Prevalence of low-grade inflammation in depression: a systematic review and meta-analysis of CRP levels

Cerebrospinal Fluid Pathologies in Schizophrenia-Spectrum Disorder-A Retrospective Chart Review

BACKGROUND

The role of inflammatory processes in the etiology of schizophrenia is increasingly being investigated. A link between psychosis and inflammation measured with different biomarkers has been reported in the literature and needs to be further explored. To investigate the presence of inflammatory biomarkers in first-episode psychosis (FEP) we analyzed the largest available FEP cohort to date regarding routine CSF and blood diagnostics.

METHODS

We report a retrospective analysis of clinical data from all inpatients that were admitted to our tertiary care hospital with a ICD-10 diagnosis of F2x (schizophrenia-spectrum) between January 1, 2008 and August 1, 2018 and underwent a lumbar puncture.

RESULTS

A total of n = 314 FEP patients were included in our sample. 42.7% patients (134/314) showed cerebrospinal fluid (CSF) alterations. Oligoclonal bands in the CSF were present in 21.8% of patients (67/307) with 12.4% (27/217) of patients presenting OCBs type 2 or 3. 15.8% (49/310) of our cohort revealed signs of blood-brain-barrier (BBB) dysfunction with increased albumin ratios. Mean serum CRP levels were 2.4 mg/l (SD = 9.5). CRP elevation was present in 116/280 cases (41.4%).

CONCLUSIONS

This large retrospective analysis on FEP cohort greatly enriches the clinical data available on this population and contributes to the discussion around inflammation in psychosis. Of note, even though several inflammatory alterations were found both in CSF and in blood tests, we found no evidence for a significant relationship between peripheral inflammation and inflammatory CSF. Furthermore, no significant relationship between CSF alterations and peripheral inflammation measured with CRP could be established.

Assessing the effect of interaction between C-reactive protein and gut microbiome on the risks of anxiety and depression

Cumulative evidence shows that gut microbiome can influence brain function and behavior via the inflammatory processes. However, the role of interaction between gut dysbiosis and C-reactive protein (CRP) in the development of anxiety and depression remains to be elucidated. In this study, a total of 3321 independent single nucleotide polymorphism (SNP) loci associated with gut microbiome were driven from genome-wide association study (GWAS). Using individual level genotype data from UK Biobank, we then calculated the polygenetic risk scoring (PRS) of 114 gut microbiome related traits. Moreover, regression analysis was conducted to evaluate the possible effect of interaction between gut microbiome and CRP on the risks of Patient Health Questionnaire-9 (PHQ-9) (N = 113,693) and Generalized Anxiety Disorder-7 (GAD-7) (N = 114,219). At last, 11 candidate CRP × gut microbiome interaction with suggestive significance was detected for PHQ-9 score, such as F_Ruminococcaceae (β = - 0.009, P = 2.2 × 10^-3), G_Akkermansia (β = - 0.008, P = 7.60 × 10^-3), F_Acidaminococcaceae (β = 0.008, P = 1.22 × 10^-2), G_Holdemanella (β = - 0.007, P = 1.39 × 10^-2) and O_Lactobacillales (β = 0.006, P = 1.79× 10^-2). 16 candidate CRP × gut microbiome interaction with suggestive significance was detected for GAD-7 score, such as O_Bacteroidales (β = 0.010, P = 4.00×  10^-4), O_Selenomonadales (β = - 0.010, P = 1.20 × 10^-3), O_Clostridiales (β = 0.009, P = 2.70 × 10^-3) and G_Holdemanella (β = - 0.008, P = 4.20 × 10^-3). Our results support the significant effect of interaction between CRP and gut microbiome on the risks of anxiety and depression, and identified several candidate gut microbiomes for them.

Recent trends in the management of depression in persons with cancer

PURPOSE OF REVIEW

Depression is a prevalent comorbidity in cancer that significantly increases the risk for numerous negative health outcomes. This review updates the current evidence base for management of depression in cancer, highlighting new research directions based on the inflammatory hypothesis of depression.

RECENT FINDINGS

Research on pharmacotherapy and psychotherapy for depression in cancer has shown mixed efficacy partly because of methodological issues arising from the phenomenology of depression in cancer. After decades of stagnancy, more recent high-quality clinical trials are beginning to provide an evidence base to guide treatment. Inflammatory cytokine-associated depression is a subtype of depression that may have particular relevance in cancer, opening new avenues to explore therapeutic targets and biobehavioral impacts of interventions, which may improve cancer outcomes.

SUMMARY

The continuum of severity in cancer-related depression is important to consider in management approaches. Choice of treatment should be personalized to the patient and their symptom profile as there is currently insufficient evidence to recommend any particular medication or psychotherapy over another. Psychological interventions should be considered first line for mild-to-moderate depression, and pharmacological treatment added for more severe depression, which can be optimally delivered within a collaborative care model.

VIDEO ABSTRACT

http://links.lww.com/YCO/A62.

Microbiota-Gut-Brain Communication in the SARS-CoV-2 Infection

The coronavirus disease of 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome 2 (SARS-CoV-2). In addition to pneumonia, individuals affected by the disease have neurological symptoms. Indeed, SARS-CoV-2 has a neuroinvasive capacity. It is known that the infection caused by SARS-CoV-2 leads to a cytokine storm. An exacerbated inflammatory state can lead to the blood-brain barrier (BBB) damage as well as to intestinal dysbiosis. These changes, in turn, are associated with microglial activation and reactivity of astrocytes that can promote the degeneration of neurons and be associated with the development of psychiatric disorders and neurodegenerative diseases. Studies also have been shown that SARS-CoV-2 alters the composition and functional activity of the gut microbiota. The microbiota-gut-brain axis provides a bidirectional homeostatic communication pathway. Thus, this review focuses on studies that show the relationship between inflammation and the gut microbiota-brain axis in SARS-CoV-2 infection.

Pathophysiology of Major Depression by Clinical Stages

The comprehension of the pathophysiology of the major depressive disorder (MDD) is essential to the strengthening of precision psychiatry. In order to determine the relationship between the pathophysiology of the MDD and its clinical progression, analyzed by severity of the depressive symptoms and sleep quality, we conducted a study assessing different peripheral molecular biomarkers, including the levels of plasma C-reactive protein (CRP), serum mature brain-derived neurotrophic factor (mBDNF), serum cortisol (SC), and salivary cortisol awakening response (CAR), of patients with MDD (n = 58) and a control group of healthy volunteers (n = 62). Patients with the first episode of MDD (n = 30) had significantly higher levels of CAR and SC than controls (n = 32) and similar levels of mBDNF of controls. Patients with treatment-resistant depression (TRD, n = 28) presented significantly lower levels of SC and CAR, and higher levels of mBDNF and CRP than controls (n = 30). An increased severity of depressive symptoms and worse sleep quality were correlated with levels low of SC and CAR, and with high levels of mBDNF. These results point out a strong relationship between the stages clinical of MDD and changes in a range of relevant biological markers. This can assist in the development of precision psychiatry and future research on the biological tests for depression.

Assessment of Subclinical Psychotic Symptoms in Patients with Rheumatoid Arthritis and Spondyloarthritis

Inflammatory and autoimmune processes have been associated with the onset of depressive and psychotic symptoms. Rheumatoid arthritis (RA) and spondyloarthritis (SpA) are rheumatic diseases with an inflammatory etiology. A high prevalence of depressive and anxiety-related comorbidity has been reported for both diseases, with no evidence of a greater prevalence of psychosis. The objective of the present study was to evaluate for the first time subclinical psychotic symptoms in patients with RA and SpA. This is a cross-sectional, single-center study including RA and SpA patients, as well as healthy controls. Abnormal psychotic experiences (positive, negative, and depressive symptoms) were evaluated using the Community Assessment of Psychic Experiences (CAPE-42). Functional capacity was evaluated using the Short-Form Health Survey SF-12. We compared the CAPE and SF-12 scores between the three groups. We recruited 385 individuals: 218 with RA, 100 with SpA, and 67 healthy controls. According to the CAPE scale, the frequency of subclinical psychotic symptoms was greater in patients than in healthy controls (RA, 1.90 vs. 1.63, p < 0.001; SpA, 1.88 vs. 1.63, p = 0.001). Distress was also greater in patients than in controls owing to the presence of symptoms. No differences were observed between the three groups for the mental dimension scores in the SF-12 Health Survey (43.75 in RA, 45.54 in SpA, and 43.19 in healthy controls). Our findings point to a greater prevalence of subclinical psychotic symptoms in patients with RA and patients with SpA than in the general population. The results suggest an association between inflammation and depression/subclinical psychotic symptoms.

Role of inflammation in depression and anxiety: Tests for disorder specificity, linearity and potential causality of association in the UK Biobank

BACKGROUND

Concentrations of C-reactive protein (CRP), interleukin 6 (IL-6) and other inflammatory markers are elevated in people with depression and anxiety compared to controls, but evidence for disorder-specificity, linearity and potential causality is sparse.

