Peripheral cytokine and chemokine alterations in depression: a meta-analysis of 82 studies

Effects of Lycium barbarum polysaccharide on cytokines in adolescents with subthreshold depression: a randomized controlled study

JOURNAL/nrgr/04.03/01300535-202409000-00036/figure1/v/2024-01-16T170235Z/r/image-tiff Strong evidence has accumulated to show a correlation between depression symptoms and inflammatory responses. Moreover, anti-inflammatory treatment has shown partial effectiveness in alleviating depression symptoms. Lycium barbarum polysaccharide (LBP), derived from Goji berries, exhibits notable antioxidative and anti-inflammatory properties. In our recent double-blinded randomized placebo-controlled trial, we found that LBP significantly reduced depressive symptoms in adolescents with subthreshold depression. It is presumed that the antidepressant effect of LBP may be associated with its influence on inflammatory cytokines. In the double-blinded randomized controlled trial, we enrolled 29 adolescents with subthreshold depression and randomly divided them into an LBP group and a placebo group. In the LBP group, adolescents were given 300 mg/d LBP. A 6-week follow up was completed by 24 adolescents, comprising 14 adolescents from the LBP group (15.36 ± 2.06 years, 3 men and 11 women) and 10 adolescents from the placebo group (14.9 ± 1.6 years, 2 men and 8 women). Our results showed that after 6 weeks of treatment, the interleukin-17A level in the LBP group was lower than that in the placebo group. Network analysis showed that LBP reduced the correlations and connectivity between inflammatory factors, which were associated with the improvement in depressive symptoms. These findings suggest that 6-week administration of LBP suppresses the immune response by reducing interleukin-17A level, thereby exerting an antidepressant effect.

Depression in pregnant Hispanic women: Risk factors, pregnancy outcomes and plasma cytokines

Background

Maternal depression is considered a major contributor to morbidity and mortality in pregnancy. A population at risk are U.S. born or immigrant Hispanic women, and few prenatal depression or immune studies have focused on this population.

Objective

The research questions for the study were 1) What are the occurrences, risk factors and outcomes associated with depression in Hispanic pregnant women in the United States and 2) What are the associations of plasma immune cytokines and prenatal depression in this population.

Study design

Women of self-reported Hispanic ethnicity were born in the continental United States or foreign-born. Screening of potential participants (n = 690) at a first prenatal clinic visit consisted of antibody testing for Toxoplasma gondii antibodies in a larger grant, and only the women with antibody levels below the cutoff for T. gondii positivity (N = 536) were included in the present study. All participants completed a health and demographic questionnaire, the Edinburgh Postpartum Depression (EPDS) scale, the Perceived Stress Scale (PSS), and the Medical Outcomes Study Social Support (MOS) scale. We surveyed electronic health records (EHR) for risk factors and adverse pregnancy outcomes in the sample. We further measured physical and mental health and seven plasma immune cytokines at four study visits during pregnancy in a longitudinal subsample (N = 128).

Results

The frequency of EPDS scores of 10 (depression risk) or above was 18.6 % at the time of enrollment. Socioeconomic factors such as less education, greater unemployment, and U.S. born nativity were associated with greater depression risk, but these relationships became insignificant when we corrected for false discovery rate. Depression scores were not associated with adverse birth and pregnancy outcomes. The inflammatory cytokine TNF-α was significantly higher across pregnancy in women with depression risk (p < 0.03). Other inflammatory cytokines were higher in depressed women, but only at one time point in mid-pregnancy.

Conclusions

Prenatal depression occurs in early pregnancy and then declines in Hispanic women. The frequency of depression and stress were higher in U.S. born compared to immigrant Hispanic women. There was an elevation in plasma levels of TNF-α through the pregnancy in depressed women, and elevations in other cytokines, at midpregnancy. The adverse pregnancy outcomes, including preterm delivery, known to be associated with prenatal depression were not present in this cohort.

Grip strength buffers the harmful association between multimorbidity and depression among middle-aged and older adults

BACKGROUND

Grip strength (GS) is associated to both multimorbidity and depression, however its possible moderating effect is unknown. This study aimed to investigate GS moderating effect on the association between multimorbidity and depression.

METHODS

Data from SHARE wave 8 was used. Participant were 41457 middle-aged and older adults (17954 men) from 18 European countries. A regression analysis was conducted for the moderating effect of sex- and age-specific GS quartiles (W) on the association between number of chronic diseases (X1) or multimorbidity (X2) and depression symptoms (Y).

RESULTS

More chronic diseases were associated with greater depressive symptomatology (men: B = 0.39, 95 % CI: 0.35, 0.42; women: B = 0.42, 95 % CI: 0.39, 0.45). On the other hand, being in a higher GS quartile was associated with fewer depression symptoms, and this association was stronger the higher the quartile was. Having a higher GS represented a decrease in depression symptoms associated with multimorbidity for men (quartile 1: B = 0.85, 95 % CI = 0.74, 0.95 vs. quartile 4: B = 0.49, 95 % CI = 0.38, 0.61) and women (quartile 1: B = 1.08, 95 %CI = 0.97, 1.19 vs. quartile 4: B = 0.59, 95 %CI: 0.47, 0.70).

CONCLUSIONS

Strategies aiming to reduce the impact of multimorbidity on mental health should promote muscle-strengthening physical activity among middle-aged and older adults.

Inflammatory markers changes following acceptance-based behavioral psychotherapy in generalized anxiety disorder patients: Evidence from a randomized controlled trial

Introduction

Generalized anxiety disorder (GAD) has been associated with elevated levels of C-reactive protein (CRP) and proinflammatory cytokines. Despite robust evidence as an effective treatment for GAD, research on the effects of cognitive-behavioral therapies (CBT) in the inflammatory profile of patients with clinical anxiety has presented mixed results.

Objective

The present study aimed to investigate the effect of an acceptance-based behavior therapy (ABBT) on inflammatory biomarkers and their association with anxiety levels in GAD patients in comparison to supportive therapy as an active control.

Methods

Peripheral inflammatory biomarkers (CRP, IL-1β, IL-4, IL-6, IL-10, TNF-α) were measured in 77 GAD patients who participated in a 14-week 10-session randomized clinical trial of group ABBT (experimental, n = 37) or supportive group therapy (ST: active control group, n = 40).

Results

The concentrations of IL-1β decreased in the control group and the concentrations of IL-6 increased in the experimental group from baseline to post-treatment, whereas no difference was identified in IL-4, IL-10, TNF, or CRP. Although anxiety and depression levels decreased in both treatment conditions, no correlation with inflammation markers was found for most clinical and biological variables. A negative correlation between changes in IL-6 and IL-10 and anxiety symptom score changes was identified.

Conclusions

The present study results found that a short trial of acceptance-based behavior therapy did not change the proinflammatory profile which may be associated with GAD. Additional research is needed to evaluate the influence of other inflammation-related variables, longer periods of follow-up as well as the effect of supportive therapy on peripheral inflammatory biomarkers in GAD patients.

Characteristics of gut microbiota and its correlation with hs-CRP and somatic symptoms in first-episode treatment-naive major depressive disorder

OBJECTIVE

Most patients with major depressive disorder (MDD) have somatic symptoms, but little studies pay attention in the microbial-inflammatory mechanisms of these somatic symptoms. Our study aimed to investigate alterations in gut microbiota and its correlation with inflammatory marker levels and somatic symptoms in first-episode treatment-naive MDD.

METHODS

Subjects contained 160 MDD patients and 101 healthy controls (HCs). MDD patients were divided into MDD with somatic symptoms group (MDDS) and MDD without somatic symptoms group (MDDN) based on Somatic Self-rating Scale (SSS). 16S ribosomal RNA sequencing were performed to analyze the composition of the fecal microbiota. The inflammatory factors were measured using enzyme linked immunosorbent assay (ELISA). Correlation among the altered gut microbiota, inflammatory factor and severity of clinical symptoms were analysized.

RESULTS

Relative to HCs, MDD patients had higher levels of high-sensitivity C-reactive protein (hs-CRP) as well as disordered α-diversity and β-diversity of gut microbiota. Linear discriminant effect size (LEfSe) analysis showed that MDD patients had higher proportions of Bifidobacterium, Blautia, Haemophilus and lower proportions of Bacteroides, Faecalibacterium, Roseburia, Dialister, Sutterella, Parabacteroides, Bordetella, and Phascolarctobacterium from the genus aspect. Furthermore, correlation analysis showed Bacteroides and Roseburia had negative correlations with the hs-CRP, HAMD-24, the total and factor scores of SSS in all participants. Further, compared with MDDN, the Pielous evenness was higher in MDDS. Random Forest (RF) analysis showed 20 most important genera discriminating MDD-S and MDDN, HCs. The ROC analysis showed that the AUC was 0.90 and 0.81 combining these genera respectively.

CONCLUSION

Our study manifested MDD patients showed disordered gut microbiota and elevated hs-CRP levels, and altered gut microbiota was closely associated with hs-CRP, depressive symptoms, and somatic symptoms.

