Page URL:

Gene affects risk of depression

21 July 2003
By BioNews
Appeared in BioNews 217

How well people cope with stressful experiences such as divorce or unemployment is partly down to variations in a single gene, according to a new study by researchers based in the UK, US and New Zealand. The scientists, who published their findings in last week's Science, found that different versions of a gene called 5-HTT can affect a person's susceptibility to serious depression. 'We are not reporting a gene that causes a disease' said team leader Terrie Moffitt, of the Institute of Psychiatry, Kings College London. 'Instead, we believe the gene helps influence whether people are resistant to the negative psychological effects of the unavoidable stresses of life'.

The team looked at a group of 847 people born between April 1972 and March 1973 in Dunedin, New Zealand, who have been tracked since birth as part of a long-term health study. They asked the participants how many stressful events - such as divorce, bereavement and unemployment - they had experienced between the ages of 21-26, and whether they had been affected by depression during that period. The researchers then determined which versions of the 5-HTT gene they had inherited: either the 'long' or 'short' form, or one of each. They found that 43 per cent of the people who inherited two short versions of 5-HTT (one from each parent) developed serious depression after a stressful experience, whereas only 17 per cent of the people who inherited two longer versions of the gene were affected by the illness.

The 5-HTT gene codes for the serotonin transporter, a protein involved in regulating levels of the brain chemical serotonin. Previous studies have shown that animals with two long forms of the 5-HTT gene are better at coping with stressful situations, but this is the first time such a link has been conclusively demonstrated in humans. Moffit thinks that earlier attempts to look for these 'vulnerability' genes have been unsuccessful because such studies fail to take into account environmental exposure. She compared it to looking for malaria susceptibility in a sample that includes people who live in mosquito-free places.

Serious depression, the symptoms of which include persistent sadness and lethargy, is thought to affect around 121 million people worldwide. Moffitt says that the gene variants will probably not be a good diagnostic tool for depression, because the short form is so common in the population. But she thinks that the combination of stressful experiences and genetic susceptibility could help identify people at risk of the condition. 'The most exciting thing about this research is that we've found that the risk of depression is halved for people who have the long-long genes' she told BBC News Online, adding that 'it would be really wonderful if there was a way of preventing it'.

Gene influences risk of depression
The Independent |  18 July 2003
Gene-stress combination doubles depression risk
MSNBC |  17 July 2003
Scientists find depression gene
BBC News Online |  17 July 2003
Study Links Genes to Depression, Stress
Yahoo Daily News |  17 July 2003
23 May 2011 - by Dr Rosie Morley 
Scientists believe they have identified a new genetic link to severe depression....
10 March 2008 - by Dr Rebecca Robey 
British and Australian scientists have found that a person's genes can predispose them towards happiness. Reporting in the journal Psychological Science, the researchers found that genes account for 50 per cent of the factors contributing to an individual's satisfaction with life, with external influences such as health...
2 March 2006 - by BioNews 
A common genetic variation increases the chances of depression after stressful life events, Australian researchers have confirmed. The study, published in the British Journal of Psychiatry, shows that people who inherit two 'short' versions of a gene that affects the brain chemical serotonin have a high risk of becoming depressed...
11 May 2005 - by BioNews 
A gene variation previously linked to depression and anxiety affects brain regions involved in processing fear and 'dampening' negative emotions, US scientists say. The short version of the serotonin transporter (5-HTT) gene is linked to an increased risk of depression following stress. Researchers at the National Institute of Mental...
15 April 2005 - by BioNews 
A person's risk of developing a psychotic illness such as schizophrenia after smoking cannabis as a teenager is affected by their genetic make-up, say UK researchers. A new study to be published in the journal Biological Psychiatry shows that a variant of the COMT gene is linked to a five-fold...
to add a Comment.

By posting a comment you agree to abide by the BioNews terms and conditions

Syndicate this story - click here to enquire about using this story.