METHODS

Using population-based data from up to 144,890 UK Biobank cohort participants, we tested associations of circulating CRP concentrations with depression and anxiety symptom scores and probable diagnosis, including tests for linearity, disorder-specificity and sex difference. We examined potential causality using 1-sample and 2-sample Mendelian randomisation (MR) analyses testing associations of genetically-predicted CRP concentration and IL-6 activity with depression and anxiety. The study was conducted from June 2019 to February 2021.

FINDINGS

CRP concentration was associated with depressive and anxiety symptom scores and with probable diagnoses of depression and generalised anxiety disorder (GAD) in a dose-response fashion. These associations were stronger for depression than for anxiety, and for women than for men although less consistently. MR analyses provided consistent results suggesting that genetically predicted higher IL-6 activity was associated with increased risk for depressive symptoms, while genetically-predicted higher CRP concentration was associated with decreased risks of depressive and anxiety symptoms.

INTERPRETATION

Altered activity of the IL-6/IL-6R pathway could be a risk factor for depression. The field now requires experimental studies of IL-6 modulation in humans and animal models to further examine causality, mechanisms and treatment potential. Such studies are also needed to elucidate mechanisms for divergent associations of genetically-predicted higher IL-6 activity (risk increasing) and higher CRP concentrations (protective) with depression/anxiety.

FUNDING

This research was funded in whole, or in part, by the Wellcome Trust (grant code: 201486/Z/16/Z). For the purpose of open access, the author has applied a CC BY public copyright licence to any Author Accepted Manuscript version arising from this submission. This work was supported by a Data Science Award from the MQ: Transforming Mental Health (grant code: MQDS17/40) to GMK and PBJ, which also supported ZY. GMK also acknowledges funding support from the Wellcome Trust (grant code: 201486/Z/16/Z), the Medical Research Council UK (grant code: MC_PC_17213 and MR/S037675/1), and the BMA Foundation (J Moulton grant 2019). NK and SM are supported by the International Max Planck Research School of Translational Psychiatry (IMPRS-TP). GDS works in the Medical Research Council Integrative Epidemiology Unit at the University of Bristol, which is supported by the Medical Research Council (MC_UU_00011/1).

Inflammation and depression: Research designs to better understand the mechanistic relationships between depression, inflammation, cognitive dysfunction, and their shared risk factors

There is convergent evidence that the immune system is dysregulated in some depressed individuals. A psychoneuroimmunology-based understanding of depression is advancing rapidly; however, a question of fundamental importance is poorly understood: does inflammation play a causal role in the etiology of depression or are elevated inflammatory biomarkers a downstream effect of depressive behaviors? Although longitudinal studies suggest that the relationship between depression and inflammation is characterized by complex bidirectional associations, existing prospective, longitudinal research designs are poorly equipped to investigate the dynamic interplay of depression and inflammation that unfolds over a relatively short time period. In addition, the precise role played by multiple, shared, and overlapping risk factors (e.g., diet, adiposity, stress, sleep dysregulation) in the etiology of depression and a pro-inflammatory phenotype (or both) is poorly understood. In this manuscript, I highlight the benefits of research designs that (i) manipulate constructs of interest (depression/inflammation) using intervention or treatment designs and (ii) use intensive sampling approaches with an ultimate goal of better understanding the temporal sequence and causal relationships of depression, inflammation, cognitive dysfunction, and their shared risk factors. For instance, are improved depressive symptoms a downstream effect of changes in inflammatory activity caused by increases in exercise or, alternatively, are changes in inflammatory activity and depression sequelae of improvements in sleep quality caused by increases in exercise? Potential benefits of these research designs are discussed in terms of their contribution to a better understanding of the etiology of depression and a pro-inflammatory phenotype, their relevance to structural health inequalities, and better characterizing the heterogeneous clinical presentation of depression, particularly relating to the etiology of cognitive dysfunction in depression.

Efficacy of a Functional Therapy Program for Depression and C-Reactive Protein: A Pilot Study

OBJECTIVE

Affecting more than 264 million people, depression is a systemic and multifactorial disorder that represents one of the leading causes of illness and disability worldwide. Several studies showed an inflammatory response in depressed patients, including the involvement of both chronic low-grade inflammatory response and activation of cell-mediated immunity. The present study aimed to verify the efficacy of a structured functional therapy program for patients with depressed mood, and to determine whether this program can significantly reduce levels of C-reactive protein.

METHOD

28 outpatients with depressed mood received 20 individual sessions of Functional therapy. Data about socio-demographic variables, depression, self-esteem, and quality of life were collected; moreover, blood specimens were collected before and after treatment, and CRP measurement was performed by immunoenzymatic method. All measures were administered at baseline, at the end of treatment (i.e., 3 months after baseline), and at follow-up (i.e., 6 months after baseline).

RESULTS

A repeated measures ANOVA showed a significant difference after treatment on depression levels, levels of self-esteem, and all dimensions of quality of life, such as physical, psychological, social relationships, and environment. Furthermore, a statistically significant difference on levels of CRP was found. Moreover, at follow-up, improvements were maintained.

CONCLUSIONS

The study revealed initial evidence of the efficacy of a functional therapy program on treating depression and its psychological and inflammation-related markers.

Investigating whether a combination of higher CRP and depression is differentially associated with worse executive functioning in a cohort of 43,896 adults

Many depressed individuals experience difficulties in executive functioning that contribute substantially to functional impairment. It is unknown whether a subtype of depression characterized by chronic inflammation is differentially associated with worse executive functioning. This study examined whether the combination of depression and higher C reactive protein (CRP) is differentially associated with worse executive functioning and whether this association is stronger in older adults. This cross-sectional study analyzed data collected from a population-representative sample of 43,896 adults aged 44.13 years (SD = 13.52) who participated in the baseline assessment of the Lifelines cohort study. Multivariate regression models tested whether depressed individuals (established via structured interview) exhibiting higher levels of inflammation (indexed via high-sensitivity CRP assay following an overnight fast) performed worse on a behavioral test of executive functioning. Depression (B = -3.66, 95% CI: -4.82, -2.49, p < .001) and higher log-transformed CRP (B = -0.67, 95% CI: -0.87,-0.47, p < .001) were associated with worse executive functioning, after adjustment for age, sex, educational attainment, body mass index, smoking status, exposure to stressful life events and chronic stressors, sedentary behavior, and number of chronic medical conditions. Depressed individuals with higher log-transformed CRP exhibited differentially poorer executive functioning (B = -1.09, 95% CI: -2.07,-0.11, p < .001). This association did not differ based on age (B = 0.01, 95% CI: -0.08, 0.10, p = .82). Executive functioning is poorer in depressed individuals with higher CRP, even in early adulthood. Interventions that reduce inflammation may improve cognitive functioning in depression.

Nutrition, Exercise, and Stress Management for Treatment and Prevention of Psychiatric Disorders. A Narrative Review Psychoneuroendocrineimmunology-Based

Psychoneuroendocrineimmunology (PNEI) brings together knowledge acquired since the 1930s from endocrinology, immunology, neuroscience, and psychology. With PNEI, a model of research and interpretation of health and disease is emerging, which sees the human body as a structured and interconnected unit, where the psychological and biological systems are mutually coordinated. In the PNEI view, many factors could influence mental health, with the endocrine system involved in mediating the effects of environmental stress on mental health and inflammation in the onset and course of psychiatric disorders as a result of individual and collective conditions and behaviors. Among these, nutrition is one way by which the environment impacts physiology: indeed, many pieces of research showed that several elements (e.g., probiotics, fish oil, zinc) have a positive effect on mental disorders thus being potentially augmentation agents in treatment. Still, physical activity can moderate depressive symptoms, while prolonged stress increases the risk of psychopathology. Taken together, the PNEI-based approach may inform prevention and treatment strategies, also in the field of mental health care.

Adverse childhood experiences and adult cardiometabolic risk factors and disease outcomes: Cross-sectional, population-based study of adults in rural Uganda

Background

Cardiovascular diseases (CVD) pose a major threat to public health in sub-Saharan African communities, where the burden of these classes of illnesses is expected to double by 2030. Growing research suggests that past developmental experiences and early life conditions may also elevate CVD risk throughout the life course. Greater childhood stress and adversity are consistently associated with a range of adult CVDs and associated risk factors, yet little research exists on the long-term effects of early life stress on adult physical health outcomes, especially CVD risk, in sub-Saharan African contexts. This study aims to evaluate the associations between adverse childhood experiences and adult cardiometabolic risk factors and health outcomes in a population-based study of adults living in Mbarara, a rural region of southwestern Uganda.

Methods

Data come from an ongoing, whole-population social network cohort study of adults living in the eight villages of Nyakabare Parish, Mbarara. A modified version of the Adverse Childhood Experiences-International Questionnaire (ACEs) assessed past exposure to physical, emotional, and sexual adversity. Participants also took part in a health fair where medical histories on cardiometabolic risk factors and cardiovascular diseases were gathered. Multiple logistic regression models estimated the associations between ACEs and cardiometabolic risk factors and health outcomes.

