p = 0.03).

CONCLUSIONS

patients with HF with higher depressive symptoms and norepinephrine exhibited increased peripheral blood mononuclear cell CTX to isoproterenol to mild exercise, suggesting greater β-adrenergic sensitivity. Increased immune migration in patients with HF who have elevated depressive symptoms could be associated with cardiac remodeling and HF disease progression.

Subclinical depressive symptoms affect responses to acute psychosocial stress in healthy premenopausal women

Subclinical depressive symptoms constitute a primary risk factor for major depression as well as for cardiovascular conditions, which may be mediated by endocrine or immune alterations. The aim of this study was to assess the association between the extent of subclinical depressive symptoms and neuroendocrine and immune cell responses to acute psychosocial stress in healthy females. In N = 33 healthy premenopausal women, state anxiety, plasma adrenocorticotropic hormone and serum cortisol, and interleukin-6 (IL-6) concentration responses to public speaking stress were assessed. Beck depression inventory (BDI) scores were entered as a covariate in the analyses. The IL-6 response was significantly associated with BDI scores (p < 0.05). Secondary analyses revealed that women with more subclinical depressive symptoms demonstrated a reduced stress-induced increase in circulating IL-6 level (p < 0.05). By contrast, stress-induced neuroendocrine activation was not associated with depressive symptoms. Hence, subclinical depressive symptoms were associated with IL-6 responses to stress in young, healthy women. Unexpectedly, there was a reduced increase of serum IL-6 level in response to stress. Effects of depressive symptoms on the IL-6 response to stress may differ between subclinical and major depression.

Biological basis of depression in adults with diabetes

Diabetes and depression are common comorbid conditions. Although certain health behaviors and risk factors partially explain the association of depression and diabetes, other potential mechanisms have yet to be elucidated. Certain neuroendocrine alterations such as activation of the hypothalamic-pituitary-adrenal (HPA) axis and sympathetic nervous system (SNS) may contribute to the association. Additionally, presence of a proinflammatory state shown in recent literature in both diabetes and depression may contribute to this as well. The objectives of this review are to summarize and review the recent evidence showing alterations of these three biological systems-HPA axis, SNS, and inflammatory cascade--in depression, diabetes, and diabetes-related risk factors.

Association between plasma IL-6 response to acute stress and early-life adversity in healthy adults

Increased production of peripheral cytokines and other pro-inflammatory markers has been linked to psychiatric disorders such as major depressive disorder and post-traumatic stress disorder. Recent research has pointed to early-life stress, particularly childhood maltreatment, as an independent and preventable risk factor for systemic inflammation in adulthood. Some data suggest that adults with a history of childhood maltreatment exhibit a heightened inflammatory response to acute stress challenge. To further elucidate the relationship between childhood maltreatment and pro-inflammatory cytokine production, we examined plasma IL-6 response to the Trier Social Stress Test (TSST) in 69 healthy adult subjects without depression or post-traumatic stress disorder. Serial plasma IL-6 concentrations were measured during a standardized psychosocial stressor in n=19 subjects with moderate-severe childhood maltreatment (MAL), and n=50 controls without maltreatment (CTL), as indicated by self-ratings on the childhood trauma questionnaire (CTQ). CTQ total scores were positively correlated with overall change in IL-6 response, as well as the maximum IL-6 concentration during the TSST. Greater acute IL-6 release and higher IL-6 concentrations over time were observed for the MAL group relative to the CTL group. Inflammation may be an important developmental mediator linking adverse experiences in early life to poor adult physical and mental health. The results of this preliminary study warrant further investigation in a larger sample.