Differences in immunomodulatory properties between venlafaxine and paroxetine in patients with major depressive disorder

Association of sugary drinks, carbonated beverages, vegetable and fruit juices, sweetened and black coffee, and green tea with subsequent depression: A five-year cohort study

BACKGROUND & AIMS

Evidence on the impact of beverage consumption on depression is limited in the Asian population. Specifically, there is little information available on vegetable and fruit juices, while whole vegetables and fruits are reportedly protective against depression. Furthermore, evidence is scarce in differentiating the impacts of sweetened and black coffee. We aimed to examine the association of the consumption of total sugary drinks, carbonated beverages, vegetable and fruit juices, sweetened and black coffee, and green tea with subsequent depression in a general population sample.

METHODS

We studied individuals without a history of cancer, myocardial infarction, stroke, diabetes, or depression at baseline in 2011-2016, with a five-year follow-up. We used Poisson regression models and the g-formula, thereby calculating the risk difference (RD) for depression. Multiple sensitivity analyses were conducted. Missing data were handled using random forest imputation. We also examined effect heterogeneity based on sex, age, and body mass index by analyzing the relative excess risk due to interaction and the ratio of risk ratios.

RESULTS

In total, 94,873 individuals were evaluated, and 80,497 completed the five-year follow-up survey for depression. Of these, 18,172 showed depression. When comparing the high consumption group with the no consumption group, the fully adjusted RD (95% CI) was 3.6% (2.8% to 4.3%) for total sugary drinks, 3.5% (2.1% to 4.7%) for carbonated beverages, 2.3% (1.3% to 3.4%) for vegetable juice, 2.4% (1.1% to 3.6%) for 100% fruit juice, and 2.6% (1.9% to 3.5%) for sweetened coffee. In contrast, the fully adjusted RD (95% CI) was -1.7% (-2.6% to -0.7%) for black coffee. The fully adjusted RD for green tea did not reach statistical significance. The results were robust in multiple sensitivity analyses. We did not find substantial effect heterogeneity based on sex, age, and body mass index.

CONCLUSIONS

Total sugary drinks, carbonated beverages, vegetable and fruit juices, and sweetened coffee may increase the risk of depression, whereas black coffee may decrease it.

The efficacy of citalopram or escitalopram in patients with asthma and major depressive disorder

BACKGROUND

Major depressive disorder is common in people with asthma. Yet, few studies have evaluated depression treatment in those with asthma.

OBJECTIVE

To explore the relationship between antidepressant use, depressive symptoms, and asthma control, pooled data from 3 randomized trials of either citalopram or escitalopram were assessed.

METHODS

Linear fixed effects and binary logistic regression analyses were conducted with between-subject covariates including treatment group, (original) study, and demographics. The within-subject effect of visit, and a treatment group-visit (between-within) interaction effect, were also evaluated. Analyses were repeated in a high asthma exacerbation subgroup having at least 3 oral corticosteroid bursts in the previous 12 months. Outcomes included the Hamilton rating scale for depression (HAM-D17), the 7-item asthma control questionnaire (ACQ), and oral corticosteroid use (yes or no).

RESULTS

In the pooled sample (n = 255), the antidepressant treatment group exhibited lower HAM-D17 overall (P ≤ .001) and a lower likelihood for oral corticosteroid use (P ≤ .001) relative to the placebo group. In the high-exacerbation subgroup (n = 96), treatment group participants had lower overall asthma control questionnaire (P = .004) and HAM-D17 scores (P ≤ .001), and a lower likelihood of oral corticosteroid use (P = .003), relative to placebo participants. All treatment group interaction effects were not significant.

CONCLUSION

Citalopram or escitalopram exhibited efficacy in reducing depressive symptoms and the need for rescue oral corticosteroids in patients with asthma and major depressive disorder. Future work should determine whether selective serotonin reuptake inhibitors are effective at improving asthma outcomes in those with asthma who are not depressed.

TRIAL REGISTRATION

Clinicaltrials.gov Identifier: NCT00621946 and NCT01324700 (one study was conducted before ClinicalTrials.gov requirements).

Use of Serum Biomarkers to Aid Antidepressant Selection in Depressive Patients

Objective

: This study aimed to identify serum biomarkers prospectively associated with remission at 12 weeks in out-patients with depressive disorders receiving stepwise psychopharmacotherapy, according to the main antidepressant used during the treatment period.

Methods

: This study included 1,024 depressive outpatients initially treated using antidepressant monotherapy, followed by alternating pharmacological strategies during the acute phase (3-12 weeks; 3-week interval). Fourteen serum biomarkers, sociodemographics, and clinical characteristics were evaluated at baseline. Based on the use frequency and mechanism of action, four main antidepressant types were distinguished: escitalopram, other selective serotonin reuptake inhibitors (SSRIs), serotonin norepinephrine reuptake inhibitors (SNRIs), and mirtazapine. A Hamilton Depression Rating Scale score ≤ 7 was take to indicate remission.

Results

: Lower high-sensitivity C-reactive protein levels were correlated with remission at 12 weeks for all antidepressant types. Lower interleukin (IL)-6 levels and tumor necrosis factor-alpha levels were associated with remission using escitalopram and other SSRIs respectively. Lower IL-1β and leptin levels, predicted remission in association with SSRIs including escitalopram. For SNRIs, remission at 12 weeks was predicted by lower IL-4 and IL-10 levels. For mirtazapine, remission at 12 weeks was associated with lower leptin levels, and higher serotonin and folate levels.

Conclusion

: Baseline serum status, as estimated by nine serum markers, may help clinicians determine the most appropriate antidepressant to achieve remission in the acute phase of depression.

Cytokines in hepatitis C-infected patients with or without opioid maintenance therapy

OBJECTIVE

Both chronic hepatitis C virus (HCV) infection and opioids cause altered blood levels of cytokines. Previous studies have investigated levels of selected groups of cytokines in patients on opioid maintenance treatment. Little is known about the levels of multiple cytokines in patients with chronic HCV infection on opioid maintenance treatment. Our aim was to investigate the cytokine profile in patients with active HCV infection with and without opioid maintenance treatment.

METHODS

We conducted a cross-sectional study in an out-patients population included upon referral for antiviral hepatitis C infection treatment. The level of 27 cytokines was measured in serum using multiplex technology. Patients were interviewed using a modified version of the European addiction severity index. Data pertaining to weight, height, current medication, smoking habits, allergies, previous medical history and ongoing withdrawal symptoms were collected. Non-parametric testing was used to investigate differences in levels of cytokines between the two groups. A 3-model hierarchical regression analysis was used to analyse associations between cytokines and confounding variables.

RESULTS

Out of 120 included patients, 53 were on opioid maintenance treatment. Median duration of opioid treatment was 68.4 months. There were no demographical differences between the two groups other than age. IL-1β was lower and eotaxin-1 higher in the group on opioid maintenance treatment than in the non-opioid group. No other inter-group differences in the remaining cytokine levels were found.

CONCLUSION

In HCV infection patients, the impact of chronic opioid administration on peripheral circulating cytokine level is minimal.

Late chronic local inflammation, synaptic alterations, vascular remodeling and arteriovenous malformations in the brains of male rats exposed to repetitive low-level blast overpressures

In the course of military operations in modern war theaters, blast exposures are associated with the development of a variety of mental health disorders associated with a post-traumatic stress disorder-related features, including anxiety, impulsivity, insomnia, suicidality, depression, and cognitive decline. Several lines of evidence indicate that acute and chronic cerebral vascular alterations are involved in the development of these blast-induced neuropsychiatric changes. In the present study, we investigated late occurring neuropathological events associated with cerebrovascular alterations in a rat model of repetitive low-level blast-exposures (3 × 74.5 kPa). The observed events included hippocampal hypoperfusion associated with late-onset inflammation, vascular extracellular matrix degeneration, synaptic structural changes and neuronal loss. We also demonstrate that arteriovenous malformations in exposed animals are a direct consequence of blast-induced tissue tears. Overall, our results further identify the cerebral vasculature as a main target for blast-induced damage and support the urgent need to develop early therapeutic approaches for the prevention of blast-induced late-onset neurovascular degenerative processes.

