The course of mild dementia in a birth cohort

The mental health of a birth cohort has been followed until the age of 87 years. The cohort consists of all Icelanders born during a period of three years. Only three probands were lost in the follow up period from 61 to 87 years. The diagnoses were made by two methods: an indirect method based mainly on information provided by general practitioners, and the computerized diagnosis AGECAT. Many cases diagnosed as mild dementia by the indirect method had no or very few cognitive symptoms when the AGECAT was applied. The diagnosis of mild dementia is associated with high mortality. Almost 30% of cases of mild dementia diagnosed by the indirect method before the age of 75 years have no symptoms of dementia at the age of 81 years and more than 10% continue to have mild symptoms. Similar results are found at the age of 87 years. Atherosclerotic disorders are present in 48.6% of cases of mild dementia and 58.6% of severe dementia in contrast to only 25–30% of probands with a effective disorder or without psychiatric diagnosis.