Researchers identify 'depression' gene

Scientists are homing in on a specific gene which may be responsible for depression.

Researchers at the Institute of Psychiatry at London's King's College have found "solid evidence" that genetic variations on a particular chromosome could cause the disorder.

It is hoped that the discovery will help in the development of future treatments.

Researchers analysed 839 families suffering from severe and recurrent bouts of depression.

The lead author on the research, Dr Gerome Breen, said: "In a large number of families where two or more members have depression, we found robust evidence that a region called chromosome 3p25-26 is strongly linked to the disorder.

"These findings are truly exciting, as possibly for the first time we have found a genetic locus for depression.

"Though these findings will not result in a test for depression, they will help us track down specific genes that are altered in people with this disease."

He continued: "This breakthrough in understanding the risk for depression may get us closer to developing more effective therapies, though patients should not expect to see these available for 10 to 15 years.

"Any one of 40 genes in chromosome 3p25-26 could be responsible, so we are currently conducting detailed sequencing examinations in 40 of the families involved to identify specific genes and variations that are causing the linkage. (The) results of these studies should be available next year."

The findings were independently replicated by another group from Washington University and both papers are being published in the American Journal of Psychiatry.

Major depression affects about one in five people at some point in their lives and is difficult to treat.

Studies have suggested genetics account for about 40 per cent of the risk of developing the disorder, with environmental factors also playing a role.

Professor of Psychiatric Genetics Peter McGuffin, a senior author on the research, said: "These findings are groundbreaking as until now few, if any, regions of the genome have been shown to contribute to depression risk.

"We acknowledge, however, that our finding represents only a small part of the genetic risk for depression, and more and larger studies will be required to find the other parts of the genome involved."

Dr Michele Pergadia, lead author of the Washington study, said: "I think we are just beginning to make our way through the maze of influences on depression, and this is an important step toward understanding what may be happening at the genetic and molecular levels."

Marjorie Wallace, chief executive of the mental health charity Sane, said: "It is very exciting that there seems to be progress finding the gene involved in some people developing depression.

"However, we are still some distance from identifying the 'culprit' gene.

"It is encouraging that in a field that has been slow to attract funding for research so much effort is now being made."