NHS Choices

Sadness 'lasts longer' than other emotions

NHS Choices - Behind the Headlines - Mon, 03/11/2014 - 11:30

"Sadness lasts 240 times longer than other emotions, study claims," is the somewhat sobering news on the Mail Online.

Researchers surveyed 233 young adults from a Belgian high school with an average age of 17, and found emotions vary widely in duration.

Of the 27 emotions studied, sadness lasted the longest, whereas shame, surprise, fear, disgust, boredom, feeling touched, irritation and relief were the shortest-duration emotions. 

Emotions that lasted longer were associated with more important event triggers, as well as more reflection about the feelings and the consequences of the event that prompted the emotion.

While the study is intriguing, it has a number of limitations to consider. Chiefly, the sample size (233) was small for a cross-sectional study and recruited a relatively homogenous (similar) group of students, who were aged around 17 years.

Young students who are coming out of the emotional turmoil that is puberty, as well as facing exam stress, may be more likely to report feeling sad for longer periods than other groups. This means it is uncertain whether similar findings would be seen in other populations.

While the results give us a tentative estimate of the duration of different emotions in a group of young adults, this can't be generalised to other age and demographic groups at this stage.

 

Where did the story come from?

The study was carried out by researchers from the faculty of psychology and educational sciences at the University of Leuven in Belgium.

It was funded by the University of Leuven Research Fund, the Interuniversity Attraction Poles Programme, which is financed by the Belgian government, and a postdoctoral research fellowship from the Fund for Scientific Research, Flanders.

The study was published in the peer-reviewed medical journal, Motivation and Emotion. This is an open-access study, meaning anyone can read it free online.

Generally, the Mail Online reported the study results accurately, although it tended to take the findings at face value, without discussing any of the limitations inherent in the research.

However, the Mail did include a useful infographic showing the duration of all the different emotions tested, with sadness being noticeably higher.

 

What kind of research was this?

This was a cross-sectional study investigating which emotions last longest and why.

The researchers wanted to describe any differences in the duration of different emotions and attempt to explain what might be behind these differences.

From a health perspective, the researchers suggested this might be useful because the duration of emotional disturbances are symptoms of some mental health conditions, such as depression.

The researchers specifically looked at emotions, which they outlined were distinct from moods, because emotions start in response to an external or internal event.

For example, you may wake up in a grumpy mood, whereas receiving an unexpected tax bill stimulates emotions such as anxiety and anger.

 

What did the research involve?

The research team asked a small group of young adults to recall the duration of past emotions, their triggers and coping strategies.

The team recruited 233 high school students (112 women, 118 men, three no gender reported) with an average age of 17 years. Participation in the study was a compulsory part of their high school course.

Using a long questionnaire, participants were asked to recollect emotional episodes, report their duration, and answer questions regarding their appraisal of the emotion-eliciting event, as well as any strategies they used to regulate the emotion.

Each questionnaire had nine emotions to prompt recall from a larger set of 27.

These included admiration, anger, anxiety, feeling touched, boredom, compassion, contentment, desperation, disappointment, disgust, enthusiasm, fear, gratitude, guilt, hatred, hope, humiliation, irritation, jealousy, joy, pride, relaxation, relief, sadness, shame, stress and surprise.

Each questionnaire had a different set of nine questions. The different questionnaires were then randomly distributed to participants.

Participants were asked to rate the emotion-eliciting event using a number of appraisal dimensions. One of the main ones asked participants to indicate to what extent the event that elicited the emotion was important to them (importance).

They were also asked to report on a number of coping strategies, including to what extent they "kept on thinking about their feelings and the consequences of the event that elicited the emotion (rumination)".

To see whether the findings depended on the way emotion duration was defined, half of the participants were told that an emotion ends as soon it is no longer felt for the first time, whereas the other half were told that an emotion ends as soon as one has fully recovered from the event. All participants had the difference between emotions and moods explained to them.

 

What were the basic results?

Out of 27 emotions assessed, sadness lasted the longest, whereas shame, surprise, fear, disgust, boredom, feeling touched, irritation and relief were the shortest-lived emotions.

