Cognitive impairment and depression in the oldest old in a German and in U.S. communities.

Data on cognitive impairment in the oldest old is reported comparing two different samples, one in Munich, Germany, and the other in the United States (Epidemiologic Catchment Area [ECA] study). In both studies the Mini Mental State Examination (MMSE) was used for assessing cognitive impairment. The Munich sample consisted of 402 and the ECA sample of 827 very old people aged 85 years and above. The results indicate that approximately 40% of each sample scored below 24 points in the MMSE indicating at least mild cognitive impairment. Severe cognitive impairment was found in 13.4% of the Munich and in 14.6% of the American sample. The prevalence of major depression was 1.4% in Munich and 2.0% in the ECA study, and dysthymia was found in 5.1% in the Munich and in 2.0% in the ECA sample aged 85 years and above. Persons living in institutions in both studies more frequently showed signs of cognitive impairment than those living in private households. The ECA sample, but not the Munich sample, showed a significantly higher prevalence of cognitive impairment for females and for the oldest age cohort above 90 years of age. Major depression was more frequent in Munich in persons living in institutions and in the ECA study among the oldest age cohort above 90 years of age. Dysthymia in both studies did not show any association with sociodemographic factors. Most of the excess comorbidity (cognitive impairment and depression) was observed among subjects with mild (and not with severe) cognitive impairment.(ABSTRACT TRUNCATED AT 250 WORDS)