Can Knowledge of Genetic and Environmental Causal Factors of Fatal and Nonfatal Suicidal Behavior Be Translated Into Better Prevention?

In this issue, Edwards and colleagues (1) report on a study that examines twins, siblings, and half siblings in the large Swedish national registry database to estimate the heritability of fatal and nonfatal suicidal behavior. The size of this database offers the advantage that they could examine genetic and emironmental contributions to nonfatal suicide attempt and suicide death separately, and also in women and men as well as in youths and the older population. The authors found moderate heritability of both suicide attempt and suicide death, and in both men and women. The genetic load appears to be greater in women, both in youth and adulthood. By examining fatal and nonfatal suicidal behavior, Edwards et al. were able to show that there is substantial genetic overlap. From the opposite perspective, there is incomplete genetic overlap. The lack of total genetic overlap means that there may be important differences between the two types of suicidal behavior.