In a clinical view numerous authors pointed the association between depression and hetero-aggressiveness. This study's aim is to seek, with a statistical methodology, a correlation between depressive symptoms and hetero-agressive act realisation by mental sick persons. From a sample of sick sick persons hospitalized into a unit for dangerous ill individuals, the authors put in relation depressive symptoms and acts of violence. This analysis of the whole data had shown a significative statistical correlation between depression and aggressiveness, according to a linear regression. The results also recall the existence of two underpopulations : one of them is formed by patients who present depressive symptoms but who are not depressive themself, and the other is formed by patients whose aggressiveness is linked with depression. Division of this overall sample dependent to diagnosis. shows thar there is no relation between depression and aggressiveness by patients who present psychopathological trouble, whereas a great correlation can be found by schizophrenics. This study put forward at first that depressive symptoms can form a factor of risk for physical hetero-aggressiveness, and secondly that the relation between those two models of symptoms is especially strong by schizophrenics.