快猫短视频

LEAVING the shop was always the start of John鈥檚 private nightmare. After he
had paid and left, he would read and reread the receipt, and check and recheck
his change, unable to believe that he had really paid. He would go back to the
shop repeatedly to ask whether he owed the cashier any money. Often he would
phone the shop later, or write letters to the manager to check again.

Extreme 鈥渃hange-checking鈥� habits are just one of a common set of compulsions
that torment people like John who suffer from obsessive-compulsive disorder.
Terrified by the fear of contamination or catching a dangerous disease, some
wash themselves for eight or more hours each day. Others check that the door is
locked again and again and again, keeping themselves awake at night until they
practically drop from exhaustion.

Still others hoard often useless objects and arrange them in precise
configurations. Or they may feel compelled to count to a certain number before
they 鈥渇eel right鈥�. Then there are those who suffer from horrifying thoughts that
will not go away鈥攖he fear, for example, that they might stab their nearest
and dearest or sexually interfere with a child.

To add insult to injury, until recently people with OCD were considered the
weird and rare product of abusive parents or some other severe childhood
emotional trauma. Largely invisible and misunderstood, their hopes of successful
treatment were slim.

But OCD is undergoing a major rehabilitation. For a start, the disorder turns
out to be far more common than anyone expected: at least 1 million people in
Britain, and 5 million in the US, are affected. The highest estimates suggest
that as many as 3 per cent of people may suffer from OCD at some time during
their lives.

Don鈥檛 panic

OCD is also highly amenable to some new types of treatments鈥攅ven one
that is offered over the phone. And most psychiatrists have now given up on the
idea that the disorder is triggered by emotional trauma. Instead, the new
thinking is that OCD is triggered by a variety of more tangible factors,
including rogue genes, on rare occasions head injury and, most surprising and
controversial of all, a bizarre autoimmune reaction following a common childhood
infection.

But perhaps what has helped to transform the image of OCD more than anything
else is the growing understanding of how those triggers, and others that have
yet to be isolated, damage the brain and create the symptoms of the
disorder.

First, back a step. Most people鈥檚 first question about OCD is鈥攈ave I
got it? After all, most of us have one or two compulsive habits鈥攆rom
cleaning the sink to hoarding receipts. But psychiatrists are quick to point out
that there is a world of difference between a tidy-minded attention to detail,
and the nightmarish destruction of normal life that occurs when those tendencies
run out of control. A healthy obsessiveness, say with your job, can be an
advantage, as high-flyers know. Usually, their finickiness is a source of pride.
For OCD sufferers, by contrast, there is no pleasure and no benefit from the
rituals (see 鈥淒o you have OCD?鈥�).

Nor is there anything peculiarly Western about OCD. It strikes in the same
form and frequency from Sweden to China to Sudan, says Judith Rapoport, a child
psychiatrist at the National Institute of Mental Health near Washington DC. And
this cosmopolitan range may give a hint of the disease鈥檚 evolutionary
origins.

Take the island of Bali in Indonesia. There, ordinary people perform a large
number of ceremonial rituals, such as dressing statues with flowers, in the
daily practice of their particular form of Hinduism. If OCD was merely a disease
of taking everyday rituals to extremes, then Balinese people with OCD might be
expected to spend debilitating hours and hours decorating statues. They don鈥檛.
In as-yet unpublished case studies, Rapoport, and anthropologist Robert Lemelson
of the University of California, Los Angeles, describe how more than 20 Balinese
sufferers exhibit the same kind of behaviour as those in the
West鈥攅xcessive washing, counting, door-locking, and so on.

In fact, many of the behaviours that are the hallmarks of OCD in every
culture may, if not taken to extremes, be beneficial to survival. They are, as
evolutionary biologists would say, adaptive. Our primitive ancestors would have
been more likely to survive and pass on their genes if they had fussed over
hygiene, or checked a bit more than strictly necessary for the presence of
predators or other danger signs.

True, all that ritualistic grooming and pacing around would be a waste of
energy some of the time, but it would also guarantee that individuals never
became too heavily infested with parasites, and that they escaped the one time
there really were wild animals on the prowl. Checking the environment for
changes, and engaging in a little bit of protective ritualistic behaviour is
fine. The trouble starts when these behaviours are never switched off.

In OCD, the theory goes, the brain circuits that signal 鈥渟omething鈥檚 up鈥� and
trigger defensive behaviours like washing and checking locks, don鈥檛 just err on
the side of caution, they never let up. One of the most upsetting aspects of
OCD, say patients, is the constant, overwhelming sensation that 鈥渟omething is
not right鈥�.