Cardioprotective and renoprotective effects of venlafaxine on cisplatin-induced cardiotoxicity and nephrotoxicity in rats

AIM

The current work aims to demonstrate the potential defensive function of venlafaxine (VLF) in cardiotoxicity and nephrotoxicity caused by cisplatin (CP), that could be by modulating extracellular signal-regulated kinase (ERK)1/2 and nicotinamide adenine dinucleotide phosphate (NAPDH) oxidase NOX4 pathways.

MAIN METHODS

Five groups of rats were used, as follow: three control groups (control, carboxymethyl cellulose, and VLF), CP group got CP once (7 mg/kg, intraperitoneally, i.p.), and (CP+ VLF) group got CP once then after 1 h they got VLF {50 mg/kg daily, orally for 14 days}. At the end of the study; electrocardiogram (ECG) was recorded for anaesthized rats then blood samples and tissues were taken for biochemical and histopathological investigations. Caspase 3, a marker of cellular damage and apoptosis was detected by immunohistochemistry.

KEY FINDINGS

CP treatment significantly impaired cardiac functions as evidenced by changes in rats' ECG. Cardiac enzymes, renal markers and inflammatory markers were increased with decreased activities of the total antioxidant capacity, superoxide dismutase and glutathione peroxidase. Also, ERK1/2 and NOX4 were upregulated with histopathological and immunohistochemical alterations of heart and kidney. While, VLF markedly alleviated CP-induced functional cardiac abnormalities and improved ECG pattern. It reduced both cardiac and renal biomarkers, oxidative stress, proinflammatory cytokine with ERK1/2 and NOX4 downregulation, improved the histopathological and immunohistochemical changes induced by cisplatin in heart and kidney.

SIGNIFICANCE

VLF treatment impedes cardiotoxicity and nephrotoxicity caused by CP. This beneficial effect was mediated through reduction of oxidative stress, inflammation, and apoptosis by targeting the ERK1/2 and NOX4.

Inhibitory effects of fluoxetine on the secretion of inflammatory mediators and JAK/STAT3 and JNK/TLR4 gene expression

BACKGROUND

Selective serotonin reuptake inhibitors (SSRIs) are the most common class of medicines used for the treatment of major depression. Recent studies have reported an association between depression and inflammation and suggested the significant effects of SSRIs on inflammatory processes.

METHODS

The current study aimed to evaluate the effects of fluoxetine, an SSRI, on the level of inflammatory cytokines, including interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), in the rat serum and RAW264.7 mouse macrophage cell line, using ELISA sandwich assays. Also, the expression of inflammatory genes, including JAK/STAT3 and TLR4/JNK, was examined in macrophages, using real-time quantitative reverse transcription PCR to determine the potential mechanism of fluoxetine in inflammation. The rats received fluoxetine (10, 20, and 40 mg/kg) 30 min before lipopolysaccharide (LPS) treatment for 90 min. The cells received different doses of fluoxetine (5, 10, and 20 µg/mL) before stimulation with LPS for 24 or 48 h.

RESULTS

The serum concentrations of IL-1β, IL-6, and TNF-α were reduced in rats and cells treated with fluoxetine. Following fluoxetine administration, the expression of JAK/STAT3 and TLR4/JNK genes was significantly decreased in the RAW264.7 cells treated with LPS for 24 h. However, after 48 h of treatment with LPS, fluoxetine failed to diminish the elevated expression of JAK and JNK genes, while it significantly decreased the expression of STAT3 and TLR4 genes.

CONCLUSION

The findings revealed that fluoxetine has anti-inflammatory properties, mainly due to the reduction of inflammatory cytokines and inhibition of JAK/STAT3 and TLR4/JNK gene expression in macrophages.

White matter integrity and pro-inflammatory cytokines as predictors of antidepressant response in MDD

Major depressive disorder (MDD) is a multifactorial, serious and heterogeneous mental disorder that can lead to chronic recurrent symptoms, treatment resistance and suicidal behavior. MDD often involves immune dysregulation with high peripheral levels of inflammatory cytokines that might have an influence on the clinical course and treatment response. Moreover, patients with MDD show brain volume changes as well as white matter (WM) alterations that are already existing in the early stage of illness. Mounting evidence suggests that both neuroimaging markers, such as WM integrity and blood markers, such as inflammatory cytokines might serve as predictors of treatment response in MDD. However, the relationship between peripheral inflammation, WM structure and antidepressant response is not yet clearly understood. The aim of the present review is to elucidate the association between inflammation and WM integrity and its impact on the pathophysiology and progression of MDD as well as the role of possible novel biomarkers of treatment response to improve MDD prevention and treatment strategies.

Pre-treatment plasma cytokine levels as potential predictors of short-term remission of depression

OBJECTIVES

The response to antidepressants varies significantly among individuals and is difficult to predict before treatment. In this randomised control trial, we explored cytokines that correlate with the therapeutic effect of mirtazapine (MIR) and selective serotonin reuptake inhibitors (SSRIs) and whether they could be predictors of remission for each antidepressant.

METHODS

Plasma cytokines, such as tumour necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-2, IL-4, IL-6, IL-8, and granulocyte-macrophage colony-stimulating factor (GM-CSF) were assayed in 95 participants before medication and assayed by the enzyme-linked immunosorbent assay. The Hamilton Rating Scale for Depression assessed depressive symptoms over 4 weeks.

RESULTS

In the SSRI group, the baseline GM-CSF level was significantly higher in the remission group than in the non-remission group (p = .022). In the MIR group, the baseline level of TNF-α was significantly higher (p = .039) and IL-2 was lower (p = .032) in the remission group than in the non-remission group. In patients prescribed with MIR, the cut-off values of TNF-α (10.035 pg/mL) and IL-2 (1.170 pg/mL) calculated from the receiver operating characteristic curve suggested that the remission rate, which corresponds to a positive predictive value, could be increased from 31.3% to 60.0% and 50.0%, respectively. For those prescribed with SSRIs, the remission rate was 37.0% and using the cut-off value of GM-CSF (0.205 pg/mL), the remission rate could be almost doubled to 70%.

CONCLUSIONS

Our study shows that pre-treatment plasma concentrations of TNF-α, IL-2, and GM-CSF may suggest the predictability of remission by SSRIs or MIR.

Plasma levels of interleukin-8 and response to paroxetine in patients with major depressive disorder

OBJECTIVES

Immune dysregulation plays a key role in major depressive disorder (MDD). However, little is known about the complicated involvement of various interleukins in MDD. This study was performed to investigate the correlation between plasma interleukin-8 (IL-8) levels and treatment outcome of paroxetine (a selective serotonin reuptake inhibitor) in patients with MDD.

METHODS

A total of 115 hospitalized patients (36 males and 79 females), aged from 18 to 72 years, were enrolled. Plasma levels of IL-8 were measured before treatment initiation (baseline) and at 8 weeks after oral paroxetine treatment. Efficacy of paroxetine was evaluated by use of the Hamilton Depression Rating Scale (HAMD-17). Baseline IL-8 levels were compared between responders and non-responders to paroxetine treatment.

RESULTS

Plasma IL-8 levels decreased significantly after an 8-week antidepressant treatment in responders, in association with a dramatic decrease in HAMD-17 scores. In non-responders, plasma IL-8 levels did not change significantly at 8 weeks after antidepressant treatment. Baseline plasma IL-8 levels were found to be significantly lower in responders than in non-responders, showing a correlation between IL-8 and antidepressant response to paroxetine.

CONCLUSIONS

These results indicate that plasma IL-8 levels were related to treatment outcome of paroxetine, and therefore suggest that IL-8 could be a promising predicator of treatment response in individual patients with MDD.

