Serum BDNF Levels in Suicide Attempters Related to Psychosocial Stressors: A Comparative Study with Depression

Department of Psychiatry, Faculty of Medicine, Celal Bayar University, Manisa, Turkey.
Neuropsychobiology (Impact Factor: 2.26). 02/2007; 56(2-3):93-7. DOI: 10.1159/000111539
Source: PubMed


Although many studies have examined the neurobiological aspects of suicide, the molecular mechanisms and pathophysiologic mechanisms associated with suicide remain unclear. In this study, it is aimed to investigate whether there is a difference in serum brain-derived neurotrophic factor (BDNF) levels among suicide attempters without a major psychiatric disorder, compared to major depressive disorder patients and healthy subjects. It was undertaken with the hypothesis that suicide per se lowers serum BDNF levels, since it is a source of stress. The study was carried out in Celal Bayar University Hospital, Manisa, Turkey. Ten suicide attempters, 24 patients with major depressive disorder and 26 subjects without any psychiatric diagnosis and any psychiatric treatment were included in the study. All subjects were asked to give their written consent. Blood samples were collected at the baseline. Serum BDNF was kept at -70 degrees C before testing, and assayed with an ELISA kit (Promega; Madison, Wisc., USA) after dilution with the block and sample solution provided with the kit. The data were subjected to the Kruskal-Wallis test for nonparametric analysis of variance. Mean serum BDNF levels were significantly lower in the suicide group (21.2 +/- 12.4 ng/ml) and the major depressive disorder group (21.2 +/- 11.3 ng/ml) than the control group (31.4 +/- 8.8 ng/ml; p = 0.004). These results suggest that BDNF may play an important role in the neurobiology of suicidal behavior. BDNF levels may be a biological marker for suicidal behavior. To investigate the role of BDNF in suicide, further studies with a wider sample size and a variety of psychiatric diagnoses accompanying suicide attempt are needed.

