(p. 1517) The ageing population and the epidemiology of mental disorders among the elderly 

In the last decades the ageing of the populations has become a worldwide phenomenon. In 1990, 26 nations had more than 2 million elderly citizens aged 65 years and older, and the projections indicate that an additional 34 countries will join the list by 2030. In 2000, the number of old persons (65+ years) in the world was estimated to be 420 million and it was projected to be nearly 1 billion by 2030, with the proportion of old persons increasing from 7 to 12 per cent. The largest increase in absolute numbers of old persons will occur in developing countries; it almost triples from 249 million in 2000 to an estimated 690 million in 2030. The developing regions’ share of the worldwide ageing population will increase from 59 to 71 per cent. Developed countries, which have already seen a dramatic increase in people over 65 years of age, will experience a progressive ageing of the elderly population itself (see Fig. 8.3.1). The global trend in the phenomenon of population ageing has dramatic consequences for public health, health care financing, and delivery systems in the whole world. The absolute number of chronic diseases as well as psychiatric disorders is expected to increase. In this chapter, the epidemiological aspects of the most common psychiatric disorders of the elderly are summarized and discussed.