C-reactive protein could predict the efficacy of SSRIs in clinical practice: A cohort study of large samples in the real world

BACKGROUND

C-reactive protein (CRP) has been shown to predict antidepressant treatment outcomes in several trials, but they were limited to small-sample and strictly-restricted conditions. This study plans to verify if CRP can predict antidepressant efficacy in large samples in the real world.

METHODS

918 depressed patients who had tested CRP were included, then were followed up through their outpatient visits or by telephone to obtain information about their medication therapy (SSRIs, SNRIs, MT, NaSSA) and assess efficacy using the Clinical Global Impressions-Improvement scale (CGII). Efficacy was classified as effective and ineffective and CRP was separated into the low CRP group (CRP <1 mg/L, n = 709) and the high CRP group (CRP ≥1 mg/L, n = 209).The efficacy was compared in different groups.

RESULTS

Using Kaplan-Meier survival analysis and Cox proportional regression model to analyze, it was discovered that SNRIs were more effective than SSRIs in treating patients with high CRP(HR = 1.652, p = 0.037,95 % CI:1.031-2.654), and SSRIs were more effective in treating patients with low CRP than those with high CRP (HR = 1.257, p = 0.047,95 % CI:1.003-1.574), while no difference in efficacy between the two groups was found in patients using SNRIs, MT, NaSSA.

LIMITATIONS

Small amounts of MT and NaSSA were included, and some factors that may affect CRP value have not been controlled.

CONCLUSION

CRP could predict the efficacy of SSRIs in the real world, depressed patients with high CRP may be more likely to respond poorly to SSRIs.

Negative air ion exposure ameliorates depression-like behaviors induced by chronic mild stress in mice

The presence of negative air ions (NAI) is suggested to be a beneficial factor in improving psychological status and used in treating depression as an alternative approach. However, more biological evidence from animal models is needed to ensure the effects of NAI on the mood regulation, through which can facilitate identification of possible underlying mechanisms. In this study, the chronic mild stress (CMS) protocol was used to induce depressive-like behaviors in mice, and the effects of NAI exposure on CMS-induced depression-like behaviors were examined. Thirty-day NAI exposure prevented the CMS-induced depression-like behaviors as shown by the restoration of sucrose preference and reduced immobility time in the tail suspension test. In addition, the elevation of serous corticosterone was present in CMS-treated mice but not existed in those with the NAI exposure. Furthermore, we observed altered ratios of some cytokines secreted by type 1 T helper (Th1) cells and Th2 cells in CMS-treated mice, but it could be restored after NAI exposure. In conclusion, NAI intervention is able to ameliorate CMS-induced depression-like behaviors in mice, and this effect is associated with the alteration of corticosterone and functional rebalance between Th1 and Th2 cells.

The Relationship between Stress, Inflammation, and Depression

A narrative review about the relationship between stress, inflammation, and depression is made as follows: Chronic stress leads to various stress-related diseases such as depression. Although most human diseases are related to stress exposure, the common pathways between stress and pathophysiological processes of different disorders are still debatable. Chronic inflammation is a crucial component of chronic diseases, including depression. Both experimental and clinical studies have demonstrated that an increase in the levels of pro-inflammatory cytokines and stress hormones, such as glucocorticoids, substantially contributes to the behavioral alterations associated with depression. Evidence suggests that inflammation plays a key role in the pathology of stress-related diseases; however, this link has not yet been completely explored. In this study, we aimed to determine the role of inflammation in stress-induced diseases and whether a common pathway for depression exists. Recent studies support pharmacological and non-pharmacological treatment approaches significantly associated with ameliorating depression-related inflammation. In addition, major depression can be associated with an activated immune system, whereas antidepressants can exert immunomodulatory effects. Moreover, non-pharmacological treatments for major depression (i.e., exercise) may be mediated by anti-inflammatory actions. This narrative review highlights the mechanisms underlying inflammation and provides new insights into the prevention and treatment of stress-related diseases, particularly depression.

Changes in the Serum Levels of Cytokines: IL-1β, IL-4, IL-8 and IL-10 in Depression with and without Posttraumatic Stress Disorder

Background: Both depressive disorders (DD) and post-traumatic stress disorders (PTSD) are caused by immune system dysfunction. Affected individuals show increased proinflammatory cytokine concentration levels. Also, it has been hypothesized that DD and PTSD might be associated with a generalized proinflammatory cytokine signature. The study assessed the concentration of IL-1β, IL-4, IL-8 and IL-10 in depression alone and with PTSD. Methods: The study involved 460 participants. Out of them, 420 subjects comprised a study group and 40 subjects comprised a control group. Each study group consisted of 60 patients with mild depression (MD), moderate depression (MOD), severe depression (SeD), MD and PTSD (MD + PTSD), MOD and PTSD (MOD + PTSD), SeD and PTSD (SeD + PTSD), and with PTSD alone. All patients had serum concentration of IL-1β, IL-4, IL-8 and IL-10 measured with ELISA. Results: DD and PTSD are reflected in IL-1β, IL-4, IL-8 and IL-10 concentration levels. It was reported that mean levels of IL-1β, IL-4, IL-8 increase as depression became more severe. A regular decrease in IL-10 concentration levels was noted with the onset and exacerbation of depressive symptoms. Conclusion: The findings might be useful when considering chronic inflammation as a potential target or biomarker in depression and PTSD treatment.

Possible Involvement of the IL-6/JAK2/STAT3 Pathway in the Hypothalamus in Depressive-Like Behavior of Rats Exposed to Chronic Mild Stress

INTRODUCTION

The interleukin-6/janus kinase 2/signal transducer and activator of transcription 3 (IL-6/JAK2/STAT3) pathway plays an important role in immune function, but little research has focused on this pathway in depression. We sought to examine the relationship between the IL-6/JAK2/STAT3 pathway and depressive-like behavior.

METHODS

Using a chronic mild stress (CMS) paradigm, a total of 36 adult male Sprague-Dawley rats were divided into four matched groups: (1) control + vehicle, (2) CMS + vehicle, (3) control + paroxetine, and (4) CMS + paroxetine. We investigated the effects of CMS on depressive-like behavior by using the forced swimming test (FST). Subsequently, the mRNA levels of members of the IL-6/JAK2/STAT3 pathway were assessed by qRT-PCR.

RESULTS

We found that rats exposed to CMS displayed a significant increase in immobility time and a decrease in climbing time in the FST. Moreover, mRNA levels of IL-6, JAK2, and STAT3 in the hypothalamus were increased following CMS. We also found that mRNA levels of IL-6, JAK2, and STAT3 were normalized by paroxetine administration, which coincided with normalization of the depressive-like behavior.

CONCLUSIONS

The IL-6/JAK2/STAT3 pathway may be activated in depression, and targeting this pathway may provide a novel effective therapeutic approach for the treatment of depression.

Venlafaxine as an Adjuvant Therapy for Inflammatory Bowel Disease Patients With Anxious and Depressive Symptoms: A Randomized Controlled Trial

BACKGROUND AND AIMS

The effect of antidepressant therapy on Inflammatory Bowel Disease (IBD) remains controversial. This trial aimed to assess whether adding venlafaxine to standard therapy for IBD improved the quality of life (QoL), mental health, and disease activity of patients with IBD with anxious and depressive symptoms.

METHODS

A prospective, randomized, double-blind, and placebo-controlled clinical trial was conducted. Participants diagnosed with IBD with symptoms of anxiety or depression were randomly assigned to receive either venlafaxine 150 mg daily or equivalent placebo and followed for 6 months. Inflammatory Bowel Disease Questionnaire (IBDQ), Mayo score, Crohn's disease activity index (CDAI), Hospital Anxiety and Depression Scale (HADS), and blood examination were completed before the enrollment, during, and after the follow-up. Mixed linear models and univariate analyses were used to compare groups.

