Science Interviews


Wed, 25th May 2016

The ultimate stress test

Professor Angela Clow, University of Westminster

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How does your body react when you're feeling stressed? Graihagh did a 'stress stresstest' with Angela Clow to find out...

Nina - So this is our labs for the Psychology Department.

Hello. Iím Nina Smythe and Iím a lecturer at the University of Westminster in the Psychology Department and today Iím going to be taking you through what the trio social stress test is. It involves you to give a public speech in front of a committee (two members) and youíll be asked to do a speech about a job position.

So if youíre happy just sign and date it... I need you to collect a saliva sample. This will give us the baseline measure of cortisolÖ

Graihagh - Just chew it?

Nina - Yes just until itís wet with your saliva.

Graihagh - Mmm I wish Iíd drunk a bit of water now!

Nina - OK. So Iím going to take you into the other room.

Graihagh - In the other room were two quite stern and, if Iím honest, intimidating looking people, dressed in white lab coats. The man, who I later learnt was called Frank, didnít look up when I entered the room and the women, Angela, stared down her spectacles at me. I was told there was a camera recording my every move and to commence my speech about why I would make an excellent assistant psychologist, despite having never studied psychologyÖ.

Graihagh - So my name is Graihagh Jackson and you may be wondering why someone who has a background in radio is applying for an assistant psychologists job. Well first of all...

As expected, it was hard. Neither made eye contact with me. They offered me no empathy - no smiles or nods of encouragement - they were completely blank. Hereís Angela ClowÖ

Angela - We showed no empathy towards your condition, we had blank faces and we were powerful people. We were sitting down, you were standing up exposed. We had our symbols of power, our white coat, and we were there to make you feel little.

Graihagh - And I did indeed feel little and actually extremely anxious, despite knowing it was a stress test. I found myself fiddling with my necklace, wringing my hands and stuttering....

Graihagh - And um, and um, um...

Angela - Well this stress test has been trialled throughout the world, itís the gold standard of how to make people feel vulnerable and to threaten their self-esteem. Because youíre very confident actually and the nature of your life as a communicator, you were able to display your discomfort by being outward, and energetic, and laughing, and trying your best. Some people find it extremely intimidating and they rather clam up and they hardly say anything, and I have to keep saying you have time remaining, please continue and they just look at you blankly and, to be quite honest, some people are upset.

Graihagh - Upset is something I can seriously relate to but for me, the worst was yet to comeÖ

Frank - Weíre now going to ask you to perform a mental arithmetic task which will last five minutes. Your task is to serially subtract the number 13 from a number that I will give you.

Graihagh - Okay.

Frank - If you make a mistake I will tell you and ask to begin from the beginning, from the start number.

Graihagh - Okay.

This - for me - was worse than the public speakingÖ Because, well public speaking, I do this in my day job in some capacity - maths on the other hand, hmm, not so muchÖ

Frank - Your start number is 2,083 please beginÖ

Graihagh - So, 2083, 2070,

And after I got it wrong once, my confidence plummeted. Even listening to this makes me feel stressed.

Frank - Wrong!

Graihagh - Oh gosh. Er... 80... 78...

Frank - Wrong! Please begin again with 2,083.

Ö and so it continued like this for a very long 5 minutes.

Nina - How was it?

Graihagh - Terrifying but I kind of knew it was going to be terrifying.

Nina - OK, so what weíll do now isÖ

Graihagh - I want to know if I got the job!

Nina - I thought you did very well. Weíll collect two saliva samples - one in ten minutes and one in twenty minutes.

Graihagh - Hi Angela.

Angela - Time to debrief. Nice to meet you. Sorry what a horrible way to introduce myself!

Graighah - Turns out, in real life, Angela and Frank are surprisingly really nice! I was debriefed over of cup of tea with Angela and she talked me through what was going on in my body to elicit that kind of response.

Angela - OK. As soon as you walk in the room that would have started the process. There were three stress response systems: immediately your sympathetic nervous system, your arousal nervous system will start your heart pumping, and your adrenalin will start to be released.  But also youíll kick in, because itís such a severe psychosocial stressor it will activate the third, like the top gear of stress responding, thatís what we call the hypothalamic pituitary adrenal axis for those who want to know these things and it secretes the hormone cortisol. It takes about 15-20-30 minutes for the cortisol levels, which are activated as soon as you walk in and then start to be pumped out throughout the 10 minutes and then we can pick it up about 20 minutes after the end of the stressor.

Graihagh - So where does the saliva come into this because you made me chew lots of cotton wool throughout this test and afterwards so why did you make me do that?

Angela - Well, actually, this has been a revolution in psychophysiology, which is what we do, the combination of psychology and physiology. So, we can measure this hormone in saliva samples, and in that you have a valid reflection of the biologically active cortisol in the blood, right, and that gives us an opportunity to look at the dynamics of change of cortisol over a period of time.

