Cognitive impairment: why socioeconomic factors matter

The likelihood of developing cognitive impairment or dementia later in life is influenced by socioeconomic factors, research has found.

The University College London study, published in Scientific Reports, followed 8442 adults aged 50 and above in England over a 10-year period from 2008–09 to 2018–19, in order to examine how socioeconomic factors at the start of the study were associated with changes in cognitive status.

It found that socioeconomic factors such as education, occupation and wealth influence the likelihood of developing cognitive impairment or dementia in later life and whether a person is likely to recover.

How was the study conducted?

The researchers tracked how people moved between various states: healthy, mild cognitive impairment and dementia. They also considered the possibility of reversals, where individuals improved from a mild cognitive impairment state to a healthy one.

Information on socioeconomic factors was collected through a self-completion questionnaire. Cognitive impairment was determined using a mix of sources, including participants’ reports of a doctor’s diagnosis, cognitive test results, and their own reports of symptoms and complaints, providing a full picture of each participant’s cognitive health. In addition to these aspects, the study also accounted for demographic factors, such as age, sex and marital status.

By estimating the time spent in each cognitive state and the likelihood of transitions to neurocognitive disorders such as cognitive impairment and dementia, the researchers were able to gain a comprehensive understanding of how socioeconomic factors impact the progression of a person’s disorder, as well as the duration spent within each cognitive state over time.

The protective effect of socioeconomic advantage

The team found that people from more socioeconomically advantaged backgrounds — particularly those with post-secondary school education (such as university or college), those with managerial or professional-level occupations, and those in the wealthiest third of the population — were less likely to move from a healthy cognitive state to mild cognitive impairment, or from mild cognitive impairment to dementia, compared to those with primary education (no higher than secondary school), working in manual or routine occupations, and in the most socioeconomically disadvantaged third of the population.

For instance, having a post-secondary education level was linked with a 43% lower chance of moving from a healthy cognitive state to mild cognitive impairment.

Meanwhile, being in the wealthiest third of the population was linked with a 26% lower chance of shifting from mild cognitive impairment to dementia.

Notably, these advantaged individuals were also more likely to recover from mild cognitive impairment and return to a healthy cognitive state, with wealthy individuals being 56% more likely and those with a post-secondary education level being 81% more likely to improve, compared to socioeconomically disadvantaged individuals.

Senior author Dr Dorina Cadar (UCL Department of Behavioural Science and Health and Brighton and Sussex Medical School) said: “Our study highlights the critical role of wealth, education and occupation not only in reducing the risk of transitioning from mild cognitive impairment to dementia but also in increasing the likelihood of reversing cognitive impairment to a healthy cognitive state, which is promising.

“This potential recovery is critical for enhancing the quality of life in later years and reducing the long-term burden of cognitive impairment on healthcare systems, families and society as a whole.

“Our findings highlight the potential protective power of financial stability and access to resources in promoting brain health and cognitive resilience, underscoring the importance of social policies that support mental and cognitive wellbeing across all income levels.”

Why does socioeconomic advantage make a difference?

The study cannot provide exact explanations as to why certain socioeconomic factors impact cognitive health. However, the authors believe there may be several reasons behind their findings.

Lead author and PhD candidate Aswathikutty Gireesh (UCL Epidemiology & Health Care) said: “It is possible that education and intellectually demanding jobs provide more mental stimulation and help to build a stronger brain reserve to help protect individuals against cognitive impairment and dementia.

“Additionally, people with higher education, more intellectually demanding jobs and wealth have better access to health care and health-promoting resources such as a nutritious diet, exercise and preventive care — all of which can support cognitive health. These resources could also offer opportunities to stabilise or improve cognitive function, especially when cognitive impairment is detected early.”

The researchers hope that their findings will open new avenues for further exploration into how socioeconomic factors, particularly wealth, might protect against early progression to cognitive impairment.

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