The psychiatric aspects of ageing are a major problem in any country which, like our own, has a low net reproduction rate and a high standard of social responsibility: the proportion of old people in the community steadily increases, so that they provide an increasingly high proportion of our mentally infirm population who must be cared for. But it is not only senile dementia and the other senile and presenile psychoses described in textbooks that make up the problem: less conspicuous failings which may accompany old age also call for attention if the social and preventive sides of our work are to be given due weight. Therefore it is psychiatric aspects of ageing rather than senile psychoses alone that are intended by the title of this paper.