Chronic stress and depressive disorders in older adults.

Current and lifetime rates of Diagnostic and Statistical Manual (rev. 3rd ed.) disorders were compared in 86 older adults caring for a spouse with a progressive dementia and 86 sociodemographically matched control subjects. Dementia caregivers were significantly more dysphoric than non-care givers. The frequencies of depressive disorders did not differ between groups in the years before care giving, and there were no group differences in first-degree relatives' incidence of psychiatric disorder. During the years they had been providing care, 30% of care givers experienced a depressive disorder (major depression, dysthymia, or depression not otherwise specified) versus 1% of their matched controls in the same time period. Only two care givers who met criteria during care giving had met criteria for a depressive disorder before care giving, and family history was not even weakly related to the identification of at-risk care givers. In contrast to these group differences in depressive disorders, there were no significant differences in other Axis I disorders either before or during care giving. Thus, the chronic strains of care giving appear to be linked to the onset of depressive disorders in older adults with no prior evidence of vulnerability.