Results

Data were available on 545 adults. The average number of ACEs was 4.9 out of a possible 16. The cumulative number of ACEs were associated with having a history of heart attack and/or heart failure (adjusted odds ratio (AOR) = 1.11, 95% confidence interval (CI) = 0.999-1.234, P = 0.051), but the estimated association was not statistically significant. ACEs did not have statistically significant associations with any others measures of adult cardiometabolic risk and CVD.

Conclusions

Adverse childhood experiences are not associated with a range of adult cardiometabolic risk factors and health outcomes in this sample of rural Ugandan adults. Further research in this sample is necessary to identify the pathways that may motivate these null relationship and possibly protect against adverse cardiometabolic and cardiovascular health outcomes.

[Prospects for the use of drugs with anti-inflammatory properties for the treatment of depression]

The review briefly summarizes experimental and preclinical data of the role of pro-inflammatory cytokines in triggering pathophysiological changes associated with depression, primarily major depressive disorder (MDD), as well as the possibility of using anti-inflammatory drugs as antidepressants.

Adversity in early life and pregnancy are immunologically distinct from total life adversity: macrophage-associated phenotypes in women exposed to interpersonal violence

Early childhood and pregnancy are two sensitive periods of heightened immune plasticity, when exposure to adversity may disproportionately increase health risks. However, we need deeper phenotyping to disentangle the impact of adversity during sensitive periods from that across the total lifespan. This study examined whether retrospective reports of adversity during childhood or pregnancy were associated with inflammatory imbalance, in an ethnically diverse cohort of 53 low-income women seeking family-based trauma treatment following exposure to interpersonal violence. Structured interviews assessed early life adversity (trauma exposure ≤ age 5), pregnancy adversity, and total lifetime adversity. Blood serum was assayed for pro-inflammatory (TNF-a, IL-1ß, IL-6, and CRP) and anti-inflammatory (IL-1RA, IL-4, and IL-10) cytokines. CD14+ monocytes were isolated in a subsample (n = 42) and gene expression assayed by RNA sequencing (Illumina HiSeq 4000; TruSeq cDNA library). The primary outcome was a macrophage-associated M1/M2 gene expression phenotype. To evaluate sensitivity and specificity, we contrasted M1/M2 gene expression with a second, clinically-validated macrophage-associated immunosuppressive phenotype (endotoxin tolerance) and with pro-inflammatory and anti-inflammatory cytokine levels. Adjusting for demographics, socioeconomic status, and psychopathology, higher adversity in early life (ß = .337, p = 0.029) and pregnancy (ß = .332, p = 0.032) were each associated with higher M1/M2 gene expression, whereas higher lifetime adversity (ß = -.341, p = 0.031) was associated with lower immunosuppressive gene expression. Adversity during sensitive periods was uniquely associated with M1/M2 imbalance, among low-income women with interpersonal violence exposure. Given that M1/M2 imbalance is found in sepsis, severe COVID-19 and myriad chronic diseases, these findings implicate novel immune mechanisms underlying the impact of adversity on health.

Statins: Neurobiological underpinnings and mechanisms in mood disorders

Statins (3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors) treat dyslipidaemia and cardiovascular disease by inhibiting cholesterol biosynthesis. They also have immunomodulatory and anti-inflammatory properties. Beyond cardiovascular disease, cholesterol and inflammation appear to be components of the pathogenesis and pathophysiology of neuropsychiatric disorders. Statins may therefore afford some therapeutic benefit in mood disorders. In this paper, we review the pathophysiology of mood disorders with a focus on pharmacologically relevant pathways, using major depressive disorder and bipolar disorder as exemplars. Statins are discussed in the context of these disorders, with particular focus on the putative mechanisms involved in their anti-inflammatory and immunomodulatory effects. Recent clinical data suggest that statins may have antidepressant properties, however given their interactions with many known biological pathways, it has not been fully elucidated which of these are the major determinants of clinical outcomes in mood disorders. Moreover, it remains unclear what the appropriate dose, or appropriate patient phenotype for adjunctive treatment may be. High quality randomised control trials in concert with complementary biological investigations are needed if the potential clinical effects of statins on mood disorders, as well as their biological correlates, are to be better understood.

Physical Comorbidities and Depression in Recent and Long-Term Adult Cancer Survivors: NHANES 2007-2018

Simple Summary

Most cancer patients suffer one or more physical comorbidities (other somatic diseases present at the moment of cancer diagnosis). Previous research has shown that these comorbidities can interfere with cancer treatment and shorten the patient’s survival time. We propose that comorbidities could also interfere with the mental health of cancer patients and increase the risk of suffering depression in the years following the cancer diagnosis. We tested this possibility in a study of 2073 adult cancer survivors. We found that the number of physical comorbidities present at the moment of cancer diagnosis was related to higher risk of reporting depression in cancer survivors who were diagnosed up to 5 years before the study. This relationship was strongest among survivors of breast cancer. Information about comorbidities is usually readily available and could be useful in streamlining depression screening or targeting prevention efforts in cancer patients and survivors.

Abstract

Many adult cancer patients present one or more physical comorbidities. Besides interfering with treatment and prognosis, physical comorbidities could also increase the already heightened psychological risk of cancer patients. To test this possibility, we investigated the relationship between physical comorbidities with depression symptoms in a sample of 2073 adult cancer survivors drawn from the nationally representative National Health and Nutrition Examination Survey (NHANES) (2007–2018) in the U.S. Based on information regarding 16 chronic conditions, the number of comorbidities diagnosed before and after the cancer diagnosis was calculated. The number of comorbidities present at the moment of cancer diagnosis was significantly related to depression risk in recent but not in long-term survivors. Recent survivors who suffered multimorbidity had 3.48 (95% CI 1.26–9.55) times the odds of reporting significant depressive symptoms up to 5 years after the cancer diagnosis. The effect of comorbidities was strongest among survivors of breast cancer. The comorbidities with strongest influence on depression risk were stroke, kidney disease, hypertension, obesity, asthma, and arthritis. Information about comorbidities is usually readily available and could be useful in streamlining depression screening or targeting prevention efforts in cancer patients and survivors. A multidimensional model of the interaction between cancer and other physical comorbidities on mental health is proposed.

Distinct non-inflammatory signature of microglia in post-mortem brain tissue of patients with major depressive disorder

Findings from epidemiological studies, biomarker measurements and animal experiments suggest a role for aberrant immune processes in the pathogenesis of major depressive disorder (MDD). Microglia, the resident immune cells of the brain, are likely to play a key role in these processes. Previous post-mortem studies reported conflicting findings regarding microglial activation and an in-depth profiling of those cells in MDD is lacking. The aim of this study was therefore to characterize the phenotype and function of microglia in MDD. We isolated microglia from post-mortem brain tissue of patients with MDD (n = 13-19) and control donors (n = 12-25). Using flow cytometry and quantitative Polymerase Chain Reaction (qPCR), we measured protein and mRNA levels of a panel of microglial markers across four different brain regions (medial frontal gyrus, superior temporal gyrus, thalamus, and subventricular zone). In MDD cases, we found a significant upregulation of CX3CR1 and TMEM119 mRNA expression and a downregulation of CD163 mRNA expression and CD14 protein expression across the four brain regions. Expression levels of microglial activation markers, such as HLA-DRA, IL6, and IL1β, as well as the inflammatory responses to lipopolysaccharide and dexamethasone were unchanged. Our findings suggest that microglia enhance homeostatic functions in MDD but are not immune activated.

Polygenic risk for immuno-metabolic markers and specific depressive symptoms: A multi-sample network analysis study

BACKGROUND

About every fourth patient with major depressive disorder (MDD) shows evidence of systemic inflammation. Previous studies have shown inflammation-depression associations of multiple serum inflammatory markers and multiple specific depressive symptoms. It remains unclear, however, if these associations extend to genetic/lifetime predisposition to higher inflammatory marker levels and what role metabolic factors such as Body Mass Index (BMI) play. It is also unclear whether inflammation-symptom associations reflect direct or indirect associations, which can be disentangled using network analysis.

METHODS

This study examined associations of polygenic risk scores (PRSs) for immuno-metabolic markers (C-reactive protein [CRP], interleukin [IL]-6, IL-10, tumour necrosis factor [TNF]-α, BMI) with seven depressive symptoms in one general population sample, the UK Biobank study (n = 110,010), and two patient samples, the Munich Antidepressant Response Signature (MARS, n = 1058) and Sequenced Treatment Alternatives to Relieve Depression (STAR*D, n = 1143) studies. Network analysis was applied jointly for these samples using fused graphical least absolute shrinkage and selection operator (FGL) estimation as primary analysis and, individually, using unregularized model search estimation. Stability of results was assessed using bootstrapping and three consistency criteria were defined to appraise robustness and replicability of results across estimation methods, network bootstrapping, and samples.