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Available from: Omer Aydemir, Feb 12, 2015
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    • "Animal models suggest that cortical BDNF levels are highly correlated with peripheral BDNF (e.g. in serum sBDNF ) levels (Karege et al., 2002; Sartorius et al., 2009; Elfving et al., 2011). Furthermore, peripheral BDNF is a sensitive marker of alteration in brain function, and either low or high levels have been associated with both traumatic events in adults (Kauer-Sant'Anna et al., 2007; Grassi-Oliveira et al., 2008; Elzinga et al., 2011; Hauck et al., 2011) and adult psychopathology (Deveci et al., 2007; Katoh-Semba et al., 2007; Rizos et al., 2008; Xiu et al., 2009; Maina et al., 2010; Grande et al., 2010; Bocchio-Chiavetto et al., 2011; Molendijk et al., 2011; Zhang et al., 2011). This putative biomarker could be seen as a sensitive surrogate for alteration in brain function, especially if this change is related to traumatic experiences. "
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    ABSTRACT: The objective of this study is to investigate if a polymorphism in the NR3C2 gene moderates the association between childhood trauma on serum levels of brain derived neurothrophic factor (sBDNF). sBDNF was used here as a general marker of alteration in brain function. This is a community cross sectional study comprising 90 adolescents (54 with anxiety disorders). DNA was extracted from saliva in order to genotype the MR-2G/C (rs2070951) polymorphism using real time PCR. Blood was collected for sBDNF Elisa immunoassay. The Childhood Trauma Questionnaire (CTQ) was used to evaluate childhood abuse and neglect. Main effects and gene environment interactions were tested using linear regression models. Anxiety disorders were not associated with the MR-2G/C polymorphism or with sBDNF levels, but the number of C alleles of the MR-2G/C polymorphism was significantly associated with higher sBDNF levels (b = 8.008; p-value = 0.001). Subjects with intermediate and high exposure to physical neglect showed higher sBDNF levels if compared to subjects non-exposed (b = 11.955; p = 0.004 and b = 16.186; p = 0.009, respectively). In addition, we detected a significant physical neglect by MR-2G/C C allele interaction on sBDNF levels (p = 0.005), meaning that intermediate and high exposure to childhood neglect were only associated with increased sBDNF levels in subjects with the CC genotype, but not in subjects with other genotypes. Our findings suggest that genetic variants in NR3C2 gene may partially explain plastic brain vulnerability to traumatic events. Further studies are needed to investigate the moderating effects of NR3C2 gene in more specific markers of alteration in brain function.
    Journal of Psychiatric Research 09/2014; 59. DOI:10.1016/j.jpsychires.2014.08.022 · 3.96 Impact Factor
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    • "Several clinical studies have examined BDNF levels in the blood serum or plasma of patients with major depression and patients who have attempted suicide. Deveci et al. (2007) investigated serum BDNF levels among 10 suicide attempters without major psychiatric disorders, 24 patients with major depression, and 26 healthy subjects, and they found that serum BDNF levels were lower among both suicide attempters and depressed patients than among healthy controls. Our research group has examined plasma BDNF levels among patients with major depression who attempted and who did not attempt suicide. "
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    ABSTRACT: Previous studies have shown that dysfunctions in the serotonin system and hypothalamic-pituitary-adrenal axis (HPA) are associated strongly with suicidal behavior and suicide, especially among individuals with major depressive disorder. Suicidal behavior has been explained using both the stress-diathesis model and the state-trait interaction model. Specifically, diatheses, or trait-dependent risk factors, are associated with dysfunctions in the serotonin system; however, stress responses, or state-dependent factors, are associated with HPA hyperactivity. Decreases in cholesterol and brain-derived neurotrophic factor (BDNF) levels have been associated with impaired brain plasticity among individuals with suicidal behavior. Decreased serotonin functioning has been measured using cerebral spinal fluid (CSF) 5-HIAA, fenfluramine challenge studies, and platelet 5-HT2A receptors. HPA axis dysfunction has been evaluated with the dexamethasone suppression test. Cholesterol and BDNF levels have been measured in blood serum or plasma. Nevertheless, challenges to finding promising and accessible neurobiological predictors of suicide and suicidal behavior remain. As suicide behavior is a complex phenomenon, a combined or multidimensional approach, including each of the aforementioned methods, may be required to predict suicide risk among individuals with major depressive disorder.
    Progress in Neuro-Psychopharmacology and Biological Psychiatry 06/2011; 35(4):842-7. DOI:10.1016/j.pnpbp.2010.08.001 · 3.69 Impact Factor
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    • "Clinical studies have examined BDNF levels in serum or plasma of MDD patients who have or have not attempted suicide. MDD patients who attempted suicide had lower serum BDNF levels than healthy controls.50 Our study found that plasma BDNF was significantly lower in suicidal MDD patients than in non-suicidal ones.40,51 "
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    ABSTRACT: Neurotrophic factors are critical regulators of the formation and plasticity of neuronal networks. Brain-derived neurotrophic factor (BDNF) is abundant in the brain and periphery, and is found in both human serum and plasma. Animal studies have demonstrated that stress reduces BDNF expression or activity in the hippocampus and that this reduction can be prevented by treatment with antidepressant drugs. A similar change in BDNF activity occurs in the brain of patients with major depression disorder (MDD). Recently, clinical studies have indicated that serum or plasma BDNF levels are decreased in untreated MDD patients. Antidepressant treatment for at least four weeks can restore the decreased BDNF function up to the normal value. Therefore, MDD is associated with impaired neuronal plasticity. Suicidal behavior can be a consequence of severe impaired neuronal plasticity in the brain. Antidepressant treatment promotes increased BDNF activity as well as several forms of neuronal plasticity, including neurogenesis, synaptogenesis and neuronal maturation. BDNF could also play an important role in the modulation of neuronal networks. Such a neuronal plastic change can positively influence mood or recover depressed mood. These alterations of BDNF levels or neuronal plasticity in MDD patients before and after antidepressant treatment can be measured through the examination of serum or plasma BDNF concentrations. BDNF levels can therefore be useful markers for clinical response or improvement of depressive symptoms, but they are not diagnostic markers of major depression.
    Psychiatry investigation 12/2010; 7(4):231-5. DOI:10.4306/pi.2010.7.4.231 · 1.28 Impact Factor
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