The role of brain-derived neurotrophic factor in the pathophysiology of adolescent suicidal behavior

Adolescent suicide research has mostly focused on demographic risk factors. Such studies focus on who is at risk, but do not explain why certain adolescents are at risk for suicide. Studies of the neurobiology of adolescent suicide could clarify why some youths are more suicidal than others and help to find biological markers of suicidal behavior in teenagers. Over the past decade the role of brain-derived neurotrophic factor (BDNF) in the pathophysiology of suicidal behavior has attracted significant attention of scientists. BDNF is involved in the pathophysiology of many psychiatric disorders associated with suicidal behavior including depression, post-traumatic stress disorder, schizophrenia, and obsessive-compulsive disorder. BDNF dysregulation could be associated with increased suicidality independently of psychiatric diagnoses. BDNF plays an important role in the regulation and growth of neurons during childhood and adolescence. Prominent among the brain regions undergoing developmental change during adolescence are stressor-sensitive areas. The serotonin dysfunction found in adolescent and adult suicidal behavior could be related to the low level of BDNF, which impedes the normal development of serotonin neurons during brain development. BDNF dysfunction could play a more significant role in the pathophysiology of psychiatric disorders and suicidal behavior in adolescents than in adults. Treatment-induced enhancement in the BDNF function could reduce suicidal behavior secondary to the improvement in psychiatric pathology or independently of improvement in psychiatric disorders. It is interesting to hypothesize that BDNF could be a biological marker of suicidal behavior in adolescents or in certain adolescent populations.