[wordup] The science of voodoo: When mind attacks body

[Adam Shand]

I love this stuff, I can't help myself!  It's as close to magic as we  
get anymore ... :-)

Adam.

Source: http://www.newscientist.com/article/mg20227081.100-the-science-of-voodoo-when-mind-attacks-body.html?full=true

The science of voodoo: When mind attacks body
13 May 2009 by Helen Pilcher

Editorial: Breaking the voodoo spell
Late one night in a small Alabama cemetery, Vance Vanders had a run-in  
with the local witch doctor, who wafted a bottle of unpleasant- 
smelling liquid in front of his face, and told him he was about to die  
and that no one could save him.

Back home, Vanders took to his bed and began to deteriorate. Some  
weeks later, emaciated and near death, he was admitted to the local  
hospital, where doctors were unable to find a cause for his symptoms  
or slow his decline. Only then did his wife tell one of the doctors,  
Drayton Doherty, of the hex.

Doherty thought long and hard. The next morning, he called Vanders's  
family to his bedside. He told them that the previous night he had  
lured the witch doctor back to the cemetery, where he had choked him  
against a tree until he explained how the curse worked. The medicine  
man had, he said, rubbed lizard eggs into Vanders's stomach, which had  
hatched inside his body. One reptile remained, which was eating  
Vanders from the inside out.

Great ceremony
Doherty then summoned a nurse who had, by prior arrangement, filled a  
large syringe with a powerful emetic. With great ceremony, he  
inspected the instrument and injected its contents into Vanders' arm.  
A few minutes later, Vanders began to gag and vomit uncontrollably. In  
the midst of it all, unnoticed by everyone in the room, Doherty  
produced his pièce de résistance - a green lizard he had stashed in  
his black bag. "Look what has come out of you Vance," he cried. "The  
voodoo curse is lifted."

Vanders did a double take, lurched backwards to the head of the bed,  
then drifted into a deep sleep. When he woke next day he was alert and  
ravenous. He quickly regained his strength and was discharged a week  
later.

The facts of this case from 80 years ago were corroborated by four  
medical professionals. Perhaps the most remarkable thing about it is  
that Vanders survived. There are numerous documented instances from  
many parts of the globe of people dying after being cursed.

With no medical records and no autopsy results, there's no way to be  
sure exactly how these people met their end. The common thread in  
these cases, however, is that a respected figure puts a curse on  
someone, perhaps by chanting or pointing a bone at them. Soon  
afterwards, the victim dies, apparently of natural causes.

Voodoo nouveau
You might think this sort of thing is increasingly rare, and limited  
to remote tribes. But according to Clifton Meador, a doctor at  
Vanderbilt School of Medicine in Nashville, Tennessee, who has  
documented cases like Vanders, the curse has taken on a new form.

Take Sam Shoeman, who was diagnosed with end-stage liver cancer in the  
1970s and given just months to live. Shoeman duly died in the allotted  
time frame - yet the autopsy revealed that his doctors had got it  
wrong. The tumour was tiny and had not spread. "He didn't die from  
cancer, but from believing he was dying of cancer," says Meador. "If  
everyone treats you as if you are dying, you buy into it. Everything  
in your whole being becomes about dying."

He didn't die from cancer but from believing he was dying of cancer
Cases such as Shoeman's may be extreme examples of a far more  
widespread phenomenon. Many patients who suffer harmful side effects,  
for instance, may do so only because they have been told to expect  
them. What's more, people who believe they have a high risk of certain  
diseases are more likely to get them than people with the same risk  
factors who believe they have a low risk. It seems modern witch  
doctors wear white coats and carry stethoscopes.

The nocebo effect
The idea that believing you are ill can make you ill may seem far- 
fetched, yet rigorous trials have established beyond doubt that the  
converse is true - that the power of suggestion can improve health.  
This is the well-known placebo effect. Placebos cannot produce  
miracles, but they do produce measurable physical effects.

The placebo effect has an evil twin: the nocebo effect, in which dummy  
pills and negative expectations can produce harmful effects. The term  
"nocebo", which means "I will harm", was not coined until the 1960s,  
and the phenomenon has been far less studied than the placebo effect.  
It's not easy, after all, to get ethical approval for studies designed  
to make people feel worse.

