Decrease in brain‐derived neurotrophic factor at plasma level but not in serum concentrations in suicide behavior: A systematic review and meta‐analysis

Abstract

IntroductionSuicide is known as a major health concern worldwide. There is evidence for the role of brain‐derived neurotrophic factor (BDNF) in suicide behavior. Therefore, this factor has been proposed as a biomarker for suicide behavior. Clinical studies have measured BDNF concentrations at central and peripheral levels. As a consequence, the aim of this study was to assess BDNF levels in blood plasma and serum to see whether there is a difference in concentrations in patients with suicide behavior when compared to those in controls, using a meta‐analysis approach.MethodsWe conducted a systematic review and meta‐analysis. The search strategy was performed using three databases: PubMed, EBSCO and ScienceDirect. The meta‐analysis included a total of nine case–control studies, six measured the BDNF level in serum and three in plasma in suicide behavior.ResultsA decrease in BDNF levels in plasma was observed (d = −0.73, 95% CI −1.42 to −0.03 pg/ml). In the case of serum concentrations, no BDNF differences were encountered between cases and controls (d = 0.09, 95% CI −0.31 to 0.13 ng/ml, p(Q) = .92).ConclusionsAccording to the results found in the present meta‐analysis, the plasma BDNF level could be suggest as a potential biomarker in suicide behavior. However, since the number of studies included in the analysis is limited, a larger number is necessary to determine conclusively the role of BDNF as a biomarker in suicide behavior.

Annual Research Review: Suicide among youth – epidemiology, (potential) etiology, and treatment

“…Importantly, the authors found no confounding effects of age, gender, brain pH, time between death and analysis, or antidepressant treatment. Although this study should be considered preliminary evidence as it is a small sample and the first study to examine these relationships among youth, its results match those found with adults (Salas‐Magaña et al., ), and dovetail nicely with studies on the relationship between stress and suicide among youth (e.g. Giletta et al., ).…”

Epigenetic marks and their relationship with BDNF in the brain of suicide victims

“…The role of BDNF in both pathophysiology and therapy of depressive disorders seems to be strongly confirmed [ 50 , 51 ]. Similarly, the relationship between BDNF and suicidal behavior is well documented [ 3 , 19 , 20 , 52 ]. Most published data indicate a significant decrease in BDNF levels in suicides, which is why our observations are consistent with previous studies [ 3 , 19 , 20 , 53 , 54 ].…”

“…Although BDNF seems to be a promising marker of suicidal behavior, it should be remembered that its expression in various tissues (including brain) may be region-specific [3,19,20]. Similarly, some differences between blood components were observed in suicides [52]. Altered BDNF level in suicides may be the consequence of persistent (like Val66Met polymorphism) or variable genome changes (like higher methylation status in BDNF gene promoter or changed histone code due to post-translational changes in chromatin) (see [55]).…”

Low serum brain-derived neurotrophic factor is associated with suicidal ideation in major depressive disorder

“…Our study has several limitations. We assessed serum BDNF, and peripheral BDNF has an uncertain relationship with brain levels of BDNF (Kim et al, 2007;Salas-Magaña et al, 2017). The origins of serum BDNF levels are still uncertain and it is suggested to be derived from platelet stores and vascular endothelial cells as well as from neurons and glial cells in the brain if it crosses the blood-brain barrier (Guo et al, 2008;Kim et al, 2007).…”