Mar 12th 2020

How chronic stress changes the brain – and what you can do to reverse the damage

by Barbara Jacquelyn, Sahakian Christelle Langley and Muzaffer Kaser

 

Barbara Jacquelyn Sahakian is Professor of Clinical Neuropsychology at The University of Cambridge. 

Christelle Langley is Postdoctoral Research Associate, Cognitive Neuroscience, at The University of Cambridge.

Muzaffer Kaser is Clinical Lecturer, at The University of Cambridge.

 

A bit of stress is a normal part of our daily lives, which can even be good for us. Overcoming stressful events can make us more resilient. But when the stress is severe or chronic – for example caused by the breakdown of a marriage or partnership, death in the family or bullying – it needs to be dealt with immediately.

That’s because repeated stress can have a huge impact on our brain, putting us at risk of a number of physical and psychological problems.

Repeated stress is a major trigger for persistent inflammation in the body. Chronic inflammation can lead to a range of health problems, including diabetes and heart disease. The brain is normally protected from circulating molecules by a blood-brain barrier. But under repeated stress, this barrier becomes leaky and circulating inflammatory proteins can get into the brain.

The brain’s hippocampus is a critical brain region for learning and memory, and is particularly vulnerable to such insults. Studies in humans have shown that inflammation can adversely affect brain systems linked to motivation and mental agility.

There is also evidence of chronic stress effects on hormones in the brain, including cortisol and corticotropin releasing factor (CRF). High, prolonged levels of cortisol have been associated with mood disorders as well as shrinkage of the hippocampus. It can also cause many physical problems, including irregular menstrual cycles.

Mood, cognition and behaviour

It is well established that chronic stress can lead to depression, which is a leading cause of disability worldwide. It is also a recurrent condition – people who have experienced depression are at risk for future bouts of depression, particularly under stress.

There are many reasons for this, and they can be linked to changes in the brain. The reduced hippocampus that a persistent exposure to stress hormones and ongoing inflammation can cause is more commonly seen in depressed patients than in healthy people.

Chronic stress ultimately also changes the chemicals in the brain which modulate cognition and mood, including serotonin. Serotonin is important for mood regulation and wellbeing. In fact, selective serotonin reuptake inhibitors (SSRIs) are used to restore the functional activity of serotonin in the brain in people with depression.

Sleep and circadian rhythm disruption is a common feature in many psychiatric disorders, including depression and anxiety. Stress hormones, such as cortisol, play a key modulatory role in sleep. Elevated cortisol levels can therefore interfere with our sleep. The restoration of sleep patterns and circadian rhythms may therefore provide a treatment approach for these conditions.

Depression can have huge consequences. Our own work has demonstrated that depression impairs cognition in both non-emotional domains, such as planning and problem-solving, and emotional and social areas, such as creating attentional bias to negative information.

In addition to depression and anxiety, chronic stress and its impact at work can lead to burnout symptoms, which are also linked to increased frequency of cognitive failures in daily life. As individuals are required to take on increased workload at work or school, it may lead to reduced feelings of achievement and increased susceptibility to anxiety, creating a vicious cycle.

Stress can also interfere with our balance between rational thinking and emotions. For example, the stressful news about the global spread of the novel Coronavirus has caused people to hoard hand sanitisers, tissues and toilet paper. Shops are becoming empty of these supplies, despite reassurance by the government that there is plenty of stock available.

This is because stress may force the brain to switch to a “habit system”. Under stress, brain areas such as the putamen, a round structure at the base of the forebrain, show greater activation. Such activation has been associated with hoarding behaviour. In addition, in stressful situations, the ventromedial prefrontal cortex, which plays a role in emotional cognition – such as evaluation of social affiliations and learning about fear – may enhance irrational fears. Eventually, these fears essentially override the brain’s usual ability for cold, rational decision-making.

Overcoming stress

So what should you do if you are suffering from chronic stress? Luckily there are ways to tackle it. The UK Government Foresight Project on Mental Capital and Wellbeing has recommended evidenced-based ways to mental wellbeing.

We know, for example, that exercise has established benefits against chronic stress. Exercise tackles inflammation by leading to an anti-inflammatory response. In addition, exercise increases neurogenesis – the production of new brain cells – in important areas, such as the hippocampus. It also improves your mood, your cognition and your physical health.

Another key way to beat stress involves connecting with people around you, such as family, friends and neighbours. When you are under stress, relaxing and interacting with friends and family will distract you and help reduce the feelings of stress.

Learning may be a less obvious method. Education leads to a cognitive reserve – a stockpile of thinking abilities – which provides some protection when we have negative life events. In fact, we know that people are less likely to suffer from depression and problems in cognition if they have better cognitive reserve.

Other methods include mindfulness, allowing us to take notice and be curious of the world around us and spend time in the moment. Giving is another – volunteering or donating to a charity activates the reward system in your brain and promotes positive feelings about life.

