Increased serum tumor necrosis factor-alpha levels and treatment response in major depressive disorder

Tuğlu, Cengiz; Kara, Suzan; Çalıyurt, Okan; Vardar, Erdal; Abay, Ercan

doi:10.1007/s00213-003-1566-z

Cited by 354 publications

(243 citation statements)

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“…Several investigators [75][76][77][78] have found increased levels in IL-1b in patients with dysthymia or major depressive disorder. Similarly, TNF-a has been found to be increased in the plasma of patients with depressive mood 79 or with major depressive disorder 80 and even IL-6 has sometimes been found to be over expressed in elderly patients with major depressive disorder. 79,81,82 Two studies have also found that IL-18 was over expressed in serum of patients with depression.…”

Section: Resultsmentioning

confidence: 99%

“…Administration of proinflammatory cytokines in animals induce a depression-like status 73,74 Depression has been reported to accompany diseases affecting the immune system (HIV, autoimmune illnesses) where cytokines are strongly dysregulated 71 Patients with depression have increased level of proinflammatory cytokines [75][76][77][78][79][80][81][82][83][84] Cytokine therapy may cause depression as side effect 72,[88][89][90][91][92] Antidepressive drugs may prevent depression induced by cytokine therapy in human 91,92 Antidepressive drugs may have a cytokine-linked anti-inflammatory effect 91,106,107 Inhibitors of proinflammatory cytokines may relieve depressive symptoms in humans 108 Anti-inflammatory drugs able to inhibit proinflammatory cytokine production may have antidepressive effect 109 mainly based on cytokine plasma level determinations and such circulating molecule concentrations do not necessarily reflect the activity of cytokines within the CNS. The activation of brain cytokines might involve different mechanisms and currently it is not possible to measure cytokines in specific areas of living human brain.…”

Section: Findings Referencesmentioning

confidence: 99%

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The etiology of poststroke depression: a review of the literature and a new hypothesis involving inflammatory cytokines

et al. 2006

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Although poststroke depression is unlikely to represent a single disorder and numerous etiologies for different kinds of poststroke depression will likely emerge as the result of future research, we believe that a number of poststroke depressive disorders are likely to be the result of specific changes in brain pathology and neurophysiology. Nevertheless, there are relatively few hypotheses about the pathophysiology of poststroke depression. This paper, therefore, proposes a new hypothesis for poststroke depression involving increased production of proinflammatory cytokines resulting from brain ischemia in cerebral areas linked to the pathogenesis of mood disorders. This paper reviews the evidence supporting the hypothesis that proinflammatory cytokines are involved in the occurrence of stroke as well as mood disorders linked to the brain damage. The increased production of proinflammatory cytokines such as IL-1b, TNF-a or IL-18 resulting from stroke may lead to an amplification of the inflammatory process, particularly in limbic areas, and widespread activation of indoleamine 2,3-dioxygenase (IDO) and subsequently to depletion of serotonin in paralimbic regions such as the ventral lateral frontal cortex, polar temporal cortex and basal ganglia. The resultant physiological dysfunction may lead to poststroke depression. Future investigations may explore this hypothesis through more extensive studies on the role of proinflammatory cytokines, such as IL-1b, TNF-a or even IL-18, in patients with poststroke depression. Molecular Psychiatry (2006) 11, 984-991.

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Section: Resultsmentioning

confidence: 99%

Section: Findings Referencesmentioning

confidence: 99%

The etiology of poststroke depression: a review of the literature and a new hypothesis involving inflammatory cytokines

et al. 2006

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“…The peripheral levels of IL-6, TNF-α, and IL-1β are increased in patients with depression [13][14][15][16][17] , and antidepressant treatments reverse this effect [18][19][20] . These consistent results demonstrate that IL-6, TNF-α, and IL-1β are putative biomarkers for depression.…”

Section: Infl Ammatory Biomarkers Of Depressionmentioning

confidence: 99%

Inflammation: a mechanism of depression?

Han

2014

Neurosci. Bull.

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In recent decades, major depression has become more prevalent and research has shown that immune activation and cytokine production may be involved. This review is mainly focused on the contribution of infl ammation to depression. We fi rst briefl y introduce the infl ammatory biomarkers of depression, then discuss the sources of cytokines in the brain, and fi nally describe the neuroimmunological mechanisms underlying the association between infl ammation and depression.Keywords: depression; infl ammation; cytokines; hypothalamic-pituitary-adrenal axis; 5-HT; neuroplasticity ·Review· IntroductionThe prevalence of major depression has increased dramatically over the past few decades [1] , and women are nearly twice as likely as men to develop depressive disorder [2] . Depression is classified as a brain disorder, but its symptomatology includes some behaviors that also occur during chronic infl ammatory stress [3] . Research has shown that immune activation and the production of cytokines may be involved in depression [4] , so this relationship has received much attention. In fact, three causal pathways have been proposed: depression to inflammation, inflammation to depression, and a bidirectional relationship [5] . In this review, we focus on the impact of inflammation on depression and the underlying mechanisms. Cytokines are small cell-signaling proteins that mediate and regulate immune responses and inflammation, and can be divided into two categories:the pro-inflammatory cytokines interleukin (IL)-1 β, IL-6, IL-8, and tumor necrosis factor (TNF)-α, and the anti-inflammatory cytokines IL-1Rα, IL-4, IL-10, and transforming growth factor (TGF)-β1. Generally, t he proinfl ammatory cytokines promote systemic infl ammation and are essential for the initiation of an infl ammatory response to disease [6] , while the anti-inflammatory cytokines antagonize these actions to reduce inflammation and promote healing [6,7] . Moreover, some cytokines play dual roles [8] . In the central nervous system (CNS), the cellular source, function, and mechanisms of action of cytokines differ from those in the periphery. In the following, we briefl y introduce the current research on infl ammatory biomarkers of depression. Infl ammatory Biomarkers of DepressionSo far, there are neither universally accepted or defi nitive biomarkers of depression [9] , nor effective methods to assess the severity, endophenotypes, or response to treatment [10] .However, sufficient evidence has suggested changes in the circulating levels of cytokines in depressed patients, which can be reversed by antidepressant treatments [11,12] .So, many studies have aimed to clarify the neurobiological changes in depression and to establish inflammatory biomarkers. The peripheral levels of IL-6, TNF-α, and IL-1β are increased in patients with depression [13][14][15][16][17] , and antidepressant treatments reverse this effect [18][19][20] . These consistent results demonstrate that IL-6, TNF-α, and IL-1β are putative biomarkers for depression. However, due to the he...

