IFN-alpha-induced motor slowing is associated with increased depression and fatigue in patients with chronic hepatitis C

DNA Damage-driven Inflammatory Cytokines: Reprogramming of Tumor Immune Microenvironment and Application of Oncotherapy

DNA damage occurs across tumorigenesis and tumor development. Tumor intrinsic DNA damage can not only increase the risk of mutations responsible for tumor generation but also initiate a cellular stress response to orchestrate the tumor immune microenvironment (TIME) and dominate tumor progression. Accumulating evidence documents that multiple signaling pathways, including cyclic GMP-AMP synthase-stimulator of interferon genes (cGAS-STING) and ataxia telangiectasia-mutated protein/ataxia telangiectasia and Rad3-related protein (ATM/ATR), are activated downstream of DNA damage and they are associated with the secretion of diverse cytokines. These cytokines possess multifaced functions in the anti-tumor immune response. Thus, it is necessary to deeply interpret the complex TIME reshaped by damaged DNA and tumor-derived cytokines, critical for the development of effective tumor therapies. This manuscript comprehensively reviews the relationship between the DNA damage response and related cytokines in tumors and depicts the dual immunoregulatory roles of these cytokines. We also summarize clinical trials targeting signaling pathways and cytokines associated with DNA damage and provide future perspectives on emerging technologies.

Dopamine Transmission Imbalance in Neuroinflammation: Perspectives on Long-Term COVID-19

Dopamine (DA) is a key neurotransmitter in the basal ganglia, implicated in the control of movement and motivation. Alteration of DA levels is central in Parkinson’s disease (PD), a common neurodegenerative disorder characterized by motor and non-motor manifestations and deposition of alpha-synuclein (α-syn) aggregates. Previous studies have hypothesized a link between PD and viral infections. Indeed, different cases of parkinsonism have been reported following COVID-19. However, whether SARS-CoV-2 may trigger a neurodegenerative process is still a matter of debate. Interestingly, evidence of brain inflammation has been described in postmortem samples of patients infected by SARS-CoV-2, which suggests immune-mediated mechanisms triggering the neurological sequelae. In this review, we discuss the role of proinflammatory molecules such as cytokines, chemokines, and oxygen reactive species in modulating DA homeostasis. Moreover, we review the existing literature on the possible mechanistic interplay between SARS-CoV-2-mediated neuroinflammation and nigrostriatal DAergic impairment, and the cross-talk with aberrant α-syn metabolism.

Effects of an experimentally induced inflammatory stimulus on motivational behavior in remitted depressed patients

BACKGROUND

Acute inflammation is associated with sickness behavior characterized by reduced motivation for pleasurable activities in humans. The current study investigated the effect of an experimentally induced inflammatory stimulus on motivational reward in people who remitted from depression.

METHODS

This randomized, double-blind crossover study involved 12 participants, 5 with remitted major depressive disorder (rMDD) and 7 healthy controls (HC), who received an injection of typhoid vaccine and placebo (or vice-versa) intramuscularly at least one week apart. At baseline and between 4 and 6 h post-injection on both days, participant mood was measured using the profile of mood states (POMS), and injection blood samples were collected for cytokines measurement. All participants completed the Effort Expenditure for Rewards Task (EEfRT), a behavioral paradigm measuring effort-based decision-making before and 4 h post-both injections. Generalized linear mixed modeling was used to evaluate group differences in choosing the hard over easy task to obtain a monetary reward.

RESULTS

Typhoid vaccine increased IL-6 in all participants. On the EEfRT, a significant interaction between treatment condition (typhoid vs. placebo) and participant group (HC vs. rMDD) was found (p = .004). Analyses of simple effects within treatment conditions found that after placebo, HCs were more likely to choose the harder task than rMDD (OR = 3.21; p = .013). However, after the typhoid vaccine, no differences were found between rMDD and HC (p = .397). Analyses within participant groups found that the probability of choosing a hard task was higher after placebo for HC (OR = 1.37; p = .045), but not different within rMDD (p = .241). For HC at baseline, mood was significantly lower following injection with typhoid vaccine, relative to placebo (b = -1.03, p < .001); however, this effect should be considered coincidental, given that mood rating was taken prior to injection. For rMDD patients 4-6 h post-injection, mood was significantly lower following typhoid vaccine, relative to placebo (b = -0.981, p < .001 b = -0.77, p < .001). Finally, for HC receiving placebo, mood was significantly lower 4-6 h post-injection, relative to baseline (b = -1.76, p < .001).

CONCLUSIONS

Our preliminary findings suggest persistent deficits in motivational reward processing function despite clinical improvement in remitted depressed patients.

Inflammation-Related Functional and Structural Dysconnectivity as a Pathway to Psychopathology

Findings from numerous laboratories and across neuroimaging modalities have consistently shown that exogenous administration of cytokines or inflammatory stimuli that induce cytokines disrupts circuits and networks involved in motivation and motor activity, threat detection, anxiety, and interoceptive and emotional processing. While inflammatory effects on neural circuits and relevant behaviors may represent adaptive responses promoting conservation of energy and heightened vigilance during immune activation, chronically elevated inflammation may contribute to symptoms of psychiatric illnesses. Indeed, biomarkers of inflammation such as cytokines and acute phase reactants are reliably elevated in a subset of patients with unipolar or bipolar depression, anxiety-related disorders, and schizophrenia and have been associated with differential treatment responses and poor clinical outcomes. A growing body of literature also describes higher levels of endogenous inflammatory markers and altered, typically lower functional or structural connectivity within these circuits in association with transdiagnostic symptoms such as anhedonia and anxiety in psychiatric and at-risk populations. This review presents recent evidence that inflammation and its effects on the brain may serve as one molecular and cellular mechanism of dysconnectivity within anatomically and/or functionally connected cortical and subcortical regions in association with transdiagnostic symptoms. We also discuss the need to establish reproducible methods to assess inflammation-associated dysconnectivity in relation to behavior for use in translational studies or biomarker-driven clinical trials for novel pharmacological or behavioral interventions targeting inflammation or its effects on the brain.

Lipopolysaccharide-induced changes in effort-related motivational function: Interactions with 2-deoxyglucose

Inflammation is linked to motivational deficits seen in depression and other disorders. Lipopolysaccharide (LPS) induces an inflammatory response and impairs motivated behavior in humans and rodents. It has been suggested that inflammation can shift metabolic needs to functions that warrant more response to the perceived threat (e.g., fighting infection), therefore altering aspects of motivation. Animal models have been developed to assess alterations in motivated behavior by giving the animal the option to work (i.e., lever press) for a highly palatable food reward vs. approaching and consuming a freely available, albeit less preferred, food. This model was used to determine if administration of 2-deoxy-D-glucose (2DG), a substance that inhibits glucose uptake and glycolysis, could reverse the motivational deficits induced by LPS in rats. A food preference/intake task was also conducted to see if LPS affected intake of the highly palatable vs. less palatable foods when both are freely available. It was hypothesized that 2-DG would reverse the motivational deficits caused by LPS and there would be no effect on food preference/intake of the highly palatable food. Results showed that 2-DG significantly reversed LPS effects at the lowest dose, while methylphenidate did not. The food intake/preference tests showed that LPS significantly decreased food intake of both foods but did not alter preference for the highly palatable food compared to vehicle. These results suggest that in addition to having effects on exertion of effort during instrumental behavior, LPS also has direct effects on primary food motivation.

Fatigue in Patients with Chronic Hepatitis C

This study aimed to explore the factors associated with fatigue in chronic hepatitis C patients before and at 4, 8, 12, 16, 20, and 24 weeks after antiviral therapy. The study employed a prospective and repeated-measures design. The Chinese version of the brief fatigue inventory (BFI-C) and the Pittsburg sleep quality index (PSQI) were employed to collect data. Pegylated Interferon plus Ribavirin dosages and serum values (hemoglobin, alanine aminotransferase [ALT], and aspartate aminotransferase [AST]) were monitored before and during the antiviral therapy at 4, 8, 12, 16, 20, and 24 weeks. The study enlisted 115 patients as participants. Multivariate analysis indicated that gender, educational level, body mass index (BMI), and hemoglobin level were significant determinants of patients’ fatigue. When hemoglobin levels in the patients decreased in week 4 and continued to fall to the nadir at week 12, it prompted the healthcare providers to assess their fatigue levels and initiate proactive interventions as needed.

Inflammatory stress responses and future mental health outcomes in people with type 2 diabetes

Background

Inflammatory dysregulation may be linked with mental health disturbances in people with Type 2 Diabetes (T2D), however no previous studies have examined longitudinal associations between inflammatory stress responses and mental health outcomes in T2D.