RESULTS

Network analysis results displayed to-be-expected PRS-PRS and symptom-symptom associations (termed edges), respectively, that were mostly positive. Using FGL estimation, results further suggested 28, 29, and six PRS-symptom edges in MARS, STAR*D, and UK Biobank samples, respectively. Unregularized model search estimation suggested three PRS-symptom edges in the UK Biobank sample. Applying our consistency criteria to these associations indicated that only the association of higher CRP PRS with greater changes in appetite fulfilled all three criteria. Four additional associations fulfilled at least two consistency criteria; specifically, higher CRP PRS was associated with greater fatigue and reduced anhedonia, higher TNF-α PRS was associated with greater fatigue, and higher BMI PRS with greater changes in appetite and anhedonia. Associations of the BMI PRS with anhedonia, however, showed an inconsistent valence across estimation methods.

CONCLUSIONS

Genetic predisposition to higher systemic inflammatory markers are primarily associated with somatic/neurovegetative symptoms of depression such as changes in appetite and fatigue, consistent with previous studies based on circulating levels of inflammatory markers. We extend these findings by providing evidence that associations are direct (using network analysis) and extend to genetic predisposition to immuno-metabolic markers (using PRSs). Our findings can inform selection of patients with inflammation-related symptoms into clinical trials of immune-modulating drugs for MDD.

Controversies involving the use of SSRIs during pregnancy and the increased risk of having a child with autism spectrum disorders – a case report and literature review

Introduction: There is an ongoing debate as to whether the use of selective serotonin reuptake inhibitors (SSRIs) by pregnant women increases the risk of developing autism spectrum disorders (ASD) in the offspring.

Aim: The aim of the study was to

1) present, based on a case report, the potential factors that may affect the development of ASD in a child,

2) review the literature on the risk of ASD in the case of using SSRIs by a pregnant woman.

Case report: The case report concerns a child of a 33-year-old patient, previously treated for an episode of depression at the age of 23. At the beginning of the 15th week of planned pregnancy, when she was 28 years old, sleep disturbances were observed. Over the next few weeks, she gradually developed a full-blown depressive syndrome which required the use of sertraline. The child was born through a natural delivery, a healthy boy, who was diagnosed with ASD at the age of 2.5 years, which was the trigger for the development of the third episode of depression in the patient.

Conclusions: The results of the research indicate that SSRIs can penetrate the placental barrier, influencing the processes of serotoninergic transmission in the fetus, disrupting neurodevelopmental processes. On the other hand, a higher risk of ASD development in children of depressed mothers who do not use pharmacotherapy was confirmed, compared to the general population and in the case of the occurrence of depressive episodes in mother in the past and in relation to the male fetuses. The greater risk of ASD in children of mothers who take SSRIs may not only be associated with the medication itself but also with the presence of depression and the probable common genetic basis for both disorders. In each case, other risk factors for the development of ASD should also be taken into consideration, e.g. vitamin D3 deficiencies, unsaturated fatty acids, oxytocin levels, the presence of intestinal dysbiosis.

The longitudinal associations of inflammatory biomarkers and depression revisited: systematic review, meta-analysis, and meta-regression

The innate immune system is dysregulated in depression; however, less is known about the longitudinal associations of depression and inflammatory biomarkers. We investigated the prospective associations of depression and inflammatory biomarkers [interleukin-6 (IL-6), Tumor Necrosis Factor-Alpha (TNF-α), and C-reactive protein (CRP)] in community samples, both unadjusted and adjusted for covariates. The review, registered with PROSPERO, searched for published and unpublished studies via MEDLINE/PsycINFO/PsycARTICLES/EMBASE/Proquest Dissertation. Standardized Fisher transformations of the correlation/beta coefficients, both unadjusted and adjusted for covariates, were extracted from studies examining the prospective associations of depression and inflammatory biomarkers. Systematic review conducted in January, 2019 included 38 studies representing 58,256 participants, with up to 27 studies included in random-effects meta-analysis. Higher CRP/IL-6 were associated with future depressive symptoms, and higher depressive symptoms were associated with higher future CRP/IL-6 in both unadjusted and adjusted analyses - this is the first meta-analysis reporting an adjusted association of IL-6 with future depression. The adjusted prospective associations of depression with CRP/CRP with depression were substantially attenuated and small in magnitude. No significant associations were observed for TNF-α. No conclusive results were observed in studies of clinical depression. Meta-regression indicated that the association of CRP and future depression was larger in older samples and in studies not controlling for possible infection. Small, prospective associations of depression and inflammatory biomarkers are observed in both directions, particularly for IL-6; however, the strength and importance of this relationship is likely obscured by the heterogeneity in depression and profound study/methodological differences. Implications for future studies are discussed.

Gut microbiota variations in patients diagnosed with major depressive disorder-A systematic review

OBJECTIVE

The etiology of major depressive disorder (MDD) is multi-factorial and has been associated with a perturbed gut microbiota. Thus, it is therefore of great importance to determine any variations in gut microbiota in patients with MDD.

METHODS

A systematic literature search was conducted including original research articles based on gut microbiota studies performed in patients with MDD. Demographic and clinical characteristics, applied methodology and observed gut microbiota composition were compared between included studies.

RESULTS

Seventeen studies were included with a total of 738 patients with MDD and 782 healthy controls using different DNA purification methods, sequencing platforms and data analysis models. Four studies found a reduced α-diversity in patients with MDD, while gut microbiota compositions clustered separately according to β-diversity between patients and controls in twelve studies. Additionally, there was an increase in relative abundance of Eggerthella, Atopobium, and Bifidobacterium and a decreased relative abundance of Faecalibacterium in patients with MDD compared with healthy controls.

CONCLUSION

Gut microbiota differs significantly when comparing patients with MDD and healthy controls, though inconsistently across studies. The heterogeneity in gut microbiota compositions between the studies may be explained by variations in study design.

Elevated C-Reactive Protein in Patients With Depression, Independent of Genetic, Health, and Psychosocial Factors: Results From the UK Biobank

OBJECTIVE

The authors investigated the pathways (genetic, environmental, lifestyle, medical) leading to inflammation in major depressive disorder using C-reactive protein (CRP), genetic, and phenotypic data from the UK Biobank.

METHODS

This was a case-control study of 26,894 participants with a lifetime diagnosis of major depressive disorder from the Composite International Diagnostic Interview and 59,001 control subjects who reported no mental disorder and had not reported taking any antidepressant medication. Linear regression models of log CRP level were fitted to regress out the effects of age, sex, body mass index (BMI), and smoking and to test whether the polygenic risk score (PRS) for major depression was associated with log CRP level and whether the association between log CRP level and major depression remained after adjusting for early-life trauma, socioeconomic status, and self-reported health status.

RESULTS

CRP levels were significantly higher in patients with depression relative to control subjects (2.4 mg/L compared with 2.1 mg/L, respectively), and more case than control subjects had CRP levels >3 mg/L (21.2% compared with 16.8%, respectively), indicating low-grade inflammation. The PRS for depression was positively and significantly associated with log CRP levels, but this association was no longer significant after adjustment for BMI and smoking. The association between depression and increased log CRP level was substantially reduced, but still remained significant, after adjustment for the aforementioned clinical and sociodemographic factors.

CONCLUSIONS

The data indicate that the "genetic" contribution to increased inflammation in depression is due to regulation of eating and smoking habits rather than an "autoimmune" genetic predisposition. Moreover, the association between depression and increased inflammation even after full adjustment indicates either the presence of yet unknown or unmeasured psychosocial and clinical confounding factors or that a core biological association between depression and increased inflammation exists independently from confounders.

Study on the interaction mechanism between C-reactive protein and platelets in the development of acute myocardial infarction

Background

Myocardial infarction (MI) is the single most critical event in coronary disease. Platelets are involved in the processes of acute MI (AMI). They lack nuclear DNA but retain megakaryocyte mRNAs, hence, their transcriptome could provide information preceding coronary events. However, their mechanisms are not clear. In this study, we obtained a gene expression atlas of platelets from patients after their very first AMI, and our purpose was to clarify the mechanisms of platelet involvement in the occurrence of AMI through bioinformatics analyses and animal models of AMI in vivo.

Methods

We obtained a gene expression atlas of platelets from patients after their very first AMI from the Gene Expression Omnibus (GEO). Differentially expressed genes (DEGs) were retrieved using R language. Weighted gene co-expression network analysis (WGCNA) was implemented in order to construct a gene co-expression correlation network among DEGs. Animal models of AMI in vivo were constructed to confirm the results of the bioinformatics analysis.

Results

Gene integration analysis yielded 2,852 DEGs (P<0.05, |log2FC| >1). Bioinformatics analysis demonstrated a significant association between C-reactive protein (CRP) and Staphylococcus aureus infection (SAI) (P=0.015). Data from in vivo experiments showed that CRP increased significantly in AMI rats (P<0.001), and the expression of FCGR2B mRNA and HLA-DRB4 mRNA was elevated in response to the increase of CRP (P<0.001).

Conclusions

From the results of this study, we speculate that in the development of AMI, the increase in CRP activates platelets and induces platelets to play an anti-inflammatory role.

