Genes link different psychotic illnesses

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Genes link different psychotic illnesses

Patricia Reaney

Reuters

http://www.abc.net.au/science/news/health/HealthRepublish_939591.htm

Friday, 5 September 2003

 

 

 

Could mental illness like schizophrenia and manic depression be linked?

(Andreas Meyer-Lindenberg, NIMH)

 

 

The two major psychotic illnesses, schizophrenia and manic depression, are

related to each other and may have similar genetic causes, say British

scientists.

 

The new findings by Dr Sabine Bahn and colleagues at the Babraham Institute

in Cambridge are reported in this week's issue of the medical journal, The

Lancet.

 

The researchers have shown that sufferers of the two disorders have

abnormalities in key genes responsible for proteins in the central nervous

system related to a compound called myelin. Myelin insulates brain cells or

neurons, like using plastic to protect an object from damage.

 

" We found abnormalities in the proteins which compact the myelin, " Dr Sabine

Bahn explained in an interview. The team has also confirmed earlier research

which showed that patients with both disorders also had a reduction in cells

in the brain called oligodendrocytes which make myelin.

 

" We believe that our results provide strong evidence for oligodendrocyte and

myelin dysfunction in schizophrenia and bipolar disorder, " Bahn explained.

 

Schizophrenia and manic depression, which is also known as bipolar disorder,

affect about two percent of the population worldwide and are incurable,

chronic, relapsing disorders.

 

Diagnosing and differentiating between the two is based on interviews with

patients and the type and duration of symptoms.

 

" In manic depression patients get episodes of illness (highs and lows) and

they recover when you treat them, whereas in schizophrenia you have a social

decline in most cases and the cognitive impairment is more profound, " Bahn

added.

 

She said the findings, if confirmed, could form the basis of a diagnostic

test to identify people at risk of schizophrenia or bipolar disorder

(bipolar disorder - also known as .

 

" If you know people who are at risk of the diseases you can treat them

before they get the illness because the evidence is that having the illness

causes the damage, " said Bahn.

 

The scientists discovered the abnormalities by comparing post-mortem brain

samples from 15 people who had suffered from schizophrenia or manic

depression and 15 others who did not. They found clear changes in key genes

in patients with the psychotic illnesses.

 

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New theory on manic depression, 7.30 Report – ABC TV 30 Nov 1999