Purpose

To better understand the biological mechanisms that might predispose people with T2D to poor mental health in the future.

Methods

At baseline, 140 participants with T2D participated in a laboratory stress testing study (mean age = 64 years). Participants underwent two mental stress tasks and blood was sampled before and up to 45 min post-stress to detect plasma interleukin (IL)-6. The Center for Epidemiological Studies-Depression scale and the Short Form-36 Health Survey were completed at baseline and 7.5 years later. We tested associations between IL-6 stress responses and a) depression symptoms and b) mental health-related quality of life (QoL) at baseline and at follow-up using linear regression analyses adjusting for age, sex, and body mass index (BMI). Results: Up to 66 participants provided follow-up data. In cross-sectional analyses, increased IL-6 stress responses immediately post-task were associated with lower mental health-related quality of life (B = -21.73, p = 0.005, 95% CI [-36.82, -6.63]) adjusting for age, sex, and BMI. In longitudinal analyses, increased IL-6 stress responses at 45 min post-task were associated with increased depressive symptoms (B = 10.31 p = 0.048, 95% CI [0.10, 20.51]) and decreased mental health-related QoL (B = -21.18 p = 0.031, 95% CI [-40.34, -2.02]) adjusting for age, sex, and BMI. The association between the 45-min IL-6 response and depressive symptoms at follow-up was diminished after further adjustment for physical health-related QoL and baseline depressive symptoms (B = 10.14, p = 0.055, 95% CI [-0.21,20.48]).

Conclusions

This study supports the link between inflammatory stress responsivity and future mental health outcomes in people with T2D. Further research involving a larger sample size is required.

Neurocognitive Performance in Depressed Patients with low-grade inflammation and somatic symptoms

BACKGROUND

The link between inflammation and depression has been investigated extensively. Cognitive dysfunction in depression is an unmet treatment need. A better understanding of possible links between inflammation and cognition in people with depression may help to identify new treatment targets.

METHODS

We report findings from a study comparing a range of cognitive functions between 80 depressed patients with (C-reactive protein ≥3 ​mg/L; n ​= ​37) and without (CRP<3 ​mg/L; n ​= ​43) evidence of inflammation. All participants met the International Classification of Diseases 10th Revision criteria for current depressive episode and had somatic symptoms of depression. All participants completed cognitive testing and clinical assessment and were screened for acute infection.

RESULTS

Patients with evidence of inflammation, compared to those without, had slower psychomotor speed as measured by symbol coding task (mean difference ​= ​0.06, 95% CI ​= ​0.003-0.11) and slower reaction time, as measured by a simple movement time task (mean difference ​= ​26.56, 95% CI ​= ​-48.92 to -4.20). These effects were fully explained after controlling for age, sex, and body mass index. Measures of emotional processing, memory, and planning were comparable between two groups.

CONCLUSIONS

Certain cognitive domains, particularly processing speed and reaction time may be more affected in depressed patients with evidence of low-grade inflammation and somatic symptoms. Further studies with larger samples are required for a clearer understanding of the association between inflammation and cognitive dysfunction in depression.

The Association between Modifiable Lifestyle Behaviors and Depression among Asian Americans with Chronic Hepatitis B by Medication Status

Asian Americans are disproportionately affected by chronic hepatitis B (CHB), with incidence and mortality rates well above those experienced by non-Hispanic white populations. The goal of this study was to examine the association between depression and modifiable lifestyle behaviors among Asian Americans with CHB, with a comparison between those on hepatitis medication and those not on medication. In total, 313 Asian Americans with CHB were recruited through outpatient clinics and community-based organizations to participate in an in-person baseline assessment. We collected data on participants’ sociodemographic characteristics, health-related behaviors, depression symptoms, and modifiable lifestyle behaviors. Bivariate analyses (two sample t-test and chi-square test of independence) and multivariable logistic regression were conducted. We found a high prevalence of depression among individuals living with CHB (41.81% among those not on antiviral medication and 39.71% among those on medication). Multivariate logistic regression results showed that Chinese ethnicity (vs. Vietnamese) and lack of physical activity were significantly associated with a higher risk of mild/severe depression, regardless of medication status. However, the protective effect of physical activity was strong for those on antiviral medication. Furthermore, being employed was significantly associated with a lower risk for depression among Asian Americans on medication, while younger age and being currently married were significantly associated with lower risk of depression among those not on medication. Our findings highlight the significance of physical activity among Asian Americans with CHB, especially for those on antiviral medication. Future prospective research efforts are needed to better identify the potential behavioral mechanisms of depression and provide insights for the psychopharmacological management in this vulnerable population.

Influences of dopaminergic system dysfunction on late-life depression

Deficits in cognition, reward processing, and motor function are clinical features relevant to both aging and depression. Individuals with late-life depression often show impairment across these domains, all of which are moderated by the functioning of dopaminergic circuits. As dopaminergic function declines with normal aging and increased inflammatory burden, the role of dopamine may be particularly salient for late-life depression. We review the literature examining the role of dopamine in the pathogenesis of depression, as well as how dopamine function changes with aging and is influenced by inflammation. Applying a Research Domain Criteria (RDoC) Initiative perspective, we then review work examining how dopaminergic signaling affects these domains, specifically focusing on Cognitive, Positive Valence, and Sensorimotor Systems. We propose a unified model incorporating the effects of aging and low-grade inflammation on dopaminergic functioning, with a resulting negative effect on cognition, reward processing, and motor function. Interplay between these systems may influence development of a depressive phenotype, with an initial deficit in one domain reinforcing decline in others. This model extends RDoC concepts into late-life depression while also providing opportunities for novel and personalized interventions.

Brick by Brick: Building a Transdiagnostic Understanding of Inflammation in Psychiatry

ABSTRACT

Inflammatory phenomena are found in many psychiatric disorders-notably, depression, schizophrenia, and posttraumatic stress disorder. Inflammation has been linked to severity and treatment resistance, and may both contribute to, and result from, the pathophysiology of some psychiatric illnesses. Emerging research suggests that inflammation may contribute to symptom domains of reward, motor processing, and threat reactivity across different psychiatric diagnoses. Reward-processing deficits contribute to motivational impairments in depression and schizophrenia, and motor-processing deficits contribute to psychomotor slowing in both depression and schizophrenia. A number of experimental models and clinical trials suggest that inflammation produces deficits in reward and motor processing through common pathways connecting the cortex and the striatum, which includes the nucleus accumbens, caudate nucleus, and putamen.The observed effects of inflammation on psychiatric disorders may cut across traditional conceptualizations of psychiatric diagnoses. Further study may lead to targeted immunomodulating treatments that address difficult-to-treat symptoms in a number of psychiatric disorders. In this review, we use a Research Domain Criteria framework to discuss proposed mechanisms for inflammation and its effects on the domains of reward processing, psychomotor slowing, and threat reactivity. We also discuss data that support contributing roles of metabolic dysregulation and sex differences on the behavioral outcomes of inflammation. Finally, we discuss ways that future studies can help disentangle this complex topic to yield fruitful results that will help advance the field of psychoneuroimmunology.

The association between cytokines and psychomotor speed in a spectrum of psychotic disorders: A longitudinal study

Background

In schizophrenia, impaired psychomotor speed is a common symptom predicting worse functional outcome. Inflammation causes changes in white matter integrity, which may lead to reduced psychomotor speed. Therefore, we wanted to investigate if peripheral inflammation assessed with cytokines affected performance on psychomotor speed in patients with a spectrum of psychotic disorders.

Methods

The current study is a prospective cohort study, including participants from a pragmatic, randomised controlled trial comparing three atypical antipsychotics in patients with a spectrum of psychotic disorders. For the purposes of this sub-study, we analysed drug treatment groups collectively. Psychomotor speed was assessed at baseline, and at weeks 6, 12, 26 and 52 of follow-up, using the neuropsychological tests trail making test (TMT) A and B, and symbol coding. Serum concentration of the following cytokines were measured: interleukin (IL)-β, IL-2, IL-4, IL-6, IL-10, IL12 p70, IL-17a, interferon (IFN)-γ and tumor necrosis factor (TNF)-α. Blood samples were collected at baseline and after 1, 3, 6, 12, 26, 39 and 52 weeks. We analysed the effect of cytokines levels on psychomotor speed over time in linear mixed effects models.

