Use of the GDS-15 as a Depression Screen in Older Adults with Mild to Moderate Cognitive Impairment

Few studies have examined the performance of the 15-item Geriatric Depression Scale (GDS-15) among older adults with cognitive impairment. The GDS-15 was administered to 166 cognitively impaired and 144 cognitively normal older volunteers. We compared the two groups on total score, individual item endorsement, and three factor scores: General Depressive Affect, Withdrawal, and Life Satisfaction. We hypothesized that cognitively impaired subjects would have higher scores in areas of the GDS-15 where depressive and cognitive symptoms are potentially confounded, e.g. Withdrawal and memory loss. In two-group MANCOVA analysis on factor scores, controlling for age and gender, the impaired group was significantly more symptomatic; univariate contrasts showed this was due to elevated General Depressive Affect scores. Higher levels of missing data were problematic among the cognitively impaired respondents, but controlled tests on factor scores lend support to the ability of the GDS-15 to detect depressive symptoms in the cognitively impaired group.