Chronic inflammation is associated with worsening working memory performance: Preliminary evidence from a diverse, longitudinal cohort of adolescents and young adults

Many depressed individuals experience cognitive difficulties that persist when depression is in remission. Inflammation is hypothesized to play a role in cognitive dysfunction in depression; however, many aspects of this relationship are not well characterized. The current study examined whether inflammation is associated with specific cognitive deficits in individuals with a history of depression and with progressively worsening working memory over time. Adolescents who participated in a prospective, longitudinal study of adolescent-onset depression were recruited to complete a follow-up cognitive assessment. The sample was comprised of 82 participants (52.4% female; 37.8% white; 42.7% low socioeconomic status) who were aged 22.61 years (SD = 1.50) at the time of the follow-up cognitive assessment. Prior to the follow-up cognitive assessment, they had completed an average of 6.24 (SD = 1.80) prior annual assessments over 6.24 years (SD = 2.08) as part of the parent longitudinal study in which C-reactive protein (CRP), depressive symptoms, and working memory were assessed repeatedly. First, using linear regression, we tested whether individuals exhibiting inflammation (CRP ≥3 mg/L) at multiple timepoints and a history of likely depression (Children's Depression Inventory ≥19) exhibited differentially worse executive functioning, episodic memory, or psychomotor speed. Second, using hierarchical linear modeling, we tested whether the combination of inflammation and likely past depression was associated with poorer working memory over time. Chronic inflammation was associated with worsening working memory over time, but no significant associations were observed in cross-sectional analyses. These preliminary data indicate that chronic inflammation may lead to progressive decline in working memory over time.

A novel biomarker of interleukin 6 activity and clinical and cognitive outcomes in depression

BACKGROUND

Inflammatory cytokines like interleukin-6 (IL-6) are implicated in depression, but most studies have hitherto focused on circulating levels of IL-6 rather than its activity. IL-6 trans-signalling is thought to be responsible for most of the pathogenic effects of IL-6 and is implicated in autoimmune diseases like rheumatoid arthritis. We tested the association between a multi-protein-derived measure of IL-6 trans-signalling and clinical and cognitive outcomes in patients with depression. We hypothesised that this novel measure of IL-6 activity/bioavailability would be associated with clinical and cognitive measures previously reported to be associated with inflammation in depression.

METHODS

Using data from 86 patients with International Classification of Diseases-10 diagnosis of depression, we calculated a ratio score representing IL-6 activity/bioavailability using serum IL-6, soluble IL-6 receptor (sIL-6R), and soluble glycoprotein 130 levels. We tested the relationship of this novel biomarker with 12 cytokines using correlation analyses and with cognitive and clinical measures using multivariable linear regression, following z-transformation of all immune exposures.

RESULTS

The novel measure of IL-6 activity/bioavailability was correlated with IL-6 (r=0.42, P=0.03), C-reactive protein (CRP) (r=0.42, P=0.03), sIL-6R (r=0.91, P<0.01), and tumour necrosis factor alpha (r=0.43, P=0.03). The IL-6 activity/bioavailability measure was associated with higher somatic symptoms of depression (β=1.09; 95% CI 0.30, 1.88; PFDR=0.01), fatigue (β=4.34; 95% CI 1.26, 7.42; PFDR=0.03), depression severity (β=3.06; 95% CI 0.71, 5.40; P=0.02), poorer quality of life (β=-0.07; 95% CI -0.13, -0.01; PFDR=0.045), and decreased psychomotor speed (β=-5.46; 95% CI -9.09, -1.84; PFDR=0.01),. There was little evidence of associations with reaction time, anhedonia, anxiety, emotional perception and recall, executive function, and sustained attention (Ps>0.05). The effect estimates for the associations of the novel measure with depression outcomes were comparable to those for individual immune proteins (i.e., IL-6, CRP, sIL-6R).

CONCLUSION

A novel multi-protein-derived measure of IL-6 activity/bioavailability shows robust associations with various inflammation-related clinical and cognitive outcomes in depression and performs well in comparison to single inflammatory proteins. We need replication of these findings in other samples, experiments for mechanistic validity of this novel biomarker, and clinical studies to assess its usefulness as a marker of illness risk and prognosis.

Unveiling the hidden pathways: Exploring astrocytes as a key target for depression therapy

Depressive disorders are widely debilitating psychiatric disease. Despite the considerable progress in the field of depression therapy, extensive research spanning many decades has failed to uncover pathogenic pathways that might aid in the creation of long-acting and rapid-acting antidepressants. Consequently, it is imperative to reconsider existing approaches and explore other targets to improve this area of study. In contemporary times, several scholarly investigations have unveiled that persons who have received a diagnosis of depression, as well as animal models employed to study depression, demonstrate a decrease in both the quantity as well as density of astrocytes, accompanied by alterations in gene expression and morphological attributes. Astrocytes rely on a diverse array of channels and receptors to facilitate their neurotransmitter transmission inside tripartite synapses. This study aimed to investigate the potential processes behind the development of depression, specifically focusing on astrocyte-associated neuroinflammation and the involvement of several molecular components such as connexin 43, potassium channel Kir4.1, aquaporin 4, glutamatergic aspartic acid transporter protein, SLC1A2 or GLT-1, glucocorticoid receptors, 5-hydroxytryptamine receptor 2B, and autophagy, that localized on the surface of astrocytes. The study also explores novel approaches in the treatment of depression, with a focus on astrocytes, offering innovative perspectives on potential antidepressant medications.

A comprehensive review of natural product-derived compounds acting on P2X7R: The promising therapeutic drugs in disorders

BACKGROUND

The P2X7 receptor (P2X7R) is known to play a significant role in regulating various pathological processes associated with immune regulation, neuroprotection, and inflammatory responses. It has emerged as a potential target for the treatment of diseases. In addition to chemically synthesized small molecule compounds, natural products have gained attention as an important source for discovering compounds that act on the P2X7R.

PURPOSE

To explore the research progress made in the field of natural product-derived compounds that act on the P2X7R.

METHODS

The methods employed in this review involved conducting a thorough search of databases, include PubMed, Web of Science and WIKTROP, to identify studies on natural product-derived compounds that interact with P2X7R. The selected studies were then analyzed to categorize the compounds based on their action on the receptor and to evaluate their therapeutic applications, chemical properties, and pharmacological actions.

RESULTS

The natural product-derived compounds acting on P2X7R can be classified into three categories: P2X7R antagonists, compounds inhibiting P2X7R expression, and compounds regulating the signaling pathway associated with P2X7R. Moreover, highlight the therapeutic applications, chemical properties and pharmacological actions of these compounds, and indicate areas that require further in-depth study. Finally, discuss the challenges of the natural products-derived compounds exploration, although utilizing compounds from natural products for new drug research offers unique advantages, problems related to solubility, content, and extraction processes still exist.

CONCLUSION

The detailed information in this review will facilitate further development of P2X7R antagonists and potential therapeutic strategies for P2X7R-associated disorders.

Correlations between personality traits, personality disorders, and immunometabolic markers

Evidence links immune system alterations to major psychiatric disorders. The few previous studies on personality traits or personality disorders (PDs) indicate that immunometabolic dysregulation may be prevalent in this population. This study aimed to investigate relationships between personality traits, PDs, and immunometabolic markers in peripheral blood. We hypothesized that neuroticism would be correlated with elevated leptin. Participants were recruited as young adults seeking care for general psychiatric disorders. They responded to a personality inventory and were assessed for PDs, and reevaluated again at a 12 years follow-up. Blood samples were collected at the follow-up and analyzed for 29 immunometabolic markers. A positive correlation was found between the personality trait neuroticism and leptin (ρ = 0.31, p = 0.02). An exploratory analysis also revealed a positive correlation between brain-derived neurotrophic factor (ρ = 0.36, p < 0.01) and neuroticism. These findings remained after adjusting for other variables in general linear models. There were no relationships between PDs and any immunometabolic markers. Results both confirm previous findings of correlations between the immunometabolic system and personality traits and suggest directions for future research.

Concurrent inflammation-related brain reorganization in multiple sclerosis and depression

BACKGROUND

Neuroinflammation affects brain tissue integrity in multiple sclerosis (MS) and may have a role in major depressive disorder (MDD). Whether advanced magnetic resonance imaging characteristics of the gray-to-white matter border serve as proxy of neuroinflammatory activity in MDD and MS remain unknown.

METHODS

We included 684 participants (132 MDD patients with recurrent depressive episodes (RDE), 70 MDD patients with a single depressive episode (SDE), 222 MS patients without depressive symptoms (nMS), 58 MS patients with depressive symptoms (dMS), and 202 healthy controls (HC)). 3 T-T1w MRI-derived gray-to-white matter contrast (GWc) was used to reconstruct and characterize connectivity alterations of GWc-covariance networks by means of modularity, clustering coefficient, and degree. A cross-validated support vector machine was used to test the ability of GWc to stratify groups according to their depression symptoms, measured with BDI, at the single-subject level in MS and MDD independently.

FINDINGS

MS and MDD patients showed increased modularity (ANOVA partial-η2 = 0.3) and clustering (partial-η2 = 0.1) compared to HC. In the subgroups, a linear trend analysis attested a gradient of modularity increases in the form: HC, dMS, nMS, SDE, and RDE (ANOVA partial-η2 = 0.28, p < 0.001) while this trend was less evident for clustering coefficient. Reduced morphological integrity (GWc) was seen in patients with increased depressive symptoms (partial-η2 = 0.42, P < 0.001) and was associated with depression scores across patient groups (r = -0.2, P < 0.001). Depressive symptoms in MS were robustly classified (88 %).

CONCLUSIONS

Similar structural network alterations in MDD and MS exist, suggesting possible common inflammatory events like demyelination, neuroinflammation that are caught by GWc analyses. These alterations may vary depending on the severity of symptoms and in the case of MS may elucidate the occurrence of comorbid depression.