In the past few years, neuroscientists such as Lewis Baxter of the University
of Alabama, Birmingham, his colleague Jeffrey Schwartz at UCLA, and Susan Swedo,
a neuroscientist also at the National Institute of Mental Health, have begun to
get hints of the defects in the neural machinery that create this constant state
of anxiety. Their chief tool has been the imaging technique of positron emission
tomography (PET), which shows the relative activity of different regions of the
brain.

In studies that are as bizarre as they are fascinating, the researchers
deliberately trigger the sufferer鈥檚 symptoms by talking to them about their own
particular fears. In John鈥檚 case, they might ask him to imagine he had just
bought a box of cereal at the supermarket, and then hand him his change. As the
anxieties and ritual checking begin, they watch what happens on the PET
scan.

To get a fix on healthy brains and see how their activity differs, the
researchers have to set off some of the emotions that OCD sufferers experience
(extreme disgust, for example, and anxiety) in normal volunteers. To induce
disgust, says Swedo, the researchers may ask the 鈥渘ormal鈥� volunteers to read a
story about a filthy public toilet. 鈥淚t has everything imaginable,鈥� says Swedo,
who describes how the volunteers are asked to visualise being so desperate to
urinate that they have no choice but to use the toilet. In another experiment,
the researchers induce anxiety in the healthy volunteers by asking them to
imagine that their child has been kidnapped.

It鈥檚 worth it, though, because they find clear differences between the OCD
sufferers and healthy volunteers experiencing roughly similar emotions. In OCD,
two brain regions are overactive: a slice of the prefrontal cortex, a part of
the brain that plays a role in 鈥渉igher鈥� functions such as judgment, emotions and
planning; and the more primitive basal ganglia, a set of structures deep within
the brain. In particular, one part of the basal ganglia, the pecan-sized caudate
nucleus, is hyperactive. The PET scans seem to make sense because it turns out
that the neurons in the prefrontal cortex are essential for detecting
changes鈥攖hat 鈥渟omething鈥檚 up鈥濃�攊n the world outside.

Back in 1983, neuroscientist Edmund Rolls at the University of Oxford
observed how monkeys learn to associate blue or green lights with different
drinks. A blue light might be associated with nice fruit juice, a green light
with the much nastier salty water. The monkeys quickly learnt which light meant
juice. Every so often, the researchers would switch the stimuli round, so that
green meant juice and blue, salt water. The monkeys quickly adapted.

What caught the researchers attention, however, was that when the coloured
lights were first switched and the monkeys made a mistake, getting salty water
instead of juice, neurons in the prefrontal cortex fired strongly, for as long
as 10 seconds at a time. The cells were not responding with a 鈥淵uk鈥� reaction
because they did not respond this way to salty water at other times. What made
the neurons fire was the detection of an error鈥攖he 鈥淯h-oh, something has
changed鈥� reaction. After the cells had fired, the monkeys changed their
responses, suggesting that the region is also involved in adapting to changing
circumstances.

Slack gatekeeper

In more recent studies, Rolls and his colleagues have shown that when the
human prefrontal cortex is damaged by a head injury, people are often
slow鈥攐r even unable鈥攖o correct their mistakes when they choose the
wrong pattern on a screen in lab tests. This suggests that the same
error-detection region exists in humans. Baxter and Schwartz hypothesise that in
OCD, the brain鈥檚 error-detection region has got stuck in 鈥渙n鈥� mode, so that it
sends out a constant 鈥淯h-oh鈥� message.

But this is only part of the story. Impulses from the prefrontal cortex pass
through the basal ganglia. These structures act as a kind of 鈥済atekeeper鈥� for
incoming information, deciding which impulses to send, via the thalamus, back to
the prefrontal region and other parts of the cortex, including those that deal
with movement. Through this neural circuit, the basal ganglia may help reinforce
routine, repetitive behaviours such as hand-washing.

The theory favoured by Baxter, Schwartz and Swedo is that in OCD the
overactive caudate nucleus in the basal ganglia is like a gate that is stuck
open so that impulses which are normally locked out are let through. This means
that perceptions of something wrong keep coming in, and keep driving the
sufferer to act to put things 鈥渞ight鈥�, even after the sufferer has washed her
hands or checked his change.