RESULTS

Forty-five patients with IBD were included, of whom 25 were randomized to receive venlafaxine. The mean age was 40.00 (SD = 13.12) years old and 25 (55.6%) were male. Venlafaxine showed a significant improvement on QoL (p < 0.001) and disease course (p = 0.035), a greater reduction in HADS (anxiety: p < 0.001, depression: p < 0.001), Mayo scores (p < 0.001), and CDAI (p = 0.006) after 6 months. Venlafaxine had no effect on IL-10 expression, endoscopic scores, relapse rate, and use rate of biologics and corticosteroids, but did reduce serum level of erythrocyte estimation rate (ESR; p = 0.003), C-reactive protein (CRP; p < 0.001) and tumor necrosis factor-α (TNF-α; p = 0.009).

CONCLUSIONS

Venlafaxine has a significantly beneficial effect on QoL, IBD activity, and mental health in patients with IBD with comorbid anxious or depressive symptoms. (Chinese Clinical Trial Registry, ID: ChiCTR1900021496).

Inflammatory Cytokines Changed in Patients With Depression Before and After Repetitive Transcranial Magnetic Stimulation Treatment

Studies have found that repetitive transcranial magnetic stimulation rTMS can produce antidepressant effects by affecting inflammatory cytokines in patients with depression, which plays a key role in the therapeutic mechanism of antidepressants. This study aimed to explore the changes in inflammatory cytokine levels in patients with depression after 4 weeks of rTMS treatment to determine the possible antidepressant mechanism of rTMS. This prospective, double-blind, pseudo-stimulus-controlled study was conducted, and a total of 57 patients with depression and 30 healthy controls were recruited. Patients were randomly divided into the active rTMS (n = 29) and sham rTMS groups (n = 28). The Hamilton Depression Scale was used to evaluate depressive symptoms and their severity. The serum levels of seven inflammatory cytokines were measured using enzyme-linked immunosorbent assay. Inflammatory cytokines include high-sensitivity C-reactive protein (CRP-hc); tumor necrosis factor (TNF-α); interferon (IFN-γ); interleukin-2 (IL-2); interleukin-4 (IL-4); interleukin-6 (IL-6); and interleukin-8 (IL-8). At baseline, TNF-α (F = 36.699, p < 0.001), IFN-γ (F = 8.907, p < 0.001), IL-4 (F = 66.256, p < 0.001), and IL-2 (F = 9.162, p < 0.001) levels in the depression group were significantly different from those of healthy controls. In the self-control analysis of the active rTMS group, the levels of IL-2 and CRP-hc increased significantly after 2 and 12 weeks of treatment. In the sham-rTMS group, IFN-γ increased after 2 and 12 weeks of treatment. Our results revealed that the changes in inflammatory cytokines after rTMS treatment showed different patterns compared to the sham group, suggesting that the antidepressant effect of rTMS may be related to changes in inflammatory cytokines.

Comparisons of Serum Interleukin-8 Levels in Major Depressive Patients With Drug-Free Versus SSRIs Versus Healthy Controls

OBJECTIVE

The interleukin-8 (IL-8) has been reported to play an important role in depression, which might be modulated by the selective serotonin reuptake inhibitors (SSRIs). Thus, the aim of this study was to investigate serum IL-8 levels, depressive symptom, and their associations in drug-free MDD patients, MDD patients with SSRIs, and healthy controls (HCs).

METHODS

Fifty-seven drug-free MDD patients (male/female = 35/22, mean age: 39.24 years), 30 MDD patients with SSRIs (male/female = 11/19, mean age: 39.73 years), and 101 HCs (male/female = 52/49, mean age: 37.38 years) were recruited in this cross-sectional study. Serum IL-8 levels and depressive symptom were assessed using the Flow Cytometer and Hamilton Depression Scale (HAMD). The analysis of variance was used for the comparison between groups. The relationship between serum log₁₀ IL-8 levels and HAMD score was analyzed by Pearson correlation.

RESULTS

Serum log₁₀IL-8 levels were lower in all patients than HCs after controlling for covariates (F = 4.86, p = 0.03). There was significant difference in serum Log₁₀IL-8 levels among three groups after controlling for covariates (F = 14.63, p < 0.001). Serum Log₁₀IL-8 levels in drug-free patients were lower compared to HCs (F = 19.38, p < 0.001) or patients with SSRIs (F = 21.89, p < 0.001) after controlling for covariates. However, there was not difference in serum log₁₀IL-8 levels between patients with SSRIs and HCs after controlling for covariates. Moreover, serum Log₁₀IL-8 levels were negatively correlated with HAMD score in all patients (r = -0.37, p = 0.02). Also, serum Log₁₀IL-8 levels were negatively correlated with HAMD score in drug-free patients (r = -0.74, p = 0.01), but not in patients with SSRIs.

CONCLUSION

Our data supported that the decline in serum IL-8 levels was association with depression. Moreover, the SSRIs might modulate increased serum IL-8 levels of depression.

Gut Bacteria and Neuropsychiatric Disorders

Bacteria in the gut microbiome plays an intrinsic part in immune activation, intestinal permeability, enteric reflex, and entero-endocrine signaling. Apart from physiological and structural changes brought about by gut bacteria on entero-epithelial cells and mucus layers, a vast number of signals generated in the gastro-intestinal tract (GIT) reaches the brain via the vagus nerve. Research on the gut–brain axis (GBA) has mostly been devoted to digestive functions and satiety. Less papers have been published on the role gut microbiota play in mood, cognitive behavior and neuropsychiatric disorders such as autism, depression and schizophrenia. Whether we will be able to fully decipher the connection between gut microbiota and mental health is debatable, especially since the gut microbiome is diverse, everchanging and highly responsive to external stimuli. Nevertheless, the more we discover about the gut microbiome and the more we learn about the GBA, the greater the chance of developing novel therapeutics, probiotics and psychobiotics to treat gastro-intestinal disorders such as inflammatory bowel disease (IBD) and irritable bowel syndrome (IBS), but also improve cognitive functions and prevent or treat mental disorders. In this review we focus on the influence gut bacteria and their metabolites have on neuropsychiatric disorders.

Purinergic receptor ligands: the cytokine storm attenuators, potential therapeutic agents for the treatment of COVID-19

The coronavirus disease-19 (COVID-19), at first, was reported in Wuhan, China, and then rapidly became pandemic throughout the world. Cytokine storm syndrome (CSS) in COVID-19 patients is associated with high levels of cytokines and chemokines that cause multiple organ failure, systemic inflammation, and hemodynamic instabilities. Acute respiratory distress syndrome (ARDS), a common complication of COVID-19, is a consequence of cytokine storm. In this regard, several drugs have been being investigated to suppress this inflammatory condition. Purinergic signaling receptors comprising of P1 adenosine and P2 purinoceptors play a critical role in inflammation. Therefore, activation or inhibition of some subtypes of these kinds of receptors is most likely to be beneficial to attenuate cytokine storm. This article summarizes suggested therapeutic drugs with potential anti-inflammatory effects through purinergic receptors.

The Relationship Between the Gut Microbiome-Immune System-Brain Axis and Major Depressive Disorder

Major depressive disorder (MDD) is a prominent cause of disability worldwide. Current antidepressant drugs produce full remission in only about one-third of MDD patients and there are no biomarkers to guide physicians in selecting the best treatment for individuals. There is an urgency to learn more about the etiology of MDD and to identify new targets that will lead to improved therapy and hopefully aid in predicting and preventing MDD. There has been extensive interest in the roles of the immune system and the gut microbiome in MDD and in how these systems interact. Gut microbes can contribute to the nature of immune responses, and a chronic inflammatory state may lead to increased responsiveness to stress and to development of MDD. The gut microbiome-immune system-brain axis is bidirectional, is sensitive to stress and is important in development of stress-related disorders such as MDD. Communication between the gut and brain involves the enteric nervous system (ENS), the autonomic nervous system (ANS), neuroendocrine signaling systems and the immune system, and all of these can interact with the gut microbiota. Preclinical studies and preliminary clinical investigations have reported improved mood with administration of probiotics and prebiotics, but large, carefully controlled clinical trials are now necessary to evaluate their effectiveness in treating MDD. The roles that several gut microbe-derived molecules such as neurotransmitters, short chain fatty acids and tryptophan play in MDD are reviewed briefly. Challenges and potential future directions associated with studying this important axis as it relates to MDD are discussed.

