The probability of any American having dementia in their lifetime may be far greater than previously thought.
For instance, a 2025 study that tracked a large sample of American adults across more than three decades found that their average likelihood of developing dementia between ages 55 to 95 was 42 per cent, and that figure was even higher among women, Black adults and those with genetic risk.
Now, a great deal of attention is being paid to how to stave off cognitive decline in the aging American population. But what is often missing from this conversation is the role that chronic stress can play in how well people age from a cognitive standpoint, as well as everybody’s risk for dementia.
We are professors at Penn State in the Center for Healthy Aging, with expertise in health psychology and neuropsychology. We study the pathways by which chronic psychological stress influences the risk of dementia and how it influences the ability to stay healthy as people age.
Recent research shows that Americans who are currently middle-aged or older report experiencing more frequent stressful events than previous generations.
A key driver behind this increase appears to be rising economic and job insecurity, especially in the wake of the 2007-2009 Great Recession and ongoing shifts in the labour market.
Many people stay in the workforce longer due to financial necessity, as Americans are living longer and face greater challenges covering basic expenses in later life.
Therefore, it may be more important than ever to understand the pathways by which stress influences cognitive aging.
Social isolation & stress
Although everyone experiences some stress in daily life, some people experience stress that is more intense, persistent or prolonged. It is this relatively chronic stress that is most consistently linked with poorer health.
In a recent review paper, our team summarised how chronic stress is a hidden but powerful factor underlying cognitive aging, or the speed at which your cognitive performance slows down with age.
It is hard to overstate the impact of stress on your cognitive health as you age. This is in part because your psychological, behavioral and biological responses to everyday stressful events are closely intertwined, and each can amplify and interact with the other.
For instance, living alone can be stressful – particularly for older adults – and being isolated makes it more difficult to live a healthy lifestyle, as well as to detect and get help for signs of cognitive decline.
Moreover, stressful experiences – and your reactions to them – can make it harder to sleep well and to engage in other healthy behaviours, like getting enough exercise and maintaining a healthy diet. In turn, insufficient sleep and a lack of physical activity can make it harder to cope with stressful experiences.
Stress is often missing from dementia prevention efforts A robust body of research highlights the importance of at least 14 different factors that relate to your risk of Alzheimer’s disease, a common and devastating form of dementia and other forms of dementia. Although some of these factors may be outside of your control, such as diabetes or depression, many of these factors involve things that people do, such as physical activity, healthy eating and social engagement.
What is less well-recognised is that chronic stress is intimately interwoven with all of these factors that relate to dementia risk.
Our work and research by others that we reviewed in our recent paper demonstrate that chronic stress can affect brain function and physiology, influence mood and make it harder to maintain healthy habits. Yet, dementia prevention efforts rarely address stress.
Avoiding stressful events and difficult life circumstances is typically not an option.
Where and how you live and work plays a major role in how much stress you experience. For example, people with lower incomes, less education or those living in disadvantaged neighbourhoods often face more frequent stress and have fewer forms of support – such as nearby clinics, access to healthy food, reliable transportation or safe places to exercise or socialise – to help them manage the challenges of aging As shown in recent work on brain health in rural and underserved communities, these conditions can shape whether people have the chance to stay healthy as they age.
Over time, the effects of stress tend to build up, wearing down the body’s systems and shaping long-term emotional and social habits.
Lifestyle changes to manage stress and lessen dementia risk The good news is that there are multiple things that can be done to slow or prevent dementia, and our review suggests that these can be enhanced if the role of stress is better understood.
Whether you are a young, midlife or an older adult, it is not too early or too late to address the implications of stress on brain health and aging. Here are a few ways you can take direct actions to help manage your level of stress:
1) Follow lifestyle behaviours that can improve healthy aging. These include: following a healthy diet, engaging in physical activity and getting enough sleep. Even small changes in these domains can make a big difference.
2) Prioritise your mental health and well-being to the extent you can. Things as simple as talking about your worries, asking for support from friends and family and going outside regularly can be immensely valuable.
3) If your doctor says that you or someone you care about should follow a new health care regimen, or suggests there are signs of cognitive impairment, ask them what support or advice they have for managing related stress.
4) If you or a loved one feel socially isolated, consider how small shifts could make a difference. For instance, research suggests that adding just one extra interaction a day – even if it’s a text message or a brief phone call – can be helpful, and that even interactions with people you don’t know well, such as at a coffee shop or doctor’s office, can have meaningful benefits.
Walkable neighbourhoods, lifelong learning A 2025 study identified stress as one of 17 overlapping factors that affect the odds of developing any brain disease, including stroke, late-life depression and dementia. This work suggests that addressing stress and overlapping issues such as loneliness may have additional health benefits as well. However, not all individuals or families are able to make big changes on their own. Research suggests that community-level and workplace interventions can reduce the risk of dementia. For example, safe and walkable neighbourhoods and opportunities for social connection and lifelong learning – such as through community classes and events – have the potential to reduce stress and promote brain health.
Importantly, researchers have estimated that even a modest delay in disease onset of Alzheimer’s would save hundreds of thousands of dollars for every American affected. Thus, providing incentives to companies who offer stress management resources could ultimately save money as well as help people age more healthfully. (The Conversation)
