Cognitive impairment and social distress as different pathways to depression in the elderly: a cross-sectional study.

BACKGROUND

This study investigates the recent suggestion that some putative aetiological factors for depression, such as cerebral deterioration and social distress, may act differentially in the aetiology of depression in old age.

METHOD: In a cross-sectional study, a community sample of 654 elderly subjects were interviewed with Short-CARE to assess the prevalence of depression and cognitive impairment. Information was collected for a variety of potential risk factors for depression such as exposure to social support deficit, threatening life events, impairment, disability and handicap.

RESULTS

The prevalence of depression was 17% and that of a broad concept of cognitive impairment 23.9%. This analysis found associations between depression and exposure to social support deficits and threatening life events in the year prior to interview. These associations were considerably stronger for those subjects with no cognitive impairment than for those with cognitive impairment. We also found a progressive lowering in the strength of these associations the higher the chance of cognitive impairment measured as a longitudinal variable using both the Dementia Diagnostic Scale (DDS) and the Organic Brain Syndrome Scale (OBS) included in Short-CARE.

CONCLUSIONS

The results of this theory-driven analysis lend some support to the notion of at least two differential pathways to depression in the elderly, one via social distress factors and another mediated by cerebral deterioration clinically expressed as cognitive impairment.