Abstract
OBJECTIVES: Recent interest has been generated about reports of declining incidence in cognitive impairment among more recently born cohorts. At the same time, attained education, which is related to cognition, has increased in recent cohorts of older adults. We examined cohort differences in cognitive function in a nationally representative sample of Americans aged 25 and older followed for 25 years (1986-2011) and considered the extent to which cohort differences in education account for differences. METHOD: Data come from the Americans' Changing Lives Study (N = 3,617). Multiple cohort latent growth models model trajectories of cognition (errors on the Short Portable Mental Status Questionnaire) across four 15-year birth cohorts. Demographic factors, educational attainment, and time-varying health conditions were covariates. RESULTS: Significant cohort differences were found in the mean number of cognitive errors (e.g., 0.26 more errors at age 65 in cohort born pre-1932 vs cohort born 1947-1961, p < .001). Although demographic and health conditions were associated with level and rate of change in cognitive dysfunction, education solely accounted for cohort differences. DISCUSSION: Compression of cognitive morbidity is seen among the highly educated, and increasing educational opportunities may be an important strategy for decreasing the risk for cognitive impairment in later life.