What we do know suggests the impact of nocebo is far-reaching. "Voodoo  
death, if it exists, may represent an extreme form of the nocebo  
phenomenon," says anthropologist Robert Hahn of the US Centers for  
Disease Control and Prevention in Atlanta, Georgia, who has studied  
the nocebo effect.

Life threatening
In clinical trials, around a quarter of patients in control groups -  
those given supposedly inert therapies - experience negative side  
effects. The severity of these side effects sometimes matches those  
associated with real drugs. Aretrospective study of 15 trials  
involving thousands of patients prescribed either beta blockers or a  
control showed that both groups reported comparable levels of side  
effects, including fatigue, depressive symptoms and sexual  
dysfunction. A similar number had to withdraw from the studies because  
of them.

Occasionally, the effects can be life-threatening (see "The  
overdose"). "Beliefs and expectations are not only conscious, logical  
phenomena, they also have physical consequences," says Hahn.

Nocebo effects are also seen in normal medical practice. Around 60 per  
cent of patients undergoing chemotherapy start feeling sick before  
their treatment. "It can happen days before, or on the journey on the  
way in," says clinical psychologist Guy Montgomery from Mount Sinai  
School of Medicine in New York. Sometimes the mere thought of  
treatment or the doctor's voice is enough to make patients feel  
unwell. This "anticipatory nausea" may be partly due to conditioning -  
when patients subconsciously link some part of their experience with  
nausea - and partly due to expectation.

Catching
Alarmingly, the nocebo effect can even be catching. Cases where  
symptoms without an identifiable cause spread through groups of people  
have been around for centuries, a phenomenon known as mass psychogenic  
illness. One outbreak(see "It's catching") inspired a recent study by  
psychologists Irving Kirsch and Giuliana Mazzoni of the University of  
Hull in the UK.

They asked some of a group of students to inhale a sample of normal  
air, which all participants were told contained "a suspected  
environmental toxin" linked to headache, nausea, itchy skin and  
drowsiness. Half of the participants also watched a woman inhale the  
sample and apparently develop these symptoms. Students who inhaled  
were more likely to report these symptoms than those who did not.  
Symptoms were also more pronounced in women, particularly those who  
had seen another apparently become ill - a bias also seen in mass  
psychogenic illness.

The study shows that if you hear of or observe a possible side effect,  
you are more likely to develop it yourself. That puts doctors in a  
tricky situation. "On the one hand people have the right to be  
informed about what to expect, but this makes it more likely they will  
experience these effects," says Mazzoni.

Catch 22
This means doctors need to choose their words carefully so as to  
minimise negative expectations, says Montgomery. "It's all about how  
you say it."

Hypnosis might also help. "Hypnosis changes expectancies, which  
decreases anxiety and stress, which improves the outcome," Montgomery  
says. "I think hypnosis could be applied to a wide variety of symptoms  
where expectancy plays a role."

Is the scale of the nocebo problem serious enough to justify such  
countermeasures? We just don't know, because so many questions remain  
unanswered. In what circumstances do nocebo effects occur? And how  
long do the symptoms last?

It appears that, as with the placebo response, nocebo effects vary  
widely, and may depend heavily on context. Placebo effects in clinical  
settings are often much more potent than those induced in the  
laboratory, says Paul Enck, a psychologist at the University Hospital  
in Tübingen, Germany, which suggests the nocebo problem may have  
profound effects in the real world. For obvious reasons, though, lab  
experiments are designed to induce only mild and temporary nocebo  
symptoms.

Real consequences
It is also unclear who is susceptible. A person's optimism or  
pessimism may play a role, but there are no consistent personality  
predictors. Both sexes can succumb to mass psychogenic illness, though  
women report more symptoms than men. Enck has shown that in men,  
expectancy rather than conditioning is more likely to influence nocebo  
symptoms. For women, the opposite is true. "Women tend to operate more  
on past experiences, whereas men seem more reluctant to take history  
into a situation," he says.