Venlafaxine reduces the striatal il6/il10 ratio and increases hippocampal GR expression in female mice subjected to chronic social instability stress

Women are twice as likely as men to develop depression and antidepressant treatment is more frequent in females. Moreover, neuroinflammatory changes related to affective disorders differ in accordance with sex. Despite this evidence, female populations have been largely omitted from preclinical experiments studying antidepressants. The aim of this work is to analyze the potential restorative effect of venlafaxine on an animal model of depression. Female CD1 mice were subjected to chronic social instability (CSI) stress for 7 weeks, and were administered venlafaxine during the last 3 weeks of the stress period. Behavioral and physiological parameters were then analyzed. Stressed mice showed a decreased sucrose preference and increased whisking behavior, and had a lower body weight, higher plasma corticosterone levels and increased hypothalamic GR expression. They also had lower levels of 5-HT, 5-HIAA and NA and a higher KYN/TRYP ratio in the hippocampus. Moreover, CSI increased striatal IL-6 mRNA expression levels. Venlafaxine treatment reduced the striatal IL-6/IL-10 ratio and increased hippocampal GR expression, although it did not reverse stress-induced behavioral changes. In conclusion, seven weeks of exposure to CSI produced depressive-like alterations in female mice. The venlafaxine treatment regimen was found to have a modest anti-inflammatory effect in the striatum and increased hippocampal GR mRNA, although it failed to redress stress-induced behavioral disturbances.

Sudden cessation of fluoxetine before alcohol drinking reinstatement alters microglial morphology and TLR4/inflammatory neuroadaptation in the rat brain

Preclinical studies on the effects of abrupt cessation of selective serotonin reuptake inhibitors (SSRIs), a medication often prescribed in alcohol use disorder (AUD) patients with depression, results in alcohol consumption escalation after resuming drinking. However, a potential neuroinflammatory component on this escalation remains unexplored despite the immunomodulatory role of serotonin. Here, we utilized a rat model of 14-daily administration of the SSRI fluoxetine (10 mg/kg/day) along alcohol self-administration deprivation to study the effects of fluoxetine cessation on neuroinflammation after resuming alcohol drinking. Microglial morphology and inflammatory gene expression were analyzed in prelimbic cortex, striatum, basolateral amygdala and dorsal hippocampus. Results indicated that alcohol drinking reinstatement increased microglial IBA1 immunoreactivity and altered morphometric features of activated microglia (fractal dimension, lacunarity, density, roughness, and cell area, perimeter and circularity). Despite alcohol reinstatement, fluoxetine cessation modified microglial morphology in a brain region-specific manner, resulting in hyper-ramified (spatial complexity of branching), reactive (lower heterogeneity and circularity)-like microglia. We also found that microglial cell area correlated with changes in mRNA expression of chemokines (Cx3cl1/fractalkine, Cxcl12/SDF1α, Ccl2/MCP1), cytokines (IL1β, IL6, IL10) and the innate immune toll-like receptor 4 (TLR4) in dorsal hippocampus. Specifically, TLR4 correlated with microglial spatial complexity assessed by fractal dimension in striatum, suggesting a role in process branching. These findings suggest that alcohol drinking reinstatement after fluoxetine treatment cessation disturbs microglial morphology and reactive phenotype associated with a TLR4/inflammatory response to alcohol in a brain region-specific manner, facts that might contribute to alcohol-induced damage through the promotion of escalation of alcohol drinking behavior.

Effects of Venlafaxine, Risperidone and Febuxostat on Cuprizone-Induced Demyelination, Behavioral Deficits and Oxidative Stress

Multiple sclerosis (MS) is a demyelinating, autoimmune disease that affects a large number of young adults. Novel therapies for MS are needed considering the efficiency and safety limitations of current treatments. In our study, we investigated the effects of venlafaxine (antidepressant, serotonin-norepinephrine reuptake inhibitor), risperidone (atypical antipsychotic) and febuxostat (gout medication, xanthine oxidase inhibitor) in the cuprizone mouse model of acute demyelination, hypothesizing an antagonistic effect on TRPA1 calcium channels. Cuprizone and drugs were administered to C57BL6/J mice for five weeks and locomotor activity, motor performance and cold sensitivity were assessed. Mice brains were harvested for histological staining and assessment of oxidative stress markers. Febuxostat and metabolites of venlafaxine (desvenlafaxine) and risperidone (paliperidone) were tested for TRPA1 antagonistic activity. Following treatment, venlafaxine and risperidone significantly improved motor performance and sensitivity to a cold stimulus. All administered drugs ameliorated the cuprizone-induced deficit of superoxide dismutase activity. Desvenlafaxine and paliperidone showed no activity on TRPA1, while febuxostat exhibited agonistic activity at high concentrations. Our findings indicated that all three drugs offered some protection against the effects of cuprizone-induced demyelination. The agonistic activity of febuxostat can be of potential use for discovering novel TRPA1 ligands.

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.

Understanding Why Post-Stroke Depression May Be the Norm Rather Than the Exception: The Anatomical and Neuroinflammatory Correlates of Post-Stroke Depression

Ischemic Stroke precedes depression. Post-stroke depression (PSD) is a major driver for poor recovery, negative quality of life, poor rehabilitation outcomes and poor functional ability. In this systematic review, we analysed the inflammatory basis of post-stroke depression, which involves bioenergetic failure, deranged iron homeostasis (calcium influx, Na influx, potassium efflux etc), excitotoxicity, acidotoxicity, disruption of the blood brain barrier, cytokine-mediated cytotoxicity, reactive oxygen mediated toxicity, activation of cyclooxygenase pathway and generation of toxic products. This process subsequently results in cell death, maladapted, persistent neuro-inflammation and deranged neuronal networks in mood-related brain regions. Furthermore, an in-depth review likewise reveals that anatomic structures related to post-stroke depression may be localized to complex circuitries involving the cortical and subcortical regions.

Analysis of cytokine levels, T regulatory cells and serotonin content in patients with depression

Alterations in peripheral serotonin concentrations and an imbalanced immune system have been reported in patients with depression. Cytokines and T regulatory (Treg) cells may play an important role in the development of depression. This study investigates the levels of cytokines and Treg cells, as well as the concentration of serotonin (5-HT) in the blood of 89 patients suffering from depression and 89 healthy participants between two acquisitions. We investigated the state of health before (T1) and after (T2) psychological and pharmacological therapy. Both cytokine (IL-6, IL-10, TNF-α, and INF-γ) and 5-HT levels in the blood were measured by enzyme-linked immunosorbent assays. The levels of CD4⁺ CD25⁺ Treg cells were determined by flow cytometric analysis. Patients with depression showed significantly higher serum levels of IL-6 and INF-γ, no altered serum levels of IL-10 and TNF-α, and decreased platelet and serum 5-HT levels compared with healthy participants at the first acquisition. In addition, the symptoms of depression and anxiety, the TNF-α level, and the amount of CD4⁺ CD25⁺ cells in the blood were decreased from the first to the second acquisition. Further, a correlation between IL-6 and platelet 5-HT has been observed in patients. An imbalance of the immune system in patients with depression and an association of the serotonergic system and cytokines were observed. These results indicate that the development of depression might be related to several interacting proteins, including cytokines and 5-HT, and the treatment affects imbalances of these factors.

Postviral Depression

A previously healthy 68-year-old man rapidly developed a severe melancholic depression following influenza infection. There is an evolving understanding of the complex and possibly bidirectional relationship between depression and inflammation. We review the literature concerning this relationship in the context of viral infection and discuss possible implications for treatment.

