Posts archived in Abnormality
June 19, 2010 by Evie Bentley.
We’ve known for ages that far more females than males suffer from depression and anxiety disorders, but it is frequently hypothesised that this is not the true state of things. This is because, in Western industrialised cultures, it is more acceptable to admit vulnerability especially psychological vulnerability if one is female, not male. The macho nature of these cultures is, if you like, a confounding variable. However, there could be more to this than social and cultural relativism.
A recent interesting finding in rats shows that females are definitely more sensitive to stress. Their brain cells respond far more strongly to the precursor to corticosteroid stress hormones, a neurochemical called corticotropin-releasing factor, CRF. Female rat neurons are activated by CRF, male rat neurons adapt to it and less stress hormones are produced.
But does this rat behaviour also happen in humans? Well, we don’t know; but we do know that CRF regulation gets disrupted in human stress-related psychological disorders, so there could be a similarity, although one needs always to be very careful in generalising between species.
June 10, 2010 by Cara Flanagan.
A student recently pointed out an error in the AS Book on page 119 – in the Do it yourself feature we have suggested that one way to help yourself to remember the terms related to the body’s response to stress is to use more familiar ideas to represent the different words. For example, you might try to remember those Spanish cousins ‘Adrena Cortez’ (the adrenaline junkie) ‘Adrena Medulla’ (with her cortisol habit). However that is the wrong way round – Adrena Cortez has the cortisol habit. Sorry! Thanks to Jasmine Nelson for pointing this out (and telling us how much she liked this blog).
May 2, 2010 by Adrian Frost.
There really are some beautiful charts and diagrams here…. truly ‘descriptive statistics’. I can’t really do any of it justice by cramming it into a tiny blog post, but it’s well worth having a look at this venn diagram about drugs, for example. Or this interactive representation of the link between stress and work.
January 20, 2010 by Cara Flanagan.
A team at the University of London have just published a report of their study linking stress to atheroschlerosis (narrowing of the arteries), which is a major factor in heart attacks. Hamer et al. (2010) worked with 514 healthy men and women (mean age 62.9 years). The participants were given various tasks to increase their stress levels (such as the Stroop task). Cortisol levels in the saliva were measured before and after the stress tasks (cortisol is a hormone produced when we are stressed). Coronary artery calcification (thickening) was also assessed. The study found that only 40% of the participants had raised cortisol levels after the task but of this group there were significantly more people with thickened arteries. These results support the idea that hypothalamic pituitary adrenal activity (which produces cortisol) is a risk factor for CHD.
December 8, 2009 by Evie Bentley.
Diathesis-stress is an example of nature AND nurture, as it can be interpreted as a gene or genes switched on by environmental factors. Recently it’s been suggested that being lonely and stressed could affect the expression of cancer-linked genes, triggering their action. The research has been done in the USA on rats, comparing those kept in isolation with those living in groups. The former group had over three times the frequency of breast tumours than the latter group, and their breast tumours were also more aggressive and deadly. The isolated rats also produced more stress hormones and were more reactive to stressful situations. Rats, like ourselves, are social animals and so being isolated is likely to cause stress.
September 2, 2009 by Evie Bentley.
Research due to be published this autumn in the USA journal Cancer suggests that too much stress can impact on surviving cancer. This study was a meta-analysis of 3.8 million people, cancer sufferers diagnosed between 1973 and 2004. Married people were found to have a 5 year survival rate of 63% compared to a 45% rate for those who were separated. The explanation offered is that the stress of a break-up in a serious relationship interferes with healing and recovery, and hence survival rates. The researchers suggest that the love and support of a partner is a key factor in battling illness, even one as serious as cancer, and their findings are supported by many previous studies. Of course, important other factors are also relevant – how many can you think of?
January 29, 2009 by Cara Flanagan.
We recently received the question above from Claire Matthews of The Castle School in Bristol and thought some of you would be interested in the answer: The SAM system concerns the adrenal medulla and the release of adrenaline/noradrenaline which has the effect of creating physiological (sympathetic) arousal and producing the fight or flight response. The HPA access concerns the adrenal cortex which produces corticosteroids such as cortisol, which help the body to recover after stress but also have negative effects e.g. reduced immune function. Now to the question – do they happen simultaneously or does the SAM system come first and the HPA second?
The answer is both. Essentially both systems are triggered by a stressor but one (SAM) is an instantaneous response like lighting a match, whereas the other (HPA) is much slower and doesn’t happen very easily (like lighting a fire). It is harder to achieve (needs a continuing stressor) and is only activated in more extreme circumstances. So in a sense the HPA response does come second because, even though it is triggered at the same time as the SAM, its response is seen some time later – well after the fight/flight response.
July 17, 2008 by Evie Bentley.
Nature – the great outdoors, trees, sky, flowers, water – has a psychological and physiological effect which can help lower stress levels; at least that is what researchers at the University of Washington have demonstrated. They had student participants who completed quite difficult mental tests. During these tests some had a view of trees and grass through the window, whilst others had the same view but on a huge plasma screen. The students were also linked up to heart monitors. All the students glanced up at the real life or televised view, but those with the real view through windows lowered their heart rates, which relate to their stress levels, the most.
So why don’t we all try and get a glimpse of the natural world, especially if we are working hard, anxious or worried, generally stressed, and see if this can help us manage our stress better?
June 15, 2008 by Cara Flanagan.
We contacted Donald Meichenbaum, the man who developed Stress Inoculation Training (SIT), to get permission to use his photograph in the latest edition of The Complete Companion. He asked to receive a copy of the finished book and has written to use saying ‘Please send my congratulations to the authors Mike and Cara. The book is engaging and informative. I appreciate the attention they have devoted to my work on Stress Inoculation Training (SIT).’ However he did also point out that one of our criticisms might be a tad unjustified. We suggest that one disadvantage of SIT is that the treatment takes a long time. He says, in fact, it has been applied successfully in as short as one hour in helping medical patients prepare for surgery and for cardiac catherization examinations. He further points out that one of the strengths of SIT is its adapatability to meet the varying demands of populations. Finally he mentions his own website which you may find interesting.
April 10, 2008 by Adrian Frost.
A recent interesting finding in rats shows that females are definitely more sensitive to stress. Their brain cells respond far more strongly to the precursor to corticosteroid stress hormones, a neurochemical called corticotropin-releasing factor, CRF. Female rat neurons are activated by CRF, male rat neurons adapt to it and less stress hormones are produced.