What is becoming clear is that these apparently psychological  
phenomena have very real consequences in the brain. Using PET scans to  
peer into the brains of people given a placebo or nocebo, Jon-Kar  
Zubieta of the University of Michigan, Ann Arbor, showed last year  
that nocebo effects were linked with a decrease in dopamine and opioid  
activity. This would explain how nocebos can increase pain. Placebos,  
unsurprisingly, produced the opposite response.

Meanwhile, Fabrizio Benedetti of the University of Turin Medical  
School in Italy has found that nocebo-induced pain can be suppressed  
by a drug called proglumide, which blocks receptors for a hormone  
called cholecystokinin (CCK). Normally, expectations of pain induce  
anxiety, which activates CCK receptors, enhancing pain.

Ultimate cause
The ultimate cause of the nocebo effect, however, is not  
neurochemistry but belief. According to Hahn, surgeons are often wary  
of operating on people who think they will die - because such patients  
often do. And the mere belief that one is susceptible to a heart  
attack is itself a risk factor. One study found that women who  
believed they are particularly prone to heart attack are nearly four  
times as likely to die from coronary conditions than other women with  
the same risk factors.

Despite the growing evidence that the nocebo effect is all too real,  
it is hard in this rational age to accept that people's beliefs can  
kill them. After all, most of us would laugh if a strangely attired  
man leapt about waving a bone and told us we were going to die. But  
imagine how you would feel if you were told the same thing by a  
smartly dressed doctor with a wallful of medical degrees and a  
computerful of your scans and test results. The social and cultural  
background is crucial, says Enck.

Meador argues that Shoeman's misdiagnosis and subsequent death shares  
many of the crucial elements found in hex death. A powerful doctor  
pronounces a death sentence, which is accepted unquestioningly by the  
"victim" and his family, who then start to act upon that belief.  
Shoeman, his family and his doctors all believed he was dying from  
cancer. It became a self-fulfilling prophecy.

Nothing mystical
"Bad news promotes bad physiology. I think you can persuade people  
that they're going to die and have it happen," Meador says. "I don't  
think there's anything mystical about it. We're uncomfortable with the  
idea that words or symbolic actions can cause death because it  
challenges our biomolecular model of the world."

Perhaps when the biomedical basis of voodoo death is revealed in  
detail we will find it easier to accept that it is real - and that it  
can affect any one of us.

Editorial: Breaking the voodoo spell

----

The overdose
Depressed after splitting up with his girlfriend, Derek Adams took all  
his pills... then regretted it. Fearing he might die, he asked a  
neighbour to take him to hospital, where he collapsed. Shaky, pale and  
drowsy, his blood pressure dropped and his breaths came quickly.

Yet lab tests and toxicology screening came back clear. Over the next  
4 hours Adams received 6 litres of saline, but improved little.

Then a doctor arrived from the clinical trial of an antidepressant in  
which Adams had been taking part. Adams had enrolled in the study  
about a month earlier. Initially he had felt his mood buoyed, but an  
argument with his ex-girlfriend saw him swallow the 29 remaining  
tablets.

The doctor revealed that Adams was in the control group. The pills he  
had "overdosed" on were harmless. Hearing this, Adams was surprised  
and tearfully relieved. Within 15 minutes he was fully alert, and his  
blood pressure and heart rate had returned to normal.

----

It's catching
In November 1998, a teacher at a Tennessee high school noticed a  
"gasoline-like" smell, and began complaining of headache, nausea,  
shortness of breath and dizziness. The school was evacuated and over  
the next week more than 100 staff and students were admitted to the  
local emergency room complaining of similar symptoms.

After extensive tests, no medical explanation for the reported  
illnesses could be found. A questionnaire a month later revealed that  
the people who reported symptoms were more likely to be female, and to  
have known or seen a classmate who was ill. It was the nocebo effect  
on a grand scale, says psychologist Irving Kirsch at the University of  
Hull in the UK. "There was, as far as we can tell, no environmental  
toxin, but people began to feel ill."

Kirsch thinks that seeing a classmate develop symptoms shaped  
expectancies of illness in other children, triggering mass psychogenic  
illness. Outbreaks occur all over the world. In Jordan in 1998, 800  
children apparently suffered side effects after a vaccination and 122  
were admitted to hospital, but no problem was found with the vaccine.