Ranges of psychiatric morbidity in the old and the very old--results from the Berlin Aging Study (BASE).

The purpose of this study was to determine prevalence rates of psychiatric morbidity in the elderly, distinguishing different levels of psychiatric caseness as compared to the diagnoses of the DSM-III-R. In a cross-sectional population-based study in Berlin (West), Germany, 516 people aged 70 to 95+ were randomly selected from the obligatory city registry (1990-1993) and stratified by age and gender (N = 43 men and N = 43 women in each of six 5-year age groups). Psychiatric and physical examinations were carried out in an extensive standardized assessment. Distinct psychopathological syndromes occurred in 72.7% of the elderly (54.6% of the men, 79.1% of the women). A clinically defined psychiatric disorder was found in 49.4% of the elderly (95% confidence interval 43.9%- 54.9%; 36.4% of the men, 54.0% of the women). Excluding insomnia, the overall psychiatric morbidity was 40.4% (30.9% m, 43.8% w). Excluding clinical diagnoses that were not otherwise specified in the DSM-III-R, the overall prevalence of specified DSM-III-R diagnoses was 23.5% (16.3% m, 26.0% w). Excluding dementia, which is known to be age-related, the prevalence was 11.3% (8.5% m, 12.2% w) and no significant effect between the age groups was seen. A considerable proportion of clinically relevant psychiatric morbidity in the elderly does not meet the criteria of specified DSM-III-R diagnoses, although these cases are in need of care. The data show that the threshold and severity of caseness accounts for important differences when overall psychiatric morbidity is assessed.