What family studies teach us about suicidal behavior: implications for research, treatment, and prevention.

Suicidal behavior is transmitted within families, above and beyond the transmission of psychiatric disorder. The familial phenotype of suicidal behavior includes suicide completion and attempts, but not suicidal ideation, the latter of which is transmitted along with depression. The familial transmission of early-onset suicidal behavior is co-transmitted with, and appears to be mediated by the transmission of impulsive aggression. Additionally, the familial transmission of suicidal behavior is, in part, mediated by the familial transmission of abuse. Moreover, high family loading for mood disorder and suicidal behavior are related to multi-generational abuse, impulsive aggression, and early-onset of mood disorder and of suicidal behavior.