Recovery of synaptic loss and depressive-like behavior induced by GATA1 through blocking of the neuroinflammatory response

GATA1, a member of the GATA transcription factor family, is a critical factor in hematopoietic system development. In a previous study, we demonstrated the increased expression of GATA1 in the dorsolateral prefrontal cortex (dlPFC) of patients suffering from depression and described its role as a transcriptional repressor of synapse-related genes. In this study, we investigated how GATA1 globally altered gene expression using multi-omics approaches. Through the combined analyses of ChIPseq, mRNAseq, and small RNAseq, we profiled genes that are potentially affected by GATA1 in cultured cortical neurons, and Gene Ontology (GO) analysis revealed that GATA1 might be associated with immune-related functions. We hypothesized that GATA1 induces immune activation, which has detrimental effects including synapse loss and depressive-like behavior. To test this hypothesis, we first performed a microglial morphometric analysis of a brain having overexpression of GATA1 because microglia are the resident immune cells of the central nervous system. Fractal analysis showed that the ramification and process length of microglia decreased in brains having GATA1 overexpression compared to the control, suggesting that GATA1 overexpression increases the activation of microglia. Through flow cytometry and immunohistochemical analysis, we found that activated microglia showed pro-inflammatory phenotypes characterized by the expression of CD86 and CD68. Finally, we demonstrated that the effects of GATA1 overexpression including synapse loss and depressive-like behavior could be blocked by inhibiting microglial activation using minocycline. These results will elucidate the regulatory mechanisms of GATA1 that affect pathophysiological conditions such as depression and provide a potential target for the treatment of depression.

Metabolic Status Influences Probiotic Efficacy for Depression-PRO-DEMET Randomized Clinical Trial Results

Probiotics may represent a safe and easy-to-use treatment option for depression or its metabolic comorbidities. However, it is not known whether metabolic features can influence the efficacy of probiotics treatments for depression. This trial involved a parallel-group, prospective, randomized, double-blind, controlled design. In total, 116 participants with depression received a probiotic preparation containing Lactobacillus helveticus Rosell®-52 and Bifidobacterium longum Rosell®-175 or placebo over 60 days. The psychometric data were assessed longitudinally at five time-points. Data for blood pressure, body weight, waist circumference, complete blood count, serum levels of C-reactive protein, cholesterol, triglycerides, and fasting glucose were measured at the beginning of the intervention period. There was no advantage of probiotics usage over placebo in the depression score overall (PRO vs. PLC: F(1.92) = 0.58; p = 0.45). However, we found a higher rate of minimum clinically important differences in patients supplemented with probiotics than those allocated to placebo generally (74.5 vs. 53.5%; X2(1,n = 94) = 4.53; p = 0.03; NNT = 4.03), as well as in the antidepressant-treated subgroup. Moreover, we found that the more advanced the pre-intervention metabolic abnormalities (such as overweight, excessive central adipose tissue, and liver steatosis), the lower the improvements in psychometric scores. A higher baseline stress level was correlated with better improvements. The current probiotic formulations may only be used as complementary treatments for depressive disorders. Metabolic abnormalities may require more complex treatments. ClinicalTrials.gov identifier: NCT04756544.

Depression and dental caries in US adults, NHANES 2015-2018

PURPOSE

This study aimed to investigate the link between depression and untreated dental caries among adults in the United States.

METHODS

Data were collected from the National Health and Nutrition Survey (2015-2018); respondents aged 20 years or older who completed a patient health questionnaire and underwent a comprehensive oral examination were included. Participants were categorized into three groups according to depressive symptoms as follows: those with no, mild, or moderate to severe depression. Data were weighted, and multiple potential covariates were included in the analysis to provide national estimates and account for the complex sample design. A multivariable weighted logistic regression model was performed to test the hypothesis that varying degrees of depression in American adults are associated with untreated dental caries. Subgroup analyses were performed based on age and gender after adjusting for potential covariates. A P value of <.05 was considered significant.

RESULTS

Among 8740 participants, the prevalence of untreated coronal and root caries was 20.50% and 12.92%, respectively. Moderate to severe depression was a significant risk factor (odds ratio, 1.25; 95% confidence interval, 1.09-1.66) for untreated root caries. The risk of untreated root caries increased by 87% in young adults (aged 20-44 years) and by 46% in women with moderate to severe depression. The suest analysis revealed that the impact of moderate to severe depressive disorder on untreated root caries was non-significantly different between the age subgroup (p=0.09) and sex subgroup (p=0.51). However, depression was non-significantly associated with untreated coronal caries (mild depression: OR, 1.07; 95% CI, 0.85-1.34; moderate to severe depression 1.06; 95% CI, 0.83-1.36; respectively).

CONCLUSION

The results of this study suggested a significant association between moderate and severe depression and untreated root caries; however, the association with untreated coronal caries was non-significant. In the United States, moderate and severe depression in adults is associated with root caries.

The mind-skin connection: A narrative review exploring the link between inflammatory skin diseases and psychological stress

Inflammatory skin diseases are known to negatively impact patient psychology, with individuals experiencing higher rates of stress and subsequent diminished quality of life, as well as mental health issues including anxiety and depression. Moreover, increased psychological stress has been found to exacerbate existing inflammatory skin diseases. The association between inflammatory skin diseases and psychological stress is a timely topic, and a framework to better understand the relationship between the two that integrates available literature is needed. In this narrative review article, we discuss potential neurobiological mechanisms behind psychological stress due to inflammatory skin diseases, focusing mainly on proinflammatory cytokines in the circulating system (the brain-gut-skin communications) and the default mode network in the brain. We also discuss potential descending pathways from the brain that lead to aggravation of inflammatory skin diseases due to psychological stress, including the central and peripheral hypothalamic-pituitary-adrenal axes, peripheral nerves and the skin barrier function.

Peripheral inflammation is associated with impaired sadness recognition in euthymic bipolar patients

BACKGROUND

Inflammation impairs cognitive function in healthy individuals and people with psychiatric disorders, such as bipolar disorder (BD). This effect may also impact emotion recognition, a fundamental element of social cognition. Our study aimed to investigate the relationships between pro-inflammatory cytokines and emotion recognition in euthymic BD patients and healthy controls (HCs).

METHODS

We recruited forty-four euthymic BD patients and forty healthy controls (HCs) and measured their inflammatory markers, including high-sensitivity C-reactive protein (hs-CRP), interleukin-6 (IL-6), and TNF-α. We applied validated cognitive tasks, the Wisconsin Card-Sorting Test (WCST) and Continuous Performance Test (CPT), and a social cognitive task for emotion recognition, Diagnostic Analyses of Nonverbal Accuracy, Taiwanese Version (DANVA-2-TW). We analyzed the relationships between cytokines and cognition and then explored possible predictive factors of sadness recognition accuracy.

RESULTS

Regarding pro-inflammatory cytokines, TNF-α was elevated in euthymic BD patients relative to HCs. In euthymic BD patients only, higher TNF-α levels were associated with lower accuracy of sadness recognition. Regression analysis revealed that TNF-α was an independent predictive factor of sadness recognition in patients with euthymic BD when neurocognition was controlled for.

CONCLUSIONS

We demonstrated that enhanced inflammation, indicated by increased TNF-α, was an independent predictive factor of impaired sadness recognition in BD patients but not in HCs. Our findings suggested a direct influence of TNF-α on sadness recognition and indicated vulnerability to depression in euthymic BD patients with chronic inflammation.

Duloxetine protected indomethacin-induced gastric mucosal injury by increasing serotonin-dependent RANTES expression and activating PI3K-AKT-VEGF pathway

Antidepressant duloxetine has been shown protective effect on indomethacin-induced gastric ulcer, which was escorted by inflammation in the gastric mucosa. Cytokines are the principal mediators of inflammation. Thus, by screening the differential expression of cytokines in the gastric mucosa using cytokine array at 3 h after indomethacin exposure, when the gastric ulcer began to format, we found that indomethacin increased cytokines which promoted inflammation responses, whereas duloxetine decreased pro-inflammatory cytokines increased by indomethacin and increased RANTES expression. RANTES was consistently increased by pretreated with both 5 mg/kg and 20 mg/kg duloxetine at 3 h and 6 h after indomethacin exposure in male rats. Selective blockade of RANTES-CCR5 axis by a functional antagonist Met-RANTES or a CCR5 antagonist maraviroc suppressed the protection of duloxetine. Considering the pharmacologic action of duloxetine on reuptake of monoamine neurotransmitters, we examined the serotonin (5-HT), norepinephrine and dopamine contents in the blood and discovered 20 mg/kg duloxetine increased 5-HT levels in platelet-poor plasma, while treatment with 5-HT promoted expression of RANTES in the gastric mucosa and alleviated the indomethacin-induced gastric injury. Furthermore, duloxetine activated PI3K-AKT-VEGF signaling pathway, which was regulated by RANTES-CCR5, and selective inhibitor of VEGF receptor axitinib blocked the prophylactic effect of duloxetine. Furthermore, duloxetine also protected gastric mucosa from indomethacin in female rats, and RANTES was increased by duloxetine after 6 h after indomethacin exposure too. Together, our results identified the role of cytokines, particularly RANTES, and the underlying mechanisms in gastroprotective effect of duloxetine against indomethacin, which advanced our understanding in inflammatory modulation by monoamine-based antidepressants.

Chronically socially isolated mice exhibit depressive-like behavior regulated by the gut microbiota

Objectives

Chronic loneliness is a widespread issue, and the gut-brain axis is known to be crucial in facilitating communication between the gut and brain. However, the precise mechanism by which chronic loneliness affects the gut-brain axis remains uncertain.

Methods

Fourteen 55-week-old Balb/c mice were used in the experiment, with seven mice being randomly assigned to the chronic social isolation (CSI) group. The CSI group mice underwent 12 weeks of isolation to simulate the psychiatric state of a population in prolonged social isolation. The mental state of the CSI mice was assessed through animal behavior analysis, while plasma cytokines were measured using ELISA. Additionally, the composition of the gut microbiota was analyzed using 16S rRNA sequencing, and the metabolite composition of the intestinal contents was examined using nontargeted metabolomics. The Student-T test was used to determine significant mean differences.

