Age Group Differences in Depressive Symptoms among Older Adults with Functional Impairments

It is estimated that about 5 percent of the U.S. population age 55 and older suffer from major clinical depression and that 20 percent suffer from depressive symptoms that do not meet the full criteria for major depression (U.S. Department of Health and Human Services, 1999). Even mild or moderate depression, if untreated, contributes to a low quality of life for older adults and exacerbates the caregiving stress and burden of their informal caregivers (Langa, Valenstein, Fendrick, Kabeto, & Vijan, 2004; Sewitch, McCusker, Dendukuri, & Yaffe, 2004). Compared with their nondepressed peers, older adults suffering from depression, regardless of race or ethnicity, were also found to have visited doctors and emergency rooms more often, had longer hospital stays, had higher outpatient costs, used more medication, and had higher rates of premature institutionalization and mortality (Black, Markides, & Ray, 2003; Linden & Horgas, 1997; Unutzer et al., 1997; Yaffe, Edwards, Covinsky, Lui, & Eng, 2003). Katon and colleagues (2003) found that total health care costs for depressed older adults were, on average, $1,045 to $1,700 higher than those of their nondepressed counterparts over a six-month period. Research findings have shown that the prevalence of depression increases with age among older adults. In 1998, about 15 percent of the U.S. population ages 65 to 79 had severe depressive symptoms, whereas 21 percent of the U.S. population ages 80 to 84 and 23 percent age 85 or older had severe depressive symptoms (Federal Interagency Forum on Aging-Related Statistics, 2000). Palsson and colleagues' (2001) study also found that the rates of the incidence of first-onset depression increased from 5.6 percent to 13 percent from age 70 to age 85 and that the incidence was higher in older women than in older men. The higher rates of depressive symptoms among advanced-age groups may, in large part, be attributed to the increasing prevalence of disability and other health-related problems with advanced age, as many earlier studies have found older adults' chronic illness and disability to be significant risk factors for their depression (see Bruce, 2001, for a summary of studies of the relationships between disability and depressive symptoms; Cole & Dendukuri, 2003, for a summary of 20 prospective studies of risk factors for depressive symptoms among community-dwelling older adults).With the rapidly increasing number of older adults in the population, however, more research is needed to better understand and examine possible age group differences in the effect of health status on late-life depression. Especially given the significant association between disability and late-life depressive symptoms, the purpose of this study was to examine possible age group differences in self-reported depressive symptoms among a representative national sample of functionally impaired, community-dwelling adults age 55 and older. In addition to deteriorating health and increasing frailty, old age, in general, can be fraught with other stressful life events and conditions, such as shrinking social support because of the deaths of spouses and friends, reduced social interaction, and decreasing financial resources as a result of increasing medical costs. Given that these stressful life events and conditions have also been found to be risk factors for depression in later life (Devanand, Kiln, Paykina, & Sackeim, 2002; Schoevers et al., 2000), older adults in advanced-age groups may still be more likely to be depressed than younger older adults, even when health status is controlled for. On the other hand, when health status is controlled for, older adults in advanced-age groups may be less likely to be depressed than younger older adults, as earlier studies also showed that older age groups tend to have more positive attitudes toward their health problems and to rate their own health more positively than do members of younger age groups (Benyamini, Leventhal, & Leventhal, 1999; George, 2001). …