Many people look forward to retirement, thinking of all the wonderful things they will finally be able to do. However, what no one expects is that retirement can have a negative effect on their cognitive functioning. This is what a long-term study carried out by the University of London in the United Kingdom found. The study tracked 3,433 civil servants for the 14 years before retirement, and then another 14 years afterward. The participants were given periodic examinations to assess their cognitive functioning (verbal memory, abstract reasoning, etc.).
The researchers found that when people did eventually retire, they experienced decline in their verbal memory 38 percent faster than before they stopped working. They concluded that the act of retirement significantly accelerates verbal memory decline. They also found that a higher employment grade was protective against verbal memory decline while people were still working, but this ‘protective effect’ was lost when individuals retired, resulting in a similar rate of decline after retirement across the different employment grades.
The researchers pointed out that the adverse effect of retirement on verbal memory is consistent with the results of other studies. That's why they stress how important it is to continue undertaking mentally stimulating activities after retirement in order to prevent this decline. The researchers felt that the study results supported the ‘use it or lose it’ hypothesis regarding verbal memory function. But the good news was that retirement seemed to have little impact on other domains of cognitive functions, such as abstract reasoning and verbal fluency. They just showed normal age-related declines over time.
From European Journal of Epidemiology: Effect of retirement on cognitive function: the Whitehall II cohort study
According to the ‘use it or lose it’ hypothesis, a lack of mentally challenging activities might exacerbate the loss of cognitive function. On this basis, retirement has been suggested to increase the risk of cognitive decline, but evidence from studies with long follow-up is lacking. We tested this hypothesis in a cohort of 3433 civil servants who participated in the Whitehall II Study, including repeated measurements of cognitive functioning up to 14 years before and 14 years after retirement. Piecewise models, centred at the year of retirement, were used to compare trajectories of verbal memory, abstract reasoning, phonemic verbal fluency, and semantic verbal fluency before and after retirement.
We found that all domains of cognition declined over time. Declines in verbal memory were 38% faster after retirement compared to before, after taking account of age-related decline. In analyses stratified by employment grade, higher employment grade was protective against verbal memory decline while people were still working, but this ‘protective effect’ was lost when individuals retired, resulting in a similar rate of decline post-retirement across employment grades. We did not find a significant impact of retirement on the other cognitive domains. In conclusion, these findings are consistent with the hypothesis that retirement accelerates the decline in verbal memory function. This study points to the benefits of cognitively stimulating activities associated with employment that could benefit older people’s memory.