Status of inflammation and alcohol use in a 6-month follow-up study of patients with major depressive disorder

Depression and HIV: a scoping review in search of neuroimmune biomarkers

People with HIV are at increased risk for depression, though the neurobiological mechanisms underlying this are unclear. In the last decade, there has been a substantial rise in interest in the contribution of (neuro)inflammation to depression, coupled with rapid advancements in the resolution and sensitivity of biomarker assays such as Luminex, single molecular array and newly developed positron emission tomography radioligands. Numerous pre-clinical and clinical studies have recently leveraged these next-generation immunoassays to identify biomarkers that may be associated with HIV and depression (separately), though few studies have explored these biomarkers in co-occurring HIV and depression. Using a systematic search, we detected 33 publications involving a cumulative N = 10 590 participants which tested for associations between depressive symptoms and 55 biomarkers of inflammation and related processes in participants living with HIV. Formal meta-analyses were not possible as statistical reporting in the field was highly variable; future studies must fully report test statistics and effect size estimates. The majority of included studies were carried out in the United States, with samples that were primarily older and primarily men. Substantial further work is necessary to diversify the geographical, age, and sex distribution of samples in the field. This review finds that alterations in concentrations of certain biomarkers of neuroinflammation (interleukin-6, tumour necrosis factor-α, neopterin) may influence the association between HIV and depression. Equally, the chemokines monocyte chemoattractant protein-1 (MCP-1) and interleukin-8 (IL-8) or the metabolic index kynurenine:tryptophan (Kyn:Trp), which have been the focus of several studies, do not appear to be associated with depressive symptoms amongst people living with HIV, as all (MCP-1) or most (IL-8 and Kyn:Trp) available studies of these biomarkers reported non-significant associations. We propose a biomarker-driven hypothesis of the neuroimmunometabolic mechanisms that may precipitate the increased risk of depression among people with HIV. Chronically activated microglia, which trigger key neuroinflammatory cascades shown to be upregulated in people with HIV, may be the central link connecting HIV infection in the central nervous system with depressive symptoms. Findings from this review may inform research design in future studies of HIV-associated depression and enable concerted efforts towards biomarker discovery.

Cytokine level in patients with mood disorder, alcohol use disorder and their comorbidity

OBJECTIVES

Because alcohol use disorder (AUD) is often accompanied by mood disorder (MD) and both alcoholism and depression result in activation of the immune system, this study compares serum cytokine levels in the presence of co-morbidity with those in either AUD or MD alone.

METHODS

In this naturalistic prospective study the levels of 15 different cytokines were measured in serum samples of patients with MD (n = 43), participants with combined AUD-MD (n = 44) and AUD without MD (n = 42). The levels were compared cross-sectionally among themselves and with those in 50 healthy volunteers.

RESULTS

Pro-inflammatory IFN-2α levels were consistently significantly higher and anti-inflammatory IL-1RA significantly lower in all study groups in comparison to healthy volunteers. In the MD only group we found increased IL-6 (p = 0.001), IL-7 (p = 0.001) and IL-13 (p = 0.006) levels, and decreased TNFα (p = 0.0001), IL-1RA (p = 0.012), IL-10 (p = 0.002) compared with group MD + AUD. Patients with AUD only showed elevated levels of IL-1β (p = 0.046), IL-2 (p = 0.004), IL-7 (p = 0.0001), IL-4 (p = 0.049) and IL-13 (p = 0.015) in contrast with MD + AUD group.

CONCLUSIONS

Because the interactions of alcohol with peripheral and cerebral immune systems are multifaceted, the pertinent connection to the mechanism how alcohol consumption contributes to the development of mood disorders cannot be properly explored.

Methylation of genes and regulation of inflammatory processes on emotional response in young adults with alcoholic parents

Many Americans are adult children of an alcoholic parent (ACoA), which can confer an increased risk of trauma and hazardous alcohol use, as well as heritable and environmental genetic influence. Psychological health and related neural activity can be influenced by inflammation responses, but it is not clear how these factors interact regarding risk or resilience to hazardous alcohol use. The goals of this study were to better understand the relationships between current alcohol use and inflammation, how these are modified by single nucleotide polymorphisms (SNPs) and/or epigenetic modifications of inflammation-associated genes; and how these alter neural reactivity to emotionally-salient stimuli. To do so, ACoA participants were dichotomized as resilient (not engaged in hazardous alcohol use) or vulnerable (currently engaged in hazardous alcohol use). Measures of blood-oxygen-level-dependent (BOLD) activity within regions of interest (ROIs), SNPs and DNA methylation of specific inflammation regulatory genes, and biological markers of inflammation were compared between these groups. Vulnerable ACoAs exhibited higher plasma C-reactive protein (CRP) and greater BOLD activity in the right hippocampus and ventral anterior cingulate cortex in response to emotional cues as well as reduced methylation of CRP and glucocorticoid-related genes. Path analysis revealed significant relationships between alcohol use, SNPs, DNA methylation of inflammatory-related genes, CRP levels, and BOLD activity to emotional stimuli. Taken together, these findings suggest a complex association related to hazardous alcohol use in ACoAs that may predict current inflammation and neural reactivity to emotional stimuli. A better understanding of these associations could direct the future of individual treatment options.

