Effect of exposure to suicidal behavior on suicide attempt in a high-risk sample of offspring of depressed parents.

OBJECTIVE: Exposure to suicidal behavior in peers and relatives is thought to increase risk for suicidal behavior in vulnerable individuals, possibly as a result of imitation or modeling. This study examines exposure to suicidal behavior and likelihood of suicide attempt in a high-risk cohort of offspring of a depressed parent.
METHOD: A total of 449 offspring of 255 probands with a mood disorder were enrolled in a family study. Probands and offspring were assessed for psychopathology and suicide attempt history, and offspring for suicide exposure. Generalized estimating equations (GEE) and generalized least squares models were used to compare suicide attempt history in exposed and nonexposed offspring as well as characteristics of exposure in exposed offspring suicide attempters and exposed nonattempters. GEE was used to compare exposure occurring before first attempt in attempter offspring and exposure occurring before the same age in matched nonattempter offspring.
RESULTS: Offspring reporting exposure to suicidal behavior were four times more likely to report a lifetime suicide attempt compared with unexposed offspring, controlling for age. Suicide attempt status was not associated with age at first exposure, total number or degree (attempt or threat) of exposures, or relationship. Analysis of exposure occurring before age at first suicide attempt found no association between exposure and suicide attempt.
CONCLUSIONS: Offspring exposed to suicidal behavior are more likely to report a lifetime suicide attempt than nonexposed offspring. However, when examining the temporal sequence of exposure and attempt, the association is no longer significant, suggesting that imitation is not sufficient explanation.