Results

Mice that were exposed to the CSI exhibited increased immobility time lengths in forced swimming and hanging tail experiments, and decreased movement lengths and number of times traversing the intermediate region, compared to control mice. Additionally, CSI decreased the abundance of the probiotics Ruminococcaceae, Akkermansiaceae, and Christensenellaceae. Additionally, CSI reduced the production of the metabolites oleamide and tryptophan. Furthermore, IL-1β, IL-4, and IL-6 were significantly increased, while TNF-α was significantly decreased.

Conclusion

CSI induces a dysbiotic gut microbiota and the production of neurorelated metabolites, which in turn increase inflammatory responses and result in depressive behaviors in CSI mice. Therefore, these findings suggest that the gut microbiota may serve as a target for the treatment of long-term social isolation-induced mental disorders.

Exploring the Association between Elevated Anxiety Symptoms and Low Skeletal Muscle Mass among Asymptomatic Adults: A Population-Based Study in Republic of Korea

Individuals with mental health problems are at higher risk of musculoskeletal diseases. However, the association between low muscle mass (LMM) and anxiety symptoms remains uninvestigated. This cross-sectional study enrolled 174,262 adults (73,833 women, 100,429 men), aged 18 to 89, who completed the anxiety scale and body composition analyses. Using bio-electrical impedance analysis, skeletal muscle mass index (SMI) was calculated based on appendicular skeletal muscle mass (ASM) (kg)/height (m2). LMM was defined as SMI < 7.0 kg/m2 in men and <5.4 kg/m2 in women. Anxiety symptoms were screened using the Clinical Useful Anxiety Outcome Scale (CUXOS) with cut-off scores of 20, 30, and 40. Multivariable logistic regression analyses were performed. LMM prevalence was 20.17% in women, 3.86% in men (p < 0.001). The prevalence of anxiety symptoms in LMM group decreased from mild (CUXOS > 20: women, 32.74%, men, 21.17%) to moderate (CUXOS > 30: 13.34%, 7.32%), to severe anxiety symptoms (CUXOS > 40: 4.00%, 1.73%). In multivariable-adjusted models, LMM was associated with mild (aOR (95% confidence interval)), women, 1.13 (1.08-1.17); men, 1.17 (1.08-1.27)), moderate (1.17 (1.11-1.24); 1.35 (1.19-1.53) and severe anxiety symptoms (1.18 (1.07-1.3), 1.36 (1.06-1.74)), demonstrating an increased risk of ORs with escalating anxiety severity. LMM was independently associated with a higher prevalence of anxiety symptoms.

The antidepressant effect of whole-body hyperthermia is associated with the classical interleukin-6 signaling pathway

There is urgent need for novel antidepressant treatments that confer therapeutic benefits via engagement with identified mechanistic targets. The objective of the study was to determine whether activation of the classical anti-inflammatory interleukin-6 signaling pathways is associated with the antidepressant effects of whole-body hyperthermia. A 6-week, randomized, double-blind study compared whole-body hyperthermia with a sham condition in a university-based medical center. Medically healthy participants aged 18-65 years who met criteria for major depressive disorder, were free of psychotropic medication use, and had a baseline 17-item Hamilton Depression Rating Scale score ≥ 16 were randomized with 1-to-1 allocation in blocks of 6 to receive whole-body hyperthermia or sham. Of 338 individuals screened, 34 were randomized, 30 received interventions and 26 had ≥ 2 blood draws and depressive symptom assessments. Secondary data analysis examined change in the ratio of IL-6:soluble IL-6 receptor pre-intervention, post-intervention, and at weeks 1 and 4. Hierarchical linear modeling tested whether increased IL-6:soluble IL-6 receptor ratio post-intervention was associated with decreased depressive symptom at weeks 1, 2, 4 and 6 for those randomized to whole-body hyperthermia. Twenty-six individuals were randomized to whole-body hyperthermia [n = 12; 75 % female; age = 37.9 years (SD = 15.3) or sham [n = 14; 57.1 % female; age = 41.1 years (SD = 12.5). When compared to the sham condition, active whole-body hyperthermia only increased the IL-6:soluble IL-6 receptor ratio post-treatment [F(3,72) = 11.73,p < .001], but not pre-intervention or at weeks 1 and 4. Using hierarchical linear modeling, increased IL-6:sIL-6R ratio following whole-body hyperthermia moderated depressive symptoms at weeks 1, 2, 4 and 6, such that increases in the IL-6:soluble IL-6 receptor ratio were associated with decreased depressive symptoms at weeks 1, 2, 4 and 6 for those receiving the active whole-body hyperthermia compared to sham treatment (B = -229.44, t = -3.82,p < .001). Acute activation of classical intereukin-6 signaling might emerge as a heretofore unrecognized novel mechanism that could be harnessed to expand the antidepressant armamentarium.

Depressive disorder and elevated risk of bell's palsy: a nationwide propensity score-weighting study

BACKGROUND

Prior studies have reported a potential relationship between depressive disorder (DD), immune function, and inflammatory response. Some studies have also confirmed the correlation between immune and inflammatory responses and Bell's palsy. Considering that the pathophysiology of these two diseases has several similarities, this study investigates if DD raises the risk of developing Bell's palsy.

METHODS

This nationwide propensity score-weighting cohort study utilized Taiwan National Health Insurance data. 44,198 patients with DD were identified as the DD cohort and 1,433,650 adult subjects without DD were identified as the comparison cohort. The inverse probability of treatment weighting (IPTW) strategy was used to balance the differences of covariates between two groups. The 5-year incidence of Bell's palsy was evaluated using the Cox proportional-hazard model, presenting results in terms of hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

The average age of DD patients was 48.3 ± 17.3 years, and 61.86% were female. After propensity score-weighting strategy, no significant demographic differences emerged between the DD and comparison cohort. The Cox proportional hazards model revealed a statistically significant adjusted IPTW-HR of 1.315 (95% CI: 1.168-1.481) for Bell's palsy in DD patients compared to comparison subjects. Further independent factors for Bell's palsy in this model were age (IPTW-HR: 1.012, 95% CI: 1.010-1.013, p < 0.0001), sex (IPTW-HR: 0.909, 95% CI: 0.869-0.952, p < 0.0001), hypertension (IPTW-HR: 1.268, 95% CI: 1.186-1.355, p < 0.0001), hyperlipidemia (IPTW-HR: 1.084, 95% CI: 1.001-1.173, p = 0.047), and diabetes (IPTW-HR: 1.513, 95% CI: 1.398-1.637, p < 0.0001) CONCLUSION: This Study confirmed that individuals with DD face an elevated risk of developing Bell's palsy. These findings hold significant implications for both clinicians and researchers, shedding light on the potential interplay between mental health and the risk of certain physical health outcomes.

Assessing causality between chronic obstructive pulmonary disease with depression: A bidirectional Mendelian randomization study

PURPOSE

Our investigation utilized a two-sample Mendelian randomization approach to explore the ambiguous bidirectional relationship between Chronic Obstructive Pulmonary Disease (COPD) and depression, furthering insights from existing observational studies.

METHODS

In this study, we conducted a bidirectional Mendelian randomization using genome-wide association studies (GWAS) datasets. We initially analyzed depression data from the Psychiatric Genomics Consortium and the UK Biobank (n = 500,199), alongside COPD data from the FinnGen Consortium (n = 329,552). The second phase involved comparing depression data from FinnGen (n = 372,472) with COPD data from the UK Biobank (n = 361,194). Our Mendelian analysis employs various methods to guarantee a comprehensive and rigorous investigation.

RESULTS

In the initial analytic phase utilizing the inverse variance weighted (IVW) method, COPD does not significantly contribute to the incidence of depression (IVW odds ratio (OR) = 0.989, 95 % confidence interval (CI) = 0.895 to 1.092, P = 0.824). Conversely, the data suggested a statistically significant association where depression may precipitate the development of COPD, with a notable increase in risk (IVW OR = 1.421, 95 % CI = 1.149 to 1.756, P = 0.001). Subsequent validation through a second-step analysis reinforced the hypothesis that depression elevates the likelihood of COPD onset (IVW OR = 1.002, 95 % CI = 1.0003 to 1.0046, P = 0.028).

CONCLUSION

Our study, utilizing Mendelian randomization analysis, determined that COPD does not escalate the risk of depression. Conversely, our analysis suggests that depression may elevate the risk of developing COPD. This insight underscores the importance of enhancing prevention, screening, and treatment strategies for COPD in individuals with depression.

Long-Term Immunomodulatory Impact of VNS on Peripheral Cytokine Profiles and Its Relationship with Clinical Response in Difficult-to-Treat Depression (DTD)

Vagus nerve stimulation (VNS) represents a long-term adjunctive treatment option in patients with difficult-to-treat depression (DTD). Anti-inflammatory effects have been discussed as a key mechanism of action of VNS. However, long-term investigations in real-world patients are sparse. In this naturalistic observational study, we collected data on cytokines in peripheral blood in n = 6 patients (mean age 47.8) with DTD and VNS treatment at baseline and at 6 months follow-up. We have identified clusters of peripheral cytokines with a similar dynamic over the course of these 6 months using hierarchical clustering. We have investigated cytokine changes from baseline to 6 months as well as the relationship between the cytokine profile at 6 months and long-term response at 12 months. After 6 months of VNS, we observed significant correlations between cytokines (p < 0.05) within the identified three cytokine-pairs which were not present at baseline: IL(interleukin)-6 and IL-8; IL-1β and TNF-α; IFN-α2 and IL-33. At 6 months, the levels of all the cytokines of interest had decreased (increased in non-responders) and were lower (5-534 fold) in responders to VNS than in non-responders: however, these results were not statistically significant. VNS-associated immunomodulation might play a role in long-term clinical response to VNS.