Increased peripheral inflammation in schizophrenia is associated with worse cognitive performance and related cortical thickness reductions

While the biological substrates of brain and behavioural changes in persons with schizophrenia remain unclear, increasing evidence implicates that inflammation is involved. In schizophrenia, including first-episode psychosis and anti-psychotic naïve patients, there are numerous reports of increased peripheral inflammation, cognitive deficits and neuropathologies such as cortical thinning. Research defining the relationship between inflammation and schizophrenia symptomatology and neuropathology is needed. Therefore, we analysed the level of C-reactive protein (CRP), a peripheral inflammation marker, and its relationship with cognitive functioning in a cohort of 644 controls and 499 schizophrenia patients. In a subset of individuals who underwent MRI scanning (99 controls and 194 schizophrenia cases), we tested if serum CRP was associated with cortical thickness. CRP was significantly increased in schizophrenia patients compared to controls, co-varying for age, sex, overweight/obesity and diabetes (p < 0.006E-10). In schizophrenia, increased CRP was mildly associated with worse performance in attention, controlling for age, sex and education (R =- 0.15, p = 0.001). Further, increased CRP was associated with reduced cortical thickness in three regions related to attention: the caudal middle frontal, the pars opercularis and the posterior cingulate cortices, which remained significant after controlling for multiple comparisons (all p < 0.05). Together, these findings indicate that increased peripheral inflammation is associated with deficits in cognitive function and brain structure in schizophrenia, especially reduced attention and reduced cortical thickness in associated brain regions. Using CRP as a biomarker of peripheral inflammation in persons with schizophrenia may help to identify vulnerable patients and those that may benefit from adjunctive anti-inflammatory treatments.

Longitudinal association between CRP levels and risk of psychosis: a meta-analysis of population-based cohort studies

Meta-analyses of cross-sectional studies suggest that patients with psychosis have higher circulating levels of C-reactive protein (CRP) compared with healthy controls; however, cause and effect is unclear. We examined the prospective association between CRP levels and subsequent risk of developing a psychotic disorder by conducting a systematic review and meta-analysis of population-based cohort studies. Databases were searched for prospective studies of CRP and psychosis. We obtained unpublished results, including adjustment for age, sex, body mass index, smoking, alcohol use, and socioeconomic status and suspected infection (CRP > 10 mg/L). Based on random effect meta-analysis of 89,792 participants (494 incident cases of psychosis at follow-up), the pooled odds ratio (OR) for psychosis for participants with high (>3 mg/L), as compared to low (≤3 mg/L) CRP levels at baseline was 1.50 (95% confidence interval [CI], 1.09-2.07). Evidence for this association remained after adjusting for potential confounders (adjusted OR [aOR] = 1.31; 95% CI, 1.03-1.66). After excluding participants with suspected infection, the OR for psychosis was 1.36 (95% CI, 1.06-1.74), but the association attenuated after controlling for confounders (aOR = 1.23; 95% CI, 0.95-1.60). Using CRP as a continuous variable, the pooled OR for psychosis per standard deviation increase in log(CRP) was 1.11 (95% CI, 0.93-1.34), and this association further attenuated after controlling for confounders (aOR = 1.07; 95% CI, 0.90-1.27) and excluding participants with suspected infection (aOR = 1.07; 95% CI, 0.92-1.24). There was no association using CRP as a categorical variable (low, medium or high). While we provide some evidence of a longitudinal association between high CRP (>3 mg/L) and psychosis, larger studies are required to enable definitive conclusions.

The kynurenine pathway in major depression: What we know and where to next

Major depression is a serious psychiatric disorder, occurring in up to 20 % of the population. Despite its devastating burden, the neurobiological changes associated with depression are not fully understood. A growing body of evidence suggests the kynurenine pathway is implicated in the pathophysiology of depression. In this review, we bring together the literature examining elements of the kynurenine pathway in depression and explore the implications for the pathophysiology and treatment of depression, while highlighting the gaps in the current knowledge. Current research indicates an increased potential for neurotoxic activity of the kynurenine pathway in peripheral blood samples but an increased activation of the putative neuroprotective arm in some brain regions in depression. The disconnect between these findings requires further investigation, with a greater research effort on elucidating the central effects of the kynurenine pathway in driving depression symptomology. Research investigating the benefits of targeting the kynurenine pathway centred on human brain findings and the heterogenous subtypes of depression will help guide the identification of effective drug targets in depression.

Loneliness and Risk for Cardiovascular Disease: Mechanisms and Future Directions

Purpose of review

In this review, we synthesise recent research on the association between loneliness and cardiovascular disease (CVD). We present evidence for mechanisms underlying this association and propose directions for future research.

Recent findings

Loneliness is related to increased risk of early mortality and CVD comparable to other well-established risk factors such as obesity or smoking.

Summary

Loneliness has been linked to higher rates of incident CVD, poorer CVD patient outcomes, and early mortality from CVD. Loneliness likely affects risk for these outcomes via health-related behaviours (e.g. physical inactivity and smoking), biological mechanisms (e.g. inflammation, stress reactivity), and psychological factors (e.g. depression) to indirectly damage health.

Bidirectional Associations between Handgrip Strength and Depressive Symptoms: A Longitudinal Cohort Study

OBJECTIVES

This study aimed to examine the bidirectional associations between handgrip strength and depressive symptoms in a nationally representative sample.

DESIGN

Cohort study with a 4-year follow-up.

SETTING AND PARTICIPANTS

A total of 13,208 participants from the China Health and Retirement Longitudinal Study were included in the analyses.

METHODS

Depressive symptoms were assessed using the 10-item Center for Epidemiological Studies-Depression Scale. Separate generalized estimating equations were used to analyze the cross-sectional and longitudinal associations between handgrip strength and depressive symptoms. Restricted cubic spline models were performed to explore the shape of the dose-response relationship.

RESULTS

Decreased handgrip strength was related to subsequent increased risk of depressive symptoms, such that participants in the lowest quartile of handgrip strength were found to have an approximately 36% increased in their risk of depressive symptoms compared with those in the highest quartile [odds ratio (OR) 1.36, 95% confidence interval (CI) 1.17, 1.58]. There was a linear dose-response relationship between handgrip strength and risk of depressive symptoms (P_nonlinearity = .25), in that a 5-unit increment in handgrip strength may lead to an 11% decrease in the risk of depressive symptoms (OR 0.89, 95% CI 0.85, 0.92). Conversely, depressive symptoms were prospectively associated with subsequent decreased handgrip strength (β = -0.84, 95% CI -1.13, -0.55). An approximatively L-shaped dose-response pattern was found for the association between depressive symptoms level and handgrip strength (P_nonlinearity = .02).

CONCLUSIONS AND IMPLICATIONS

The present study identified bidirectional associations between handgrip strength and depressive symptoms, and the associations were found to have a dose-response pattern. It provides important insights into integrated mental and physical health intervention strategies that simultaneously promote handgrip strength and depressive symptoms.

Investigating whether depressed youth exhibiting elevated C reactive protein perform worse on measures of executive functioning, verbal fluency and episodic memory in a large, population based sample of Dutch adolescents

Cognitive functioning is disrupted during a depressive episode and cognitive dysfunction persists when depression is in remission. A subtype of depressed individuals who exhibit elevated inflammatory biomarkers may be at particular risk for cognitive dysfunction. We examined whether an elevated inflammatory biomarker (C-reactive protein: CRP) in acute and/or remitted depression was associated with specific deficits in executive functioning, episodic memory, and verbal fluency. Data were drawn from a population-based sample of Dutch adolescents (N = 1066; 46% male) recruited at the age of 11 and followed over the course of eight years. We tested whether adolescents with either, (i) a history of depression (Wave 1-3) or (ii) current depression (Wave 4), and elevated levels of C-reactive protein measured in blood at Wave 3 performed worse on cognitive assessments at Wave 4. Eight measures of cognitive functioning were hypothesized to load on to one of three dimensions of cognitive functioning (executive functioning, episodic memory, and verbal fluency) within a structural equation model framework. Higher levels of CRP were associated with worse future executive functioning in adolescents with and without current/prior depression. A current depression diagnosis also was associated with worse executive functioning. There was consistent evidence linking low socioeconomic status and health-related covariates (high body mass index/sedentary behavior) with worse performance across multiple measures of cognitive functioning and, importantly, the association of depression/CRP and executive functioning was no longer significant when controlling for these covariates. Future studies may benefit from investigating whether specific depressogenic behaviors (e.g., sedentary behavior/substance use) mediate a relationship between depression and worse executive functioning, potentially via a prospective pathway through elevated inflammation.

