Mental health of octogenarians in Iceland. An epidemiological study

The purpose of this work was to study the prevalence and incidence of mental disorders in octogenarians in Iceland and the relation of these variables to several sociodemographic variables. Beside this a comparison between two different methods of collecting clinical data on mental health were done. In chapter 2 recent research on the epidemiology of mental disorders in the very old population is reviewed. A comparison between different studies is very difficult but most studies agree on the prevalence of severe dementia. In chapter 3 the material and methods of the study is described. The sample consists of all Icelanders borne in the years of 1895-1897. Two methods of data collection are described, the indirect method where information from general practitioners, hospital files and other sources are used to make a mental diagnosis, and the Geriatric Mental States Schedule, which is a semi-structured interview. In chapter 4 demography of the cohort is described and in chapter 5 the reliability of the Icelandic translation of the Geriatric Mental States Schedule is discussed and the reliability of the Icelandic translation of G.M.S. is within acceptable limits. In chapter 6 two methods of making mental diagnosis in the elderly are compared. In chapter 7 the prevalence of dementia at the age of 81.5 and 87 years is discussed. There is a considerable increase in prevalence of severe dementia, or from 7.8% at the age of 81.5 years to 15.1% at the age of 87 years. The incidence of dementia in the age period 74-85 years is discussed in chapter 8. At the age of 84 years the incidence is about one case per 100 per year, but at the age of 85 the incidence is about 4 cases per 100 per year. In chapter 9 the mortality of dementia in the age period from 74-85 years is discussed. The standard mortality ratio is 2.46 for males and 2.29 for females in this age period. In chapter 10 and 11 the prevalence, incidence and mortality of affective disorders are discussed. The prevalence of affective disorders does not change significantly with age from 81.5-87 years, being 8-9%, while the mortality of affective disorders in the age period of 74-85 years is similar to that in the general population. The incidence does not change significantly from 74-85 years being about 0.6 case per 100 per year for males and about 1.1 cases per 100 per year for females.(ABSTRACT TRUNCATED AT 400 WORDS)