Unique and interactive effects of depression, age, socioeconomic advantage, and gender on cognitive performance of normal healthy older people.

A sample of 4,243 residents of Manchester, England and Newcastle-upon-Tyne, England, aged 50 to 93 years, completed the Beck Depression Scale (A.T. Beck, C.H. Ward, M. Mendelson, J. Mock, & J. Erbaugh, 1961) and a battery of 6 different cognitive tests. Beck scores were low, indicating gradations of dysphoria rather than clinical depression. Beck scores did not vary with age but were significantly higher for women than for men and for disadvantaged than for advantaged socioeconomic groups. Measures of fluid, but not of crystallized, ability declined as age increased. Socioeconomic disadvantage was associated with poorer performance on all cognitive tests. Men scored higher on a test of spatial reasoning, and women scored higher on a test of word definition and on 2 tests of verbal memory and learning. However, after variance associated with all these demographic and individual-difference variables was considered, and within a range indicative of dysphoria rather than clinical depression, higher Beck scores were associated with significantly poorer performance on both crystallized and fluid measures of cognitive ability. This association was less marked in women than in men, but age, socioeconomic advantage, and estimated lifetime intellectual ability did not act as protective or risk factors for vulnerability of cognitive processes to dysphoria.