Preclinical symptoms of major depression in very old age: a prospective longitudinal study

The authors' goal was to examine whether individuals diagnosed as having major depression experienced greater levels of depressive symptoms and cognitive dysfunction up to 3 years before the clinical diagnosis was rendered.

The study included 185 subjects 75 years old or older who participated in a population-based longitudinal survey in Stockholm. Ten of the subjects were diagnosed as depressed up to 3 years after initial screening, and these individuals were compared with the 175 subjects who were not depressed at 3-year follow-up. Depression was diagnosed according to DSM-III-R and DSM-IV criteria. Psychiatric signs and symptoms were assessed by physicians using a structured interview. Cognitive functioning was assessed with the Mini-Mental State.

At the initial screening, the patients later diagnosed as depressed had a greater number of depressive symptoms, such as dysphoria and appetite disturbance, and their symptoms were also more severe than those of the nondepressed subjects. Moreover, the depressed subjects suffered from a more severe lack of interest and psychomotor disturbance and had lower Mini-Mental State scores.

There are preclinical markers for individuals who will become depressed after a 3-year interval. Major depression may have a more chronic nature in very old age, in contrast to the relatively short clinical onset of depression seen in younger adults. The authors conclude that standard diagnostic instruments such as DSM-IV may have to take this lengthy course of impairment into consideration when dealing with very old adults.