Importantly, when you experience chronic stress, do not wait and let things get the better of you. Early detection and early effective treatment is the key to a good outcome and good wellbeing. Remember to act in a holistic manner to improve your mood, your thinking and your physical health.

And you don’t have to wait until you are overwhelmed with stress. Ultimately, it is important that we learn from an early age to keep our brain fit throughout our whole life course.'

 

Barbara Jacquelyn Sahakian, Professor of Clinical Neuropsychology, University of Cambridge; Christelle Langley, Postdoctoral Research Associate, Cognitive Neuroscience, University of Cambridge, and Muzaffer Kaser, Clinical Lecturer, University of Cambridge

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Browse articles by author

More Essays

May 23rd 2020
EXTRACT: "The QAnon movement began in 2017 after someone known only as Q posted a series of conspiracy theories about Trump on the internet forum 4chan. QAnon followers believe global elites are seeking to bring down Trump, whom they see as the world’s only hope to defeat the “deep state.” OKM is part of a network of independent congregations (or ekklesia) called Home Congregations Worldwide (HCW). The organization’s spiritual adviser is Mark Taylor, a self-proclaimed “Trump Prophet” and QAnon influencer with a large social media following on Twitter and YouTube."
May 23rd 2020
EXTRACT: "The aim of my research for the Understanding Unbelief programme was to investigate the worldviews of non-believers, since little is known about the diversity of these non-religious beliefs, and what psychological functions they serve. I wanted to explore the idea that while non-believers may not hold religious beliefs, they still hold distinct ontological, epistemological and ethical beliefs about reality, and the idea that these secular beliefs and worldviews provide the non-religious with equivalent sources of meaning, or similar coping mechanisms, as the supernatural beliefs of religious individuals."
May 22nd 2020
EXTRACT: "Psalm 91, for example, reassures believers that God will protect them from “the pestilence that walketh in darkness… A thousand shall fall at thy side, and ten thousand at thy right hand; but it shall not come nigh thee”.............Luther was a devout believer but insisted that religious faith had to be joined with practical, physical defences against sickness. It was a good Christian’s duty to work to keep themselves and others safe, rather than relying solely on the protection of God. "
May 22nd 2020
EXTRACT: "Evidence from this study shows clearly that eating foods rich in flavonoids over your lifetime is significantly linked to reducing Alzheimer’s disease risk. However, their consumption will be even more beneficial alongside other lifestyle changes, such as quitting smoking, managing a healthy weight and exercising."
May 5th 2020
EXTRACT: "It’s possible that the answers to questions like, “how do I live a virtuous life?” or “how do we build a good society?” are not the same as they were a few weeks ago."
May 2nd 2020
EXTRACT: "Strangely, those with strong beliefs tend to be admired. The human mind hates uncertainty, so it is comforting to be told what to think, and to form settled opinions. But it is not rational. As the philosopher Bertrand Russell wrote: “The fundamental cause of the trouble is that in the modern world the stupid are cocksure while the intelligent are full of doubt.”
Apr 21st 2020
Extract: "Humans, Boccaccio seems to be saying, can think of themselves as upstanding and moral – but unawares, they may show indifference to others. We see this in the 10 storytellers themselves: They make a pact to live virtuously in their well-appointed retreats. Yet while they pamper themselves, they indulge in some stories that illustrate brutality, betrayal and exploitation. Boccaccio wanted to challenge his readers, and make them think about their responsibilities to others. “The Decameron” raises the questions: How do the rich relate to the poor during times of widespread suffering? What is the value of a life? In our own pandemic, with millions unemployed due to a virus that has killed thousands, these issues are strikingly relevant.
Apr 20th 2020
Extract: "If we do not seize this crisis as a moment for transformation, then we will have lost the war. If doing so requires reviving notions of collective guilt and responsibility – including the admittedly uncomfortable view that every one of us is infinitely responsible, then so be it; as long we do not morally cop out by blaming some group as the true bearers of sin, guilt, and God’s heavy judgment. A pandemic clarifies the nature of action: that with our every act we answer to each other. In that light, we have a duty to seize this public crisis as an opportunity to reframe our mutual responsibility to one another and the world."
Apr 16th 2020
EXTRACT: "Death is the common experience which can make all members of the human race feel their common bonds and their common humanity."
Apr 7th 2020
EXTRACT: "A crisis such as this one demands that we exercise what the philosopher Immanuel Kant called the ‘public use of reason’ – as opposed to merely the ‘private use of reason’ where, briefly put, the expert, the specialist is tasked with resolving a defined problem. The private use of reason is sufficient when we are dealing with a problem that can be solved by simply applying the appropriate expertise...............The public use of reason asks: how we are defining the problem? Is our definition – our conceptualization of the problem – perhaps part of the problem itself? Is this pandemic solely a problem of public health, or is it also a problem of extreme economic inequality? ..............Since this crisis began, the greatest failure of the administration is not the denial, the lies, the lack of preparedness, but the inability to rally and unify the nation against this common threat, the lack of genuine leadership – Trump’s utter inability to bring the nation together."