Results

In our linear mixed effects models controlling for possible confounders, IFN-γ had a significant negative effect on TMT-A and symbol coding performance. None of the other tests for psychomotor speed were significantly associated with cytokines. Overall psychomotor speed performance increased significantly across the study period while cytokine levels remained stable.

Conclusion

Our study indicates a negative association between IFN-γ and psychomotor speed, which might be of importance when understanding the mechanisms behind psychomotor deviations in psychotic disorders.

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The cytokine interferon (IFN) – γ is related to psychomotor speed in patients with psychotic disorders.

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For majority of cytokines, we found no significant association with psychomotor speed.

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Cytokines remained stable during the study period of 52 weeks.

Neuropsychological effects of direct-acting antiviral treatment for Hepatitis C virus subjects: A systematic review

Direct-acting antivirals (DAAs) have been approved in recent years to treat patients infected by the Hepatitis C virus (HCV). The DAAs treatment is well tolerated and increases sustained virological responses, but there is no consensus about the neuropsychological functioning related to the treatment. This systematic review aims to provide an overview of the recent findings exploring the cognitive effects of DAAs treatment in patients with HCV. After a systematic search on PubMed, Embase, Scopus and LILACS, studies that assessed neuropsychological data related to DAAs treatment were included. We found nine articles, considering the inclusion and exclusion criteria. Three other manuscripts were included after searching for the references listed in the previously mentioned articles. We observed methodological heterogeneity in terms of neuropsychological tests used, cognitive domain explored and the sample characteristic presented between the studies. Studies presented data from HCV subjects monoinfected with or without cirrhosis, advanced liver disease and post-transplant patients; and HCV subjects coinfected with human immunodeficiency virus (HIV). Most results from the 12 studies that explored the effect of DAAs treatment in HCV subjects' neurocognitive functioning demonstrated cognitive improvement following treatment. In general, HCV and HCV/HIV subjects improved processing speed, verbal fluency and verbal/visual episodic memory. The DAAs treatment is effective for neurocognitive functioning in HCV monoinfected and coinfected subjects, with or without advanced liver disease, since neuropsychological scores increased after treatment. Further studies, however, are needed to confirm these findings.

Transcriptomic signatures of psychomotor slowing in peripheral blood of depressed patients: evidence for immunometabolic reprogramming

Inflammation impacts basal ganglia motor circuitry in association with psychomotor retardation, a key symptom of major depression (MD). We previously reported associations between circulating protein inflammatory biomarkers and psychomotor slowing as measured by neuropsychological tests probing psychomotor speed in patients with MD. To discover novel transcriptional signatures in peripheral blood immune cells related to psychomotor slowing, microarray data were analyzed in a primary cohort of 88 medically-stable, unmedicated, ambulatory MD patients. Results were confirmed and extended in a second cohort of 57 patients with treatment resistant depression (TRD) before and after anti-inflammatory challenge with the tumor necrosis factor antagonist infliximab versus placebo. Composite scores reflecting pure motor and cognitive-motor processing speed were linearly associated with 403 and 266 gene transcripts in each cohort, respectively (|R| > 0.30, p < 0.01), that were enriched for cytokine signaling and glycolysis-related pathways (p < 0.05). Unsupervised clustering in the primary cohort revealed two psychomotor slowing-associated gene co-expression modules that were enriched for interferon, interleukin-6, aerobic glycolysis, and oxidative phosphorylation pathways (p < 0.05, q < 0.1). Transcripts were predominantly derived from monocytes, plasmacytoid dendritic cells, and natural killer cells (p's < 0.05). In infliximab-treated TRD patients with high plasma C-reactive protein concentrations (>5 mg/L), two differential co-expression modules enriched for oxidative stress and mitochondrial degradation were associated with improvements in psychomotor reaction time (p < 0.05). These results indicate that inflammatory signaling and associated metabolic reprogramming in peripheral blood immune cells are associated with systemic inflammation in depression and may affect relevant brain circuits to promote psychomotor slowing.

Neuronal Mitochondrial Dysfunction and Bioenergetic Failure in Inflammation-Associated Depression

Depression is a leading cause of disability and affects more than 4% of the population worldwide. Even though its pathophysiology remains elusive, it is now well accepted that peripheral inflammation might increase the risk of depressive episodes in a subgroup of patients. However, there is still insufficient knowledge about the mechanisms by which inflammation induces alterations in brain function. In neurodegenerative and neuroinflammatory diseases, extensive studies have reported that inflammation negatively impacts mitochondrial health, contributing to excitotoxicity, oxidative stress, energy deficits, and eventually neuronal death. In addition, damaged mitochondria can release a wide range of damage-associated molecular patterns that are potent activators of the inflammatory response, creating a feed-forward cycle between oxidative stress, mitochondrial impairment, inflammation, and neuronal dysfunction. Surprisingly, the possible involvement of this vicious cycle in the pathophysiology of inflammation-associated depression remains understudied. In this mini-review we summarize the research supporting the association between neuroinflammation, mitochondrial dysfunction, and bioenergetic failure in inflammation-associated depression to highlight the relevance of further studies addressing this crosstalk.

Integrating the monoamine and cytokine hypotheses of depression: Is histamine the missing link?

Psychiatric diseases, like depression, largely affect the central nervous system (CNS). While the underlying neuropathology of depressive illness remains to be elucidated, several hypotheses have been proposed as molecular underpinnings for major depressive disorder, including the monoamine hypothesis and the cytokine hypothesis. The monoamine hypothesis has been largely supported by the pharmaceuticals that target monoamine neurotransmitters as a treatment for depression. However, these antidepressants have come under scrutiny due to their limited clinical efficacy, side effects, and delayed onset of action. The more recent, cytokine hypothesis of depression is supported by the ability of immune-active agents to induce "sickness behaviour" akin to that seen with depression. However, treatments that more selectively target inflammation have yielded inconsistent antidepressive results. As such, neither of these hypotheses can fully explain depressive illness pathology, implying that the underlying neuropathological mechanisms may encompass aspects of both theories. The goal of the current review is to integrate these two well-studied hypotheses and to propose a role for histamine as a potential unifying factor that links monoamines to cytokines. Additionally, we will focus on stress-induced depression, to provide an updated perspective of depressive illness research and thereby identify new potential targets for the treatment of major depressive disorder.

Vaccination and Immunotherapy for Major Depression

Depression is a very common disease with increasing incidence resulting from complex interactions of genetic, environmental, and immunological processes. To this day, the etiopathogenesis and treatment of depression unfortunately seem to be stuck in the synaptic gap. Despite highly potent antidepressants, the treatment rate cannot reach 100%, the treatment resistant group cannot be eliminated, and relapse cannot be prevented. These problems lead researchers to further and different research to understand and treat psychopathology. Immune dysfunction and neuroinflammation have been one of the main issues that psychiatry has focused on in recent years and helps us to understand depression. Extraneuronal components of all neuropsychiatric disorders, especially depression, have begun to be revealed in detail thanks to a better understanding of the immune system and an increase in experimental and technological possibilities. There is increasing evidence of a causal relationship between the etiopathogenesis of major depression and low-level chronic neuroinflammation. In this article, the role of neuroinflammation in the etiopathogenesis of depression and the possibilities of vaccination and immunotherapy are discussed.

In Vivo TSPO Signal and Neuroinflammation in Alzheimer's Disease

In the last decade, positron emission tomography (PET) and single-photon emission computed tomography (SPECT) in in vivo imaging has attempted to demonstrate the presence of neuroinflammatory reactions by measuring the 18 kDa translocator protein (TSPO) expression in many diseases of the central nervous system. We focus on two pathological conditions for which neuropathological studies have shown the presence of neuroinflammation, which translates in opposite in vivo expression of TSPO. Alzheimer's disease has been the most widely assessed with more than forty preclinical and clinical studies, showing overall that TSPO is upregulated in this condition, despite differences in the topography of this increase, its time-course and the associated cell types. In the case of schizophrenia, a reduction of TSPO has instead been observed, though the evidence remains scarce and contradictory. This review focuses on the key characteristics of TSPO as a biomarker of neuroinflammation in vivo, namely, on the cellular origin of the variations in its expression, on its possible biological/pathological role and on its variations across disease phases.

