Four genetic variants have been found to be more common in suicide victims.
Scientists analysed DNA samples from more than 1300 people who had died from suicide in the state of Utah in the USA. Their results, published in Medical Psychiatry, suggest a genetic component to an individual's risk of suicide.
The team's hope is that their work will help identify particularly susceptible individuals, as open up new prevention possibilities
'The first step is to find the genes that increase risk. Identifying specific genes may lead to new treatments for those who suffer,' said study author Professor Douglas Gray at the University of Utah in Salt Lake City.
Using data from suicides of distantly related people in 43 high-risk families (with genealogical information going back nine generations) allowed them to focus on the genetic risks of suicide while minimising shared environmental effects.
The team were also able to link the DNA results to the Utah Population Database, which contains genealogical and medical records from more than eight million people, as well as death certificates dating back to 1904. The researchers were able to identify four gene variants that may confer increased risk of suicide.
The researchers also identified a further 207 genes for targeted follow-up. A total of 18 of these genes had been previously linked to suicide risk. Fifteen of these 18 genes have known associations with inflammatory conditions, which may add to the accumulating evidence now linking inflammation and suicide risk.
However, the team admits that the study has multiple limitations. One is the fact that the samples were of almost entirely northern European ancestry and that not every individual will have accurately recorded mental health conditions.
'Clearly genetics is only one part of risk when it comes to suicide,' said Professor Hilary Coon, first author on the article. 'But we are hoping these discoveries will lead us to highly susceptible individuals so we can develop better interventions to help them circumvent this risk.'
Professor Coon added: 'We think these results are just the tip of the iceberg. We will continue to search for additional gene changes that lead to risk.'