This article reviews the data supporting the role of genetic factors in the predisposition to suicidal behaviour & examines whether or not these factors are part of the genetic liability to mood disorders. The author finds that there is consistent evidence suggesting that genetic factors play an important role in the predisposition to suicide & suicidal behaviours, & that there is some support for a role of some genes that code for components of the serotonergic pathway in the etiology of suicidal behaviour. (114 refs)