A Preliminary Study of Cytokines in Suicidal and Nonsuicidal Adolescents with Major Depression

New York University School of Medicine , NYU Child Study Center, New York, New York 10016, USA.
Journal of child and adolescent psychopharmacology (Impact Factor: 2.93). 08/2009; 19(4):423-30. DOI: 10.1089/cap.2008.0140
Source: PubMed


Increased systemic cytokine levels, modulators of the immune system, have been repeatedly documented in adult and adolescent major depressive disorder (MDD). This preliminary study extends this work to test the role of cytokines in suicidal symptomatology in adolescent MDD. Hypotheses were that acutely suicidal depressed adolescents would have: (1) increased plasma levels of interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and IL-1beta, and (2) a proinflammatory/antiinflammatory cytokine imbalance (indexed by plasma IFN-gamma/IL-4), compared to nonsuicidal depressed adolescents and healthy controls.
Twelve suicidal adolescents with MDD (7 females [58%]; 5 medication-free/naïve), 18 nonsuicidal adolescents with MDD (12 females [67%]; 8 medication-free/naïve), and 15 controls (8 females [53%]) were enrolled. MDD had to be of at least 6 weeks duration, with a minimum severity score of 40 on the Children's Depression Rating Scale-Revised. Plasma cytokines were examined using enzyme-linked immunosorbent assays. Nonparametric tests were used to compare subject groups.
Unexpectedly, suicidal adolescents with MDD had significantly decreased plasma TNF-alpha concentrations compared to nonsuicidal adolescents with MDD (1.33 +/- 2.95 pg/mL versus 30.9 +/- 110.9 pg/mL; p = 0.03). IFN-gamma was increased in both suicidal and nonsuicidal adolescents with MDD compared to controls (2.14 +/- 6.22 and 4.20 +/- 14.48 versus 0.37 +/- 0.64; p < 0.02, p = 0.005). Findings remained evident when controlled for age and gender.
Our preliminary findings suggest that immune system dysregulation may be associated with suicidal symptomatology in adolescent MDD. These findings should be replicated in larger samples with medication-free adolescents.

