New theory on manic depression

[Guest guest]

New theory on manic depression

http://www.abc.net.au/7.30/stories/s69879.htm

 

 

KERRY O'BRIEN: An Australian scientist's own mental illness has led to the

development of a controversial new theory on manic depression.

 

After studying his own responses to a simple visual test, Professor John

Pettigrew has become convinced the disorder is linked to a slow switching

mechanism in the brain.

 

Now he's developing the test which he hopes may be able to help in the early

diagnosis of the illness.

 

Genevieve Hussey reports.

 

GENEVIEVE HUSSEY: For most of his life, Professor John Pettigrew has been

researching the way the brain works.

 

The irony is, 10 years ago he discovered there was something different about

his own brain -- he suffered from bipolar disorder, or manic depression.

 

PROFESSOR JOHN PETTIGREW, UNIVERSITY OF QUEENSLAND: I'm bipolar.

 

In retrospect, I can see that I had these transient episodes.

 

I've always been a transient person -- big spikes of achievement and then a

dark period for a while.

 

GENEVIEVE HUSSEY: Now by chance, during his latest research, John Pettigrew

has made a discovery that's attracted worldwide interest.

 

While administering a visual test to his students, he noted the difference

between his ability and theirs.

 

PROFESSOR JOHN PETTIGREW: I worked on about 100 undergraduates here, so I

knew what the normal population range was for this switch rate and when I

discovered I was much slower than the slowest kid that I saw in my classes,

then I started to think.

 

GENEVIEVE HUSSEY: The test which Professor Pettigrew performed so slowly is

designed to measure the speed at which people switch between the right and

left sides of the brain.

 

KAREN HESLOP, UNIVERSITY OF QUEENSLAND: When they look the glasses, they'll

see vertical lines through the left side of the glasses, and horizontal

lines through the right side.

 

Each time they see that image they push on the buttons here and record which

images they're seeing.

 

PROFESSOR JOHN PETTIGREW: You present the stimulus which is hard to

understand.

 

It's conflicting.

 

You present it constantly.

 

It's the same thing, the person seeing's the same thing, but their brain

switches between the two possibilities.

 

The two possible interpretations switch backwards and forwards and the

rhythm of that switch is remarkably stable in an individual.

 

GENEVIEVE HUSSEY: Professor Pettigrew believes the two sides of the brain

perform different functions and must work in harmony, or a person's emotions

are thrown out of balance.

 

His research indicates people with bipolar disorder switch more slowly

between the two sides and are likely to become stuck in either the left or

right hemisphere.

 

PROFESSOR JOHN PETTIGREW: The right hemisphere's " stop and be cautious " , and

the left hemisphere's, " go, get off your bum and do something " .

 

There's an enormous amount of evidence showing that hemispheres and mood are

connected.

 

If you let the right hemisphere take control, if it's overactive -- that's

depression.

 

GENEVIEVE HUSSEY: Experts in mental illness say the research is still in its

infancy but they hope it'll help pinpoint a biological cause for manic

depression.

 

DR FRANK VARGHESE, PRINCESS ALEXANDRA HOSPITAL: I think it's very exciting

research and very interesting work, because what Doctor Pettigrew has given

us, I think, is a window into manic depression that wasn't available to us

before.

 

So we can now -- we have a way of examining what may be the underlying cause

of the disorder and that leads to possibilities of treatment.

 

GENEVIEVE HUSSEY: People like Melanie Scott, who've been diagnosed with the

disorder, say, while it's important to discover the cause, it's also vital

not to focus just on the negative aspects of the illness.

 

MELANIE SCOTT: Bipolar has, I think, contributed a lot to our society in the

area of, well, art and culture I suppose, but also in science and politics

and business.

 

A lot of people who think outside the square have bipolar disorder and it

does worry me that we're looking at curing a condition that has contributed

so much to society.

 

GENEVIEVE HUSSEY: John Pettigrew hopes the test may one day prove useful for

the early diagnosis and prevention of manic depression.

 

PROFESSOR JOHN PETTIGREW: After three or four episodes which are triggered

by real-life problems, you have a really hard knock in life.

 

After three or four episodes of mania or depression, the next one comes

almost spontaneously.

 

You just look at them and then they get depressed, or you just look at them

and they go manic.

 

If that's true, what that means is that the whole major episode series may

be preventable.

 

GENEVIEVE HUSSEY: For doctors that's an exciting prospect, but one they say

which should be treated with caution.

 

DR FRANK VARGHESE: Psychiatry has always hankered after a test for a

specific illness and we haven't got one and we continue looking for one.

 

So having a test that indicated a propensity to a particular illness would

be clinically useful as long as it was just that, looking at a propensity

for an illness rather than diagnosing an illness.

 

Because I think there would be dangers of making assumptions about diagnosis

based on a test that tested predisposition, in the absence of any

suggestions of illness.

 

GENEVIEVE HUSSEY: While the theory is still being tested, researchers say

it's an important first step in unlocking the mysteries of bipolar disorder.

 

PROFESSOR JOHN PETTIGREW: Now I'm working a lot with patients because I can

help them and they can help me.

 

I learn as much from them as they learn from me.

 

KERRY O'BRIEN: And we are talking about a condition affecting up to 200,000

Australians.

 

 

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