Background: Although adoption, twin, and family studies have shown that suicidal behavior is familial, the risk factors for familial transmission from parent to child remain unclear.
Methods: A high-risk family study was conducted comparing the offspring of 2 mood-disordered groups: suicide attempters and nonattempters. Recruited from 2 sites, probands were 81 attempters and 55 nonattempters, with 183 and 116 offspring, respectively. Offspring were assessed by investigators masked to proband status. Probands and offspring were assessed with respect to psychopathologic findings, suicide attempt history, impulsive aggression, and exposure to familial environmental stressors.
Results: Offspring of attempters had a 6-fold increased risk of suicide attempts relative to offspring of nonattempters. Familial transmission of suicide attempt was more likely if (1) probands had a history of sexual abuse and (2) offspring were female and had a mood disorder, substance abuse disorder, increased impulsive aggression, and a history of sexual abuse.
Conclusions: The offspring of mood-disordered suicide attempters are at markedly increased risk for suicide attempts themselves. Familial transmission of suicidal behavior in families with mood disorders almost always requires transmission of a mood disorder and is also related to the offspring's impulsive aggression and the familial transmission of sexual abuse. Early treatment of mood disorders and targeting impulsive aggression and sexual trauma may be helpful in the prevention and treatment of suicidal behavior in families with mood disorders.