One appraisal dimension and one regulation strategy accounted for almost half of the variability in duration between emotions.

Compared with short emotions, persistent emotions were elicited by events of high importance and were associated with high levels of rumination (reflection or musing on an event).

The study group reported these broad findings held true across the two different emotion duration definitions, as well as when taking into account how recent and intense the emotion being recalled was.

 

How did the researchers interpret the results?

The research team summed up that their "present study revealed that meaningful differences in duration between emotions exist and that these differences can be partially explained by differences in one appraisal dimension (event importance) and one regulation strategy (rumination)".

 

Conclusion

This small cross-sectional survey of young adults suggests emotions vary widely in duration. Of the 27 emotions the researchers looked at, sadness lasted the longest by far.

Emotions that lasted longer were associated with more important event triggers, as well as more rumination about the feelings and the consequences of the event that elicited the emotion.

The study is intriguing, but has a number of limitations to consider. The sample size, for example, was small for a cross-sectional study at just 233.

It also recruited a relatively homogenous group of students aged around 17 years, so emotional duration may be very different for other age groups and groups from other educational backgrounds.

The accuracy of recalling emotions may be a further source of error, as some emotions may be far easier to recall than others: consider recalling instances of hatred, compared with hope.

This was partly addressed by the researchers by adjusting for the intensity of the emotion, but may not have completely eliminated a potential recall bias.

The results are also perhaps only as would be expected. For example, it makes logical sense that sadness is likely to be a more persistent emotion.

Sadness is likely to be influenced by a particular situation or trigger and, if there is no immediate resolution to this situation, continuing to reflect on it or being troubled by it is likely to result in a longer-lasting emotional effect.

Meanwhile, emotions such as surprise or disgust are likely to be the result of more transient events that would not have longer-term effects on the person, so they would be expected to be much shorter-term emotions.

Overall, the results give us some indication of the emotional duration of a group of young adults, but limited wider implications can be drawn from this research.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Feeling sad? It could take up to FIVE DAYS to shift your mood: Sadness lasts 240 times longer than other emotions, study claims. Mail Online, October 31 2014

Links To Science

Verduyn V, Lavrijsen S. Which emotions last longest and why: The role of event importance and rumination. Motivation and Emotion. Published online October 31 2014

Categories: NHS Choices

Brain differences linked to chronic fatigue syndrome

NHS Choices - Behind the Headlines - Fri, 31/10/2014 - 11:00

"Scientists find three differences in the brain [of people with chronic fatigue syndrome]," the Mail Online reports.

Chronic fatigue syndrome (CFS) affects around a quarter of a million people in the UK and causes persistent symptoms, such as fatigue, that can have a significant adverse impact on people's quality of life. The cause of CFS is unknown and the condition continues to be researched. 

The study behind this headline used a specialised type of MRI scan to examine whether there were any differences in the brain volume and structure of 15 people with CFS, compared with 14 people without.

The researchers found the volume of white matter (brain cell nerve fibres) was lower in the group with CFS. There were also some differences on the right side of the brain in the nerve fibres that connect the temporal to the frontal brain regions.

These are interesting developments in furthering our understanding of CFS. However, the study only involved a very small sample of 15 people, and we don't know how representative they are of all people with the condition.

The design of the study is able to demonstrate brain features that may be associated with the condition, but it cannot show cause and effect. We also don't know the order in which events happened.

It's not known whether these differences could have led to the development of CFS (and if so, whether they were always present, or whether some other unknown factors caused them to occur), or whether these are new changes that have occurred since the people developed CFS.

The next step would be to try to understand how these differences are associated with the condition's development.

 

Where did the story come from?

The study was carried out by researchers from Stanford University School of Medicine in California.

Financial support was provided by the Division of Infectious Disease Chronic Fatigue Syndrome Fund, and one of the authors received support from GE Healthcare.

The study was published in the peer-reviewed medical journal, Radiology.

The Mail Online's headline, "Is this proof chronic fatigue DOES exist?", casts doubt upon whether CFS actually exists. It's known CFS affects many thousands of people, with often severely debilitating consequences, so its existence is not in doubt.