Effects of sleep deprivation on anxiety-depressive-like behavior and neuroinflammation

BACKGROUND

Depression is defined by a persistent low mood and disruptions in sleep patterns, with the WHO forecasting that major depression will rank as the third most prevalent contributor to the global burden of disease by the year 2030. Sleep deprivation serves as a stressor that triggers inflammation within the central nervous system, a process known as neuroinflammation. This inflammatory response plays a crucial role in the development of depression by upregulating the expression of inflammatory mediators that contribute to symptoms such as anxiety, hopelessness, and loss of pleasure.

METHODS

In this study, sleep deprivation was utilized as a method to induce anxiety and depressive-like behaviors in mice. The behavioral changes in the mice were then evaluated using the EZM, EPM, TST, FST, and SPT. H&E staining and Nissl staining was used to detect morphological changes in the medial prefrontal cortical (mPFC) regions. Elisa to assess serum CORT levels. Detection of mRNA levels and protein expression of clock genes, high mobility genome box-1 (Hmgb1), silent message regulator 6 (Sirt6), and pro-inflammatory factors by RT-qPCR, Western blotting, and immunofluorescence techniques.

RESULTS

Sleep deprivation resulted in decreased exploration of unfamiliar territory, increased time spent in a state of despair, and lower sucrose water intake in mice. Additionally, sleep deprivation led to increased secretion of serum CORT and upregulation of clock genes, IL6, IL1β, TNFα, Cox-2, iNOS, Sirt6, and Hmgb1. Sleep.

CONCLUSIONS

Sleep deprivation induces anxiety-depressive-like behaviors and neuroinflammation in the brain. Transcription of clock genes and activation of the Sirt6/Hmgb1 pathway may contribute to inflammatory responses in the mPFC.

Human olfactory neural progenitor cells reveal differences in IL-6, IL-8, thrombospondin-1, and MCP-1 in major depression disorder and borderline personality disorder

Background

Discovering biological markers is essential for understanding and treating mental disorders. Despite the limitations of current non-invasive methods, neural progenitor cells from the olfactory epithelium (hNPCs-OE) have been emphasized as potential biomarker sources. This study measured soluble factors in these cells in Major Depressive Disorder (MDD), Borderline Personality Disorder (BPD), and healthy controls (HC).

Methods

We assessed thirty-five participants divided into MDD (n=14), BPD (n=14), and HC (n=7). MDD was assessed using the Hamilton Depression Rating Scale. BPD was evaluated using the DSM-5 criteria and the Structured Clinical Interview for Personality Disorders. We isolated hNPCs-OE, collected intracellular proteins and conditioned medium, and quantified markers and soluble factors, including Interleukin-6, interleukin-8, and others. Analysis was conducted using one-way ANOVA or Kruskal-Wallis test and linear regression.

Results

We found that hNPCs-OE of MDD and BPD decreased Sox2 and laminin receptor-67 kDa levels. MASH-1 decreased in BPD, while tubulin beta-III decreased in MDD compared to controls and BPD. Also, we found significant differences in IL-6, IL-8, MCP-1, and thrombospondin-1 levels between controls and MDD, or BPD, but not between MDD and BPD.

Conclusions

Altered protein markers are evident in the nhNPCs-OE in MDD and BPD patients. These cells also secrete higher concentrations of inflammatory cytokines than HC cells. The results suggest the potential utility of hNPCs-OE as an in vitro model for researching biological protein markers in psychiatric disorders. However, more extensive validation studies are needed to confirm their effectiveness and specificity in neuropsychiatric disorders.

Immunoregulatory role of the gut microbiota in inflammatory depression

Inflammatory depression is a treatment-resistant subtype of depression. A causal role of the gut microbiota as a source of low-grade inflammation remains unclear. Here, as part of an observational trial, we first analyze the gut microbiota composition in the stool, inflammatory factors and short-chain fatty acids (SCFAs) in plasma, and inflammatory and permeability markers in the intestinal mucosa of patients with inflammatory depression (ChiCTR1900025175). Gut microbiota of patients with inflammatory depression exhibits higher Bacteroides and lower Clostridium, with an increase in SCFA-producing species with abnormal butanoate metabolism. We then perform fecal microbiota transplantation (FMT) and probiotic supplementation in animal experiments to determine the causal role of the gut microbiota in inflammatory depression. After FMT, the gut microbiota of the inflammatory depression group shows increased peripheral and central inflammatory factors and intestinal mucosal permeability in recipient mice with depressive and anxiety-like behaviors. Clostridium butyricum administration normalizes the gut microbiota, decreases inflammatory factors, and displays antidepressant-like effects in a mouse model of inflammatory depression. These findings suggest that inflammatory processes derived from the gut microbiota can be involved in neuroinflammation of inflammatory depression.

Sleep deprivation-induced anxiety-like behaviors are associated with alterations in the gut microbiota and metabolites

The present study aimed to characterize the gut microbiota and serum metabolome changes associated with sleep deprivation (SD) as well as to explore the potential benefits of multi-probiotic supplementation in alleviating SD-related mental health disorders. Rats were subjected to 7 days of SD, followed by 14 days of multi-probiotics or saline administration. Open-field tests were conducted at baseline, end of SD (day 7), and after 14 days of saline or multi-probiotic gavage (day 21). Metagenomic sequencing was conducted on fecal samples, and serum metabolites were measured by untargeted liquid chromatography tandem-mass spectrometry. At day 7, anxiety-like behaviors, including significant decreases in total movement distance (P = 0.0002) and staying time in the central zone (P = 0.021), were observed. In addition, increased levels of lipopolysaccharide (LPS; P = 0.028) and decreased levels of uridine (P = 0.018) and tryptophan (P = 0.01) were detected in rats after 7 days of SD. After SD, the richness of the gut bacterial community increased, and the levels of Akkermansia muciniphila, Muribaculum intestinale, and Bacteroides caecimuris decreased. The changes in the host metabolism and gut microbiota composition were strongly associated with the anxiety-like behaviors caused by SD. In addition, multi-probiotic supplementation for 14 days modestly improved the anxiety-like behaviors in SD rats but significantly reduced the serum level of LPS (P = 0.045). In conclusion, SD induces changes in the gut microbiota and serum metabolites, which may contribute to the development of chronic inflammatory responses and affect the gut-brain axis, causing anxiety-like behaviors. Probiotic supplementation significantly reduces serum LPS, which may alleviate the influence of chronic inflammation.

IMPORTANCE

The disturbance in the gut microbiome and serum metabolome induced by SD may be involved in anxiety-like behaviors. Probiotic supplementation decreases serum levels of LPS, but this reduction may be insufficient for alleviating SD-induced anxiety-like behaviors.

Adverse childhood experiences and recent negative events are associated with activated immune and growth factor pathways, the phenome of first episode major depression and suicidal behaviors

This research assessed the effects of adverse childhood experiences (ACEs) and negative life events (NLEs) on forty-eight cytokines/chemokines/growth factors, in 71 FE-MDMD patients and forty heathy controls. ACEs are highly significantly associated with the classical M1 macrophage, T helper (Th)-1, Th-1 polarization, IRS, and neurotoxicity immune profiles, and not with the alternative M2, and Th-2 immune profiles. There are highly significant correlations between ACEs and NLEs and different cytokines/chemokines/growth factors, especially with interleukin (IL)-16, CCL27, stem cell growth factor, and platelet-derived growth factor. Partial Least Squares analysis showed that 62.3 % of the variance in the depression phenome (based on severity of depression, anxiety and suicidal behaviors) was explained by the regression on IL-4 (p = 0.001, inversely), the sum of ACEs + NLEs (p < 0.0001), and a vector extracted from 10 cytokines/chemokines/growth factors (p < 0.0001; both positively associated). The latter partially mediated (p < 0.0001) the effects of ACE + NLEs on the depression phenome. In conclusion, part of the effects of ACEs and NLEs on the depression phenome is mediated via activation of immune and growth factor networks. These pathways have a stronger impact in subjects with lowered activities of the compensatory immune-regulatory system.

Systemic Inflammation in Asthma: What Are the Risks and Impacts Outside the Airway?

Airway inflammation in asthma has been well recognized for several decades, with general agreement on its role in asthma pathogenesis, symptoms, propensity toward exacerbation, and decline in lung function. This has led to universal recommendation in asthma management guidelines to incorporate the use of inhaled corticosteroid as an anti-inflammatory therapy for all patients with persistent asthma symptoms. However, there has been limited attention paid to the presence and potential impact of systemic inflammation in asthma. Accumulating evidence from epidemiological observations and cohort studies points to a host of downstream organ dysfunction in asthma especially among patients with longstanding or more severe disease, frequent exacerbations, and underlying risk factors for organ dysfunction. Most studies to date have focused on cognitive impairment, depression/anxiety, metabolic syndrome, and cardiovascular abnormalities. In this review, we summarize some of the evidence demonstrating these abnormalities and highlight the proposed mechanisms and potential benefits of treatment in limiting these extrapulmonary abnormalities in patients with asthma. The goal of this commentary is to raise awareness of the importance of recognizing potential extrapulmonary conditions associated with systemic inflammation of asthma. This area of treatment of patients with asthma is a large unmet need.