Acute inflammation and psychomotor slowing: Experimental assessment using lipopolysaccharide administration in healthy humans

Data from clinical and cross-sectional studies suggest that inflammation contributes to psychomotor slowing and attentional deficits found in depressive disorder. However, experimental evidence is still lacking. The aim of this study was to clarify the effect of inflammation on psychomotor slowing using an experimental and acute model of inflammation, in which twenty-two healthy volunteers received an intravenous injection of lipopolysaccharide (LPS, dose: 0.8 ​ng/kg body weight) and of placebo, in a randomized order following a double-blind within-subject crossover design. A reaction time test and a go/no-go test were conducted 3 ​h after the LPS/placebo injection and interleukin (IL)-6 and tumor necrosis factor (TNF)-α concentrations were assessed. No effect of experimental inflammation on reaction times or errors for either test was found. However, inflammation was related to worse self-rated performance and lower effort put in the tasks. Exploratory analyses indicated that reaction time fluctuated more over time during acute inflammation. These data indicate that acute inflammation has only modest effects on psychomotor speed and attention in healthy subjects objectively, but alters the subjective evaluation of test performance. Increased variability in reaction time might be the first objective sign of altered psychomotor ability and would merit further investigation.

Fatigue in inflammatory rheumatic disorders: pathophysiological mechanisms

Today, inflammatory rheumatic disorders are effectively treated, but many patients still suffer from residual fatigue. This work presents pathophysiological mechanisms of fatigue. First, cytokines can interfere with neurotransmitter release at the preterminal ending. Second, a long-term increase in serum concentrations of proinflammatory cytokines increase the uptake and breakdown of monoamines (serotonin, noradrenaline and dopamine). Third, chronic inflammation can also decrease monoaminergic neurotransmission via oxidative stress (oxidation of tetrahydrobiopterin [BH4]). Fourth, proinflammatory cytokines increase the level of enzyme indoleamine-2, 3-dioxygenase activity and shunt tryptophan away from the serotonin pathway. Fifth, oxidative stress stimulates astrocytes to inhibit excitatory amino acid transporters. Sixth, astrocytes produce kynurenic acid that acts as an antagonist on the α7-nicotinic acetylcholine receptor to inhibit dopamine release. Jointly, these actions result in increased glutamatergic and decreased monoaminergic neurotransmission. The above-described pathophysiological mechanisms negatively affect brain functioning in areas that are involved in fatigue.

Inflammation and the dimensions of depression: A review

Patients with depressive disorders show a wide range of clinical manifestations including cognitive and neurovegetative symptoms. Importantly, these symptoms can differ in terms of biological etiology, and deconstructing depression into specific symptoms may provide valuable insight into the underlying neurobiology. Little research has examined inflammation in the context of depressive dimensions. Here we conduct a narrative review of the existing literature (21 studies) to elucidate whether the depression-inflammation link is symptom specific. Overall, there is evidence that an association exists between neurovegetative symptoms of depression and inflammation, independent of cognitive symptoms. The same cannot be said of cognitive symptoms and inflammation. There is also some evidence of gender differences in the directionality of the relationship between depression and inflammation. Potential explanations for these findings, limitations of the existing literature and recommendations for future research design are discussed.

Aging as a Context for the Role of Inflammation in Depressive Symptoms

Inflammation has been implicated in the pathogenesis and maintenance of depressive symptoms. The role of inflammation in depressive symptomatology may be complex, varying within endophenotypes and across the lifespan. Aging is associated with myriad changes in the structure and function of the brain. Yet, little attention has been given to the role of inflammation in depressive symptoms within a lifespan developmental framework. In this study, we examined whether the association between inflammation and depressive symptom domains varied by age. Participants were a community sample of individuals (N = 2,077, Range = 30-84) who participated in the Biomarker projects of the MIDUS2, MIDUS Refresher, or the MIDJA study. Inflammation was indexed by two inflammatory markers consistently implicated in depressed individuals, interleukin 6 (IL-6) and C-reactive protein (CRP), measured in blood. Depressive symptom domains, including depressed affect, anhedonia, somatic complaints, and interpersonal problems, were reported via the Center for Epidemiologic Studies-Depression Scale (CES-D). Inflammatory markers were associated with more somatic complaints, more interpersonal problems, and less anhedonia. Age moderated the relationship between inflammatory markers and two depressive symptom subscales. Specifically, the positive association between inflammation and somatic complaints and the negative association between inflammation and anhedonia increased with age. These observations offer preliminary evidence from a large community sample that aging may be an important context for the role of inflammatory signaling in different aspects of psychological and behavioral well-being.

Assessment of cognitive functions and psychiatric symptoms in hepatitis C patients receiving pegylated interferon alpha and ribavirin: A prospective cohort study

Objective

This study aimed to prospectively evaluate cognitive functioning in hepatitis C virus patients before, during, and after interferon alpha and to assess the psychiatric side effects of interferon alpha such as depression and anxiety.

Methods

A total of 100 chronic hepatitis C virus patients eligible for interferon therapy from the hepatitis outpatient clinic of Assiut University Hospital were included. A full medical and psychiatric assessment was done using the Hamilton Depression Rating Scale (HAM-D) and Hamilton Anxiety Rating Scale (HAM-A). Cognitive assessment was done using The Mini-Mental State Examination (MMSE), Memory Assessment Scales (MAS), and Wechsler Adult Intelligence Scale (WAIS). Medical, cognitive, and psychiatric assessments were conducted at the start of the study and after starting the treatment at two, four, and six months.

Results

There was a significant increase in the mean scores of HAM-D (t = 7.739, p < 0.001; t = 5.707, p < 0.001; t = 5.115, p < 0.001) and HAM-A (t = 6.237, p < 0.001; t = 4.154, p < 0.001; t = 3.955, p < 0.001) scales at the two, four, and six month follow-ups, respectively, in comparison to the baseline measurements. As regards to the MAS, repeated assessments after two, four, and six months showed no statistically significant difference from the baseline apart from deterioration in the verbal memory performance after six months in comparison to the baseline (t = −2.605, p = 0.011). As regards to MMSE, the verbal intelligence quotient (IQ), performance IQ, and total IQ, there was a significant improvement in the patients’ cognitive performance, in comparison to the baseline, after two months (t = 2.144, p = 0.035), four months (t = 2.868, p = 0.002), and six months (t = 3.505, p = 0.001), respectively. There was also a significant negative correlation between HAM-D mean scores and the MAS verbal mean scores of the patients (r = −.219, p = 0.039).

Conclusion

There were increases in symptoms of depression and anxiety during interferon alpha and ribavirin treatment, which do not correlate with the patients’ cognitive performance. There was a significant improvement in cognitive performance except in verbal memory with the progress of interferon alpha treatment. Years of education, socioeconomic status, and lower quantitative polymerase chain reaction are predictors for better cognitive performance.

Hierarchical control systems for the regulation of physiological homeostasis and affect: Can their interactions modulate mood and anhedonia?

Predominant concepts assert that conscious willful processes do not assert a significant influence on autonomic functions associated with physiological homeostasis (e.g., thermal regulation). The singular purpose of this review is to promote a reappraisal of concepts regarding the circumscribed role of hierarchical control systems. To effect this reappraisal, we assess the interaction between top-down and bottom-up regulatory mechanisms, specifically by highlighting the intersection between the "physiological" (specifically thermoregulatory pathways) and the "psychological" (specifically mood/anhedonia related processes). This reappraisal suggests that the physiological and psychological processes can interact in unanticipated ways, and is grounded in multiple lines of recent experimental evidence. For example, behavioral techniques that through a combination of hormesis (forced breathing, cold exposure) and meditation appear to exert unusual effects on homeostatic function (cold tolerance) and suppression of aberrant auto-immune responses. The molecular correlates of these effects (the putative release of endogenous cannabinoids and endorphins) may exert salutary effects on mood/anhedonia, even more significant than those exerted by cognitive behavioral techniques or meditation alone. By focusing on this interaction, we present a putative mechanistic model linking physiology with psychology, with particular implications for disturbances of mood/anhedonia. We suggest that volitional changes in breathing patterns can activate primary control centers for descending pain/cold stimuli in periaqueductal gray, initiating a stress-induced analgesic response mediated by endocannabinoid/endorphin release. The analgesic effects, and the feelings of euphoria generated by endocannbinoid release are prolonged via a top-down "outcome expectancy" control mechanism regulated by cortical areas. By focusing on modification strategies that principally target homeostatic function (but may also exert ancillary effects on mood), we articulate a novel framework for how hierarchical control systems for the regulation of physiological homeostasis and affect interact. This interaction may allow practitioners of focused modification strategies to assert increased control over key components of the affective system, allowing for viable treatment approaches for patients with disturbances of mood/anhedonia.

