Brain-derived neurotrophic factor levels in combat veterans with or without a history of suicide attempt
Leo Sher, M.D.
Our research work, “Brain-derived neurotrophic factor in war veterans with or without a history of suicide attempt” is published in the July 2022 issue of the Journal of Affective Disorders (1). Combat veterans with a history of psychiatric disorders are a unique clinical population. We examined whether there is a difference with regard to plasma BDNF levels between war 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 (MADRS), the Barratt Impulsivity Scale (BIS) and the Scale for Suicidal Ideation (SSI). Suicide attempts were defined as self-directed potentially injurious behavior with intent to die.
Reaction to the most recent suicide attempt was evaluated using item 16 of the Suicide Intent Scale. Attempters were classified into the two groups: those who regretted that they made suicide attempt (“Sorry that he made attempt; feels foolish, ashamed”) and those who did not regret suicide attempt (“Accepts both attempt and its failure” and “Regrets failure of attempt”). 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. Veterans with a history of suicide attempt had significantly higher SSI scores, and a trend toward higher MADRS scores in comparison to veterans without such history. 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.
Our study demonstrates that BDNF may be involved in the pathophysiology of suicidal behavior in combat veterans. Therapeutic targeting of multiple psychological and biological domains may be necessary to mitigate increased suicide risk 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.
- Sher L, Bierer LM, Flory J, Makotkine I, Yehuda R. Brain-derived neurotrophic factor in war veterans with or without a history of suicide attempt. J Affect Disord. 2022 Jul 1;308:160-165. doi: 10.1016/j.jad.2022.04.047. Epub 2022 Apr 12.