Abstract
Recent progress in molecular genetics and neurobiology has attracted much attention and provided a new insight into the nature-nurture controversy in respect of the aetiology of psychiatric disorders. Affective illness, including the various subtypes of depressive and manic syndromes, has been the subject of a considerable amount of research on the relative importance of hereditary and environmental factors. This paper provides a critical review of the most relevant literature on the genetics of depression and mania.