Cognitive impairments in HCV infection: From pathogenesis to neuroimaging

Extrahepatic manifestations of hepatitis C virus (HCV) infection, in particular cognitive impairments, can be present in the absence of clinical liver dysfunction. Executive memory, attention, and concentration are cognitive domains that are most frequently affected. Microstructural and functional changes in cortical gray matter and basal ganglia associate these neuropsychiatric changes in early HCV infection. No study has covered the relationship between imaging features of HCV-related cognitive impairment and HCV pathology. Herein we summarize evidence suggesting a direct pathology of HCV in microglia, astrocytes, and microvascular endothelial cells, and a neuroinflammatory response in HCV-related cognitive decline. Lipoproteins and their receptors mediate HCV infectivity in the central nervous system and confer susceptibility to HCV-related cognitive decline. Magnetic resonance spectroscopy has revealed changes compatible with reactive gliosis and microglial activation in basal ganglia, frontal and occipital white matter, in the absence of cirrhosis or hepatic encephalopathy. Similarly, diffusion imaging shows evidence of structural disintegrity in the axonal fibers of white matter tracts associated with temporal and frontal cortices. We also discuss the cognitive benefits and side-effects of the two most popular therapeutic protocols interferon-based therapy and interferon-free therapy using direct acting anti-virals. Evidences support a network-based pattern of disruption in functional connectivity in HCV patients and a common neuronal substrate for HCV-related and interferon-therapy-associated cognitive decline. These evidences might help identify patients who benefit from either interferon-based or interferon-free treatment regimen.

What Is the Role of Dietary Inflammation in Severe Mental Illness? A Review of Observational and Experimental Findings

Severe mental illnesses (SMI), including major depressive disorder, bipolar disorder, and schizophrenia, are associated with increased inflammation. Given diet's role in modulating inflammatory processes, excessive calorie-dense, nutrient-deficient processed food intake may contribute toward the heightened inflammation observed in SMI. This review assesses the evidence from observational and experimental studies to investigate how diet may affect physical and mental health outcomes in SMI through inflammation-related pathways. Cross-sectional studies indicate that individuals with SMI, particularly schizophrenia, consume more pro-inflammatory foods and fewer anti-inflammatory nutrients than the general population. Cohort studies indicate that high levels of dietary inflammation are associated with increased risk of developing depression, but there is currently a lack of evidence for schizophrenia or bipolar disorder. Randomized controlled trials show that dietary interventions improve symptoms of depression, but none have tested the extent to which these benefits are due to changes in inflammation. This review summarizes evidence on dietary inflammation in SMI, explores the directionality of these links, and discusses the potential use of targeted nutritional interventions for improving psychological well-being and physical health outcomes in SMI. Establishing the extent to which diet explains elevated levels of inflammatory markers observed in SMI is a priority for future research.

Cytokine Research in Depression: Principles, Challenges, and Open Questions

Cytokines have been implicated in the pathology of depression. Currently, the evidence is based on cross-sectional studies and meta-analytic research comparing blood concentrations of T helper type 1 (TH1), T helper type 2 (TH2), pro-inflammatory or anti-inflammatory cytokines of patients with a depressive disorder to those of healthy controls. Additionally, multiple longitudinal studies have investigated cytokine levels during antidepressant treatment. According to the current literature, it seems that peripheral levels of interleukin (IL)-6, IL-10, IL-12, IL-13, and tumor necrosis factor (TNF)-α are elevated and that interferon (IFN)-γ levels are lower in patients with depression compared to healthy controls. However, the overlap of cytokine values between acutely depressed patients, remitted and recovered patients and healthy controls is considerable. Thus, the discriminative power of cytokine concentrations between depressed and non-depressed people is likely weak. Treatment with certain antidepressants appears to decrease peripheral levels of IL-6, IL-10, and TNF-α. However, weight gain-inducing psychopharmacological substances, such as the antidepressant mirtazapine, have been reported to potentially increase the production of pro-inflammatory cytokines. Even though cytokines are often discussed as biomarkers for depression, they have also been shown to be altered in other psychiatric disorders. Moreover, many environmental, social, psychological, biological, and medical factors are also associated with cytokine changes. Thus, cytokine alterations seem extremely unspecific. The interpretation of the results of these studies remains a challenge because it is unknown which type of cells are most responsible for cytokine changes measured in the blood nor have the main target cells or target tissues been identified. The same cytokine can be produced by multiple cell types, and the same cell can produce various cytokines. Additionally, redundancy, synergy, antagonism, and signaling cascades of cytokine signaling must be considered. Cytokines might not be associated with the diagnosis of depression according to the currently used diagnostic manuals, but rather with specific subtypes of depression, or with depressive symptoms across different psychiatric diagnoses. Therefore, the currently available diagnostic systems may not be the ideal starting point for psychiatric cytokine research.

Cytokines in Relation to Motor Activity in an Acute Psychiatric Population

Background: Deviations in motor activity are important clinical features of several psychiatric disorders in an acute state. Immune activity is associated with several psychiatric disorders and may affect motor activity. We aimed to examine the association between immune activity measured as serum levels of cytokines and deviations in motor activity, in an acute psychiatric setting. Methods: Data on motor activity and immune markers were available on 277 patients admitted to an acute psychiatric inpatient department. The degree of increased or decreased motor activity was clinically assessed at admission. Serum concentrations of the following immune markers were measured: interleukin (IL) -1β, IL-4, IL-6, IL-10, tumor necrosis factor (TNF) -α, interferon (IFN) -γ, and transforming growth factor (TGF) -β. Results: Scores of increased motor activity were negatively correlated with IFN-γ (rho = -0.128, p = 0.033) in an acute psychiatric population. There was also a trend towards an association between motor activity and TGF-β (rho = 0.118, p = 0.050). In a multiple-linear-regression model correcting for age, gender, and body-mass index (BMI, kg/m²), the association did not remain significant. No significant correlations between motor retardation and circulating cytokines were found. Conclusions: After adjustment for potential confounders our study did not reveal any significant association between cytokines and motor activity. However, there is an indication of increased Th17 and decreased Th1 responses in relation to increased motor activity in line with the few previous reports in the field. The phenomenon however needs further exploration.

Role of Inflammation in Depression and Treatment Implications

Approximately one third of depressed patients fail to respond to currently available antidepressant therapies. Therefore, new conceptual frameworks are needed to identify pathophysiologic pathways and neurobiological targets for the development of novel treatment strategies. In this regard, recent evidence suggests that inflammation may contribute to symptoms relevant to a number of psychiatric disorders and particularly depression. Numerous studies (including meta-analyses) have found elevated peripheral and central inflammatory cytokines and acute phase proteins in depression. Chronic exposure to increased inflammation is thought to drive changes in neurotransmitters and neurocircuits that lead to depressive symptoms and that may also interfere with or circumvent the efficacy of antidepressants. Indeed, patients with high inflammation have been shown to exhibit poor response to conventional antidepressant therapies. Recent developments in our ability to understand and measure the effects of inflammation on the brain in patients have opened new doors for the testing of novel treatment strategies that target the immune system or its consequences on neurotransmitter systems. Such recent developments in the field of behavioral immunology and their translational implications for the treatment of depression are discussed herein.

Inflammatory Profiles in Depressed Adolescents Treated with Fluoxetine: An 8-Week Follow-up Open Study

Changes in cytokine levels in major depression and during treatment have been reported in adults. However, few studies have examined cytokine levels in an adolescent sample despite this being a common age of onset. Methods. We measured proinflammatory (IL-2, IFN-γ, IL-1β, TNF-α, IL-6, IL-12, and IL-15) and anti-inflammatory (IL-4, IL-5, IL-13, IL-1Ra, and IL-10) cytokine serum levels in 22 adolescents with major depression and 18 healthy volunteers. Cytokines were measured by multiplex bead-based immunoassays at baseline, and 4 and 8 weeks after commencement of fluoxetine administration in the clinical group. Results. Compared to healthy volunteers, adolescents with major depression at baseline showed significant increases in all pro- and anti-inflammatory cytokines, except IL-1Ra and IL-10. Significant changes were observed in fluoxetine treatment compared to baseline: proinflammatory cytokines IFN-γ, IL-1β, TNF-α, IL-6, IL-12, and IL-15 were decreased only at week 4 whereas IL-2 was increased only at week 8; anti-inflammatory cytokines IL-4 and IL-5 were increased at week 8 while IL-1Ra was reduced only at week 4. There were no significant correlations between cytokine levels and symptomatic improvement in HDRS. Discussion. The results suggest a significant interplay between cytokine levels, the depressive state, and the stage of treatment with an SSRI. To the best of our knowledge, this is the first report in depressed adolescents with elevated IL-12, IL-13, and IL-15 levels. Further studies are necessary to clarify the role and mechanisms of altered cytokine levels in the pathogenesis and physiopathology of major depressive disorder.