Goal-striving tendencies moderate the relationship between reward-related brain function and peripheral inflammation

Inflammation is associated with both lower and higher activity in brain regions that process rewarding stimuli. How can both low and high sensitivity to rewards be associated with higher inflammation? We propose that one potential mechanism underlying these apparently conflicting findings pertains to how people pursue goals in their environment. This prediction is based on evidence that both an inability to disengage from unattainable goals and low interest in and pursuit of important life goals are associated with poor health outcomes, including inflammation. Accordingly, this study examined the relationship between reward-related brain function and peripheral inflammation among individuals with different levels of ambitious goal-striving tendencies. Eighty-three participants completed an ambitious goal-striving tendency measure, an fMRI Monetary Incentive Delay task assessing orbitofrontal cortex (OFC) and nucleus accumbens (NAc) activation during reward anticipation and outcome, and a venous blood draw to assess the inflammatory biomarkers interleukin (IL)-6, IL-8, tumor necrosis factor-alpha, and C-reactive protein, from which we computed an inflammation composite score. We observed a reward anticipation by goal-striving interaction on inflammation, such that high OFC and NAc activation to reward anticipation (but not outcome) were associated with more inflammation, among high goal-striving individuals. By contrast, low NAc activation during reward anticipation (but not outcome) was associated with more inflammation, among low goal-striving individuals. The current study provides further evidence that both blunted and elevated reward function can be associated with inflammation. It also highlights the role that goal-striving tendencies may play in moderating the relationship between neural reward anticipation and inflammation.

The handgrip strength and risk of depressive symptoms: a meta-analysis of prospective cohort studies

PURPOSE

Many studies have investigated the association between handgrip strength (HGS) and depressive symptoms, but the conclusion remain controversial. We performed a meta-analysis to evaluate the longitudinal association between HGS and risk of depressive symptoms.

METHODS

PubMed, PSYCINFO and EMBASE databases were searched for eligible publications up to April 2020. Pooled relative risks (RRs) with 95% confidence intervals were calculated using random-effects model. Publication bias was estimated using Egger's test and the funnel plot. Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of eligible studies.

RESULTS

The present meta-analysis included 8 cohort studies with 30,727 participants. Overall, higher HGS was related to a decreased risk of depressive symptoms: the pooled risk ratio (RR) of 0.74 [95% confidence intervals (CI) 0.65-0.85] with a moderate heterogeneity (I² = 60.5%, P = 0.013). HGS was significantly associated with a reduced risk of depressive symptoms in males (RR = 0.69; 95% CI 0.50-0.94), but not in females.

CONCLUSIONS

Lower HGS was associated with an increased risk of depressive symptoms. Further studies are needed to confirm these findings and to investigate the sex differences.

Major Depressive Disorder in Older Patients as an Inflammatory Disorder: Implications for the Pharmacological Management of Geriatric Depression

Depression is a common and highly disabling condition in older adults. It is a heterogenous disorder and there is emerging evidence of a link between inflammation and depression in older patients, with a possible inflammatory subtype of depression. Persistent low-level inflammation, from several sources including psychological distress and chronic disease, can disrupt monoaminergic and glutaminergic systems to create dysfunctional brain networks. Despite the evidence for the role of inflammation in depression, there is insufficient evidence to recommend use of any putative anti-inflammatory agent in the treatment of depression in older adults at this stage. Further characterisation of markers of inflammation and stratification of participants with elevated rates of inflammatory markers in treatment trials is needed.

Effects of Antidepressant Treatment on Peripheral Biomarkers in Patients with Major Depressive Disorder (MDD)

Major depressive disorder (MDD) is one of the most prevalent mental illness and a leading cause of disability worldwide. Despite a range of effective treatments, more than 30% of patients do not achieve remission as a result of conventional therapy. In these circumstances the identification of novel drug targets and pathogenic factors becomes essential for selecting more efficacious and personalized treatment. Increasing evidence has implicated the role of inflammation in the pathophysiology of depression, revealing potential new pathways and treatment options. Moreover, convergent evidence indicates that MDD is related to disturbed neurogenesis and suggests a possible role of neurotrophic factors in recovery of function in patients. Although the influence of antidepressants on inflammatory cytokines balance was widely reported in various studies, the exact correlation between drugs used and specific cytokines and neurotrophins serum levels often remains inconsistent. Available data suggest anti-inflammatory properties of selective serotonin reuptake inhibitors (SSRIs), selective serotonin and noradrenaline inhibitors (SNRIs), and tricyclic antidepressants (TCAs) as a possible additional mechanism of reduction of depressive symptoms. In this review, we outline emerging data regarding the influence of different antidepressant drugs on a wide array of peripheral biomarkers such as interleukin (IL)-1ß, IL-2, IL-5, IL-6, IL-8, IL-10, C-reactive protein (CRP), or interferon (IFN)-γ. Presented results indicate anti-inflammatory effect for selected drugs or lack of such effect. Research in this field is insufficient to define the role of inflammatory markers as a predictor of treatment response in MDD.

Diet-Related Inflammation is Associated with Major Depressive Disorder in Bahraini Adults: Results of a Case-Control Study Using the Dietary Inflammatory Index

PURPOSE

This case-control study aimed to examine the association between the inflammation potential of the diet and depression.

PATIENTS AND METHODS

Ninety-six patients with major depression disorder were matched with 96 age- and sex-matched healthy controls. Energy-adjusted DII (E-DIITM) scores were calculated based on the participants' responses to a detailed nutritional assessment using a quantitative food frequency questionnaire. Descriptive results were reported. Logistic regression was used to estimate odds ratios and 95% confidence intervals associated with E-DII scores and depression adjusting for covariates including age, sex, body mass index, comorbidities, level of education, and employment.

RESULTS

The mean E-DII score of participants in the study was 1.32±1.08, indicating a generally pro-inflammatory diet. Patients with depression had elevated E-DII scores compared to age- and sex-matched controls with E-DII scores of 1.72± 1.09 vs 0.90±0.90, respectively (P=0.001). Results of logistic regression analysis revealed that patients with depression were nearly three times more likely to be in the extreme ends of pro-inflammatory diet (OR 2.75; 95% CI 1.82-4.15).

CONCLUSION

Adult Bahraini patients with depression have higher dietary inflammation potential compared to the general population controls. Further research is needed to confirm these results and provide effective interventions to reduce the burden of this dietary inflammation.

Sex-related patterns of the gut-microbiota-brain axis in the neuropsychiatric conditions

Sex differences are often observed in psychiatric patients, especially major depressive disorders (MDD), schizophrenia, and developmental disorders, including autism spectrum disorders (ASDs). The prevalence rates between males and females seem variate according to the clinical condition. Although the findings are still incipient, it is suggested that these differences can involve neuroanatomical, neurochemical, and physiological sex differences. In this context, the microbiota-gut-brain axis hypothesis arises to explain some aspects of the complex pathophysiology of neuropsychiatric disorders. The microbiota composition is host-specific and can change conforming to age, sex, diet, medication, exercise, and others. The communication between the brain and the gut is bidirectional and may impact the entire system homeostasis. Many pathways appear to be involved, including neuroanatomic communication, neuroendocrine pathways, immune system, bacteria-derived metabolites, hormones, neurotransmitters, and neurotrophic factors. Although the clinical and preclinical studies are sparse and not very consistent, they suggest that sex differences in the gut microbiota may play an essential role in some neuropsychiatric conditions. Thus, this narrative review has as a mainly aim to show the points sex-related patterns associated to the gut-microbiota-brain axis in the MDD, ASDs, and schizophrenia.

[COPD, anxiety-depression and cognitive disorders: Does inflammation play a major role?]

COPD is a chronic respiratory disease, often associated with extrapulmonary manifestations. Co-morbidities, including anxiety, depression and cognitive impairment, worsen its progression and quality of life. The prevalence of these disorders is high, yet they are often poorly understood and inadequately managed. In the development of psychological disorders, there is accumulated evidence highlighting the major role of systemic inflammation, as well as chronic disease, genetics, the consequences of smoking, hypoxaemia, oxidative stress, and the gut microbiome In addition to traditional treatments such as bronchodilatator medications, respiratory rehabilitation and smoking cessation, systemic inflammation is an interesting therapeutic target, with the use of anti-inflammatory drugs, anti-cytokines, and nutritional interventions.

Childhood inflammatory markers and risks for psychosis and depression at age 24: Examination of temporality and specificity of association in a population-based prospective birth cohort

BACKGROUND

Cross-sectional studies have reported elevated concentrations of inflammatory markers in psychosis and depression. However, questions regarding temporality and specificity of association, crucial for understanding the potential role of inflammation, remain.

METHODS

Based on 2224 ALSPAC birth cohort participants, we used regression analyses to test associations of interleukin-6 (IL-6) and C-reactive protein (CRP) levels at age 9 with risks for psychosis (psychotic experiences; negative symptoms; psychotic disorder), and depression (depressive episode; symptom score) at age 24. Regression models were adjusted for sex, ethnicity, social class and body mass index. We tested for linearity (using quadratic terms) and specificity (using bi-variate probit regression) of association, and used multiple imputation to explore the impact of missing data.

RESULTS

After adjustments, higher IL-6 levels at age 9 were associated with increased risk of psychotic disorder (OR = 1.56; 95% C.I., 1.09-2.21 per SD increase in IL-6; OR=2.60; 95% C.I., 1.04-6.53 for the top compared with bottom third of IL-6) and depressive episode (OR = 1.14; 95% C.I., 0.99-1.32 per SD increase in IL-6; OR = 1.49; 95% C.I., 1.02-2.18 for the top compared with bottom third of IL-6). IL-6 was associated with negative symptoms after adjusting for depression (β = 0.09; 95% C.I., 0.01-0.22). There was no evidence for outcome-specific associations of IL-6. Childhood CRP was not associated with adult psychosis or depression.

