Although cognitive performance levels in old age have increased in most countries, recent evidence documents a slowing down or even decline in cohort gains in highly developed countries. The aim of this study was to assess trends and determinants in secular cohort gains in cognitive functioning among older individuals and whether cohort gains are levelling off in most advanced countries.
Data for individuals aged between 50 and 84 years from the Survey of Health, Ageing and Retirement in Europe in 10 European countries between 2004 and 2013 (n=92 739) were used to assess country and age-specific changes in immediate word recall. Multivariate random intercept models were used to assess associations between secular cohort changes in immediate word recall, initial performance levels and changes in country-level socio-demographic characteristics.
Performance in immediate word recall improved in all countries between 2004 and 2013 (from 4.40 to 5.08 words, P<0.05). However, secular cohort gains were significantly smaller in countries with initially higher performance levels (coeff.=–0.554, 95% CI –0.682 to –0.426). Changes in socio-demographic and health conditions, including decreases in cardiovascular disease, physical activity and educational achievement, were associated with larger secular cohort gains.
Results may either reflect that some countries are approaching the limits of cognitive plasticity, are slowing in their progress or that societal structures have not yet been optimised to improve cognitive abilities in midlife and beyond, or a combination of these interpretations.