[Quality of life : theoretical and empirical perspectives.].

The idea of maintaining or improving ' 'quality of life' ' is frequently raised as a desired objective in mental health intervention. Furthermore, this notion is primarily brought up with regard to people who experience severe difficulty in living within their community. This article outlines the evolution of such a concept, describes certain theoretical models and deals with research data concerning factors associated with a positive perception of living conditions. Also discussed is the concept's usefulness in the planning and evaluation of mental health services.