Role of interleukin 8 in depression and other psychiatric disorders

Low grade neuroinflammation has been suggested as one of the underlying mechanisms of many psychiatric diseases as well as cognitive disorders. Interleukin 8 (IL-8), a proinflammatory cytokine produced by many cell types including macrophage and microglia, mainly functions as a neutrophil chemoattractant in the bloodstream. IL-8 is also found in the brain, where it is released from microglia in response to proinflammatory stimuli. In this review, we highlight studies focusing on the role of IL-8 in psychiatric diseases such as major depression, bipolar disorder, schizophrenia, sleep disorder, autism spectrum disorder, anxiety disorders and dementia. Increased peripheral IL-8 levels have been reported in these diseases, particularly in schizophrenic disorder, bipolar disorder, obstructive sleep apnea and autism spectrum disorder. The literature on IL-8 and major depression is inconsistent. IL-8 has been found to be a factor associated with schizophrenic prognosis and therapeutic response, and may affect a wide range of symptomatology. Considering that the exact role of immune alterations is still under research, the success of immune-based therapies in psychiatric diseases is limited for the time being.

Differential and paradoxical roles of new-generation antidepressants in primary astrocytic inflammation

Background

Selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) are commonly used new-generation drugs for depression. Depressive symptoms are thought to be closely related to neuroinflammation. In this study, we used up-to-date protocols of culture and stimulation and aimed to understand how astrocytes respond to the antidepressants.

Methods

Primary astrocytes were isolated and cultured using neurobasal-based serum-free medium. The cells were treated with a cytokine mixture comprising complement component 1q, tumor necrosis factor α, and interleukin 1α with or without pretreatments of antidepressants. Cell viability, phenotypes, inflammatory responses, and the underlying mechanisms were analyzed.

Results

All the SSRIs, including paroxetine, fluoxetine, sertraline, citalopram, and fluvoxamine, show a visible cytotoxicity within the range of applied doses, and a paradoxical effect on astrocytic inflammatory responses as manifested by the promotion of inducible nitric oxide synthase (iNOS) and/or nitric oxide (NO) and the inhibition of interleukin 6 (IL-6) and/or interleukin 1β (IL-1β). The SNRI venlafaxine was the least toxic to astrocytes and inhibited the production of IL-6 and IL-1β but with no impact on iNOS and NO. All the drugs had no regulation on the polarization of astrocytic A1 and A2 types. Mechanisms associated with the antidepressants in astrocytic inflammation route via inhibition of JNK1 activation and STAT3 basal activity.

Conclusions

The study demonstrated that the antidepressants possess differential cytotoxicity to astrocytes and function differently, also paradoxically for the SSRIs, to astrocytic inflammation. Our results provide novel pieces into understanding the differential efficacy and tolerability of the antidepressants in treating patients in the context of astrocytes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-021-02097-z.

Bupropion monotherapy alters neurotrophic and inflammatory markers in patients of major depressive disorder

BACKGROUND

Emerging hypotheses in the pathophysiology of major depressive disorder (MDD) indicate the role of neurotrophic factors and inflammation. This study assessed the association between therapeutic response of bupropion and serum brain-derived neurotrophic factor (BDNF) and tumour necrosis factor-α (TNF-α) levels in patients with MDD.

METHODS

Thirty patients (aged 18 to 60 years) with MDD diagnosed by DSM-5 criteria, with Hamilton Depression Rating scale (HAM-D) score ≥ 20 were included in the study. Patients were given bupropion sustained release (SR) in the doses of 150 mg once daily. All patients were followed up for 12 weeks.

RESULTS

HAM-D score at the start of the treatment was 25.57 ± 1.85 which significantly reduced to 10.8 ± 4.24 at 12 weeks of treatment. The serum BDNF level increased significantly (p < 0.05) from 2.42 ± 0.19 ng/ml to 2.97 ± 0.10 ng/ml and the levels of serum TNF-α reduced significantly (p < 0.05) from 4.45 ± 0.95 pg/ml to 2.11 ± 0.84 pg/ml at 12 weeks of treatment, in responders to treatment.

CONCLUSION

The results of our study suggest that bupropion SR monotherapy is effective and well tolerated in MDD patients with moderate to severe depression, and its therapeutic efficacy is accompanied by an increase in serum BDNF levels and a decrease in serum TNF-α levels.

The anti-inflammatory role of SSRI and SNRI in the treatment of depression: a review of human and rodent research studies

RATIONALE

Depression has the topmost prevalence of all psychiatric diseases. It is characterized by a high recurrence rate, disability, and numerous and mostly unclear pathogenic mechanisms. Besides the monoamine or the neurotrophic hypothesis of depression, the inflammatory mechanism has begun to be supported by more and more evidence. At the same time, the current knowledge about the standard treatment of choice, the selective serotonin reuptake inhibitors (SSRIs) and serotonin and noradrenaline reuptake inhibitors (SNRIs), is expanding rapidly, adding more features to the initial ones.

OBJECTIVES

This review summarizes the in vivo anti-inflammatory effects of SSRIs and SNRIs in the treatment of depression and outlines the particular mechanisms of these effects for each drug separately. In addition, we provide an overview of the inflammation-related theory of depression and the underlying mechanisms.

RESULTS

SSRIs and SNRIs decrease the neuroinflammation through multiple mechanisms including the reduction of blood or tissue cytokines or regulating complex inflammatory pathways: nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), inflammasomes, Toll-like receptor 4 (TLR4), peroxisome proliferator-activated receptor gamma (PPARγ). Also, SSRIs and SNRIs show these effects in association with an antidepressant action.

CONCLUSIONS

SSRIs and SNRIs have an anti-neuroinflammatory role which might contribute the antidepressant effect.

No association between CYP2C19 genetic polymorphism with treatment remission to antidepressant venlafaxine in Han Chinese population

OBJECTIVE

Major depressive disorder (MDD) is a global mental health problem. As a serotonin-noradrenaline reuptake inhibitor (SNRI), the antidepressant venlafaxine is used to alleviate MDD clinically. Recent research has shown that Cytochrome P450 (CYP) enzymes affect venlafaxine efficacy by mediating its metabolism. The present study investigates genetic polymorphisms of cytochrome P450 family 2 subfamily C member 19 (CYP2C19) are associated with remission after venlafaxine treatment for MDD.

METHODS

A total of 175 Han Chinese patients with depression were recruited to accept a 6-week treatment with venlafaxine. Three single-nucleotide polymorphisms of CYP2C19 were selected from dbSNP and previous literature to compare the allele and genotype frequencies between patients in remission and nonremission. Seventeen items Hamilton Depression Scale (17-HAMD) was used to access the outcomes of patients' depressive symptoms through the study. Our results denied the role of CYP2C19 polymorphisms for remission after venlafaxine treatment in MDD patients.

RESULT & CONCLUSION

CYP2C19 genetic polymorphism may not have association with SNRI venlafaxine treatment remission in the Han Chinese population.

Inflammation-Associated Synaptic Alterations as Shared Threads in Depression and Multiple Sclerosis

In the past years, several theories have been advanced to explain the pathogenesis of Major Depressive Disorder (MDD), a neuropsychiatric disease that causes disability in general population. Several theories have been proposed to define the MDD pathophysiology such as the classic "monoamine-theory" or the "glutamate hypothesis." All these theories have been recently integrated by evidence highlighting inflammation as a pivotal player in developing depressive symptoms. Proinflammatory cytokines have been indeed claimed to contribute to stress-induced mood disturbances and to major depression, indicating a widespread role of classical mediators of inflammation in emotional control. Moreover, during systemic inflammatory diseases, peripherally released cytokines circulate in the blood, reach the brain and cause anxiety, anhedonia, social withdrawal, fatigue, and sleep disturbances. Accordingly, chronic inflammatory disorders, such as the inflammatory autoimmune disease multiple sclerosis (MS), have been associated to higher risk of MDD, in comparison with overall population. Importantly, in both MS patients and in its experimental mouse model, Experimental Autoimmune Encephalomyelitis (EAE), the notion that depressive symptoms are reactive epiphenomenon to the MS pathology has been recently challenged by the evidence of their early manifestation, even before the onset of the disease. Furthermore, in association to such mood disturbance, inflammatory-dependent synaptic dysfunctions in several areas of MS/EAE brain have been observed independently of brain lesions and demyelination. This evidence suggests that a fine interplay between the immune and nervous systems can have a huge impact on several neurological functions, including depressive symptoms, in different pathological conditions. The aim of the present review is to shed light on common traits between MDD and MS, by looking at inflammatory-dependent synaptic alterations associated with depression in both diseases.

