# Genetic Association Study of Brain-Derived Neurotrophic Factor (BDNF) and Serotonin-Related Gene Variants in Suicide Attempters with Major Depressive Disorder and Control Persons

## TL;DR

This study explores how genetic variations in BDNF and serotonin-related genes are linked to suicide attempts in people with major depressive disorder in Korea.

## Contribution

The study identifies a specific BDNF gene variant associated with suicide attempts in Korean individuals with major depression.

## Key findings

- The rs11030101 (BDNF) genotype and allele were significantly associated with suicide attempts in Korean patients.
- The rs3813034 (SLC6A4) recessive genotype was also significantly linked to suicide attempts.
- No significant associations were found for serotonin-related polymorphisms after multiple testing correction.

## Abstract

Objective: Suicide attempts have become one of the most serious problems worldwide in recent years. Suicide attempts are known to be genetically highly associated with serotonin and BDNF in international studies. Methods: In this study, we investigated the association with rs6265 (BDNF), and rs11030101 (BDNF), rs3813034 (Serotonin Transporter, SLC6A4) rs4680 (TPH1), rs1800532 (TPH1), rs1386493 (TPH2), rs6311 (HTR2A), rs6313 (HTR2A), rs6314 (HTR2A), rs6296 (HTR1B), gene polymorphism in Korean suicides with major depressive disorder who visited the emergency room. Results: A case-control study was conducted with 226 suicide and suicide attempts with major depressive disorder and 1469 general controls, and genotypes were determined by PCR-RFLP method. Significant associations between the rs11030101 (BDNF) genotype and suicide/suicide attempters were confirmed (OR 0.44, 95% CI 0.23–0.84, p = 0.0004), and significant associations between the rs11030101 (BDNF) allele and suicide/suicide attempters were confirmed (OR 0.63, 95% CI 0.50–0.80, p = 0.0002), in addition to the recessive genotype (OR 0.55, 95% CI 0.29–1.03, p = 0.03) and overdominant genotype (OR 0.66, 95% CI 0.49–0.88, p = 0.0046). Also, significant associations between the rs3813034 (SLC6A4) recessive genotype and suicide/suicide attempts were confirmed in the study results (OR 2.03, 95% CI 1.12–3.68, p = 0.028). After correction for multiple testing, none of the serotonin-related polymorphisms displayed any significant case–control differences. Conclusions: The BDNF gene may influence suicide attempts in Korean patients with major depression who have performed a suicide attempt. Replication in larger studies and other populations is needed.