Graihagh - Now you mentioned cortisol before. Can you tell me what is that and why are you so interested in it?

Angela - Oh well, cortisol is endlessly fascinating. It is a hormone - it is essential for life, so cortisol is not bad for you, you cannot live without cortisol.  So cortisol is fundamental for life, itís got lots of roles where it regulates biological process. Things that you're not aware of, so cortisol is doing a job that weíre not aware of and itís keeping us fit and healthy. However, in addition to that role, we call it a housekeeping role looking after our body, itís also the stress response system, so itís got two roles. So you can see if itís such a vital, if it  gets abused by being secreted over, and over again incessantly, then those vital roles that it normally looks after become compromised because there's too much cortisol going on at the wrong time, etc., etc.

Graihagh - If we plotted, letís say, on the horizontal axis and the amount of cortisol on the vertical axis, what does that graph look like?

Angela - Iím so pleased you pointed that out because the way that cortisol executes its housekeeping role is by changing concentrations over the day. Itís got a direct hotline to the bodyís biological clock and so, at night when weíre asleep, cortisol levels are really nice and low so you can snooze away and in the hours before you wake up, it gradually increases as your brainís beginning to activate. And then when you wake up, for me this is the most fascinating part, thereís a tipping point where you get this sudden surge in cortisol, and you get a doubling in concentration within 15-20-30 minutes. Itís called the cortisol awakening response and then after that peak, about 30 minutes after youíve woken up, it tracks down gradually over the day till the evening.

Graihagh - Iím intrigued to see what my results are because Iíve chewed four bits of cotton wool now and youíve got my measurementsÖ

Angela - Iím very intrigued to see them as well and it's going to be fascinating to see how stressed you are. You didnít look at all stressed when you were doing this job interview aspect but, I have to say, you did look under pressure when we put you through the mental arithmetic task.

Graihagh - When can I come back - when can I get the results?

Angela - Well, weíre hoping to run your saliva samples this afternoon. Weíll put them through the express mode and so Iíd like to speak you on Thursday, and then we can talk about how you did.

Graihagh - Two days later, I went back to see Professor Angela Clow to get my resultsÖ

Angela - Well the results are in, as they say. And you started off with beautiful low cortisol so, obviously, youíre journey here to London hadnít really stressed you out. You were in a nice relaxed state when you came in.

Then we took a sample immediately before you came into the room and were confronted by Frank and myself and then we took one immediately after the end of the stressor, which was ten minutes and, already, your cortisol levels had started to go up.

Ten minutes after that, itís gone up, itís about double, and then ten minutes after that at the peak you are up 25% again. So weíve got a change from 3 nano mls per litre at base to 11 nano mls per litre, so quite a substantial rise. We succeeded in stressing you.

Graihagh - In this particular instant, weíd just see a sort of blip up in the timeline and then slowly go back down to normal. But, I imagine if youíre continually stressed, that graph becomes very jagged with lots of bursts of cortisol.

Angela - Absolutely. Youíve got an underlying drive for cortisol secretion across the day which peaks in the morning and goes down over the day, and superimposed upon that you have these stress responses which are brought about by real life events. I should emphasise that people are very resilient in the short term, but if these are going on for years at a time and youíre constantly exposed to these stresses across your day, then the impact of that is that it affects the regulation of your underlying pattern so that your body is less able to produce those nice dynamic changes and you end up a flat pattern across the day.

Graihagh - Why is that - what is the effect? Is it that your cells become resistant cortisol, much like when people have diabetes you become resistant to insulin?

Angela - Thatís exactly what happens because you become overflooded with the hormone and, therefore, the body downregulates its ability to detect it and, therefore you become less efficient at shutting it down.

Graihagh - Whatís the implications of that?

Angela - First of all your cortisol is your master hormone regulating downstream biological processes like your immune system, cardiovascular system, metabolic system and so, if that message isnít giving clear instructions about day and night to those biological processes, then theyíre not going to function properly.

Also, there are implications for inflammation - I mentioned the immune system but modern research is demonstrating that a lot of conditions are associated with inflammatory processes across the body. If youíre flooding your body with cortisol at inappropriate times of day, the inflammatory immune cells, which should normally be shut off by cortisol, also become desensitised to cortisol so it promotes the inflammatory process.

We know that high inflammatory processes are associated with such a wide range of ill health conditions, for example, clinical depression is associated with inflammatory processes. As well as Alzheimerís disease and a range of cardiovascular diseases. So many things have inflammatory processes at their root really.

Graihagh - Yes, absolutely. I find that kind of shocking that stress over the long term can have such physical and, also, huge effects on your mental health as well.

Angela - Well thatís why itís so interesting to study and, depending on what your biological vulnerability is, then chronic stress will be associated with a different range of conditions, thatís why thereís not a single stress condition. It would be so much easier for people like me is if you just end up with a big spot on your face and you say, oh youíre just suffering from stress. But itís not like that because stress can manifest in a hundred different ways.


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