CONCLUSIONS

Evidence for similar, longitudinal, dose-response associations suggest that elevated childhood IL-6 could be a shared risk factor for adult psychosis and depression. The IL-6 pathway may represent a novel target for treatment and prevention of these disorders.

Augmentation therapy with minocycline in treatment-resistant depression patients with low-grade peripheral inflammation: results from a double-blind randomised clinical trial

This study aimed to investigate the role of baseline levels of peripheral inflammation when testing the efficacy of antidepressant augmentation with minocycline in patients with treatment-resistant depression. We conducted a 4-week, placebo-controlled, randomised clinical trial of minocycline (200 mg/day) added to antidepressant treatment in 39 patients selected for elevated levels of serum C-reactive protein (CRP ≥ 1 mg/L), n = 18 randomised to minocycline (M) and n = 21 to placebo (P). The main outcome was the change in Hamilton Depression Rating Scale (HAM-D-17) score from baseline to week 4, expressed both as mean and as full or partial response, in the overall sample and after further stratification for baseline CRP≥3 mg/L. Secondary outcomes included changes in other clinical and inflammatory measures. Changes in HAM-D-17 scores and the proportion of partial responders did not differ between study arms. After stratification for CRP levels <3 mg/L (CRP-) or ≥3 mg/L (CRP+), CRP+/M patients showed the largest changes in HAM-D-17 scores (mean ± SD = 12.00 ± 6.45) compared with CRP-/M (2.42 ± 3.20, p < 0.001), CRP+/P (3.50 ± 4.34, p = 0.003) and CRP-/P (2.11 ± 3.26, p = 0.006) patients, and the largest proportion (83.3%, p = 0.04) of partial treatment response at week 4. The threshold point for baseline CRP to distinguish responders from non-responders to minocycline was 2.8 mg/L. Responders to minocycline had higher baseline IL-6 concentrations than non-responders (p = 0.03); IFNγ was significantly reduced after treatment with minocycline compared with placebo (p = 0.03). Our data show some evidence of efficacy of add-on treatment with minocycline in MDD patients but only in those with low-grade inflammation defined as CRP ≥3 mg/L.

Prenatal stress induced depressive-like behavior and region dependently high CRP level in offspring rats

INTRODUCTION

To explore the changes in C-reactive protein (CRP) level in different regions of one old offspring rats exposed to prenatal stress (PS).

METHODS

The rat model was constructed with prenatal restraint stress on pregnant dams on days 14-20 of gestation. Offspring rats were randomly divided into PS susceptibility (PS-S) group and control (CON) group. Behavioral experiments including sucrose preference test (SPT), open-field test (OFT), and forced swimming test (FST) were used to measure depressive-like behaviors. Immunohistochemistry, qRT-PCR, and Western blotting were applied to detect the changes in CRP level.

RESULTS

The results showed that PS could cause depressive-like behaviors in all SPT, OFT, and FST. Concomitantly, CRP mRNA and protein expression significantly increased in hippocampus, prefrontal cortex, and hypothalamus in the PS-S group when compared that in the CON group, while no significantly changes in liver, heart, olfactory bulb, striatum, and cerebellum in the PS-S group when compared that in the CON group.

CONCLUSION

Increasing of CRP expression in hippocampus, prefrontal cortex, and hypothalamus may play a critical role in the mechanism under depressive-like behavior in offspring rats exposed to PS.

Association between psoriasis and dementia: A systematic review

INTRODUCTION

Risk factors for dementia include genetic factors, aging, environmental factors, certain diseases, and unhealthy lifestyle; most types of dementia share a common chronic systemic inflammatory phenotype. Psoriasis is also considered to be a chronic systemic inflammatory disease. It has been suggested that psoriasis may also contribute to the risk of dementia. The aim of this study was to systematically review the literature on the association between psoriasis and dementia.

DEVELOPMENT

Articles were selected according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We searched the PubMed and Web of Science databases to identify articles published in peer-reviewed journals and studying the association between psoriasis and dementia. Studies meeting the inclusion criteria were reviewed. We used the Newcastle-Ottawa Scale to assess the quality of each study. After applying the inclusion and exclusion criteria, we included 8 studies for review, 3 of which were found to present a higher risk of bias. Six of the 8 studies supported the hypothesis that prior diagnosis of psoriasis increases the risk of dementia; one study including only a few cases reported that psoriasis decreased the risk of dementia, and one study including relatively young patients found no significant association between psoriasis and the risk of dementia.

CONCLUSION

Most studies included in this review supported the hypothesis that psoriasis constitutes a risk factor for dementia. However, well-designed stratified cohort studies assessing both psoriasis severity and treatment status are still required to determine the real effect of psoriasis on the risk of dementia and its subtypes.

Circadian depression: A mood disorder phenotype

Major mood syndromes are among the most common and disabling mental disorders. However, a lack of clear delineation of their underlying pathophysiological mechanisms is a major barrier to prevention and optimised treatments. Dysfunction of the 24-h circadian system is a candidate mechanism that has genetic, behavioural, and neurobiological links to mood syndromes. Here, we outline evidence for a new clinical phenotype, which we have called 'circadian depression'. We propose that key clinical characteristics of circadian depression include disrupted 24-h sleep-wake cycles, reduced motor activity, low subjective energy, and weight gain. The illness course includes early age-of-onset, phenomena suggestive of bipolarity (defined by bidirectional associations between objective motor and subjective energy/mood states), poor response to conventional antidepressant medications, and concurrent cardiometabolic and inflammatory disturbances. Identifying this phenotype could be clinically valuable, as circadian-targeted strategies show promise for reducing depressive symptoms and stabilising illness course. Further investigation of underlying circadian disturbances in mood syndromes is needed to evaluate the clinical utility of this phenotype and guide the optimal use of circadian-targeted interventions.

The Immunology of Stress and the Impact of Inflammation on the Brain and Behavior

Exposure to acute versus chronic stressors and threats activates the immune system in adaptive and maladaptive manners, respectively. While acute activation of the immune system in response to threat is homeostatically regulated by glucocorticoid negative feedback, chronic activation of the immune system arising from persistent stress exposure can contribute to an allostatic load with an inflammatory diathesis that has been implicated in stress-related psychopathology, including of depression and anxiety. Increased inflammation in the periphery and in the brain arising from chronic stress exposure can alter neurotransmitter metabolism and impact activation of brain regions to increase adverse behavioral health symptoms (e.g. anhedonia, anxiety, fatigue) and emotion dysregulation. While interventions targeting the immune system and its downstream effects on the brain for the treatment of depression and other psychiatric disorders has been of great interest as they have shown some efficacy in treating stress-related behavioral health disorders, future studies are necessary to better characterize the contexts under which anti-inflammatory agents should be used to treat stress-related psychopathology.

Is dynapenia associated with the onset and persistence of depressive and anxiety symptoms among older adults? Findings from the Irish longitudinal study on ageing

OBJECTIVES

The aim of the current study was to assess the associations between dynapenia and the onset and persistence of depression and anxiety among older adults.

METHODS

This prospective cohort study enrolled community-living older adults (N = 5271; 51.1% females) aged ≥ 50 years (mean age = 63.2, standard deviation = 9.0) from The Irish Longitudinal Study on Aging (TILDA), Ireland. At baseline, participants completed a handgrip assessment. Depression was defined by a score ≥ 16 in the Center of Epidemiology Studies Depression (CES-D) tool and anxiety was considered when participants scored ≥ 8 on the anxiety section of the Hospital Anxiety and Depression Scale (HADS). Outcomes were incident and persistent depression and anxiety at two years follow-up. Multivariable logistic regression models were built for each outcome.

RESULTS

After controlling for age, sex, education, marital status, employment status, smoking, body mass index, number of chronic conditions, physical activity, and cognitive function, low handgrip strength indicative of dyapenia (< 30 Kg for men and < 20 Kg for women) was associated with a greater likelihood for incident depressive (OR = 1.44; 95%CI: 1.08-1.92) as well as for persistent depressive (OR = 1.61; 95% CI: 1.01-2.58) and anxiety (OR = 1.61; 95% CI: 1.20-2.14) symptoms.

CONCLUSIONS

Dynapenia was associated with a higher odds of developing depressive symptoms as well as a greater likelihood to persistent depressive and anxiety symptoms among older adults. Our data suggest that interventions targeting muscle strength may prevent the onset of late-life depression and also may hold promise as novel therapeutic opportunities for depression and anxiety in later life.

