Are you middle-aged and having trouble doing the crossword or sodoku puzzle these days? Fishing vainly for the right word, or scrambling words as they come out? Perhaps it’s time to look at your working hours, because new research strongly suggests that consistently working overtime in mid-life is linked with such signs of mild cognitive impairment (MCI). And that could put you on the road to dementia and a premature death, say the experts. They already knew that long working hours are linked with cardiovascular disease, diabetes, fatigue and depression. Now it seems the impact on mental health might be comparable to the health effects of smoking.

The Whitehall II study followed British civil servants -- 1694 men and 520 women -- with a mean age of 52 for several years. Some 39 per cent worked 35 to 40 hours a week; 53 per cent worked 41 to 55 hours; and 8 per cent worked more than 55 hours. On average, those who worked more than 55 hours a week performed significantly worse on vocabulary and reasoning tests. The effect on vocabulary did not show up for women -- a finding which won’t surprise their husbands, although it that could be due to the smaller number of women in the study.

Compared with those who worked a standard 35 to 40-hour week, those who accumulated 15 to 20 hours or more overtime every week were likely to be married men with a higher education level, a higher job level, and a higher income. They also slept fewer hours and had greater psychological distress and alcohol consumption, but they did have greater social support. ~ “Long Working Hours in Middle Age May Impair Cognition,” Marianna Virtanen et al, American Journal of Epidemiology, January 6