Explaining Different Rates of Cognitive Decline across Europe

Differences in cognitive performance and cognitive decline across Europe suggest that socioeconomic factors influence cognitive ageing.

(July 2019) The decline in cognitive functioning in older adults is one of the primary concerns for European countries. They need to address the rising prevalence of cognitive impairment related to increasing life expectancy as well as the accompanying dependency on the limited number of caregivers. To better understand regional variation in cognitive functioning across Europe, researchers Formanek, Kagstrom, Winkler and Cermakova compared the level of cognitive performance and the rate of cognitive decline in Scandinavia, Western Europe, Central and Eastern Europe, and Mediterranean countries. They found substantial inequalities in cognitive functioning and a counterintuitive relationship between the level of cognitive performance and the rate of cognitive decline. The researchers suggest that differing levels of cognitive reserve might explain these substantial differences. “Reserve” is understood as protection against cognitive decline provided by better socioeconomic conditions, educational opportunities, social and physical activity, life styles, and quality in health care over the life-course.

SHARE’s Assessment of Cognition

For their study, Formanek et al. used data from SHARE waves 1 to 6 (except for wave 3) to trace the cognitive development of more than 22,000 individuals over more than 10 years. Participants’ cognitive abilities were assessed by measuring verbal fluency, immediate recall, and delayed recall. To test the verbal fluency, interviewers asked respondents to name as many animals as possible within 60 seconds. Both immediate and delayed recall were assessed by asking the participants to recall a ten-word list. The data allowed the researchers to add a perspective from Central and Eastern Europe to the current research, as the evidence on cognitive aging from these countries is scarce.

Differences in Cognitive Abilities across Europe

The data showed large differences in cognitive abilities across European regions, with Scandinavians demonstrating the highest baseline cognitive scores and individuals from Mediterranean countries showing the lowest. The second-highest scores were detected in Western Europeans, followed by Central and Eastern Europeans. Formanek et al. note how this variation in cognitive performance persists even after adjusting for a complex set of sociodemographic and clinical characteristics. However, while Scandinavians had the highest baseline score, they also showed the highest rate of cognitive decline. The authors ascribe this to the possession of more neural resources, which allow losing cognitive abilities while still delaying the onset of symptoms of neurodegenerative diseases.

Protective Cognitive Reserve

Given that the development of cognitive impairment has been linked, in addition to genetic susceptibility and gene-environment interactions, to a low level of education, vascular risk factors and cardiovascular disease, depression and social isolation, Formanek et al. point out that the risk for experiencing cognitive decline could be partially modifiable by reducing inequalities in the opportunity to build a protective reserve.

Study by Tomas Formanek, Anna Kagstrom, Petr Winkler and Pavla Cermakova (2019): Differences in Cognitive Performance and Cognitive Decline across European Regions: A Population-based Prospective Cohort Study. European Psychiatry 58 (2019), 80-86.

URL: https://doi.org/10.1016/j.eurpsy.2019.03.001

Photo: Adobe Stock / Robert Kneschke