Annual Research Review: Neuroimmune network model of depression: a developmental perspective

Depression is a serious public health problem, and adolescence is an 'age of risk' for the onset of Major Depressive Disorder. Recently, we and others have proposed neuroimmune network models that highlight bidirectional communication between the brain and the immune system in both mental and physical health, including depression. These models draw on research indicating that the cellular actors (particularly monocytes) and signaling molecules (particularly cytokines) that orchestrate inflammation in the periphery can directly modulate the structure and function of the brain. In the brain, inflammatory activity heightens sensitivity to threats in the cortico-amygdala circuit, lowers sensitivity to rewards in the cortico-striatal circuit, and alters executive control and emotion regulation in the prefrontal cortex. When dysregulated, and particularly under conditions of chronic stress, inflammation can generate feelings of dysphoria, distress, and anhedonia. This is proposed to initiate unhealthy, self-medicating behaviors (e.g. substance use, poor diet) to manage the dysphoria, which further heighten inflammation. Over time, dysregulation in these brain circuits and the inflammatory response may compound each other to form a positive feedback loop, whereby dysregulation in one organ system exacerbates the other. We and others suggest that this neuroimmune dysregulation is a dynamic joint vulnerability for depression, particularly during adolescence. We have three goals for the present paper. First, we extend neuroimmune network models of mental and physical health to generate a developmental framework of risk for the onset of depression during adolescence. Second, we examine how a neuroimmune network perspective can help explain the high rates of comorbidity between depression and other psychiatric disorders across development, and multimorbidity between depression and stress-related medical illnesses. Finally, we consider how identifying neuroimmune pathways to depression can facilitate a 'next generation' of behavioral and biological interventions that target neuroimmune signaling to treat, and ideally prevent, depression in youth and adolescents.

A Novel Anti-Inflammatory Formulation Comprising Celecoxib and Cannabidiol Exerts Antidepressant and Anxiolytic Effects

Background: Ample research shows that anti-inflammatory drugs, particularly celecoxib, exert antidepressant effects, especially in patients with microglia activation. However, substantial cardiovascular adverse effects limit celecoxib's usefulness. Given that cannabidiol (CBD) exerts anti-inflammatory, microglia-suppressive, and antidepressant effects, we hypothesized that it may potentiate the therapeutic effects of celecoxib. Methods: The effects of celecoxib, CBD, and their combination were examined in murine models of antidepressant- and anxiolytic-like behavioral responsiveness, including the forced swim test (FST), elevated plus maze (EPM), lipopolysaccharide (LPS)-induced neuroinflammation, and chronic social defeat stress (CSDS), as well as in microglia cell cultures. Results: Acute administration of a combination of celecoxib plus CBD, at doses that had no effects by themselves (10 and 5 mg/kg, respectively), produced significant antidepressant- and anxiolytic-like effects in the FST and EPM, in male and female mice. In the LPS model, combinations of celecoxib (10 or 20 mg/kg) plus CBD (30 mg/kg) reversed the anxiety-like behavior in the open-field test (OFT) and anhedonia in the sucrose preference test (SPT), with minimal effects of celecoxib or CBD by themselves. In the CSDS paradigm, a combination of celecoxib plus CBD (each at 30 mg/kg) reversed the deficits in the OFT, EPM, social exploration, and SPT, whereas celecoxib or CBD by themselves had partial effects. In BV2 microglia cultures stimulated with LPS or α-synuclein, CBD markedly potentiated the suppressive effects of celecoxib over TNFα (tumor necrosis factor-α) and IL (interleukin)-1β secretion. Conclusions: Combinations of celecoxib plus CBD produce efficacious antidepressant- and anxiolytic-like effects, which may depend on their synergistic microglia-suppressive effects.

Plasma levels of hydrogen sulfide and homocysteine correlate with the efficacy of antidepressant agents and serve as potential diagnostic and therapeutic markers

OBJECTIVE

Hydrogen sulfide (H2S) is associated with depressive-like behavior in rodents. We undertook cross-sectional and longitudinal analyses of plasma levels of H2S and its substrate homocysteine (Hcy) in depression and assessed the association of both parameters with psychopathology and cognitive function.

METHODS

Forty-one patients suffering from depression (PSDs) and 48 healthy volunteers were recruited. PSDs were treated for 8 weeks. Analyzable data were collected from all participants for assessment of their psychopathology and cognitive function. Plasma was collected for determination of levels of H2S and Hcy, and data were correlated to determine their potential as plasma biomarkers.

RESULTS

Cross-sectional analyses revealed PSDs to have a low plasma H2S level and high Hcy level. Longitudinal analyses revealed that 8 weeks of treatment reversed the changes in plasma levels of H2S and Hcy in PSDs. Plasma levels of H2S and Hcy were associated with psychopathology and cognitive function in depression. The area under the receiver operating characteristic curve (AUC) for a combination of plasma levels of H2S and Hcy and expression of the TNF gene (i.e., H2S-Hcy-TNF) was 0.848 for diagnosing depression and 0.977 for predicting the efficacy of antidepressant agents.

CONCLUSION

Plasma levels of H2S and Hcy reflect changes in psychopathology and cognitive function in depression and H2S-Hcy-TNF has the potential to diagnose depression and predict the efficacy of antidepressant medications.

Associations of inflammatory cytokines and cortisol with nonmotor features of Huntington's disease

OBJECTIVE

Huntington's disease (HD) is an inherited neurodegenerative disease involving progressive motor abnormalities, cognitive decline, and psychiatric disturbances. Depression and cognitive difficulties are among the most impactful symptoms of HD, yet the pathogenesis of these symptoms is not fully understood. HD involves low-level chronic inflammation and dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, which are linked to depression and cognitive impairment in non-HD populations. However, previous research on the relationships of these pathologies with depression and cognition in HD is limited and inconsistent.

METHODS

Fifty-three adults with the HD gene expansion (30 premanifest and 23 manifest) completed measures of depression and cognitive functioning. Forty-eight out of 53 participants provided hair samples for quantification of cortisol, and 34 participants provided blood samples for quantification of peripheral inflammatory cytokines. We examined the associations of four cytokines (interleukin [IL]-6, IL-10, IL-1β, and tumor necrosis factor [TNF]-α) and cortisol levels with depression and cognitive scores.

RESULTS

In unadjusted models, higher levels of plasma IL-6, IL-10, and TNF-α correlated with higher depression scores, and higher levels of IL-10 and TNF-α correlated with poorer cognitive performance. After controlling for age, sex, and body mass index, only the correlations of IL-10 with depression and cognitive performance remained significant. No correlations were evident with hair cortisol.

INTERPRETATIONS

Peripheral inflammation is associated with depression symptoms and cognitive impairment in HD. Our findings suggest that interactions between the immune and nervous systems are important in HD, and highlight the potential of chronic inflammation as a therapeutic target in early stages of HD.

Association between allostatic load and depression in patients with sleep disorders: Evidence from national health and nutrition examination survey

OBJECTIVE

Allostatic load (AL) is an indicator of cumulative wear and tear on the body's physiological systems that can predict the onset of a range of health problems. However, the relationship between AL and depression in patients with sleep disorders remains unclear. This study aimed to explore the association between AL and depression in patients with sleep disorders.

METHODS

Using data from the 2015-2016 National Health and Nutrition Examination Survey, a total of 4618 adults aged 18 years and older in the United States were included in this cross-sectional analysis. AL was calculated using nine biological markers, with a score of ≥3 indicating a high level. Depression was assessed using the Patient Health Questionnaire-9, and a score of 10 or higher indicated a potential risk of depression. Logistic regression models were employed to analyze the relationship between AL and depression.

RESULTS

Among the 1309 participants diagnosed with sleep disorders, 212 (16.2%) were identified as being at risk of depression. A total of 55.2% (n = 117) of the depressed persons had high AL levels. In the unadjusted model, AL levels were associated with depression in those with sleep disorders (OR:1.53, 95% CI = 1.14-2.05; P < .01). This relationship remained significant in the adjusted model (OR:1.52, 95% CI = 1.11-2.10, P < .05), after controlling for potential confounding factors.

CONCLUSION

The findings showed that high AL levels in patients with sleep disorders were positively associated with depression, indicating that elevated AL may increase the risk of depression in this population, or alternatively, depression may increase the risk of AL.

Preliminary evidence for preserved synaptic density in late-life depression

Late-life depression has been consistently associated with lower gray matter volume, the origin of which remains largely unexplained. Recent in-vivo PET findings in early-onset depression and Alzheimer's Disease suggest that synaptic deficits contribute to the pathophysiology of these disorders and may therefore contribute to lower gray matter volume in late-life depression. Here, we investigate synaptic density in vivo for the first time in late-life depression using the synaptic vesicle glycoprotein 2A receptor radioligand 11C-UCB-J. We included 24 currently depressed adults with late-life depression (73.0 ± 6.2 years, 16 female, geriatric depression scale = 19.5 ± 6.8) and 36 age- and gender-matched healthy controls (70.4 ± 6.2 years, 21 female, geriatric depression scale = 2.7 ± 2.9) that underwent simultaneous 11C-UCB-J positron emission tomography (PET) and 3D T1- and T2-FLAIR weighted magnetic resonance (MR) imaging on a 3-tesla PET-MR scanner. We used analyses of variance to test for 11C-UCB-J binding and gray matter volumes differences in regions implicated in depression. The late-life depression group showed a trend in lower gray matter volumes in the hippocampus (p = 0.04), mesial temporal (p = 0.02) and prefrontal cortex (p = 0.02) compared to healthy control group without surviving correction for multiple comparison. However, no group differences in 11C-UCB-J binding were found in these regions nor were any associations between 11C-UCB-J and depressive symptoms. Our data suggests that, in contrast to Alzheimer's Disease, lower gray matter volume in late-life depression is not associated with synaptic density changes. From a therapeutic standpoint, preserved synaptic density in late-life depression may be an encouraging finding.