Differences in cytokines between patients with generalised anxiety disorder and panic disorder

OBJECTIVE

The purpose of this study was to evaluate the differences among panic disorder (PD), generalised anxiety disorder (GAD) and controls in inflammatory cytokines. We also analysed the correlation between inflammatory cytokines and response to escitalopram in PD and GAD patients.

METHODS

Eighty-six patients with PD, 86 patients with GAD and 86 healthy controls were recruited for this study. All participants were, respectively, assessed for severity of anxiety and panic symptoms using the Hamilton Anxiety Rating Scale (HAMA) and the Panic Disorder Severity Scale (PDSS); all patients in the study were also assessed after 4 weeks of treatment. The serum levels of cytokines were measured using a flow fluorescence microsphere assay.

RESULTS

Both PD and GAD patients had higher serum levels of interleukin 6 (IL-6) than controls, and patients with PD showed significantly higher IL-6 than GAD patients. Significant positive correlations were found between the IFN-γ levels and the severity of anxiety in GAD patients. Higher level of IL-6 was associated with better response to escitalopram treatment in PD patients. However, the baseline levels of cytokines were not associated with treatment responses in GAD patients.

CONCLUSION

The present findings suggest that patients with PD may have higher levels of IL-6 than GAD, and higher baseline levels of IL-6 may be a better response to escitalopram in the treatment of PD.

Peripheral cytokine levels and response to antidepressant treatment in depression: a systematic review and meta-analysis

Predicting antidepressant treatment response has been a clinical challenge for major depressive disorder (MDD). The inflammation hypothesis of depression suggests that cytokines play a key role in the pathophysiology of MDD and alterations in peripheral cytokine levels are associated with antidepressant treatment outcome. Present meta-analysis aimed to examine the association between baseline peripheral cytokine levels and the response to antidepressant treatment and to evaluate whether changes of cytokine levels were associated with the response to antidepressant treatment in patients with MDD. Human-based studies published in any language in peer-reviewed journals were systematically searched from the PubMed, Embase and Web of Science databases, from inception up to October 2018. The search terms included cytokine, depressive disorder and antidepressant and their synonyms. Case-control or case-case studies reporting on levels of IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, CRP, TNF-α, IFN-γ, GM-CSF, MIP-1α, and Eotaxin-1 in patients with MDD based on validated depression scales both before and after antidepressant treatment were included. Of 7408 identified records, 44 studies met inclusion. Standardized mean differences in each cytokine were evaluated, and random-effects meta-analyses were performed. MDD patients who responded to antidepressant treatment had lower baseline IL-8 levels than the nonresponders (Hedge's g = -0.28; 95%CI, -0.43 to -0.13; P = 0.0003; FDR = 0.004). Antidepressant treatment significantly decreased levels of TNF-α (Hedge's g = 0.60; 95%CI, 0.26-0.94; P = 0.0006; FDR = 0.004) only in responders, and responders showed significantly more decreased TNF-α levels compared with nonresponders (P = 0.046). These findings suggested that alterations in peripheral cytokine levels were associated with antidepressant treatment outcomes in MDD. Further investigations are warranted to elucidate sources of heterogeneity and examine the potentiality of using inflammatory cytokines as novel predictive markers for the pharmacological treatment of MDD.

Tumor Necrosis Factor-α Variations in Patients With Major Depressive Disorder Before and After Antidepressant Treatment

Tumor necrosis factor-α (TNF-α) had been identified as a key pro-inflammatory cytokine in the pathophysiology of major depressive disorder (MDD) and the mechanism of antidepressant treatment. The primary aim of the present study was to examine the serum TNF-α levels in Chinese inpatients with MDD during the acute phase and to explore the changes in TNF-α levels after effective clinical treatment. Fifty-seven consecutive inpatients with MDD and 30 healthy controls were recruited. The serum TNF-α levels were detected using ELISA. Symptoms of depression were evaluated using the 24-item Hamilton Rating Scale for Depression (HAM-D-24). TNF-α levels and HAM-D-24 scores were assessed at baseline and after 2 and 12 weeks of follow-up. The serum TNF-α levels were higher in the MDD group than in the control group. After 2 and 12 weeks of antidepressant treatment, there were significant improvements in the patients' symptoms and significant decreases in the TNF-α levels. The baseline TNF-α levels significantly correlated with the decreased HAM-D-24 scores, particularly for the depressive symptoms of anxiety/somatization and weight loss. The present findings indicate that depression is accompanied by activation of TNF-α, which also has a predictive value for the antidepressant treatment response in patients with MDD.

Major depressive disorder is associated with changes in a cluster of serum and urine biomarkers

Major Depressive Disorder (MDD) is a heterogeneous disorder with a considerable symptomatic overlap with other psychiatric and somatic disorders. This study aims at providing evidence for association of a set of serum and urine biomarkers with MDD. We analyzed urine and serum samples of 40 MDD patients and 47 age- and sex-matched controls using 40 potential MDD biomarkers (21 serum biomarkers and 19 urine biomarkers). All participants were of Caucasian origin. We developed an algorithm to combine the heterogeneity at biomarker level. This method enabled the identification of correlating biomarkers based on differences in variation and distribution between groups, combined the outcome of the selected biomarkers, and calculated depression probability scores (the "bio depression score"). Phenotype permutation analysis showed a significant discrimination between MDD and euthymic (control) subjects for biomarkers in urine (P < .001), in serum (P = .02) and in the combined serum plus urine result (P < .001). Based on this algorithm, a combination of 8 urine biomarkers and 9 serum biomarkers were identified to correlate with MDD, enabling an area under the curve (AUC) of 0.955 in a Receiver Operating Characteristic (ROC) analysis. Selection of either urine biomarkers or serum biomarkers resulted in AUC values of 0.907 and 0.853, respectively. Internal cross-validation (5-fold) confirmed the association of this set of biomarkers with MDD.

Biomarkers for response in major depression: comparing paroxetine and venlafaxine from two randomised placebo-controlled clinical studies

The identification of biomarkers of response might speed drug development and set the premises to assist clinical practice in psychiatry. In this work, we evaluated a panel of peripheral biomarkers (including IL-6, IL-10, TNF-α, TNFRII, BDNF, CRP, MMP9 and PAI1) in depressed patients receiving paroxetine, venlafaxine, or placebo. Samples were obtained from two randomised placebo-controlled studies evaluating the efficacy and tolerability of a novel drug candidate, using either paroxetine or venlafaxine as active comparators. In both studies, the biomarker candidates were analysed in plasma collected at randomization and after 10 weeks of treatment with either placebo or active comparator (for a total of 106 and 108 subjects in the paroxetine and venlafaxine study, respectively). Data were obtained by multiplexing sandwich-ELISA system. Data were subjected to statistical analysis to assess their correlation with baseline severity and with response outcome. Increases in biomarker levels were correlated with reduction in depression severity for TNF-α, IL-6 IL-10 and CRP. Response to paroxetine treatment correlated with baseline IL-10, IL-6 and TNF-α levels, with the strongest signal being observed in males. In the venlafaxine study, a correlation was observed only between CRP level at randomisation and response, suggesting differences between the two active treatments and the two studies. Our investigations suggest that a combination of pro- and anti-inflammatory cytokines may predict response outcome in patients treated with paroxetine. The potential for IL-10, IL-6 and TNF-α as response biomarkers for a wider range of antidepressants warrants further investigations in clinical trials with other monoamine reuptake inhibitors.

