School grades can predict risk of dementia

Serhiy Dekthyar’s och Agneta Herlitz’ research (Dekthyar, Wang, Scott, Koupil, & Herlitz, 2015; American Journal of Geriatric Psychiatry) has received attention in international and national media (e.g., Time Magazine, USA Today, The Telegraph, SVT, SvD). Their research shows that school grades at age 10 are related to risk of dementia in late life.

There is considerable variation among people diagnosed with dementia in the amount of amyloid plaques and other damage in the brain. ”cognitive reserve” is a concept developed to explain the gap between the amount of brain damage and the level of memory and other cognitive symptoms an individual experiences. It has been proposed that the greater the level of cognitive reserve, the higher the brain’s ability to adapt to injury like that which causes dementia, and the more damage – and more time – required for cognitive function to decline far enought to be considered dementia. Formal education and occupational complexity have been viewed as the main contributors to cognitive reserve.

To further investigate and understand this notion, 7574 individuals aged 65+ from the Uppsala Birth Cohort Study (Centre for Health Equity Studies) for more than 20 years to detect their new cases of dementia. In addition to conventional measures of cognitive reserve, such as education and occupational attainment, they also collected data on childhood cognitive ability – school grades around age 10.

Dementia risk was elevated in people who were in the lowest 20% of childhood school grades in this population. High occupational complexity could not compensate for the effect of low childhood school marks. Lowest dementia risk was found in the group who had both higher childhood school performance and high occupational complexity.

“Our findings highlight the importance of early-life cognitive performance for the late-life risk of dementia. It appears that baseline cognitive ability – even at age 10 – may provide the foundation for successful cognitive aging much later in life, “ says Dekhtyar. “Formation of cognitive reserve is a process that apparently begins early in life.”