At the moment, the theories about which bits of the brain have gone awry are
at the rough draft stage. Indeed, some experts like Michael Jenike, a
neuropsychiatrist at Harvard University, argue that it鈥檚 still too soon to say
exactly which brain regions are involved.

But Schwartz is more bullish. He points out that there is even evidence that
the disturbed activity in the caudate nucleus and prefrontal cortex is corrected
when the symptoms improve in response to treatment. Last year, Schwartz used PET
scans to study 18 people who received ten weeks of behaviour therapy鈥攁
type of psychotherapy in which patients are taught to confront their fears in a
systematic and controlled way, while refraining from performing their rituals
for a set period of time. None was receiving drugs. Twelve of the 18 showed
significant improvement in their symptoms鈥攁nd decreased activity in the
caudate nucleus, and the prefrontal cortex.

Patients who respond to serotonin-blocking drugs such as Prozac, which are
often prescribed for OCD, show the same changes in their brains on PET scans as
those who respond well to behaviour therapy. This suggests that whatever is
changing in the sufferer鈥檚 brain chemistry is roughly similar, whether it is
brought about by drugs or behaviour therapy.

But what makes the brain circuits malfunction in the first place? Mostly
that鈥檚 still a puzzle, although researchers are gaining some clues from the
small proportion of OCD cases where the cause is known. People with the
neurodegenerative disorder Huntington鈥檚 disease can suffer classic symptoms of
OCD鈥攁 finding that intrigues researchers, because the caudate nucleus in
the basal ganglia is also damaged in this disease.

In a few cases, a blow to the head has even been known to trigger OCD. Jenike
has studied these cases without finding any single, consistent area of damage.
鈥淲e were hoping we would identify a specific region, but it is scattered.鈥�
Which, he says, is testament to how many different regions of the brain must be
involved in controlling normal security rituals.

A form of the disorder also runs in families with Tourette鈥檚 syndrome,
suggesting that OCD can be caused by defective genes. People who suffer from
Tourette鈥檚 have uncontrollable urges to perform physical and vocal 鈥渢ics鈥� such
as turning in circles, clearing their throats, or鈥攎ost
famously鈥攕wearing. Once again, abnormalities of the basal ganglia may be
to blame; some researchers think OCD may even turn out to be a sort of 鈥渕ental
迟颈肠鈥�.

But the greatest excitement has been sparked by the discovery that a mere
bacterium can trigger OCD. Infection with streptococcus normally causes nothing
more than a sore throat. Some children, however, also develop a rare
complication called Sydenham鈥檚 chorea. Sometimes overnight, and at most within
weeks of an infection, this bizarre syndrome changes a healthy child into one
who suffers jerky movements and, in many cases, oddly compulsive behaviours,
such as spinning around a set number of times before passing through a door, or
repeated hand-washing鈥攖he last thing you would expect in a normal
child.

In the early 1990s, Swedo reported another condition closely related to
Sydenham鈥檚 chorea. Following a strep infection, some children develop only the
OCD-like symptoms, but not the jerky movements of the chorea itself. Swedo
labelled the condition PANDAS鈥攆or paediatric autoimmune neuropsychiatric
disorders associated with streptococcus.

It鈥檚 been known since the 1970s that children with Sydenham鈥檚 chorea produce
antibodies against the streptococcus bacterium, and that the antibodies
mistakenly attack and destroy cells in the caudate nucleus. Swedo showed that
PANDAS children have the very same antibody. So aggressive is the antibody, that
during an acute autoimmune attack the caudate of PANDAS children appears swollen
on brain scans.

In the US, OCD support groups have seized on the PANDAS findings, seeing them
as the strongest evidence yet that their disease is not, as Swedo puts it,
鈥渟omething your mother did to you鈥�. The Obsessive-Compulsive Foundation, a
patient advocacy group, has made the panda bear its mascot and distributes
fluffy toy pandas to anyone who donates $25.

Not everyone is convinced by the PANDAS story. Harvey Singer, a neurologist
at Johns Hopkins University in Baltimore, for example, is sceptical that the
condition exists at all. Even Swedo seems uncomfortable with the hype and says
she would prefer to see others confirm her work before everyone gets too
excited.

Danger sign

Nevertheless, she鈥檚 hoping that the research will lead to ways to help
prevent OCD in children. In the January issue of the American Journal of
Psychiatry, the Swedo team reported that 85 per cent of PANDAS children
have a protein on the surface of certain immune cells, B cells, compared with
only 15 per cent of healthy children. Now, the team is assessing whether that
protein, called D8/17, could be used to gauge a child鈥檚 susceptibility to a
damaging autoimmune reaction to strep. If vulnerable children could be
identified, they could be pumped full of antibiotics at the first sign of
infection.