The Role of Inflammation in Depression and Fatigue

Depression and fatigue are conditions responsible for heavy global societal burden, especially in patients already suffering from chronic diseases. These symptoms have been identified by those affected as some of the most disabling symptoms which affect the quality of life and productivity of the individual. While many factors play a role in the development of depression and fatigue, both have been associated with increased inflammatory activation of the immune system affecting both the periphery and the central nervous system (CNS). This is further supported by the well-described association between diseases that involve immune activation and these symptoms in autoimmune disorders, such as multiple sclerosis and immune system activation in response to infections, like sepsis. Treatments for depression also support this immunopsychiatric link. Antidepressants have been shown to decrease inflammation, while higher levels of baseline inflammation predict lower treatment efficacy for most treatments. Those patients with higher initial immune activation may on the other hand be more responsive to treatments targeting immune pathways, which have been found to be effective in treating depression and fatigue in some cases. These results show strong support for the hypothesis that depression and fatigue are associated with an increased activation of the immune system which may serve as a valid target for treatment. Further studies should focus on the pathways involved in these symptoms and the development of treatments that target those pathways will help us to better understand these conditions and devise more targeted treatments.

Effects of SSRIs on peripheral inflammatory markers in patients with major depressive disorder: A systematic review and meta-analysis

INTRODUCTION

Peripheral levels of inflammatory markers are elevated in major depressive disorder (MDD). Selective serotonin reuptake inhibitors (SSRIs) affect levels of inflammatory markers in patients with MDD, but studies have reported inconsistent findings. This systematic review and meta-analysis aims to investigate the effects of SSRI treatment on peripheral levels of a range of inflammatory markers in MDD patients.

METHODS

Systematic literature search (Pubmed, Web of Science, Embase, Cochrane) for studies published before November 2018. Studies were included if they used SSRI monotherapy and peripheral levels of interleukin (IL)-1β, IL-2, IL-4, IL-6, IL-10, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ were measured before and after treatment in patients with MDD. Meta-analysis was conducted using Comprehensive Meta-analysis (version 2). Effect sizes were calculated using bias-corrected standardized mean difference (Hedges' g) between pre- and post-treatment. Sub-group analyses, meta-regression and publication bias estimates were undertaken; sensitivity analyses were performed using different estimated pre- and post-treatment correlations and after removing poor quality studies.

RESULTS

Twenty two eligible studies including 827 MDD patients were included in the meta-analysis: fifteen studies for IL-6; eleven for TNF-α; eight for IL-10; seven for IL-1β; six for IL-4; five for IL-2; and four for IFN-γ. The pooled effect estimate indicates SSRI treatment decreased levels of pro-inflammatory markers IL-6 (Hedges' g, -0.418; 95%CI, -0.663 to -0.174; I² = 89.412), TNF-α (Hedges' g, -0.554; 95%CI, -0.990 to -0.118; I² = 95.438) and IL-1β (Hedges' g = -0.574; 95%CI, -1.014 to -0.135; I² = 91.622), and anti-inflammatory marker IL-10 (Hedges' g = -0.615; 95%CI, -0.989 to -0.242; I² = 90.406). There were no significant treatment effects on levels of IL-2, IL-4, or IFN-γ. There was a high level of heterogeneity between studies. Sensitivity analyses indicated the robustness of the primary analyses.

CONCLUSIONS

The current review and meta-analysis indicates moderate immunomodulating effects of SSRI treatment for MDD, which suggests SSRIs may owe some of their therapeutic effect to their anti-inflammatory properties. High heterogeneity across studies may limit interpretation of the findings and larger randomized clinical trials are warranted.

Venlafaxine Improves the Cognitive Impairment and Depression-Like Behaviors in a Cuprizone Mouse Model by Alleviating Demyelination and Neuroinflammation in the Brain

Growing evidence has implicated that myelin deficits and neuroinflammation are the coexisted pathological features that contribute to the mood swing and cognitive decline in major depressive disorder (MDD) and multiple sclerosis (MS). Therefore, attenuation of neuroinflammation and reduction of demyelination became newly emerging treatment strategies for the mood and cognitive symptoms. Antidepressant venlafaxine has been used in depression and anxiety through its multiple neuroprotective effects. However, it is unclear whether venlafaxine can improve myelin integrity and alter inflammation status in the brain. By using a well-established cuprizone-induced acute mouse model of demyelination, we investigated the protective effects of venlafaxine on these facets. The cuprizone-fed animals exhibited cognitive impairment and mood disturbances together with myelin loss and prominent neuroinflammation in the brain. Our present study showed that a high dose of venlafaxine alleviated the loss of myelin and oligodendrocytes (OLs), mitigated depression-like behaviors, and improved cognitive function in cuprizone-fed animals. Data from the present study also showed that venlafaxine reduced microglia-mediated inflammation in the brains of cuprizone-fed animals. These findings suggest that venlafaxine may exert its therapeutic effects via facilitating myelin integrity and controlling neuroinflammation, which may provide extra benefits to MS patients with depression and anxiety beyond the symptom management.

Changes In Plasma NPY, IL-1β And Hypocretin In People Who Died By Suicide

PURPOSE

There is growing evidence showing that inflammatory cytokines and neuropeptides may be involved in the pathophysiology of suicidal behavior. However, studies have yielded contradictory data, and no biological markers that help predict suicide have been identified. This study aimed to identify biological patterns, such as NPY, IL-1β and hypocretin plasma levels, in people who died by suicide.

PATIENTS AND METHODS

Twenty-two people who died by suicide compared with 22 controls matched for age and sex were studied. In suicide and control subjects, we estimated the levels of NPY, IL-1β and hypocretin in plasma using enzyme-linked immunosorbent assay. The data are presented as the median (25th-75th percentile).

RESULTS

We found (1) a significant elevation in plasma NPY levels in suicide subjects versus control subjects (suicide: 11.38 (9.380-16.55); controls: 8.95 (7.590-10.93); P=0.013), and plasma NPY concentrations were approximately 62% higher in suicide subjects than those in control subjects; (2) a significant decrease in plasma IL-1β concentrations between suicide and control subjects (suicide: 121.1 (82.97-143.0); controls: 425.9 (233.1-835.3); P<0.001) as well as a decrease in IL-1β concentrations by almost 80%; and (3) no significant difference in plasma hypocretin levels between suicide and control subjects (suicide: 16.62 (13.62-25.77); controls: 21.63 (14.97-29.72); P=0.356).

CONCLUSION

Our results suggest that plasma NPY and IL-1β were related with suicide behavior rather than to suicide causes or suicide method. Specific combinations of plasma biomarkers may discriminate between types of suicidal behaviors and indicate increased risk for future suicide attempts.

Brain Kynurenine and BH4 Pathways: Relevance to the Pathophysiology and Treatment of Inflammation-Driven Depressive Symptoms

The prevalence of depressive disorders is growing worldwide, notably due to stagnation in the development of drugs with greater antidepressant efficacy, the continuous large proportion of patients who do not respond to conventional antidepressants, and the increasing rate of chronic medical conditions associated with an increased vulnerability to depressive comorbidities. Accordingly, better knowledge on the pathophysiology of depression and mechanisms underlying depressive comorbidities in chronic medical conditions appears urgently needed, in order to help in the development of targeted therapeutic strategies. In this review, we present evidence pointing to inflammatory processes as key players in the pathophysiology and treatment of depressive symptoms. In particular, we report preclinical and clinical findings showing that inflammation-driven alterations in specific metabolic pathways, namely kynurenine and tetrahydrobiopterin (BH4) pathways, leads to substantial alterations in the metabolism of serotonin, glutamate and dopamine that are likely to contribute to the development of key depressive symptom dimensions. Accordingly, anti-inflammatory interventions targeting kynurenine and BH4 pathways may be effective as novel treatment or as adjuvants of conventional medications rather directed to monoamines, notably when depressive symptomatology and inflammation are comorbid in treated patients. This notion is discussed in the light of recent findings illustrating the tight interactions between known antidepressant drugs and inflammatory processes, as well as their therapeutic implications. Altogether, this review provides valuable findings for moving toward more adapted and personalized therapeutic strategies to treat inflammation-related depressive symptoms.