However, the causes of CFS remain poorly understood. This study has tried to further understanding of the condition by examining brain features that may be associated with it. This study provides a starting point, but not the whole picture.

 

What kind of research was this?

This was a cross-sectional study that took brain scans of 15 people with CFS and a comparison group of age and sex-matched people without CFS. It aimed to research differences in the brain structure.

As the researchers explain, CFS is a debilitating condition characterised by six or more months of persistent or relapsing fatigue without any associated medical or mental health disorder.

The researchers consider that brain imaging may help inform diagnosis and prognosis, though conventional scan findings to date have been inconsistent and of limited help in any further understanding of the condition.

This study used a special MRI technique called diffusion tensor imaging (DTI). DTI measures the diffusion (movement or spread) of water through the brain tissues, which provides 3D images of the size, shape and microscopic structure of tissues.

 

What did the research involve?

The researchers scanned the brains of 15 people with CFS and compared them with 14 age- and gender-matched people without CFS. They were looking for any brain volume and structure differences between the two groups that may be linked to the condition.

People with CFS had to meet two inclusion criteria:

  • a clinical diagnosis of CFS made up of fatigue for six months or longer, with at least four other symptoms from: impaired memory or concentration, sore throat, tender lymph nodes, headaches, muscle pain, joint pain, unrefreshing sleep and malaise after exertion
  • ongoing memory or concentration problems causing severe enough impairment that a doctor thought brain imaging was necessary to confirm no other disease process was occurring

The group with CFS had an average age of 46 years. Eight people in the group were female (55%) and the average duration of their CFS symptoms was 12 years.

The age- and sex-matched comparison group were people without CFS, depression or substance use in the past year. Of 28 recruited, 14 chose to participate.

All participants completed a 20-item Multidimensional Fatigue Inventory (MFI-20), which assesses general, physical and mental fatigue, reduced motivation and activity. It is said to be a well-validated tool for assessing CFS, with higher MFI-20 scores indicating increased severity.

They also assessed whether each person was right- or left-handed or ambidextrous, as this is linked to differences in structure and volume in some brain areas.

The main analysis compared differences in brain volume and structure between the two groups using MRI (DTI) brain scans. This took into account variations in age, handedness and total brain volume.

 

What were the basic results?

The researchers found, on average, people with CFS had a lower total volume of white matter (nerve cell fibres) in their brain than people without.

They took a measure known as fractional anisotropy (FA), which gives a value between zero and one indicating the degree of diffusion of water, and whether there are any restrictions in any direction. A value of zero would mean that diffusion is the same in all directions.

They found significant differences in the FA of people with and without CFS in one particular region of the brain on the right side, called the right arcuate fasciculus. This is a nerve fibre tract that links the temporal region on the right side of the brain with the frontal region.

Most right-handed people with CFS had a maximum FA in the right arcuate fasciculus above 0.6, while those without CFS had a FA value below 0.6. They noticed that in people with CFS, FA of the right arcuate fasciculus tended to increase with disease severity.

The researchers also observed that people with CFS had areas of thickening in parts of the grey matter connected by the right arcuate fasciculus.

 

How did the researchers interpret the results?

The researchers concluded there is a loss of white matter in people with CFS. They also suggest the fractional anisotropy of the right arcuate fasciculus might be a biological indicator for CFS.

 

Conclusion

This study used a specialised type of MRI to examine whether there were any differences in the brain volume and structure of 15 people with CFS, compared with 14 people without.

They found the volume of white matter (nerve fibres) appeared to be lower, on average, in the people with CFS. There were also differences in the magnitude of water diffusion (a measure known as fractional anisotropy) in one particular white matter tract on the right side of the brain, which connects the temporal with the frontal brain regions.

These are interesting developments in furthering our understanding of CFS. But there are points to bear in mind when considering the meaning of these findings.

It must be remembered this research only used a very small sample of 15 people with CFS from the US, who may not be representative of the many thousands of people affected by this condition in the UK or elsewhere.

