A blood test for suicide? US study raises controversial prospect to identify people at risk

New research claims molecule measured in bloodstream can identify people intent on taking their own life

US research has raised the controversial prospect of using a blood test to detect thoughts of suicidal thoughts.

For the first time, suicide risk has been linked to biomarkers in the blood by researchers looking into predictors.

Scientists found increased amounts of specific proteins in the blood stream of people who were contemplating suicide.

The study, conducted by researchers at Indiana University, found that an enzyme called SAT1 was linked to suicidal tendencies.

The study involved taking samples from participants over an extended period of time, whilst interviewing them at three to six month intervals. 

Seventy-five males with conditions such as bipolar were used as participants  as they are at a higher risk of committing suicide than others.

Researchers then tested the samples to look for differences in protein activity.

The increased presence of this specific blood marker was apparent in a subgroup of nine patients who displayed a sudden dramatic shift to powerful suicidal thoughts.

A similar pattern was seen in blood samples taken from nine suicide victims who had succeeded in taking their own lives.

Raised levels of the biomarkers correlated with admissions to hospital after suicide attempts. The link was stronger for bipolar disorder than for schizophrenia.

Researchers in the US now argue their results are "proof of principle" for a suicide test.

Study leader Dr Alexander Niculescu, from Indiana University, said: "Suicide is a big problem in psychiatry. It's a big problem in the civilian realm, it's a big problem in the military realm and there are no objective markers.

"There are people who will not reveal they are having suicidal thoughts when you ask them, who then commit it and there's nothing you can do about it. We need better ways to identify, intervene and prevent these tragic cases.

"These seem to be good markers for suicidal behaviour in males who have bipolar mood disorders or males in the general population who commit impulsive violent suicide. In the future we want to study and assemble clinical and socio-demographic risk factors, along with our blood tests, to increase our ability to predict risk."

However because the number of participants used in the study was relatively low at 75 and all male, Dr Niculescu said he plans to conduct further research focusing on more deliberate and planned suicides with a bigger and more varied sample. "There could be gender differences," he said.

"We would also like to conduct more extensive, normative studies in the population at large."

"Over a million people each year world-wide die from suicide and this is a preventable tragedy," he added.

In their paper, the scientists point to a link between SAT1 and polyamine, a chemical involved in apoptosis, or "cell suicide" - the programmed self destruction of damaged or harmful cells.

They wrote: "It could be that.. mechanisms related to cellular survival have been recruited by evolution for higher mental functions, such as feelings, thoughts, actions and behaviours, leading to suicidality.

"In that sense, suicidality could be viewed as a whole-organism apoptosis."

Lithium, a treatment for bipolar disorder shown to prevent suicide, suppresses apoptosis at the cellular level, they pointed out.

But British scientists have warned the research should be treated with caution.

Professor Keith Hawton, director of the Centre for Suicide Research at Oxford University, said: "There is a big difference between finding differences between groups (as in this study) compared with risk in actual individuals, the latter being the real test of predictors.

"I would say that the findings are of interest and may point the way to some future research based on large samples, but no more than that."

Professor Matthew Hotopf, from the Institute of Psychiatry at King's College London, stressed the need to have the results replicated by other studies.

He added: "It's one thing to find a biomarker which might be associated at a statistical level with suicide/suicidal behaviour. It's quite another to use it to make any kind of prediction which has clinical utility.

"These findings may attract media attention, but they are very much preliminary and my money would be on failed replication and even if replication was successful, lack of predictive power to be a useful clinical tool."

Additional reporting by Press Association

Start your day with The Independent, sign up for daily news emails
ebooks
ebooksA special investigation by Andy McSmith
  • Get to the point
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Recruitment Genius: Experienced Special Needs Support Worker

£12 - £14 per hour: Recruitment Genius: We are looking for someone to join a s...

Recruitment Genius: Content Assistant / Copywriter

£15310 per annum: Recruitment Genius: An exciting opportunity has arisen for a...

Recruitment Genius: Sewing Technician

£15000 per annum: Recruitment Genius: This market leader in Medical Devices is...

Recruitment Genius: Operations Manager

£24000 - £25000 per annum: Recruitment Genius: Situated in the heart of Bradfo...

Day In a Page

Not even the 'putrid throat' could stop the Ross Poldark swoon-fest'

Not even the 'putrid throat' could stop the Ross Poldark swoon-fest'

How a costume drama became a Sunday night staple
Miliband promises no stamp duty for first-time buyers as he pushes Tories on housing

Miliband promises no stamp duty for first-time buyers

Labour leader pushes Tories on housing
Aviation history is littered with grand failures - from the the Bristol Brabazon to Concorde - but what went wrong with the SuperJumbo?

Aviation history is littered with grand failures

But what went wrong with the SuperJumbo?
Fear of Putin, Islamists and immigration is giving rise to a new generation of Soviet-style 'iron curtains' right across Europe

Fortress Europe?

Fear of Putin, Islamists and immigration is giving rise to a new generation of 'iron curtains'
Never mind what you're wearing, it's what you're reclining on

Never mind what you're wearing

It's what you're reclining on that matters
General Election 2015: Chuka Umunna on the benefits of immigration, humility – and his leader Ed Miliband

Chuka Umunna: A virus of racism runs through Ukip

The shadow business secretary on the benefits of immigration, humility – and his leader Ed Miliband
Yemen crisis: This exotic war will soon become Europe's problem

Yemen's exotic war will soon affect Europe

Terrorism and boatloads of desperate migrants will be the outcome of the Saudi air campaign, says Patrick Cockburn
Marginal Streets project aims to document voters in the run-up to the General Election

Marginal Streets project documents voters

Independent photographers Joseph Fox and Orlando Gili are uploading two portraits of constituents to their website for each day of the campaign
Game of Thrones: Visit the real-life kingdom of Westeros to see where violent history ends and telly tourism begins

The real-life kingdom of Westeros

Is there something a little uncomfortable about Game of Thrones shooting in Northern Ireland?
How to survive a social-media mauling, by the tough women of Twitter

How to survive a Twitter mauling

Mary Beard, Caroline Criado-Perez, Louise Mensch, Bunny La Roche and Courtney Barrasford reveal how to trounce the trolls
Gallipoli centenary: At dawn, the young remember the young who perished in one of the First World War's bloodiest battles

At dawn, the young remember the young

A century ago, soldiers of the Empire – many no more than boys – spilt on to Gallipoli’s beaches. On this 100th Anzac Day, there are personal, poetic tributes to their sacrifice
Dissent is slowly building against the billions spent on presidential campaigns – even among politicians themselves

Follow the money as never before

Dissent is slowly building against the billions spent on presidential campaigns – even among politicians themselves, reports Rupert Cornwell
Samuel West interview: The actor and director on austerity, unionisation, and not mentioning his famous parents

Samuel West interview

The actor and director on austerity, unionisation, and not mentioning his famous parents
General Election 2015: Imagine if the leading political parties were fashion labels

Imagine if the leading political parties were fashion labels

Fashion editor, Alexander Fury, on what the leaders' appearances tell us about them
Phumzile Mlambo-Ngcuka: Home can be the unsafest place for women

Phumzile Mlambo-Ngcuka: Home can be the unsafest place for women

The architect of the HeForShe movement and head of UN Women on the world's failure to combat domestic violence