Plasma metabolites were associated with spatial working memory in major depressive disorder

Major depressive disorder (MDD) is a common disease with both affective and cognitive disorders. Alterations in metabolic systems of MDD patients have been reported, but the underlying mechanisms still remains unclear. We sought to identify abnormal metabolites in MDD by metabolomics and to explore the association between differential metabolites and neurocognitive dysfunction.Plasma samples from 53 MDD patients and 83 sex-, gender-, BMI-matched healthy controls (HCs) were collected. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) system was then used to detect metabolites in those samples. Two different algorithms were applied to identify differential metabolites in 2 groups. Of the 136 participants, 35 MDD patients and 48 HCs had completed spatial working memory test. Spearman rank correlation coefficient was applied to explore the relationship between differential metabolites and working memory in these 2 groups.The top 5 metabolites which were found in sparse partial least squares-discriminant analysis (sPLS-DA) model and random forest (RF) model were the same, and significant difference was found in 3 metabolites between MDD and HCs, namely, gamma-glutamyl leucine, leucine-enkephalin, and valeric acid. In addition, MDD patients had higher scores in spatial working memory (SWM) between errors and total errors than HCs. Valeric acid was positively correlated with working memory in MDD group.Gamma-glutamyl leucine, leucine-enkephalin, and valeric acid were preliminarily proven to be decreased in MDD patients. In addition, MDD patients performed worse in working memory than HCs. Dysfunction in working memory of MDD individuals was associated with valeric acid.

Treatment-Resistant Depression Revisited: A Glimmer of Hope

Major Depressive Disorder (MDD) is a highly prevalent psychiatric disorder worldwide. It causes individual suffering, loss of productivity, increased health care costs and high suicide risk. Current pharmacologic interventions fail to produce at least partial response to approximately one third of these patients, and remission is obtained in approximately 30% of patients. This is known as Treatment-Resistant Depression (TRD). The burden of TRD exponentially increases the longer it persists, with a higher risk of impaired functional and social functioning, vast losses in quality of life and significant risk of somatic morbidity and suicidality. Different approaches have been suggested and utilized, but the results have not been encouraging. In this review article, we present new approaches to identify and correct potential causes of TRD, thereby reducing its prevalence and with it the overall burden of this disease entity. We will address potential contributory factors to TRD, most of which can be investigated in many laboratories as routine tests. We discuss endocrinological aberrations, notably, hypothalamic-pituitary-adrenal (HPA) axis dysregulation and thyroid and gonadal dysfunction. We address the role of Vitamin D in contributing to depression. Pharmacogenomic testing is being increasingly used to determine Single Nucleotide Polymorphisms in Cytochrome P450, Serotonin Transporter, COMT, folic acid conversion (MTHFR). As the role of immune system dysregulation is being recognized as potentially a major contributory factor to TRD, the measurement of C-reactive protein (CRP) and select immune biomarkers, where testing is available, can guide combination treatments with anti-inflammatory agents (e.g., selective COX-2 inhibitors) reversing treatment resistance. We focus on established and emerging test procedures, potential biomarkers and non-biologic assessments and interventions to apply personalized medicine to effectively manage treatment resistance in general and TRD specifically.

Structural brain correlates of serum and epigenetic markers of inflammation in major depressive disorder

Inflammatory processes are implicated in the aetiology of Major Depressive Disorder (MDD); however, the relationship between peripheral inflammation, brain structure and depression remains unclear, partly due to complexities around the use of acute/phasic inflammatory biomarkers. Here, we report the first large-scale study of both serological and methylomic signatures of CRP (considered to represent acute and chronic measures of inflammation respectively) and their associations with depression status/symptoms, and structural neuroimaging phenotypes (T1 and diffusion MRI) in a large community-based sample (Generation Scotland; NMDD cases = 271, Ncontrols = 609). Serum CRP was associated with overall MDD severity, and specifically with current somatic symptoms- general interest (β = 0.145, PFDR = 6 × 10-4) and energy levels (β = 0.101, PFDR = 0.027), along with reduced entorhinal cortex thickness (β = -0.095, PFDR = 0.037). DNAm CRP was significantly associated with reduced global grey matter/cortical volume and widespread reductions in integrity of 16/24 white matter tracts (with greatest regional effects in the external and internal capsules, βFA= -0.12 to -0.14). In general, the methylation-based measures showed stronger associations with imaging metrics than serum-based CRP measures (βaverage = -0.15 versus βaverage = 0.01 respectively). These findings provide evidence for central effects of peripheral inflammation from both serological and epigenetic markers of inflammation, including in brain regions previously implicated in depression. This suggests that these imaging measures may be involved in the relationship between peripheral inflammation and somatic/depressive symptoms. Notably, greater effects on brain morphology were seen for methylation-based rather than serum-based measures of inflammation, indicating the importance of such measures for future studies.

Dissecting the Association Between Inflammation, Metabolic Dysregulation, and Specific Depressive Symptoms: A Genetic Correlation and 2-Sample Mendelian Randomization Study

IMPORTANCE

Observational studies highlight associations of C-reactive protein (CRP), a general marker of inflammation, and interleukin 6 (IL-6), a cytokine-stimulating CRP production, with individual depressive symptoms. However, it is unclear whether inflammatory activity is associated with individual depressive symptoms and to what extent metabolic dysregulation underlies the reported associations.

OBJECTIVE

To explore the genetic overlap and associations between inflammatory activity, metabolic dysregulation, and individual depressive symptoms.

GWAS DATA SOURCES

Genome-wide association study (GWAS) summary data of European individuals, including the following: CRP levels (204 402 individuals); 9 individual depressive symptoms (3 of which did not differentiate between underlying diametrically opposite symptoms [eg, insomnia and hypersomnia]) as measured with the Patient Health Questionnaire 9 (up to 117 907 individuals); summary statistics for major depression, including and excluding UK Biobank participants, resulting in sample sizes of 500 199 and up to 230 214 individuals, respectively; insomnia (up to 386 533 individuals); body mass index (BMI) (up to 322 154 individuals); and height (up to 253 280 individuals).

DESIGN

In this genetic correlation and 2-sample mendelian randomization (MR) study, linkage disequilibrium score (LDSC) regression was applied to infer single-nucleotide variant-based heritability and genetic correlation estimates. Two-sample MR tested potential causal associations of genetic variants associated with CRP levels, IL-6 signaling, and BMI with depressive symptoms. The study dates were November 2019 to April 2020.

RESULTS

Based on large GWAS data sources, genetic correlation analyses revealed consistent false discovery rate (FDR)-controlled associations (genetic correlation range, 0.152-0.362; FDR P = .006 to P < .001) between CRP levels and depressive symptoms that were similar in size to genetic correlations of BMI with depressive symptoms. Two-sample MR analyses suggested that genetic upregulation of IL-6 signaling was associated with suicidality (estimate [SE], 0.035 [0.010]; FDR plus Bonferroni correction P = .01), a finding that remained stable across statistical models and sensitivity analyses using alternative instrument selection strategies. Mendelian randomization analyses did not consistently show associations of higher CRP levels or IL-6 signaling with other depressive symptoms, but higher BMI was associated with anhedonia, tiredness, changes in appetite, and feelings of inadequacy.

CONCLUSIONS AND RELEVANCE

This study reports coheritability between CRP levels and individual depressive symptoms, which may result from the potentially causal association of metabolic dysregulation with anhedonia, tiredness, changes in appetite, and feelings of inadequacy. The study also found that IL-6 signaling is associated with suicidality. These findings may have clinical implications, highlighting the potential of anti-inflammatory approaches, especially IL-6 blockade, as a putative strategy for suicide prevention.

A Modest Increase in 11C-PK11195-Positron Emission Tomography TSPO Binding in Depression Is Not Associated With Serum C-Reactive Protein or Body Mass Index

Background

Immune mechanisms have been implicated in the pathogenesis of depression. Translocator protein (TSPO)–targeted positron emission tomography (PET) has been used to assess neuroinflammation in major depressive disorder. We aimed to 1) test the hypothesis of significant case-control differences in TSPO binding in the anterior cingulate cortex, prefrontal cortex, and insula regions; and 2) explore the relationship between cerebral TSPO binding and peripheral blood C-reactive protein (CRP) concentration.

Methods

A total of 51 depressed subjects with Hamilton Depression Rating Scale score >13 (median 17; interquartile range, 16–22) and 25 healthy control subjects underwent dynamic brain ¹¹C-PK11195 PET and peripheral blood immune marker characterization. Depressed subjects were divided into high CRP (>3 mg/L; n = 20) and low CRP (<3 mg/L; n = 31).

Results

Across the three regions, TSPO binding was significantly increased in depressed versus control subjects (η²_p = .09; F_1,71 = 6.97, p = .01), which was not influenced by body mass index. The case-control difference was greatest in the anterior cingulate cortex (d = 0.49; t₇₄ = 2.00, p = .03) and not significant in the prefrontal cortex or insula (d = 0.27 and d = 0.36, respectively). Following CRP stratification, significantly higher TSPO binding was observed in low-CRP depression compared with controls (d = 0.53; t₅₄ = 1.96, p = .03). These effect sizes are comparable to prior major depressive disorder case-control TSPO PET data. No significant correlations were observed between TSPO and CRP measures.

Conclusions

Consistent with previous findings, there is a modest increase in TSPO binding in depressed patients compared with healthy control subjects. The lack of a significant correlation between brain TSPO binding and blood CRP concentration or body mass index poses questions about the interactions between central and peripheral immune responses in the pathogenesis of depression.