[Interaction of somatic findings and psychiatric symptoms in COVID-19. A scoping review]

An infection with SARS-CoV‑2 can affect the central nervous system, leading to neurological as well as psychiatric symptoms. In this respect, mechanisms of inflammation seem to be of much greater importance than the virus itself. This paper deals with the possible contributions of organic changes to psychiatric symptomatology and deals especially with delirium, cognitive symptoms, depression, anxiety, posttraumatic stress disorder and psychosis. Processes of neuroinflammation with infection of capillary endothelial cells and activation of microglia and astrocytes releasing high amounts of cytokines seem to be of key importance in all kinds of disturbances. They can lead to damage in grey and white matter, impairment of cerebral metabolism and loss of connectivity. Such neuroimmunological processes have been described as a organic basis for many psychiatric disorders, as affective disorders, psychoses and dementia. As the activation of the glia cells can persist for a long time after the offending agent has been cleared, this can contribute to long term sequalae of the infection.

Signaling pathways and genetics of brain Renin angiotensin system in psychiatric disorders: State of the art

Along the conventional pathways, Renin-angiotensin system (RAS) plays a key role in the physiology of the CNS and pathogenesis of psychiatric diseases. RAS is a complex regulatory pathway which is composed of several peptides and receptors and comprises two counter-regulatory axes. The classical (ACE1/AngII/AT1 receptor) axis and the contemporary (ACE2/Ang (1-7)/Mas receptor) axis. The genes coding for elements of both axes have been broadly studied. Numerous functional polymorphisms on components of RAS have been identified to serve as informative disease and treatment markers. This review summarizes the role of each peptide and receptor in the pathophysiology of psychiatric disorders (depression, bipolar disorders and schizophrenia), followed by a concise look at the role of genetic polymorphism of the RAS in the pathophysiology of these disorders.

The association between lymphocyte to high-density lipoprotein ratio and depression: Data from NHANES 2015-2018

INTRODUCTION

The relationship of lymphocyte to high-density lipoprotein ratio (LHR) with depression remains uncertain. We aimed to evaluate the association between LHR and depression in US adults.

METHODS

In this cross-sectional study, a total of 4216 participants were enrolled from the National Health and Nutrition Examination Survey (2015-2018). Depressive symptoms were measured with the Patient Health Questionnaire-9 (PHQ-9). Participants were classified as having depression if PHQ-9 scores were ≥10. Multiple logistic regression models were used to explore the relationship between the LHR and depression.

RESULTS

Overall, the LHR was significantly associated with depression (per standard deviation increment; adjusted odds ratio (OR), 1.31; 95% confidence interval (CI) [1.14, 1.50]) after adjusted potential variables. Interactions between LHR with metabolic syndrome (MetS) and body mass index (BMI) on the risk of depression were found in stratified analysis (p for interaction < .05).

CONCLUSIONS

A higher level of LHR was significantly associated with higher odds of having depression in US adults, and it was strengthened in participants with MetS or BMI ranging from 25 to 30 kg/m2 .

The effect of inflammation markers on cortical thinning in major depressive disorder: A possible mediator of depression and cortical changes

BACKGROUND

Major depressive disorder (MDD) is a prevalent mental health condition with significant societal impact. Owing to the intricate biological diversity of MDD, treatment efficacy remains limited. Immune biomarkers have emerged as potential predictors of treatment response, underscoring the interaction between the immune system and the brain. This study investigated the relationship between cytokine levels and cortical thickness in patients with MDD, focusing on the corticolimbic circuit, to elucidate the influence of neuroinflammation on structural brain changes and contribute to a deeper understanding of the pathophysiology of MDD.

METHOD

A total of 114 patients with MDD and 101 healthy controls (HC) matched for age, sex, and body mass index (BMI) were recruited. All participants were assessed for depression severity using the Hamilton Depression Rating Scale (HDRS), and 3.0 T T1 weighted brain MRI data were acquired. Additionally, cytokine levels were measured using a highly sensitive bead-based multiplex immunosorbent assay.

RESULTS

Patients diagnosed with MDD exhibited notably elevated levels of interleukin-6 (p = 0.005) and interleukin-8 (p = 0.005), alongside significant cortical thinning in the left anterior cingulate gyrus and left superior frontal gyrus, with these findings maintaining significance even after applying Bonferroni correction. Furthermore, increased interleukin-6 and interleukin-8 levels in patients with MDD are associated with alterations in the left frontomarginal gyrus and right anterior cingulate cortex (ACC).

CONCLUSIONS

This suggests a potential influence of neuroinflammation on right ACC function in MDD patients, warranting longitudinal research to explore interleukin-6 and interleukin-8 mediated neurotoxicity in MDD vulnerability and brain morphology changes.

Pathogenesis of Depression in Alzheimer's Disease

Depression is a prevalent occurrence among Alzheimer's disease (AD) patients, yet its underlying mechanism remains unclear. Recent investigations have revealed that several pathophysiological changes associated with Alzheimer's disease can lead to mood disorders. These alterations include irregularities in monoamine neurotransmitters, disruptions in glutamatergic synaptic transmission, neuro-inflammation, dysfunction within the hypothalamic-pituitary-adrenocortical (HPA) axis, diminished levels of brain-derived neurotrophic factor (BDNF), and hippocampal atrophy. This review consolidates research findings from pertinent fields to elucidate the mechanisms underlying depression in Alzheimer's disease, aiming to provide valuable insights for the study of its mechanisms and clinical treatment.

Exploring Clinical Subgroups of Participants with Major Depressive Disorder that may Benefit from Adjunctive Minocycline Treatment

Objective

: To explore illness-related factors in patients with major depressive disorder (MDD) recipients of adjunctive minocycline (200 mg/day) treatment. The analysis included participants experiencing MDD from a 12-week, double blind, placebo-controlled, randomized clinical trial (RCT).

Methods

: This is a sub-analysis of a RCT of all 71 participants who took part in the trial. The impact of illness chronicity (illness duration and number of depressive episodes), systemic illness (endocrine, cardiovascular and obesity), adverse effects and minocycline were evaluated as change from baseline to endpoint (12-week) using ANCOVA.

Results

: There was a consistent but statistically non-significant trend on all outcomes in favour of the use of adjunctive minocycline for participants without systemic illness, less illness chronicity, and fewer adverse effects.

Conclusion

: Understanding the relationship between MDD and illness chronicity, comorbid systemic illness, and adverse effects, can potentially better characterise those individuals who are more likely to respond to adjunctive anti-inflammatory medications.

Role of Inflammatory Mechanisms in Major Depressive Disorder: From Etiology to Potential Pharmacological Targets

The involvement of central and peripheral inflammation in the pathogenesis and prognosis of major depressive disorder (MDD) has been demonstrated. The increase of pro-inflammatory cytokines (interleukin (IL)-1β, IL-6, IL-18, and TNF-α) in individuals with depression may elicit neuroinflammatory processes and peripheral inflammation, mechanisms that, in turn, can contribute to gut microbiota dysbiosis. Together, neuroinflammation and gut dysbiosis induce alterations in tryptophan metabolism, culminating in decreased serotonin synthesis, impairments in neuroplasticity-related mechanisms, and glutamate-mediated excitotoxicity. This review aims to highlight the inflammatory mechanisms (neuroinflammation, peripheral inflammation, and gut dysbiosis) involved in the pathophysiology of MDD and to explore novel anti-inflammatory therapeutic approaches for this psychiatric disturbance. Several lines of evidence have indicated that in addition to antidepressants, physical exercise, probiotics, and nutraceuticals (agmatine, ascorbic acid, and vitamin D) possess anti-inflammatory effects that may contribute to their antidepressant properties. Further studies are necessary to explore the therapeutic benefits of these alternative therapies for MDD.

Gut microbiota-derived short-chain fatty acids and depression: deep insight into biological mechanisms and potential applications

The gut microbiota is a complex and dynamic ecosystem known as the 'second brain'. Composing the microbiota-gut-brain axis, the gut microbiota and its metabolites regulate the central nervous system through neural, endocrine and immune pathways to ensure the normal functioning of the organism, tuning individuals' health and disease status. Short-chain fatty acids (SCFAs), the main bioactive metabolites of the gut microbiota, are involved in several neuropsychiatric disorders, including depression. SCFAs have essential effects on each component of the microbiota-gut-brain axis in depression. In the present review, the roles of major SCFAs (acetate, propionate and butyrate) in the pathophysiology of depression are summarised with respect to chronic cerebral hypoperfusion, neuroinflammation, host epigenome and neuroendocrine alterations. Concluding remarks on the biological mechanisms related to gut microbiota will hopefully address the clinical value of microbiota-related treatments for depression.

The predictive role of early inflammation and oxidative stress and the dynamics of cytokines networks in post-stroke depression

BACKGROUNDS

Chronic inflammation and oxidative stress play an important role in the pathogenesis of PSD. The main purposes of this study were to examine the dynamic changes of cytokines networks in PSD and the predictive role of early inflammation and oxidative stress for 2-week PSD.

METHODS

Patients with ischemic stroke were recruited on day 3, and those with Hamilton Depression Rating Scale 24-Item (HAMD-24) ≥8 were classified as ischemic stroke patients with depressive symptoms and others as ischemic stroke patients without depressive symptoms. Subjects were then followed up at 2 weeks and 3 months, with those meeting diagnostic criteria for depressive symptoms on the HAMD ≥8 and the Statistical Manual of Mental Disorders-V (DSM-V) as the PSD group, and the others as the non-PSD group.

