The course of late-life depression: a six-year follow-up study
background Hardly any reliable data are available relating to the course of late-life depression.
aim To trace the course of late-life depression in the community; to determine whether the outlook for depressed persons deteriorates with age; and to find out whether failure to satisfy dsm criteria for affective disorders when the depression first manifests itself predicts the course of the depression. method The study was part of the Longitudinal Aging Study Amsterdam. Reliable data relating to 277 depressed elderly persons are available (on average 9.8 observations per respondent).
results During a 6-year period the mean severity of symptoms in the study group was remained higher than the 85th percentile score for elderly persons in the general population. Fewer than 15% of the respondents were depressed for less than 20% of the time. Of the respondents 23% went into remission, 12% went into remission but experienced recurrence, 32% fell into the chronic intermittent category and 32% fell into the chronic category. Both age at baseline and age-related risk factors predicted that the depression would take a rather less favourable course. Respondents fulfilling the DSM-criteria for depression or dysthymic disorder had the least favourable prognosis. In most cases the course of the depression in those diagnosed as having subthreshold depression at baseline was highly unfavourable and certainly far less favourable than in a control group of non-depressed elderly persons who were followed for 3 years.
conclusion The outlook for most persons with late-life depression in the community as a whole is not promising and is probably less promising than for younger adults. The DSM-criteria for depression disorders are a helpful tool for identifying the group whose depression will take the worst course. However, most of the elderly persons with symptoms of depression do not meet formal DSM-criteria. This 'grey area' in the classification of affective disorders is highly relevant, both clinically and from the point of view of public health, and therefore requires further research.