The role of inflammation in core features of depression: Insights from paradigms using exogenously-induced inflammation

A wealth of evidence has implicated inflammation in the development of depression. Yet, the heterogeneous nature of depression has impeded efforts to understand, prevent, and treat the disease. The purpose of this integrative review is to summarize the connections between inflammation and established core features of depression that exhibit more homogeneity than the syndrome itself: exaggerated reactivity to negative information, altered reward processing, decreased cognitive control, and somatic syndrome. For each core feature, we first provide a brief overview of its relevance to depression and neurobiological underpinnings, and then review evidence investigating a potential role of inflammation. We focus primarily on findings from experimental paradigms of exogenously-induced inflammation. We conclude that inflammation likely plays a role in exaggerated reactivity to negative information, altered reward reactivity, and somatic symptoms. There is less evidence supporting an effect of inflammation on cognitive control as assessed by standard neuropsychological measures. Finally, we discuss implications for future research and recommendationsfor how to test the role of inflammation in the pathogenesis of heterogeneous psychiatric disorders.

Multidimensional Fatigue Inventory in People With Hepatitis B Infection: Cross-cultural Adaptation and Psychometric Evaluation of the Persian Version

There is no valid and well-established tool to measure fatigue in people with chronic hepatitis B. The aim of this study was to translate the Multidimensional Fatigue Inventory (MFI) into Persian and examine its reliability and validity in Iranian people with chronic hepatitis B. The demographic questionnaire and MFI, as well as Chronic Liver Disease Questionnaire and EuroQol-5D (to assess criterion validity), were administered in face-to-face interviews with 297 participants. A forward-backward translation method was used to develop a culturally adapted Persian version of the questionnaire. Cronbach's α was used to assess the internal reliability of the scale. Pearson correlation was used to assess criterion validity, and known-group method was used along with factor analysis to establish construct validity. Cronbach's α for the total scale was 0.89. Convergent and discriminant validities were also established. Correlations between the MFI and the health-related quality of life scales were significant (p < .01). The scale differentiated between subgroups of persons with the hepatitis B infection in terms of age, gender, employment, education, disease duration, and stage of disease. Factor analysis indicated a four-factor solution for the scale that explained 60% of the variance. The MFI is a valid and reliable instrument to identify fatigue in Iranians with hepatitis B.

Imaging the Role of Inflammation in Mood and Anxiety-related Disorders

Background

Studies investigating the impact of a variety of inflammatory stimuli on the brain and behavior have reported evidence that inflammation and release of inflammatory cytokines affect circuitry relevant to both reward and threat sensitivity to contribute to behavioral change. Of relevance to mood and anxiety-related disorders, biomarkers of inflammation such as inflammatory cytokines and acute-phase proteins are reliably elevated in a significant proportion of patients with major depressive disorder (MDD), bipolar disorder, anxiety disorders and post-traumatic stress disorder (PTSD).

Methods

This review summarized clinical and translational work demonstrating the impact of peripheral inflammation on brain regions and neurotransmitter systems relevant to both reward and threat sensitivity, with a focus on neuroimaging studies involving administration of inflammatory stimuli. Recent translation of these findings to further understand the role of inflammation in mood and anxiety-related disorders is also discussed.

Results

Inflammation was consistently found to affect basal ganglia and cortical reward and motor circuits to drive reduced motivation and motor activity, as well as anxiety-related brain regions including amygdala, insula and anterior cingulate cortex, which may result from cytokine effects on monoamines and glutamate. Similar relationships between inflammation and altered neurocircuitry have been observed in MDD patients with increased peripheral inflammatory markers, and such work is on the horizon for anxiety disorders and PTSD.

Conclusion

Neuroimaging effects of inflammation on reward and threat circuitry may be used as biomarkers of inflammation for future development of novel therapeutic strategies to better treat mood and anxiety-related disorders in patients with high inflammation.

Inflammation-induced motivational changes: Perspective gained by evaluating positive and negative valence systems

Inflammation can profoundly impact motivated behavior, as is the case with inflammation-induced depression. By evaluating objectively measurable basic neurobehavioral processes involved in motivation, recent research indicates that inflammation generally reduces approach motivation and enhances avoidance motivation. Increased effort valuation largely mediates the effects of inflammation on approach motivation. Changes in reward valuation are not uniformly observed in approach motivation. However, inflammation increases the averseness of negative stimuli. Within the context of both approach and avoidance motivation, inflammation appears to enhance the contrast between concurrently presented stimuli. While changes in both approach and avoidance motivation appear to be mediated by midbrain dopaminergic neurotransmission to the ventral striatum, it is unclear if the enhanced contrast is mediated by the same system.

Sex differences in how inflammation affects behavior: What we can learn from experimental inflammatory models in humans

Human models demonstrate that experimental activation of the innate immune system has profound effects on brain activation and behavior, inducing fatigue, worsened mood and pain sensitivity. It has been proposed that inflammation is a mechanism involved in the etiology and maintenance of depression, chronic pain and long-term fatigue. These diseases show a strong female overrepresentation, suggesting that a better understanding of sex differences in how inflammation drives behavior could help the development of individualized treatment interventions. For this purpose, we here review sex differences in studies using experimental inflammatory models to investigate changes in brain activity and behavior. We suggest a model in which inflammation accentuates sex differences in brain networks and pre-existing vulnerability factors. This effect could render women more vulnerable to the detrimental effects of immune-to-brain communication over time. We call for systematic and large scale investigations of vulnerability factors for women in the behavioral response to inflammation.

Effort but not Reward Sensitivity is Altered by Acute Sickness Induced by Experimental Endotoxemia in Humans

Sickness behavior in humans is characterized by low mood and fatigue, which have been suggested to reflect changes in motivation involving reorganization of priorities. However, it is unclear which specific processes underlying motivation are altered. We tested whether bacterial endotoxin E. coli lipopolysaccharide (LPS) affected two dissociable constructs of motivational behavior, ie, effort and reward sensitivity. After familiarization with 5 effort levels, participants made a series of accept/reject decisions on whether the stake offered (1, 4, 8, 12, or 15 apples) was 'worth the effort' (10%, 27.5%, 45%, 62.5%, and 80% of maximal voluntary contraction in a hand-held dynamometer). Effort and reward levels were parametrically modulated to dissociate their influence on choice. Overall, 29 healthy young males were administered LPS (2 ng/kg; n=14) or placebo (0.9% saline; n=15). The effort-stake task, and self-reported depression and fatigue were assessed prior to LPS/placebo injection, 2 and 5 h post injection. Cytokines and sickness symptoms were assessed hourly till 8 h after LPS injection. LPS transiently increased interleukin-6 and tumor necrosis factor-α, sickness symptoms, body temperature and self-reported fatigue, and depression post injection relative to baseline and placebo. These changes were accompanied by LPS-induced decreases in acceptance rates of high-effort options, without significantly affecting reward sensitivity 2 h post injection, which were partially recovered 5 h post injection. We suggest that LPS-induced changes in motivation may be due to alterations to mesolimbic dopamine. Our behavioral paradigm could be used to further investigate effects of inflammation on motivational behavior in psychiatric and chronic illnesses.

Greater decline in memory and global neurocognitive function in HIV/hepatitis C co-infected than in hepatitis C mono-infected patients treated with pegylated interferon and ribavirin

The human immunodeficiency virus (HIV), hepatitis C virus (HCV), and the treatment of HCV with pegylated interferon and ribavirin (IFN/RBV) have been associated with neurocognitive and psychiatric abnormalities. The goal of this research was to prospectively evaluate neurocognitive functioning among a group of HCV mono-infected and HIV/HCV co-infected patients during the first 24 weeks of IFN/RBV treatment while accounting for practice effects, normal variations in change over time, and variations in IFN/RBV treatment exposure. Forty-four HCV mono-infected and 30 HIV/HCV co-infected patients were enrolled in a prospective study of patients beginning on IFN/RBV for chronic HCV infection. Patients were administered a depression inventory, a measure of fatigue, a structured psychiatric interview, and a neurocognitive battery at baseline and 24 weeks after initiation of treatment. Analyses were conducted to explore possible associations between neurocognitive functioning and the following: HIV/HCV co-infection vs. HCV mono-infection, IFN and RBV treatment exposure, psychiatric status, liver disease stage, and other medical characteristics. At baseline, there were no significant differences between the two groups' neuropsychiatric or neurocognitive function other than the mono-infected group had significantly higher reports of fatigue (p = 0.033). Over the course of 24 weeks of treatment after controlling for practice effects, the HIV/HCV co-infected patients experienced significantly greater declines in memory (t(56) = 2.14, p = 0.037) and global neurocognitive functioning (t(53) = 2.28, p = 0.027). In a well-characterized sample of mono-infected and co-infected patients, it appears that persons with HIV/HCV co-infection are potentially more vulnerable to neurocognitive sequalae during HCV treatment.