Apr 5th 2020
EXTRACT: "Rarely has an architectural experiment aroused such extremes of ire and admiration. One side is convinced the house is a masterpiece. The other expresses brutal condemnation of the entire project (leaky roof, danger of flooding, too-hot, too-cold interiors depending on the American Midwest weather).........Farnsworth encapsulated her personal ambiguity in her comment to a Newsweek interviewer: “This handsome pavilion I own is almost totally unworkable.” She told one journalist, “ … all I got was this glib, false sophistication. The conception of a house as a glass cage suspended in air is ridiculous.”
Apr 1st 2020
Ambrogio Lorenzetti, Effects of Good Government fresco, Palazzo Pubblico, Siena.
Mar 29th 2020
EXTRACT: "The coronavirus crisis has forced us to look at our behaviour in a way that we’re not used to. We are being asked to act in the collective good rather than our individual preservation and interest. Even for those of us with the best of intentions, this is not so easy."
Mar 23rd 2020
EXTRACT: "In March 2020, my sister Nancy and I did something that, as scholars, we had never done before: we wrote about ourselves, comparing our own experiences receiving cancer care on either side of the Atlantic. As we recently reported in the BMJ, much of our experience is similar. As twins, we both have the same form of cancer. Both of us received excellent treatment in well-established university teaching hospitals. Both of us are now in remission. But there is a glaring difference. Nancy lives in the US, covered under a good private healthcare scheme. I live in the UK, covered by the NHS."
Mar 21st 2020
EXTRACT: "In philosophy, individualism is closely linked with the concept of freedom. As soon as restrictive measures were imposed in Italy, many people felt that their freedom was threatened and started to assert their individuality in various ways. Some disagreed with the necessity of cancelling group gatherings and organised unofficial ones themselves. Others continued to go out and live as they always did. We often assume that freedom is to do as we choose, and that is contrasted with being told what to do. As long as I am doing what the government tells me, I am not free. I am going out, not because I want to, but because that shows I am free. But there is another route to freedom..........."
Mar 12th 2020
EXTRACT: "Repeated stress is a major trigger for persistent inflammation in the body. Chronic inflammation can lead to a range of health problems, including diabetes and heart disease. The brain is normally protected from circulating molecules by a blood-brain barrier. But under repeated stress, this barrier becomes leaky and circulating inflammatory proteins can get into the brain. The brain’s hippocampus is a critical brain region for learning and memory, and is particularly vulnerable to such insults. Studies in humans have shown that inflammation can adversely affect brain systems linked to motivation and mental agility. There is also evidence of chronic stress effects on hormones in the brain, including cortisol and corticotropin releasing factor (CRF). High, prolonged levels of cortisol have been associated with mood disorders as well as shrinkage of the hippocampus. It can also cause many physical problems, including irregular menstrual cycles."
Mar 12th 2020
EXTRACT: "It’s important to do things that make you happy or content as you are doing them – and doing them for yourself. Research has found that picking recovery activities you find personally satisfying and meaningful is more likely to help you feel recovered by the next morning."
Feb 22nd 2020
EXTRACTS: "A recent study of nearly 3,000 physicists found that a scientist’s most highly cited publication had an equal probability of being published at any point within the sequence of papers the scientist published.........Creativity is not the prerogative of the young, but can occur at any stage in the life cycle...........there is not a single kind of creativity, but that in virtually every intellectual discipline there are two different types of creativity, each associated with a distinct pattern of discovery over the life cycle. The bold leaps of fearless and iconoclastic young conceptual innovators are one important form of creativity. Archetypal conceptual innovators include Einstein, Picasso.......very different type of creativity, in which important new discoveries emerge gradually and incrementally from the extended explorations of older experimental innovators.......The single year from with Paul Cézanne’s work is most frequently illustrated in textbooks of art history is 1906 – the last year of his life, when he was 67."
Feb 22nd 2020
EXTRACT: "As our global population is projected to live longer than ever before, it’s important that we find ways of helping people live healthier for longer. Exercise and diet are often cited as the best ways of maintaining good health well into our twilight years. But recently, research has also started to look at the role our gut – specifically our microbiome – plays in how we age."
Feb 16th 2020
EXTRACT: "In an increasingly polarised political landscape, we see differing political views challenged, not through debate and discussion, but through tribal behaviour. We often consider the groups that we belong to as worthy of empathy, respect and tolerance – but not others. What’s more, recent research has identified that we reward our leaders for being naysayers – negating, refuting or criticising others – rather than empowering them."