The main findings are presented of a prevalence study of mental health problems (organic brain syndrome and depression) in the elderly population of Rio de Janeiro, Brazil. Three districts in the city were surveyed-Copacabana, Meier and Santa Cruz-chosen using a set of socioeconomic indicators to identify rich, middle income and poor areas. Validity and reliability studies of the survey instrument were carried out in Copacabana. Prevalence results for organic brain syndrome (OBS) were 5.95% in Copacabana, 9.84% in Meier and 29.75% in Santa Cruz, while results for depression were 22.62%, 19.67% and 35.12% respectively. The methodological problems of the survey which influence confidence in the results are discussed. Dependence and loss of autonomy in elderly people were strongly associated with organic brain syndrome and depression. The results are compared with those in the other Brazilian and international studies.
KEY WORDS-survey, mental health, dementia, population, South America.
The rationale and methodological approach to this survey in the city of Rio de Janeiro were discussed in earlier articles published in this Journal (Veras and Murphy, 1991a, b). Brazil has a rapidly growing cohort of older people over 60, comprising mainly poorly educated elderly women living alone in a rapidly developing but poor urban environment. There are, however, vast regional differences in Brazil and also extremes of social class within both rural and urban areas. For planning purposes surveys must take account of the diversity of different sectors of the population. A detailed account of the changing demography of Brazil is given in Veras and Murphy (1991a). There have been other major surveys in Brazilian cities which have drawn attention to the apparently high prevalence of mental health problems in older people. Our study was designed to focus more closely on symptoms of organic brain syndrome and depression, the two groups of disorders which cause most disability and generate higher demand for care in the developed world than * Address for correspondence other types of mental health problems of older people.
The purpose of this article is to present the results of the analysis of the mental health part of a multidimensional survey carried out in three areas of the city.
Methods
The methods have been presented in detail elsewhere (Veras and Murphy, 1991b). Briefly, the survey instrument used was the Brazil Old Age Schedule (BOAS) , which covers physical health, mental health, social resources, economic resources and activities of daily living. The BOAS is derived from the OARS (Duke University, 1978), the PAHO (Pan American Health Organization, 1985) and the mental health section from the CARE schedule (Gurland et al., 1977). The schedule was developed mainly in English, translated into Portuguese, retranslated and adjusted to preserve the original sense. The three districts chosen for the study represented the richest areas (Copacabana), the poorest areas (Santa Cruz) and a district broadly in the middle in terms of CCC 0885-6230/94/040285-11 0 1994 by John Wiley & Sons, Ltd.