Is stress linked to the risk of dementia? Our Research team decided to examine the evidence behind stress and the risk of dementia.
Many people wonder whether stress is linked to a risk of dementia, and the news often reports a link between the two. This Stress Awareness Month, our Research team explains the evidence behind stress and the risk of dementia.
What is stress?
Stress occurs when the body has to respond to a situation that could be dangerous. Symptoms include a pounding heart, sweating, and tense muscles.
These symptoms usually fade away once the danger passes, but some people may find that these stressed feelings continue. This prolonged – or chronic – stress can be very serious and have severe effects on a person emotionally, mentally and physically.
Why has stress been linked to dementia?
There are many reasons why stress could be linked to dementia. Stress affects the immune system, which is known to play an important role in the development of dementia.
A key hormone released when you’re stressed, cortisol, has been linked to problems with memory. Stress is also closely linked to conditions such as depression and anxiety. These have also been suggested as factors that could increase the risk of dementia.
Some research in animal models has found that stress appears to have a direct impact on some of the mechanisms underlying dementia.
However, as with many things in the research world, understanding whether any of these theories are correct has turned out to be a long and winding road.
A complicated situation
It is very hard for researchers to investigate stress. We all experience stress in different ways and our ability to cope with stress varies widely from person to person. It is also very difficult to measure exactly how stressed someone is.
There are also other factors that could be playing a role, which are difficult to separate out. Anxiety, depression, and lack of sleep are all associated with stress, but also with dementia risk. These complications mean that it is very difficult to do high-quality research into the role that stress has in dementia risk.
However, a few studies have attempted to untangle this mystery.
What does science say about stress and dementia?
A review of the scientific literature on stress and dementia risk concluded that stress could play a role in dementia development but is unlikely to be the only factor that causes the condition. There is still much to be understood about what mechanisms could underlie any links between stress and dementia risk.
A study funded by Alzheimer’s Society has examined whether long-term stress plays a role in development of Alzheimer’s disease.
Lead researcher Clive Holmes said: “Understanding the role of the immune system in the risk of Alzheimer’s disease is of great importance to researchers. As prolonged stress can cause changes in the immune system, we wanted to find out if this was linked to progression to dementia from mild cognitive impairment.”
The study tested people at the start of the trial and then tracked their thinking skills and whether any participants had developed dementia. At the start of the study, people with memory and thinking problems had higher stress levels compared to healthy individuals. However, the level of stress a person felt did not correspond to how much their thinking abilities declined, or whether they developed Alzheimer’s disease. This was thought to be because cortisol levels in the brain seemed to diminish as participants thinking abilities declined.
Some researchers looking into long-term stress and dementia have focused on people who are affected by Post Traumatic Stress Disorder (PTSD). This is a diagnosed condition that occurs when a person has been through a life-changing or distressing event. Alzheimer’s Society-funded research has also analysed the literature related to the link between PTSD and dementia. They found that people with PTSD have up to twice the risk of developing dementia. However, this increased risk isn’t fully understood and it is important to note that having PTSD does not mean you will definitely develop dementia.
If I am affected by stress, should I worry about getting dementia?
The current evidence indicates that while chronic stress may play a role in the development or progression of dementia, it does not necessarily cause dementia.
Hopefully, further research can begin to uncover what role stress plays in a person’s risk of developing dementia.
Having long-term stress does cause a number of health issues so if you are experiencing stress, it is a good idea to see your doctor, especially if you might be affected by PTSD.
This article was first published in 2017 and updated in November 2022.
How to deal with stress
There are a number of useful tools available now that can help to combat stress - the NHS Choices website has a list of many of them.