The BDNF Val66Met polymorphism is an independent risk factor for high lethality in suicide attempts of depressed patients

Some authors have reported an association of BDNF Val66Met polymorphism with suicidal behavior and/or clinical aspects of suicidal attempts. We evaluated, here, the impact of BDNF Val66Met polymorphism on the clinical characteristics of suicide attempts. The study was conducted on a cohort of 120 consecutive patients who were admitted to the Emergency Hospital of Porto Alegre, Brazil, due to a suicide attempt. Variables of univariate analyses were included in a logistic regression model to test whether the risk factors had independent effect. In univariate analyses, sex, BDNF genotype, intent and method of suicide attempt were all risk factors for high lethality in suicide attempts. After logistic regression analysis, male sex (O.R. = 3.03; 95% C.I = 1.34–6.84; 0.008) and the presence of BDNF 66Met allele (O.R. = 2.62; 95% C.I = 1.04–6.57; 0.04) were significantly and independently associated with the high lethality in suicide attempts. The present study showed that BDNF 66Met allele is an independent predictor of high lethality in suicide attempts of depressed patients. This finding is important because it might allow earlier identification of patients at high risk for suicide, perhaps providing better tools for clinical care of these patients in the future.