According to an article in the American Journal of Epidemiology at the beginning of March, there is a cause-and-effect relationship between long working hours and a decline in cognitive function in middle age. Various tests conducted on just over 2,200 British civil servants aged 35 to 55 showed that those who worked more than 55 hours a week saw a decline in cognitive performance, compared to those who worked 40 or fewer hours. Significant differences appeared in vocabulary and logic tests especially.
More research is necessary to determine exactly why working longer hours affects cognitive functions. For now, scientists have come up with a variety of explanations including anxiety, sleeping problems and less time spent on physical activity.
The researchers emphasized that since cognitive impairment is one of the first signs of dementia, e.g. as in Alzheimer’s, it is import to identify risk factors.