The prevalence and outcome of depression and dementia in Botany's elderly population

Background Large epidemiological studies of adult populations have reported depression to be less prevalent in old age than among younger adults, whereas studies limited to older persons have reported rates that vary considerably, some showing high rates of depression. There was, therefore, reason to check data from a study that reported high rates, and to review evidence in relation to diagnosis and outcome. Method Re-examination of data from a 1985 survey of elderly people living at home (n = 146). Depression and cognitive impairment were also assessed in a local hostel (n = 42) and nursing home (n = 74). DSM diagnoses were made by an old age psychiatrist. In the nursing home, 23 other residents could not respond to interview questions but were considered to have severe dementia. Subjects in all three settings were followed up after 4 years. Results Seven community subjects (4.5%; confidence interval 1.3-8.3%) and three in residential care fulfilled criteria for major depression. The estimated total prevalence of depressive disorders among elderly in Botany was between 13.0 and 13.6% (4.6% major depression, 3.6% dementia with depression, 5.4% other depressive disorders). In 1985, the prevalence of dementia among those living at home was 11%. Four-year mortality in the dementia cases was 60%. Conclusion Botany has a high prevalence of dementia and depression among elderly people. The recent cross-age Australian study of mental health and well-being provided an inaccurate report concerning the pattern of mental disorders in old age. Copyright (C) 2001 John Wiley & Sons, Ltd.