RESULTS

At 3 days, IFN-γ, IL-12(p70), IL-12(p40), IL-2, IL-28A/IFNλ2, and IL-19 were elevated in ischemic stroke patients with depressive symptoms. At 2 weeks, IL-12(p40), IL-19, IL-22, IFN-β and MMP-1 all were increased in PSD patients. At 3 months, IL-2, IFN-β and sCD163 increased in PSD group. Longitudinally, the inflammatory response decreased significantly in PSD group from 2 weeks to 3 months of follow-up, while it gradually decreased in non-PSD group from 3 days to 3 months of follow-up. SOD was positively related to IL-12(p70), IFN-γ and IL-20. Plasma IFN-γ at 3 days may be a potential predictive biomarker for 2-week PSD.

CONCLUSIONS

Peripheral inflammation and oxidative stress are involved in the pathogenesis of PSD, providing new insights for its diagnosis and treatment.

Major depressive disorder: hypothesis, mechanism, prevention and treatment

Worldwide, the incidence of major depressive disorder (MDD) is increasing annually, resulting in greater economic and social burdens. Moreover, the pathological mechanisms of MDD and the mechanisms underlying the effects of pharmacological treatments for MDD are complex and unclear, and additional diagnostic and therapeutic strategies for MDD still are needed. The currently widely accepted theories of MDD pathogenesis include the neurotransmitter and receptor hypothesis, hypothalamic-pituitary-adrenal (HPA) axis hypothesis, cytokine hypothesis, neuroplasticity hypothesis and systemic influence hypothesis, but these hypothesis cannot completely explain the pathological mechanism of MDD. Even it is still hard to adopt only one hypothesis to completely reveal the pathogenesis of MDD, thus in recent years, great progress has been made in elucidating the roles of multiple organ interactions in the pathogenesis MDD and identifying novel therapeutic approaches and multitarget modulatory strategies, further revealing the disease features of MDD. Furthermore, some newly discovered potential pharmacological targets and newly studied antidepressants have attracted widespread attention, some reagents have even been approved for clinical treatment and some novel therapeutic methods such as phototherapy and acupuncture have been discovered to have effective improvement for the depressive symptoms. In this work, we comprehensively summarize the latest research on the pathogenesis and diagnosis of MDD, preventive approaches and therapeutic medicines, as well as the related clinical trials.

Chronic Treatment with Nigella sativa Oil Exerts Antimanic Properties and Reduces Brain Inflammation in Rats

Nigella sativa (NS) is a native herb consumed habitually in several countries worldwide, possessing manifold therapeutic properties. Among them, anti-inflammatory features have been reported, presumably relating to mechanisms involved in the nuclear factor kappa-B pathway, among others. Given the observed association between neuroimmune factors and mental illness, the primary aim of the present study was to examine the effects of chronic NS use on manic-like behavior in rats, as well as analyze levels of brain inflammatory mediators following NS intake. Using male and female rats, baseline tests were performed; thereafter, rats were fed either regular food (control) or NS-containing food (treatment) for four weeks. Following intervention, behavioral tests were induced (an open field test, sucrose consumption test, three-chamber sociality test, and amphetamine-induced hyperactivity test). Subsequently, brain samples were extracted, and inflammatory mediators were evaluated, including interleukin-6, leukotriene B4, prostaglandin E2, tumor necrosis factor-α, and nuclear phosphorylated-p65. Our findings show NS to result in a marked antimanic-like effect, in tandem with a positive modulation of select inflammatory mediators among male and female rats. The findings reinforce the proposed therapeutic advantages relating to NS ingestion.

Association between serum omega-3 PUFAs levels and cognitive impairment in never medically treated first-episode patients with geriatric depression: A cross-sectional study

BACKGROUND

Geriatric depression increases the public health burden and health care costs, reduces quality of life. Studies have shown the association between ω-3 PUFAs levels and inflammatory markers levels and depression, but few have explored the relationship between omega-3 PUFAs, inflammatory markers, and cognitive function in geriatric depression. This study aimed to compare the differences in ω-3 PUFAs levels and inflammatory markers between geriatric depression with cognitive impairment (CI) and those without CI.

METHODS

A total of three hundred and five elderly patients were recruited. In addition to collecting basic information, their blood specimens were collected to detect serum EPA, DHA, AA, TC, LDL-C, IL-6, TNF-α, and hs-CRP levels. The Hamilton depression scale (HAMD), Hamilton anxiety scale (HAMA), and The Montreal cognitive assessment (MoCA) were used to assess their depression, anxiety, and cognitive function, respectively.

RESULTS

Compared to those without CI, geriatric depression patients with CI had higher serum TC, LDL-C levels, lower EPA, DHA, and AA levels, and more elevated IL-6, TNF-α, and hs-CRP levels (all P < 0.05). Further linear regression analysis showed that EPA, DHA, and TNF-α, hs-CRP levels were significantly associated with the occurrence and the severity of CI.

LIMITATIONS

No causal relationship could be drawn due to the cross-sectional design.

CONCLUSIONS

Omega-3 PUFAs and inflammatory factors levels may predict CI in elderly patients with MDD in the future. Our findings suggest that ω-3 PUFAs (EPA and DHA) and inflammatory factors (TNF-α and CRP) may predict the occurrence and the severity of CI among elderly MDD patients.

Circulating T-cell subsets discrepancy between bipolar disorder and major depressive disorder during mood episodes: A naturalistic, retrospective study of 1015 cases

AIMS

We aimed to investigate whether peripheral T-cell subsets could be a biomarker to distinguish major depressive disorder (MDD) and bipolar disorder (BD).

METHODS

Medical records of hospitalized patients in the Department of Psychiatry, the First Affiliated Hospital, Zhejiang University School of Medicine, from January 2015 to September 2020 with a discharge diagnosis of MDD or BD were reviewed. Patients who underwent peripheral blood examination of T-cell subtype proportions, including CD3+, CD4+, CD8+ T-cell, and natural killer (NK) cells, were enrolled. The Chi-square test, t-test, or one-way analysis of variance were used to analyze group differences. Demographic profiles and T-cell data were used to construct a random forest classifier-based diagnostic model.

RESULTS

Totally, 98 cases of BD mania, 459 cases of BD depression (BD-D), and 458 cases of MDD were included. There were significant differences in the proportions of CD3+, CD4+, CD8+ T-cell, and NK cells among the three groups. Compared with MDD, the BD-D group showed higher CD8+ but lower CD4+ T-cell and a significantly lower ratio of CD4+ and CD8+ proportions. The random forest model achieved an area under the curve of 0.77 (95% confidence interval: 0.71-0.83) to distinguish BD-D from MDD patients.

CONCLUSION

These findings imply that BD and MDD patients may harbor different T-cell inflammatory patterns, which could be a potential diagnostic biomarker for mood disorders.

Therapeutic potential and possible mechanisms of ginseng for depression associated with COVID-19

Recently, a global outbreak of COVID-19 has rapidly spread to various national regions. As the number of COVID-19 patients has increased, some of those infected with SARS-CoV-2 have developed a variety of psychiatric symptoms, including depression, cognitive impairment, and fatigue. A distinct storm of inflammatory factors that contribute to the initial disease but also a persistent post-acute phase syndrome has been reported in patients with COVID-19. Neuropsychological symptoms including depression, cognitive impairment, and fatigue are closely related to circulating and local (brain) inflammatory factors. Natural products are currently being examined for their ability to treat numerous complications caused by COVID-19. Among them, ginseng has anti-inflammatory, immune system stimulating, neuroendocrine modulating, and other effects, which may help improve psychiatric symptoms. This review summarizes the basic mechanisms of COVID-19 pneumonia, psychiatric symptoms following coronavirus infections, effects of ginseng on depression, restlessness, and other psychiatric symptoms associated with post-COVID syn-dromes, as well as possible mechanisms underlying these effects.

Age-related subtypes of late life depression and mortality: A prospective clinical cohort study

OBJECTIVES

Late Life Depression (LLD) is associated with increased mortality rates, but it remains unclear which depressed patients are at increased risk. This study examined the mortality risk of previously identified subgroups of depressed older patients based on age-related clinical features (the presence of physical and cognitive frailty).

METHODS

A six-year follow-up of a clinical cohort study including 375 depressed older patients and 132 non-depressed persons (NESDO). Depressed patients were diagnosed with the Composite International Diagnostic Interview (CIDI) according to DSM-IV criteria and classified by latent profile analysis on depressive symptom severity, cognitive domains and physical frailty. We estimated the hazard rate of mortality for the four depressed subgroups compared to non-depressed persons by applying Cox-regression analyses. Models were adjusted for age, sex and education as confounders and for explanatory variables per pathway in separate models: somatic burden, lifestyle characteristics, vascular burden or inflammation markers.

RESULTS

A total of 61/375 (16.3%) depressed patients and 8/132 (6.1%) non-depressed persons died during the 6-year follow-up. Two of the four subgroups (n = 186/375 (50%) of the depressed sample) had a higher hazard rate (HR) for mortality compared to non-depressed participants, that is, frail-depressed patients (HR = 5.25, [95%-CI: 2.13-13.0]) and pure mild depressed patients (HR = 3.32 [95%-CI: 1.46-7.58]) adjusted for confounders. Adding possible underlying pathways did not explain these associations.

CONCLUSIONS

Age-related features (the presence of physical and cognitive frailty) contribute to the increased mortality risk in late-life depression. Future studies in depressed older patients should study the additional value of a clinical geriatric assessment and integrated treatment aimed to at reduce frailty and ameliorate their mortality risk.