March 4, 2009

Schizophrenia genes 'work differently'

[Posted: Tue 03/03/2009 by Deborah Condon]

Schizophrenia could be caused by faulty signalling in the brain, the results of new research indicate.

Schizophrenia is a serious mental illness characterised by disturbances in a person's thoughts, perceptions, emotions and behaviour. Symptoms can include delusions and hallucinations. The condition affects around one in every 100 people – an estimated 41,000 people in Ireland are currently affected.

Now, in the biggest study of its kind, UK scientists have identified 49 genes that work differently in the brains of people with schizophrenia compared to people without it. The findings are based on a detailed analysis of brain samples donated by people with the condition.

According to the team from Imperial College London (ICL), many of these genes are involved in controlling cell-to-cell signalling in the brain. This supports the theory that abnormalities in the way in which cells ‘talk’ to each other are involved in the condition.

Until now, some scientists have suggested that schizophrenia could be caused by the brain producing too much dopamine – the chemical responsible for producing feelings of pleasure and satisfaction. This is partly because drugs that block dopamine action provide an effective treatment for the condition.

Another theory is that the coat surrounding nerve cells, which is made of myelin, is damaged in people with schizophrenia. However this new study found that
the genes for dopamine and for myelin were not acting any differently in
patients with schizophrenia compared with controls.

"The first step towards better treatments for schizophrenia is to really understand what is going on, to find out what genes are involved and what they are doing. Our new study has narrowed the search for potential targets for treatment,” explained one of the study’s authors, Professor Jackie de Belleroche of ICL.

The researchers noted that, as well as pointing to the cause of schizophrenia, these new findings could also lead to new ways of diagnosing it. Currently, patients are diagnosed on the basis of their behaviour.

"Most patients are diagnosed as teenagers or in their early 20s, but if they could be diagnosed earlier, they could be treated more effectively and they could have a better quality of life. To have the possibility of transforming someone's life early on instead of having to take drugs indefinitely would be wonderful," Prof de Belleroche added.

Details of these findings are published in the journal, Molecular Psychiatry.