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    • "Recent systematic review by Mills et al. (2013) supports the view that depression in adolescents is a low-grade neuro-inflammation state. The role of pro-inflammatory cytokines, such as IL-1β, tumor necrosis factor (TNF)-α and interferon (IFN)-γ, IL-6 etc. in the etiology and pathophysiology of depression is well investigated (O'Brien et al., 2007; Dhabhar et al., 2009; Dowlati et al., 2010; Janelidze et al., 2011) including their in suicidality (Simon et al., 2008; Gabbay et al., 2009b). In contrast to pro-inflammatory cytokines such as IL-6, considerably less attention has been focused on the potential role of anti-inflammatory (IL-10), immunomodulatory (TGF-β1) and autoimmune (IL-17) cytokines. "
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    ABSTRACT: The present study compares the serum cytokine levels between adolescent depression patients and healthy controls and assesses correlation between depression, anxiety scores and serum levels of eight cytokines. Study also checked the variation in serum levels with medication status (medication free/naïve vs. patients on medication). Following clinical and psychometric assessment of 77 adolescent (aged 13-18 years) depression patients (49 males and 28 females; 56 medication free/naïve) and 54 healthy controls (25 males, 29 females), eight cytokines (IL-1β, IL-2, IL-6, IL-10, TNF-α, IFN-γ, TGF-β1 and IL-17A {denoted IL-17 throughout}) were measured in serum using ELISA. Depressed adolescents had significantly high levels of IL-2 (p<0.001) and IL-6 (p=0.03) as compared to controls. The female population skewed the result of one cytokine (IL-6) in patients. Anxiety scores showed positive correlation (only in female patients) with IL-1β, IL-10 and negative correlation with TGF-β1 and IL-17. The gender effect in relationship between anxiety and cytokines was not straightforward. On comparing study groups on the medication/naïve status, IL-2 and TGF-β1 showed significant difference between the groups (p<0.001, p=0.007 higher in medicated). Depression in adolescents was associated with elevation of proinflammatory serum cytokines with a gender bias for females. Anxiety scores correlated negatively with TGF-β1 and IL-17. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
    06/2015; 229(1-2). DOI:10.1016/j.psychres.2015.06.036
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    • "The current sample is part of previous published studies examining a) plasma cytokine levels in suicidal depressed adolescents (Gabbay et al., 2009) and b) the KP in adolescent MDD (Gabbay et al., 2010a). Participants were 30 non-suicidal adolescents with MDD (mean age¼15. "
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    ABSTRACT: The neuroimmunological kynurenine pathway (KP) has been implicated in major depressive disorder (MDD) in adults and adolescents, most recently in suicidality in adults. The KP is initiated by the enzyme indoleamine 2,3-dioxygenase (IDO), which degrades tryptophan (TRP) into kynurenine (KYN) en route to neurotoxins. Here, we examined the KP in 20 suicidal depressed adolescents-composed of past attempters and those who expressed active suicidal intent-30 non-suicidal depressed youth, and 22 healthy controls (HC). Plasma levels of TRP, KYN, 3-hydroxyanthranilic acid (3-HAA), and KYN/TRP (index of IDO) were assessed. Suicidal adolescents showed decreased TRP and elevated KYN/TRP compared to both non-suicidal depressed adolescents and HC. Findings became more significantly pronounced when excluding medicated participants, wherein there was also a significant positive correlation between KYN/TRP and suicidality. Finally, although depressed adolescents with a history of suicide attempt differed from acutely suicidal adolescents with respect to disease severity, anhedonia, and suicidality, the groups did not differ in KP measures. Our findings suggest a possible specific role of the KP in suicidality in depressed adolescents, while illustrating the clinical phenomenon that depressed adolescents with a history of suicide attempt are similar to acutely suicidal youth and are at increased risk for completion of suicide. Published by Elsevier Ireland Ltd.
    Psychiatry Research 03/2015; In Press(2-3). DOI:10.1016/j.psychres.2015.03.031 · 2.47 Impact Factor
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    • "Circulating levels of IFN-␥ are elevated in major depression and anxiety related disorders [13] [30]. Moreover, Tsao et al. suggested that treatment with the selective serotonin reuptake inhibitors, like fluoxetine, decrease the mRNA expression of IFN-␥ in depressed patients [36]. "
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    ABSTRACT: A series of evidence suggests that interferon-gamma (IFN-γ) plays an important role in central nervous system (CNS) functions. However, previous studies have obtained inconsistent results regarding the role of IFN-γ in modulating emotion-related behaviors. The present study aimed to evaluate the behavioral profile of IFN-γ knockout (K.O.) mice in models of anxiety and depression. Male C57Bl6 wild type (WT) or IFN-γ K.O. mice were submitted to the following tests: contextual fear conditioning (CFC), elevated plus maze (EPM), open field (OF) and forced swimming test (FST). To explore the possible neurobiological mechanisms involved, we also assessed hippocampal neurogenesis by means of hippocampal doublecortin expression, and the levels of Brain-Derived Neurothophic Factor (BDNF) and Nerve Growth Factor (NGF) in the hippocampus and prefrontal cortex. Our results suggested that IFN-γ K.O. mice exhibited an anxiogenic profile in CFC, EPM and OF tests. In FST, the K.O. group spent more time immobile than the WT group. The number of doublecortin positive cells was reduced in the dentate gyrus, and the expression of NGF was down regulated in the prefrontal cortex of IFN-γ K.O. mice. Our results suggest that IFN-γ is involved in CNS plasticity, contributing to the modulation of anxiety e depressive states.
    Neuroscience Letters 06/2014; DOI:10.1016/j.neulet.2014.06.039 · 2.03 Impact Factor
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