Pathogen-Host Defense in the Evolution of Depression: Insights into Epidemiology, Genetics, Bioregional Differences and Female Preponderance

Significant attention has been paid to the potential adaptive value of depression as it relates to interactions with people in the social world. However, in this review, we outline the rationale of why certain features of depression including its environmental and genetic risk factors, its association with the acute phase response and its age of onset and female preponderance appear to have evolved from human interactions with pathogens in the microbial world. Approaching the relationship between inflammation and depression from this evolutionary perspective yields a number of insights that may reveal important clues regarding the origin and epidemiology of the disorder as well as the persistence of its risk alleles in the modern human genome.

Towards an Immunophenotype of Schizophrenia: Progress, Potential Mechanisms, and Future Directions

The evidence to date, coupled with advances in immunology and genetics has afforded the field an unparalleled opportunity to investigate the hypothesis that a subset of patients with schizophrenia may manifest an immunophenotype, toward new potential diagnostics and therapeutics to reduce risk, alleviate symptoms, and improve quality of life in both at-risk populations and patients with established schizophrenia. In this paper, we will first summarize the findings on immune dysfunction in schizophrenia, including (1) genetic, prenatal, and premorbid immune risk factors and (2) immune markers across the clinical course of the disorder, including cytokines; C-reactive protein; immune cells; antibodies, autoantibodies and comorbid autoimmune disorders; complement; oxidative stress; imaging of neuroinflammation; infections; and clinical trials of anti-inflammatory agents and immunotherapy. We will then discuss a potential mechanistic framework toward increased understanding of a potential schizophrenia immunophenotype. We will then critically appraise the existing literature, and discuss suggestions for the future research agenda in this area that are needed to rigorously evaluate this hypothesis.

Therapeutic Implications of Brain-Immune Interactions: Treatment in Translation

A wealth of data has been amassed that details a complex, yet accessible, series of pathways by which the immune system, notably inflammation, can influence the brain and behavior. These data have opened the window to a diverse array of novel targets whose potential efficacy is tied to specific neurotransmitters and neurocircuits as well as specific behaviors. What is clear is that the impact of inflammation on the brain cuts across psychiatric disorders and engages dopaminergic and glutamatergic pathways that regulate motivation and motor activity as well as the sensitivity to threat. Given the ability to identify patient populations with increased inflammation, the precision of interventions can be further tuned, in conjunction with the ability to establish target engagement in the brain through the use of multiple neuroimaging strategies. After a brief overview of the mechanisms by which inflammation affects the brain and behavior, this review examines the extant literature on the efficacy of anti-inflammatory treatments, while forging guidelines for future intelligent clinical trial design. An examination of the most promising therapeutic strategies is also provided, along with some of the most exciting clinical trials that are currently being planned or underway.

Inflammation Effects on Motivation and Motor Activity: Role of Dopamine

Motivational and motor deficits are common in patients with depression and other psychiatric disorders, and are related to symptoms of anhedonia and motor retardation. These deficits in motivation and motor function are associated with alterations in corticostriatal neurocircuitry, which may reflect abnormalities in mesolimbic and mesostriatal dopamine (DA). One pathophysiologic pathway that may drive changes in DAergic corticostriatal circuitry is inflammation. Biomarkers of inflammation such as inflammatory cytokines and acute-phase proteins are reliably elevated in a significant proportion of psychiatric patients. A variety of inflammatory stimuli have been found to preferentially target basal ganglia function to lead to impaired motivation and motor activity. Findings have included inflammation-associated reductions in ventral striatal neural responses to reward anticipation, decreased DA and DA metabolites in cerebrospinal fluid, and decreased availability, and release of striatal DA, all of which correlated with symptoms of reduced motivation and/or motor retardation. Importantly, inflammation-associated symptoms are often difficult to treat, and evidence suggests that inflammation may decrease DA synthesis and availability, thus circumventing the efficacy of standard pharmacotherapies. This review will highlight the impact of administration of inflammatory stimuli on the brain in relation to motivation and motor function. Recent data demonstrating similar relationships between increased inflammation and altered DAergic corticostriatal circuitry and behavior in patients with major depressive disorder will also be presented. Finally, we will discuss the mechanisms by which inflammation affects DA neurotransmission and relevance to novel therapeutic strategies to treat reduced motivation and motor symptoms in patients with high inflammation.

The levels of monoamine neurotransmitters and measures of mental and emotional health in HCV patients treated with ledipasvir (LDV) and sofosbuvir (SOF) with or without ribavirin (RBV)

Mental and emotional health (MEH) impairment is commonly encountered in hepatitis C patients. Although the exact mechanism remains unknown, alterations in neurotransmitter and cytokine levels maybe associated with hepatitis C virus (HCV)-related MEH issues.The aim of the study was to assess association of serum biomarkers with self-reports of MEH in HCV patients before treatment and after achieving sustained virologic response (SVR).The HCV genotype-1-infected patients who achieved SVR at 12 weeks after treatment with ledipasvir (LDV)/sofosbuvir (SOF) ± ribavirin (RBV) were selected. Frozen serum samples from baseline, end of treatment (EOT), and posttreatment week 4 (PTW4) were used to assay 16 cytokines and monoamine neurotransmitters. Validated self-reports were used to assess MEH.Hundred patients were evaluated. Mean age was 53 years (57% male, 86% white). Compared with baseline, emotional well-being and emotional health significantly increased by EOT, and role emotional, emotional well-being, and emotional health significantly increased at PTW4 in the RBV-containing arm (P < 0.05). In patients taking LDV/SOF + RBV, serotonin levels were significantly decreased at PTW4 compared with baseline (P = 0.046). Compared with baseline, there were significant decreases in interleukin (IL)-10 levels at EOT and PTW4 in both treatment groups. The changes in IL-8 also differed significantly between LDV/SOF + RBV and LDV/SOF groups (P < 0.05). Changes in dopamine and tryptophan levels at EOT correlated with increasing emotional health scores, whereas changes in monocyte chemoattractant protein-1 at EOT and IL-8 at PTW4 correlated with increasing mental health scores. The neurotransmitters and cytokines were found to be independent predictors of MEH scores in multiple regression analysis.Cytokine and neurotransmitter changes are associated with mental and emotional health. Patient-reported outcome scores change during and after treatment.

Effort-related motivational effects of the pro-inflammatory cytokine interleukin-6: pharmacological and neurochemical characterization

RATIONALE

Motivational dysfunctions such as anergia, fatigue, and reduced effort expenditure are common in patients with depression and other disorders. Pro-inflammatory cytokines are implicated in depression, and cytokine administration induces motivational deficits in humans.

OBJECTIVES

These studies focused on the effects of the cytokine interleukin-6 (IL-6) on effort-related decision-making.

METHODS

Rats were assessed using the concurrent fixed ratio 5-lever pressing/chow feeding choice procedure, which measures the tendency of rats to work for a preferred food (high carbohydrate pellets) in the presence of a concurrently available but less preferred substitute (lab chow).

RESULTS

IL-6 (2.0-8.0 μg/kg IP) shifted choice behavior, significantly decreasing lever pressing and increasing chow intake. Further experiments showed that the adenosine A2A antagonist MSX-3 and the stimulant methylphenidate attenuated the effort-related impairments produced by IL-6, increasing lever pressing and decreasing chow intake in IL-6 treated rats. The same doses of IL-6 did not alter food intake or preference in parallel free-feeding choice studies, demonstrating that these low doses were not altering preference for the high carbohydrate pellets or generally suppressing appetite. Also, IL-6 did not affect body temperature. Microdialysis studies showed that 8.0 μg/kg IL-6 significantly decreased extracellular dopamine in nucleus accumbens core.

CONCLUSIONS

In summary, IL-6 reduces the tendency to work for food, even at low doses that do not produce fever or loss of appetite. Dopaminergic mechanisms may be involved in these effort-related effects. This research has implications for the involvement of cytokines in motivational dysfunctions such as anergia and fatigue.

