Brain-derived neurotrophic factor in war veterans with or without a history of suicide attempt

Brain-derived neurotrophic factor (BDNF) plays a central role in brain development and plasticity and has been demonstrated to be altered in neuropsychiatric diseases and suicidal behavior. We examined whether there is a difference with regard to plasma BDNF levels between veterans who made or did not make a suicide attempt post-deployment. Combat veterans who made or did not make post-deployment suicide attempts were interviewed using Mini-International Neuropsychiatric Interview, the Montgomery-Åsberg Depression Rating Scale, the Barratt Impulsivity Scale (BIS) and the Scale for Suicidal Ideation (SSI). Reaction to the most recent suicide attempt was evaluated using item 16 of the Suicide Intent Scale. Plasma BDNF levels were determined by the BDNF ELISA kit. Controlling for age and body-mass index (BMI), BDNF levels were higher among suicide attempters than non-attempters. We observed a positive correlation between BDNF levels and SSI scores among non-attempters but not among attempters. BDNF levels positively correlated with BIS scores among suicide attempters but not among non-attempters. Suicide attempters who regretted that they made a suicide attempt had significantly higher BDNF levels in comparison to attempters who did not regret their attempts, controlling or not controlling for age and BMI. A modest sample size is a shortcoming of our study. Our study demonstrates that BDNF may be involved in the pathophysiology of suicidal behavior in combat veterans. Given the relative ease of measuring plasma BDNF levels, it may be appropriate to consider adding such assessments to studies of suicidal behavior.