For John and others like him who already have OCD, a greater comfort may come
from the revelation that in contrast to many mental illnesses such as
schizophrenia, the symptoms of OCD are relatively easy to control. Behaviour
therapy greatly reduces symptoms in 90 per cent of patients who complete the
course, though the completion rate is as low as 50 per cent because the therapy
is time-consuming and thoroughly unpleasant. Antidepressant drugs such as Prozac
help up to 60 per cent of patients, but the benefits fade as soon as the
treatment stops. Used together, however, drugs and behaviour therapy could
probably help up to 95 per cent of sufferers, says Jenike.

But only a fraction of those who need help actually get it. Many do not
approach their doctors; of those who do, some are given useless or inappropriate
treatments such as traditional psychoanalysis, while others refuse treatment.
What鈥檚 more, there is only one behaviour therapist for every hundred sufferers
in the US. In Britain, the waiting list for behaviour therapy can be 14 months
or more. Most people start to seek help when their jobs are already under
threat, and few employers are that patient.

This year, for the first time, there are reasons to hope that waiting lists
could be drastically cut. Psychiatrists in the US, Britain and Canada are
testing a highly pragmatic alternative to conventional behaviour therapy that
could soon be available to millions. They have developed a computer program
called BT STEPS, with the BT standing for Behaviour Therapy, which offers
treatment by phone (see box). Astonishing though it might seem for such a blunt
instrument to treat such disturbed minds, the early indications are that the
system works as well as conventional behaviour therapy.

Novel approaches to treating OCD, and new theories about what causes it, look
set to transform patients鈥� lives. Meanwhile, it has already transformed the
researchers鈥� views, says Swedo. 鈥淎 decade ago we used to have to go round
talking about punitive toilet training,鈥� she says. 鈥淣ow we truly understand that
OCD is a brain disorder.鈥�

* * *

Dial-a-therapy

鈥淗ELLO. Welcome to BT STEPS. Please enter your identification number using
the numbers on your phone鈥︹��

If you thought it was impossible to improve mental health with a touch-tone
phone and an instruction manual, think again. Psychiatrists John Greist of the
Dean Foundation for Health, Research and Education in Middleton, Wisconsin, and
Isaac Marks of the Institute of Psychiatry in London, and psychologist Lee Baer
at Massachusetts General Hospital, have evidence to the contrary.

By putting people with obsessive-compulsive disorder through nine longish
phone calls to a freefone number, and a lot of 鈥渉omework鈥� in between, they can
reduce their symptoms. They do it with BT STEPS, a nine-step system of
self-treatment using the principles of behaviour therapy, or BT.

Behaviour therapy itself is nothing new for OCD. It was first shown to work
during the 1980s by Marks, Baer and others. The treatment consists of
encouraging sufferers to ride out their fears, and so ultimately control them,
instead of acting on them with rituals.

For example, if you are terrified of being contaminated by a toilet seat, you
will be encouraged to touch a toilet seat and then not wash your hands. You will
be acutely uncomfortable, but over time you will learn that touching the toilet
seat does not kill you. By practising this technique daily for several weeks,
your fear of toilet seats should slowly abate.

To do it the BT STEPS way, you first have to get a specialist to sign you up.
Once you get through to BT STEPS, you hear Greist鈥檚 prerecorded voice. You
answer questions that allow the computer to calculate the severity of your
symptoms and identify your fears (such as contamination) and their triggers
(such as toilet seats). With guidance, you pledge to attain a particular goal,
for example: 鈥淚 will expose myself to toilet seats, but I will not do any
physical or mental rituals for at least two hours afterwards.鈥�

You practise between calls, and each time you call back, you report how you
got on. After each call, the computer faxes a report to your specialist. The
report is forwarded to you by mail.

The $4-million computer program, all users鈥� calls and the user manuals
are funded by the pharmaceuticals company Pfizer, which makes one of the
serotonin-blocking drugs that are effective against OCD.

In pilot studies on 60 patients, almost half said they were 鈥渋mproved鈥� or
鈥渧ery much improved鈥�. Results of a larger trial of about 250 people in the US
and Canada should be available by the end of the year.

For more information, contact the Maudsley BT Steps Clinic in London on
0171-919-3366, or in the US, the Dean Foundation in Middleton, on 608 827
2300