For example, these were people who had severe and persisting memory or concentration problems, such that their doctor thought brain imaging was required to make sure no other disease process was going on. The differences seen between these 15 people with CFS and 14 without may not be identical to differences that may be seen in a different sample.

Also, as this is a cross-sectional study, it cannot prove cause and effect: it can't tell us the order in which events happened. For example, it can't tell us whether these are structural features that occurred before people developed CFS, which may have been involved in the development of the condition, or whether these are changes that happened after the people developed CFS.

Further imagining studies in larger samples of people with this condition may reveal whether these results are consistent observations in the brain structure of people with CFS. The next step would then be to try to understand how these differences are associated with the condition's development.

These findings have no immediate treatment or preventative implications for CFS.

Analysis by Bazian. Edited by NHS ChoicesFollow Behind the Headlines on TwitterJoin the Healthy Evidence forum.

Links To The Headlines

Is this proof chronic fatigue DOES exist? Scientists find three differences in the brain that suggest condition may not just be 'in the mind'. Mail Online, October 30 2014

Chronic fatigue syndrome is real, researchers say. CNN, October 30 2014

Links To Science

Zeineh MM, Kang J, Atlas SW, et al. Right Arcuate Fasciculus Abnormality in Chronic Fatigue Syndrome. Radiology. Published online October 30 2014

Categories: NHS Choices

Genes may play a role in Ebola survival chances

NHS Choices - Behind the Headlines - Fri, 31/10/2014 - 11:00

"Genetic factors could play an important role in whether people survive the Ebola virus," BBC News reports. Researchers found around one in five mice remained unaffected by the infection.

Researchers investigated how mice with a different genetic make-up responded to Ebola infection. The research involved eight research strains of mice said to represent the majority of genetic variation seen across major mouse species. They were infected with Ebola and had their disease response examined.

The researchers found mice with different genetic profiles show variable disease response, ranging from complete resistance to infection with full recovery, to the disease being fatal.

Mice with resistance and those who died from the disease tended to have differences in the activity of certain genes, which was associated with differences in their immune and inflammatory response.

But the findings do not necessarily mean a similar pattern will be seen in humans, who have quite different genetics to mice.

Environmental factors such as access to good healthcare and hygiene standards (which, sadly, are of a low standard in West Africa), as well as the age, health and fitness of the person, are also likely to play a significant role in how infection with Ebola affects any individual.

Nevertheless, learning more about the genetic and immune responses to the Ebola virus could help contribute to the future creation of an effective anti-viral treatment.

Experts believe Ebola is highly unlikely to spread within the UK. To understand why, read Why Ebola risk is low for people in the UK.

 

Where did the story come from?

The study was carried out by researchers from the University of Washington and other research institutions in the US.

It was funded by grants from the US National Institute of Allergy and Infectious Diseases, the National Institutes of Health, and the Intramural Research Program of the National Institute of Allergy and Infectious Diseases, National Institutes of Health. 

The study was published in the peer-reviewed scientific journal Science Express on an open access basis, so it is free to read online.

The UK media's stories generally provide an accurate summary of the research, with most stating early on that the study was in mice.

However, the Mail Online's headline, "Will Ebola kill you? It depends on your genes," is overly conclusive and does not take account of the uncertainty of the research or its unproven applicability to people.

 

What kind of research was this?

This was an animal study investigating how mice with a different genetic make-up responded to Ebola infection in different ways.

The researchers explain how most animal studies examining the disease development of Ebola, or looking at the effectiveness of vaccines or treatments, have had to use primates or small mammals.

This is because when mice have been infected with Ebola in the laboratory, they don't demonstrate the same haemorrhagic syndrome (for example, complete dysfunction of the clotting system in the body) that occurs in humans.

This study specifically examined the role of host genetics in determining the severity of disease caused by Ebola infection.

 

What did the research involve?

This study involved infecting genetically diverse mice with different strains of Ebola to see if their genetics influenced the symptoms they developed, and whether they ultimately lived or died.

The study used mice from what is called the Collaborative Cross (CC) resource, a genetically diverse group of inbred mice obtained from the cross of eight mouse strains – five said to be classic laboratory strains, and three wild-type (found in nature) strains.

