The issue of various factors affecting the mortality rate of population in the light of the gender and age differences is considered. The medical demographic and medical sociological statistical data of mortality is presented in its ontogenesis and is differentiated according time periods. The issue of death-rate among the mentally ill patients depending on their gender characteristics is discussed. The focal point in the article is the evaluation of association between the age of parents and the longevity of posterity. The data revealing the relationship between mother's age and the risk of mental disease development is provided.