Brain Derived Neurotrophic Factor (BDNF) has been implicated in neuronal survival and plasticity and reported as being involved in various mental illnesses, including attempted and completed suicide. Evidence from postmortem studies has also shown an altered expression of BDNF in suicide victims brains. We previously investigated the impact of the Val66Met polymorphism of the BDNF gene in determining a suicide attempt in depressed patient and found an association between the BDNF variant and history of early maltreatment in depressed patients with suicide attempts. We then conducted a study on post-mortem brains of suicide completers and their controls to further test the hypothesis of an involvement of BDNF in suicide-related neurobiological processes.

535 specimens of brain from subjects dead either by suicide (N=271) and by other cause (N= 261) were genotyped for the Val66Met and Prom 281 CA polymorphisms of the BDNF gene.

No associations were found between either the first or the second variant of the BDNF gene and the suicidal behaviour.

as the case for other candidate genes, results from genetic studies of the BDNF gene are conflicting and arduous to replicate. Based on the analysis of bias in the study design and procedures, assimilation of methodology and increase in sample size could be helpful in addressing the result variability in such studies.