A Genetic Study of Affective Illness in Patients over 50

The genetic evidence concerning affective illness of later life is still conflicting and the relationship of such conditions to the manic-depressive psychosis unclear. Kallman (1955) believed that, genetically, involutional melancholia bore a closer relationship to schizophrenia than to the manic-depressive psychosis. An increased risk for schizophrenia amongst the relatives of such patients was not observed by Kay (1959) and Stenstedt (1952). Both these writers do however describe a lower loading for manic-depressive psychosis than would be found amongst the relations of manic-depressive patients, though a much higher incidence than in the general population. Both Stenstedt and Kay assumed that they were dealing with a heterogeneous group of patients containing both psychotic and neurotic depressions.