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Alterations of genes and alcohol use increases inflammation and affects mental health.

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Proposed model illustrating pathway for alcohol use leading to poor mental health.

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Methylation of promotor regions on mental health genes is affected by inflammation.

Prospective associations between multiple lifestyle behaviors and depressive symptoms

BACKGROUND

Our aim was to analyze the associations between multiple lifestyle behaviors and depressive symptoms.

METHODS

We included 4,725 adults (18-59y), that provided data in routine health evaluations of a hospital in Brazil, followed for a mean period of 3.1 ± 1.6 years. Physical activity, alcohol consumption (measured using Alcohol Use Disorders Identification Test) and tobacco smoking were categorized as: (1) absence of the behavior (inactivity i.e. not complying with 150 min of moderate-to-vigorous PA/week, not smoking, no risky drinking, i.e. AUDIT<5) during baseline and follow-up; (2) Absence during baseline and presence during follow-up; (3) Presence during baseline and absence during follow-up; (4) Presence during both time points. Depressive symptoms were measured with the Beck Inventory was adopted to analyze patterns of depressive symptoms over time (as exposure). C-reactive protein [HS-CRP]) was assessed and its role in the association was tested. Incidence indicators of behaviors and depressive symptoms were created and used as outcomes. We used crude and adjusted Poisson regression analysis.

RESULTS

Fully adjusted models revealed that persistently physical inactive participants (RR:1.71;95%CI:1.33-2.21), those who became physically inactive (1.68;1.19-2.26), with consistently risky drinking (1.62;1.15-2.30), and who became risky drinkers (1.62;1.15-2.30) had higher risk for incidence of elevated depressive symptoms. Vice versa participants with incidence of depressive symptoms over time presented higher risk for physical inactivity (1.44;1.11-1.87) and risky drinking (1.65;1.16-2.34) incidence. HS-CRP did not influence the associations.

LIMITATIONS

Self-reported physical activity, binary tobacco smoking, and non-probabilistic sampling.

CONCLUSIONS

There is a prospective relationship between elevated depressive symptoms and adverse lifestyle behaviors.

The role of alcohol use and adiposity in serum levels of IL-1RA in depressed patients

BACKGROUND

The role of Interleukin-1 Receptor antagonist (IL-1Ra), an innate antagonist to pro-inflammatory cytokine IL-1, has attracted increasing attention due to its potential pathogenic and therapeutic implications in depression. However, the role of alcohol and adiposity in modulating IL-1Ra cytokine pathway in depressed patients has remainned unknown. The aim of this study was to follow the changes in IL-1Ra serum levels in depressed patients with or without simultaneous alcohol use disorder (AUD) and different degrees of adiposity during 6 months of follow-up.

MATERIALS AND METHODS

A total of 242 patients with depression were followed for 6 months. At baseline 99 patients had simultaneous AUD. Levels of serum IL-1Ra and common mediators of inflammation (IL-6, hs-CRP) were measured. Clinical assessments included Body Mass Index (BMI), Montgomery-Asberg Depression Rating Scale (MADRS) and Alcohol Use Disorders Identification Test (AUDIT) scores.

RESULTS

Significant reductions in clinical symptoms and IL-1Ra were observed during 6-month follow-up. In hierarchical linear regression analysis, the effect of MADRS score, age, gender, and smoking had a combined effect of 2.4% in the model. The effect of AUDIT score increased the effect to 4.2% of variance (p = 0.08), whereas adding BMI increased the effect to 18.5% (p <  0.001).

CONCLUSION

Adiposity may influence the IL-1Ra anti-inflammatory response in depressed patients, whereas the effect of alcohol consumption in these patients seems insignificant. These findings should be considered in studies on the role of IL-1Ra in depression.

TRIAL REGISTRATION

Ostrobothnia Depression Study in ClinicalTrials.gov , Identifier NCT02520271 .