Genes linked with mental illnesses in breakthrough by scientists

Published on 01/07/2009 21:59

SCOTTISH scientists have found the first links between genes and mental illness.

In two groundbreaking pieces of research, scientists have established a link between genetic variations in the human body and the risk of developing schizophrenia, one of the world's most devastating mental disorders.

Researchers have also identified a connection between genetic variation and bipolar disorder.

The results of the two major studies, published in the scientific journal Nature, have been based on the analysis of DNA samples from tens of thousands of people across the globe and involved a team of international researchers, including scientists at Aberdeen and Edinburgh universities.

David St Clair, the professor of mental health at Aberdeen University who helped lead the groundbreaking research, said yesterday that the findings were a major step forward in piecing together the genetic jigsaw of schizophrenia – a severe mental disorder which affects one in 100 people.

But he stressed that the use of the findings to develop potential new treatments for schizophrenia was still many years in the future.

Prof St Clair said: "There has been a lot of controversy as to whether genes are even involved in psychiatric disorders. Some people think it is all just due to circumstances in their lives.

"But this is a landmark discovery in that it has been established beyond any doubt now that there are genes, and probably a lot of them, involved in these severe psychiatric disorders."

The researchers have discovered that three common genetic variants can increase the risk of developing schizophrenia.

Prof St Clair said: "These variants are present in a lot of the population, but not all of the people that have them go on to develop a mental illness.

"The individual variants on their own make us slightly more predisposed – between one and two per cent – to schizophrenia, but when combined with other genetic or environmental factors may substantially increase an individual's risk.

"Schizophrenia is one of the main causes of major mental illness. The drugs bill alone worldwide runs to $20 billion a year, not to mention the huge other costs such as hospital stays, lost employment opportunities and diminished quality of life.

"Our findings are a real scientific breakthrough since they tell us a lot more about the nature of the genetic risk of schizophrenia than we knew as little as a year ago."

He continued: "However, this is not a breakthrough that is going to change clinical practice any time soon.

"It will still be many years before our findings can be translated into new drug treatments. Much more work is also still required for us to piece together the overall genetic architecture of schizophrenia."

Douglas Blackwood, the professor of psychiatric genetics at Edinburgh University, said: "The new discoveries of genes clearly take us forward in our understanding of what causes schizophrenia.

"However, the project owes its success to the massive support received from a very large number of patients and their families who took part in the studies in several countries.

"We all now hope that these large-scale genetic studies will be the source of vital new clues about the nature of schizophrenia, opening up new possibilities for treating and defining the illness."