The eight "founder" mice strains are said to represent 90% of the common genetic variation seen across three major mouse species.

The researchers infected the eight CC founder strains with two strains of Ebola virus – a mouse strain and the wild-type strain, which doesn't normally cause haemorrhagic syndrome in mice.

They carried out a detailed analysis of the disease symptoms and the disease response in the mice.

 

What were the basic results?

When infected with the mouse strain of Ebola virus, the researchers observed different disease responses across the mice, ranging from complete resistance to infection to fatal disease. Some of the fatal cases developed disease changes consistent with haemorrhagic syndrome, while others did not.

The researchers performed more detailed analysis on two of the mouse lines – those resistant to disease and those that developed Ebola haemorrhagic fever.

Mice from both of these lines lost about 15% of their body weight in the five days following infection. The susceptible mice died on day five or six, while resistant mice fully recovered two weeks after infection.

Those that died demonstrated disease features consistent with Ebola haemorrhagic fever, including internal bleeding, prolonged blood coagulation times, spleen enlargement and liver discolouration. The resistant mice had no disease changes or alteration in their liver.

On further study, the researchers found differences in the inflammatory and immune response of mice susceptible or resistant to infection. This difference in response seemed to be mediated by differences in gene expression.

In particular, expression of the Tek gene in the liver was lower in the susceptible mice, and this was associated with onset of haemorrhagic disease. 

When infected with the wild-type Ebola strain, however, neither the susceptible nor resistant mice developed clinical disease. The animals had very low levels of the virus in their liver and spleen – up to 1,000 times lower than their levels when infected with the mouse strain.

At five days after infection, there was no longer any virus detectable, indicating that the wild-type Ebola virus is not able to replicate in mice.

 

How did the researchers interpret the results?

The researchers concluded that their results indicate genetic background determines susceptibility to Ebola hemorrhagic fever.

 

Conclusion

This research across mouse strains demonstrates that mice with different genetic profiles show variable disease response after infection with the Ebola virus. Responses ranged from complete resistance to infection with full recovery, to fatal disease, with or without changes consistent with Ebola haemorrhagic fever.

When comparing the mice that were resistant with those that developed fatal Ebola haemorrhagic syndrome, they found differences in the activity of certain genes, which was associated with different immune and inflammatory response.

However, these results in mice should not be extrapolated too far at this stage. The findings that different genetic strains of mice respond to Ebola infection in different ways does not mean the case will be exactly the same in people, who have quite different genetics to mice.

Genes may play a more or less important role in Ebola symptoms and survival in people, but at this stage we simply don't know.

Similarly, the different infection responses were seen only when mice were infected with the mouse strain of Ebola. The wild Ebola strain was not able to replicate in mice, further demonstrating the dissimilarities to human disease.

As BBC News reports, Andrew Easton, Professor of Virology at the University of Warwick, said the study "provided valuable information, but the data could not be directly applied to humans because they have a much larger variety of genetic combinations than mice".

Even if in humans (as in mice) our genetics play a role in how we respond to Ebola infection, it is unlikely to provide the whole answer. Factors such as the environment we live in – such as healthcare and hygiene standards – and our own underlying age, health and fitness are likely to play a large role in how we respond to Ebola infection.

Nevertheless, this study contributes to the wider understanding of Ebola, and may help direct further research examining the causes and effects of this devastating disease, as well as effective treatments at some point in the future.

Analysis by Bazian. Edited by NHS Choices. Follow Behind the Headlines on Twitter. Join the Healthy Evidence forum.

Links To The Headlines

Ebola virus: Genes 'play significant role in survival'. BBC News, October 31 2014

Ebola outbreak: Ebola may not be a deadly disease for everyone, scientists find. The Daily Telegraph, October 31 2014

Will Ebola kill you? It depends on your genes: Scientists discover DNA could determine if victims live or die. Mail Online, October 31 2014

Links To Science

Rasmussen AL, Okumura A, Ferris MT, et al. Host genetic diversity enables Ebola hemorrhagic fever pathogenesis and resistance. Science. Published online October 30 2014

Categories: NHS Choices

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