Conceptual convergence: increased inflammation is associated with increased basal ganglia glutamate in patients with major depression

Inflammation and altered glutamate metabolism are two pathways implicated in the pathophysiology of depression. Interestingly, these pathways may be linked given that administration of inflammatory cytokines such as interferon-α to otherwise non-depressed controls increased glutamate in the basal ganglia and dorsal anterior cingulate cortex (dACC) as measured by magnetic resonance spectroscopy (MRS). Whether increased inflammation is associated with increased glutamate among patients with major depression is unknown. Accordingly, we conducted a cross-sectional study of 50 medication-free, depressed outpatients using single-voxel MRS, to measure absolute glutamate concentrations in basal ganglia and dACC. Multivoxel chemical shift imaging (CSI) was used to explore creatine-normalized measures of other metabolites in basal ganglia. Plasma and cerebrospinal fluid (CSF) inflammatory markers were assessed along with anhedonia and psychomotor speed. Increased log plasma C-reactive protein (CRP) was significantly associated with increased log left basal ganglia glutamate controlling for age, sex, race, body mass index, smoking status and depression severity. In turn, log left basal ganglia glutamate was associated with anhedonia and psychomotor slowing measured by the finger-tapping test, simple reaction time task and the Digit Symbol Substitution Task. Plasma CRP was not associated with dACC glutamate. Plasma and CSF CRP were also associated with CSI measures of basal ganglia glutamate and the glial marker myoinositol. These data indicate that increased inflammation in major depression may lead to increased glutamate in the basal ganglia in association with glial dysfunction and suggest that therapeutic strategies targeting glutamate may be preferentially effective in depressed patients with increased inflammation as measured by CRP.

Inflammatory markers are associated with decreased psychomotor speed in patients with major depressive disorder

Previous data have demonstrated that administration of inflammatory cytokines or their inducers leads to altered basal ganglia function associated with reduced psychomotor speed. Decreased psychomotor speed, referred to clinically as psychomotor retardation, is a cardinal symptom of major depressive disorder (MDD) and has been associated with poor antidepressant treatment response. We therefore examined the association between plasma inflammatory markers and psychomotor speed in ninety-three un-medicated patients with MDD. Psychomotor speed was assessed by a range of neuropsychological tests from purely motor tasks (e.g. movement latency and finger tapping) to those that involved motor activity with increasing cognitive demand and cortical participation (e.g. Trails A and Digit Symbol Substitution Task (DSST)). Linear regression analyses were performed to determine the relationship of inflammatory markers and psychomotor task performance controlling for age, race, sex, education, body mass index, and severity of depression. MDD patients exhibited decreased psychomotor speed on all tasks relative to normative standards. Increased IL-6 was associated with decreased performance on simple and choice movement time tasks, whereas MCP-1 was associated with decreased performance on the finger tapping task and DSST. IL-10 was associated with increased performance on the DSST. In an exploratory principle component analysis including all psychomotor tasks, IL-6 was associated with the psychomotor speed factor. Taken together, the data indicate that a peripheral inflammatory profile including increased IL-6 and MCP-1 is consistently associated with psychomotor speed in MDD. These data are consistent with data demonstrating that inflammation can affect basal ganglia function, and indicate that psychomotor speed may be a viable outcome variable for anti-inflammatory therapies in depression and other neuropsychiatric disorders with increased inflammation.

Activational and effort-related aspects of motivation: neural mechanisms and implications for psychopathology

Motivation has been defined as the process that allows organisms to regulate their internal and external environment, and control the probability, proximity and availability of stimuli. As such, motivation is a complex process that is critical for survival, which involves multiple behavioural functions mediated by a number of interacting neural circuits. Classical theories of motivation suggest that there are both directional and activational aspects of motivation, and activational aspects (i.e. speed and vigour of both the instigation and persistence of behaviour) are critical for enabling organisms to overcome work-related obstacles or constraints that separate them from significant stimuli. The present review discusses the role of brain dopamine and related circuits in behavioural activation, exertion of effort in instrumental behaviour, and effort-related decision-making, based upon both animal and human studies. Impairments in behavioural activation and effort-related aspects of motivation are associated with psychiatric symptoms such as anergia, fatigue, lassitude and psychomotor retardation, which cross multiple pathologies, including depression, schizophrenia, and Parkinson's disease. Therefore, this review also attempts to provide an interdisciplinary approach that integrates findings from basic behavioural neuroscience, behavioural economics, clinical neuropsychology, psychiatry, and neurology, to provide a coherent framework for future research and theory in this critical field. Although dopamine systems are a critical part of the brain circuitry regulating behavioural activation, exertion of effort, and effort-related decision-making, mesolimbic dopamine is only one part of a distributed circuitry that includes multiple neurotransmitters and brain areas. Overall, there is a striking similarity between the brain areas involved in behavioural activation and effort-related processes in rodents and in humans. Animal models of effort-related decision-making are highly translatable to humans, and an emerging body of evidence indicates that alterations in effort-based decision-making are evident in several psychiatric and neurological disorders. People with major depression, schizophrenia, and Parkinson's disease show evidence of decision-making biases towards a lower exertion of effort. Translational studies linking research with animal models, human volunteers, and clinical populations are greatly expanding our knowledge about the neural basis of effort-related motivational dysfunction, and it is hoped that this research will ultimately lead to improved treatment for motivational and psychomotor symptoms in psychiatry and neurology.

The Role of Dopamine in Inflammation-Associated Depression: Mechanisms and Therapeutic Implications

Studies investigating the impact of a variety of inflammatory stimuli on the brain and behavior have consistently reported evidence that inflammatory cytokines affect the basal ganglia and dopamine to mediate depressive symptoms related to motivation and motor activity. Findings have included inflammation-associated reductions in ventral striatal responses to hedonic reward, decreased dopamine and dopamine metabolites in cerebrospinal fluid, and decreased availability of striatal dopamine, all of which correlate with symptoms of anhedonia, fatigue, and psychomotor retardation. Similar relationships between alterations in dopamine-relevant corticostriatal reward circuitry and symptoms of anhedonia and psychomotor slowing have also been observed in patients with major depression who exhibit increased peripheral cytokines and other inflammatory markers, such as C-reactive protein. Of note, these inflammation-associated depressive symptoms are often difficult to treat in patients with medical illnesses or major depression. Furthermore, a wealth of literature suggests that inflammation can decrease dopamine synthesis, packaging, and release, thus sabotaging or circumventing the efficacy of standard antidepressant treatments. Herein, the mechanisms by which inflammation and cytokines affect dopamine neurotransmission are discussed, which may provide novel insights into treatment of inflammation-related behavioral symptoms that contribute to an inflammatory malaise.

Major depressive disorder and generalized anxiety disorder and response to treatment in hepatitis C patients in Egypt

OBJECTIVES

The aim of the study was to estimate the prevalence and associated correlates of major depressive disorder and generalized anxiety disorder in hepatitis C virus patients before and after treatment and to investigate the relationship between major depressive disorder and generalized anxiety disorder and treatment response.

METHODS

A total of 116 consecutive hepatitis C virus patients from hepatitis C virus treatment center in Zagazig city, Egypt, were included in the study and divided into treated group (N = 58) and untreated group (N = 58). All hepatitis C virus patients were screened for major depressive disorder and generalized anxiety disorder using hospital anxiety and depression scale, and those who screened positive were interviewed to confirm the diagnosis of major depressive disorder and generalized anxiety disorder using DSM-IV-TR diagnostic criteria. These measures were done at baseline and after 12 weeks of treatment or observation.

RESULTS

At baseline, 3.5% and 12.1% of hepatitis C virus patients (treated group) had major depressive disorder and generalized anxiety disorder, respectively. After 12 weeks of treatment 37.9% of hepatitis C virus patients (treated group) had major depressive disorder and 46.6% had generalized anxiety disorder. There was a significant statistical difference between hospital anxiety and depression scale scores for depression (3.3 ± 2.3 vs. 6.4 ± 3.2, t = 9.6, p = 0.001) and for anxiety (4.6 ± 2.4 vs. 7.3 ± 3.0, t = 10.2, p = 0.001) before and after treatment. There was also significant statistical difference between treated group and untreated group regarding hospital anxiety and depression scale scores after treatment and observation (depression, treated group 6.4 ± 3.2 vs. untreated group 4.0 ± 2.4, t = 3.7, p = 0.001; anxiety, treated group 7.3 ± 3.0 vs. untreated group 4.5 ± 2.3, t = 4.4, p = 0.001). There was no association between major depressive disorder and generalized anxiety disorder and treatment response.

CONCLUSIONS

Major depressive disorder and generalized anxiety disorder are common in hepatitis C virus patients after treatment with interferon and ribavirin and were not related to treatment response.