Retirement linked to a decline in memory

"Retirement causes brain function to rapidly decline, warn scientists," The Daily Telegraph reports, before adding that "workers looking forward to enjoying a long and leisurely retirement after years of toil, may need to think again".

In fact, the study being reported on – an analysis of thinking and memory (cognitive function) in retired civil servants – only found a decline in one area. This was in "verbal memory function", which is the ability to recall words, names and other spoken information.

When taking the natural decline with age into account, verbal memory function declined 38% faster after retirement than before. The good news is that other important cognitive functions, such as the ability to think quickly and identify patterns, were largely unaffected.

It's not clear whether the faster decline of verbal memory function had meaningful clinical significance. It certainly doesn't prove that people were more likely to develop dementia.

Memory decline is a complex problem affected by many different factors, not just retirement. Staying active during retirement may also help to improve overall quality of life, maintain social networks and help prevent loneliness.

Despite the Telegraph's dire warning, it is entirely possible to "enjoy a long and leisurely retirement". Read more advice about how women and men can stay physically and mentally healthy after the age of 60.

Where did the story come from?

This study was carried out by researchers at University College London, King's College London and Queen Mary University, also in London. It was funded by the Economic and Social Research Council and the Medical Research Council. The study was published in the peer-reviewed journal the European Journal of Epidemiology.

The Daily Telegraph and Mail Online reported the results of the study accurately, but were arguably guilty of exaggerating the implications.

The Telegraph presents a particularly harsh depiction of the research and states "those looking forward to enjoying a long and leisurely retirement after years of toil may need to think again". The coverage implies a link between retirement and dementia, stating retirement "makes it more likely dementia will set in earlier". The study mainly looked at age-related cognitive decline. It noted any diagnoses of dementia, though there were very few. In any case the study can't prove direct cause and effect.

What kind of research was this?

This study looked at data from 3,433 people from the Whitehall II Study. This is an ongoing prospective cohort study looking at wellbeing and mental and physical illness in an ageing population.

Large prospective cohort studies such as this are a good way of looking at a large body of data to see whether different exposures may be linked with later outcomes. However, the best sort of study will set out with the purpose of examining the influence of a specific exposure or risk factor to ensure they have gathered the right information and assessed possible confounders.

This study wasn't specifically set up to look at the effect of retirement on cognitive decline. This means the authors can suggest association, but they can't rule out confounding from other factors.

What did the research involve?

The Whitehall II Study recruited civil servants aged 35-55 working in the London offices of 20 Whitehall departments in 1985-1988. The response rate was 73% resulting in a sample of 6,895 men and 3,413 women. The participant's employment ranged from clerical grades, through to senior administrative grades.

This particular study looked at data collected every 2 to 3 years between 1997 and 2013 (4 waves in total) when information on cognitive function was collected. This analysis included 3,433 people (72% male) who moved from work to retirement and had cognitive assessment at least once before and once after retirement.

At each of the 4 assessments self-reported employment status, memory and health status were measured. The memory examinations tested people's:

verbal memory (memory for words and verbal items)
abstract reasoning (ability to think quickly and identify patterns)
verbal fluency (retrieve specific information)

The researchers looked at the relationship between retirement and cognitive function, adjusting for the following confounders:

year of birth
gender
education
smoking status
alcohol consumption
depression symptoms
blood pressure
body mass index
total blood cholesterol
cardiovascular disease
cancer
diabetes

They also looked at whether retirement was due to long-term sickness, which was defined as health-related retirement.

What were the basic results?

Verbal memory was the only cognitive outcome linked with retirement after adjusting for age and other confounders. Retirement had no significant impact on the other cognitive domains.

Declines in verbal memory were 38% faster after retirement compared to before. After retirement, verbal memory scores declined by 0.143 every year (95% confidence interval [CI] -0.162, -0.124). The scores are based on how many of 20 words the participants could recall after 2 minutes.

Higher employment grade was protective against verbal memory decline while people were still working, but this was lost when individuals retired, resulting in a similar rate of decline post-retirement across employment grades.

How did the researchers interpret the results?

The researchers state: "In support of the 'use it or lose it hypothesis' we found that retirement is associated with faster declines in verbal memory function over time, but has little impact on other domains of cognitive functions, such as abstract reasoning and verbal fluency."

Conclusion

This study has some strengths in that it was able to assess a large number of people and look at cognitive change over a long time period, both before and after retirement. It also took into account a number of important factors that may be confounding the analyses.

However, this study only showed a decline in verbal memory. It had no effect on other areas, so certainly doesn't show that people are at risk of faster overall cognitive decline after retirement. It also doesn't show any links with a clinical diagnosis of either mild cognitive impairment or dementia.

It's unclear whether the 38% greater decline in verbal memory would make meaningful difference to a person's everyday life. The study also can't show that retirement is the direct cause of the greater decline because other factors may be involved. However, it is possible.

Verbal ability is likely to be enhanced in the work environment due to the need for self-organisation, communication and collaboration. Therefore it may be fairly normal for this to be poorer after retirement.

There were a number of other limitations that may have affected the results:

It's difficult to untangle whether verbal decline may be directly due to termination of employment, or primarily due to other social factors related with this.
The study hasn't assessed the effect of post-retirement activities such as voluntary work, social and physical activities that may modify the risk of cognitive decline. Some people may be more cognitively and physically active and therefore happier in retirement.
Compared with the general population, those recruited to the Whitehall II study (civil servants) may have more mentally challenging roles, meaning their cognition cannot be regarded as being representative of the general population.
The sample had double the amount of men to women, which may have affected the results as men and women may have different retirement patterns and activities after retirement.

Regardless of employment, memory declines with age. Staying physically and mentally active, with a good social network, can help to maintain overall quality of life and wellbeing. This may also help to maintain cognitive function.

If you have concerns that you or a loved one is experiencing memory loss it's important to visit a GP so that this can be investigated further.