Category: Mental Health

The ironic effect of stress on desire and pleasure.

Although stress causes a huge increase in people’s desire for an indulgence, like chocolate, ironically it does not increase the pleasure obtained, a new study finds.

People under stress, researchers found, made three times as much effort to just smell some chocolate, compared with other chocolate-lovers who weren’t under stress.

Eva Pool, the study’s lead author, said:

“Most of us have experienced stress that increases our craving for rewarding experiences, such as eating a tasty bar of chocolate, and it can make us invest considerable effort in obtaining the object of our desire, such as running to a convenience store in the middle of the night.

But while stress increases our desire to indulge in rewards, it does not necessarily increase the enjoyment we experience.”

The study, published in the Journal of Experimental Psychology: Animal Learning and Cognition, had some people hold their hand in ice-water while they were watched and videotaped (Pool et al., 2014).

This served to stress them out in comparison to another group who simply put their hand in lukewarm water.

Both groups, all of whom were chocolate-lovers, were then asked to a squeeze a handgrip for the chance to smell some chocolate.

The group who were under stress squeezed harder on the handgrip, suggesting they wanted the chocolate more than the other group.

However, stress didn’t make people rate the smell of the chocolate any higher.

Dr Tobias Brosch, another of the study’s authors, said:

“Stress plays a critical role in many psychological disorders and is one of the most important factors determining relapses in addiction, gambling and binge eating.

Stress seems to flip a switch in our functioning: If a stressed person encounters an image or a sound associated with a pleasant object, this may drive them to invest an inordinate amount of effort to obtain it.”

Image credit: s-inator

These cells are the key to recovery from a stroke.

A mechanism by which the brain creates new nerve cells to help it recover from a stroke has been discovered.

The research could eventually lead to new therapies for stroke sufferers, as well as Parkinson’s and Huntington’s disease.

Strokes are caused by blood vessels in the brain getting blocked by a clot — this causes nerve cells to die.

The death of vital brain cells can lead to devastating effects on people’s thinking, motor and sensory abilities.

The new study, though, shows exactly how the brain recovers from these insults and might point the way to new treatments.

Researchers in Sweden have found that after a stroke, support cells, known as astrocytes, start to form new nerve cells in the brain (Magnusson et al., 2014).

Astrocytes are the most plentiful type of cell in the human brain and they have a characteristic star-shape (see image above).

The research, published in the journal Science, induced strokes in mice, then used genetic methods to determine that the astrocytes were forming immature nerve cells, which were ultimately maturing.

Professor Zaal Kokaia, one of the study’s authors said:

“This is the first time that astrocytes have been shown to have the capacity to start a process that leads to the generation of new nerve cells after a stroke.”

Olle Lindvall, who co-authored the study, explained how the research might benefit stroke patients, as well as those with Parkinson’s and Huntington’s disease:

“One of the major tasks now is to explore whether astrocytes are also converted to neurons in the human brain following damage or disease.

Interestingly, it is known that in the healthy human brain, new nerve cells are formed in the striatum.

The new data raise the possibility that some of these nerve cells derive from local astrocytes.

If the new mechanism also operates in the human brain and can be potentiated, this could become of clinical importance not only for stroke patients, but also for replacing neurons which have died, thus restoring function in patients with other disorders such as Parkinson’s disease and Huntington’s disease.”

Image credit: Bruno Pascal

Men and women both showed equivalent empathy despite the stereotype.

Seeing another person under stress — even when you’re not involved in the situation — is enough to activate the stress hormone cortisol in your body as well, according to a new study.

In the study, conducted by German psychologists, people who were emotionally closest to each other, demonstrated the highest empathic stress response (Engert et al., 2014).

People even showed a significant empathic stress response when observing strangers under stress over a video link.

In the stress test, participants were given math tests and interviews which made 95% of participants stressed.

Those undergoing the tests were observed by both strangers and partners of those being stressed.

Overall, for 26% of the observers, the stress of the person they were watching was transmitted to them.

The study’s first author, Veronika Engert, was surprised by the findings:

“The fact that we could actually measure this empathic stress in the form of a significant hormone release was astonishing.

There must be a transmission mechanism via which the target’s state can elicit a similar state in the observer down to the level of a hormonal stress response.”

Sometimes the observers watched over a video link, rather than through a two-way mirror.

This made little difference to the transmission of stress to the observer: the average transmission of stress only dropped from 30% to 24%.

Engert pointed out:

“This means that even television programmes depicting the suffering of other people can transmit that stress to viewers.

Stress has enormous contagion potential.”

There was no difference between the empathic stress response of men and women.

This flies in the face of women’s claims in repeated surveys to be more empathic than men.

Image credit: Giulia Bartra

Could psilocybin one day be used as an effective anti-depressant?

Swiss researchers have shown that psilocybin, the bioactive component in ‘magic mushrooms’, influences the emotional centres of the brain, weakening the effect of negative emotions.

The hallucinogen has long been advocated by some as a treatment for various mental disorders, and this new study provides evidence of how it might work.

In the study, 25 healthy participants were given a moderate dose of psilocybin before having their brains scans (Krähenmann et al., 2014).

Inside the scanner, and with the hallucinogen acting on their brains, participants were shown pictures which are designed to elicit an emotional reaction.

The results of this test were compared with scans taken after a placebo was administered.

The study’s lead author, Rainer Krähenmann, said:

“Even a moderate dose of psilocybin weakens the processing of negative stimuli by modifying amygdala activity in the limbic system as well as in other associated brain regions.”

The limbic system is vital to how we process emotions as well as memories. The amygdala is part of the limbic system and has also been shown to be vital in how we process emotions.

In the study, people’s amygdalas were markedly less reactive to negative stimuli after they had taken psilocybin, compared with the placebo-control condition.

Not only that, but psilocybin put people in a much better mood.

This backs up recent evidence about the dual effects of the drug in decreasing negative emotions and increasing positive emotions:

“…support for the notion that psilocybin may have rapid antidepressant characteristics also comes from a recent clinical trial showing that in patients with depression and anxiety, a single dose of psilocybin improved mood and decreased anxiety for several months.” (Krähenmann et al., 2014).

That said, the effects of psilocybin on depression have not yet been clinically tested.

Image credit: Sasata

Over the years, Vincent van Gogh’s mental illness has been classified in 30 different ways by over 150 different physicians, not just those who originally treated him. It is becoming clear that, in the classification of madness, this is far from an isolated example. Amongst the ranks of both psychiatrists and clinical psychologists are those who argue for a radical rethink.

Continue reading “Classifying Madness: Criticisms and Alternatives”

A new survey published today in the British Medical Journal has found ‘substantial levels of stress’ amongst 31% of Londoners as a result of the London bombings. The survey questioned 1,010 people between 11 and 13 days after the London was rocked by terrorists bombings on the 7th July 2005.

Continue reading “After Bombings Londoner’s Stress Levels Rise”