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“…88 According to the sickness behavior hypothesis, the cytokines TNF-a, IL-1 and IL-6 have frequently been investigated in MD. A considerable number of studies showed elevated serum levels of TNF-a 70,86,[89][90][91][92][93] and IL-1b [94][95][96] in depressed patients, whereas only few investigators reported unchanged levels of these cytokines. 97 A study on elevated mRNA levels of TNF-a in peripheral mononuclear cells of depressed patients confirms the majority of findings on elevated serum levels.…”

Section: The Inflammatory Hypothesis Of Depressionmentioning

confidence: 99%

The immune-mediated alteration of serotonin and glutamate: towards an integrated view of depression

2007

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Beside the well-known deficiency in serotonergic neurotransmission as pathophysiological correlate of major depression (MD), recent evidence points to a pivotal role of increased glutamate receptor activation as well. However, cause and interaction of these neurotransmitter alterations are not understood. In this review, we present a hypothesis integrating current concepts of neurotransmission and hypothalamus-pituitary-adrenal (HPA) axis dysregulation with findings on immunological alterations and alterations in brain morphology in MD. An immune activation including increased production of proinflammatory cytokines has repeatedly been described in MD. Proinflammatory cytokines such as interleukin-2, interferon-c, or tumor necrosis factor-a activate the tryptophan-and serotonin-degrading enzyme indoleamine 2,3-dioxygenase (IDO). Depressive states during inflammatory somatic disorders are also associated with increased proinflammatory cytokines and increased consumption of tryptophan via activation of IDO. An enhanced consumption of serotonin and its precursor tryptophan through IDO activation could well explain the reduced availability of serotonergic neurotransmission in MD. An increased activation of IDO and its subsequent enzyme kynurenine monooxygenase by proinflammatory cytokines, moreover, leads to an enhanced production of quinolinic acid, a strong agonist of the glutamatergic N-methyl-D-aspartate receptor. In inflammatory states of the central nervous system, IDO is mainly activated in microglial cells, which preferentially metabolize tryptophan to the NMDA receptor agonist quinolinic acid, whereas astrocytes -counteracting this metabolism due to the lack of an enzyme of this metabolism -have been observed to be reduced in MD. Therefore the type 1/type 2 immune response imbalance, associated with an astrocyte/microglia imbalance, leads to serotonergic deficiency and glutamatergic overproduction. Astrocytes are further strongly involved in re-uptake and metabolic conversion of glutamate. The reduced number of astrocytes could contribute to both, a diminished counterregulation of IDO activity in microglia and an altered glutamatergic neurotransmission. Further search for antidepressant agents should take into account anti-inflammatory drugs, for example, cyclooxygenase-2 inhibitors, might exert antidepressant effects by acting on serotonergic deficiency, glutamatergic hyperfunction and antagonizing neurotoxic effects of quinolinic acid. Molecular Psychiatry (2007) 12, 988-1000; doi:10.1038/sj.mp.4002006; published online 24 April 2007 Keywords: major depression; psychoneuroimmunology; IDO; glutamate; immune system; serotonin Glutamate in depressionGlutamatergic neurotransmission is involved in depression and interacts with the serotonergic and noradrenergic systems The common therapeutic mechanism of antidepressant drugs is the enhancement of serotonergic and/or noradrenergic neurotransmission. On the basis of this pharmacological profile of antidepressant drugs, neurochemical research on major depression ...

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Increased serum tumor necrosis factor-alpha levels and treatment response in major depressive disorder

Abstract: The results emphasized that some immunological parameters, such as CRP, leukocyte count and TNF-alpha, are significantly involved in the clinical course and treatment response in MDD. TNF-alpha in particular could be considered as a potential state marker in MDD.

Cited by 354 publications

References 42 publications

The etiology of poststroke depression: a review of the literature and a new hypothesis involving inflammatory cytokines

The etiology of poststroke depression: a review of the literature and a new hypothesis involving inflammatory cytokines

Inflammation: a mechanism of depression?

The immune-mediated alteration of serotonin and glutamate: towards an integrated view of depression

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