What blood test says about suicidal intention??

Blood test has potential to show one’s suicidal intention 

The potential for a blood test to predict suicide risk has sparked much debate, with The Independent reporting that a "US study raises controversial prospect to identify people at risk".

The news is based on the results of a study that aimed to identify biomarkers that could be used objectively to assess and track suicide risk. A biomarker is a biological marker, such as a genetic variant, that can be measured to indicate normal or abnormal biological processes.

Researchers identified biomarkers for suicide risk by analysing blood samples taken from a small group of men with bipolar disorder. Blood samples were taken when the men both reported having suicidal thoughts and when they did not.

A new research, which appeared in Molecular Psychiatry on August 20, finds increased amounts of a particular protein in the bloodstream of those contemplating killing themselves.

What if a psychiatrist could tell whether someone was about to commit suicide simply by taking a sample of their blood? Suicide isn’t like a heart attack. People typically don’t reveal early symptoms to their doctor -- morbid thoughts, for example, instead of chest pain -- and there’s no equivalent of a cholesterol or high blood pressure test to identify those at most risk of killing themselves. "We are dealing with something more complex and less accessible," says Alexander Niculescu III, a psychiatrist at the Indiana University School of Medicine in Indianapolis. So some researchers are eager to find physical signs, called biomarkers, that can be measured in the bloodstream to signal when a person is at a high likelihood of committing suicide.

The new research, which appeared in Molecular Psychiatry on August 20, finds increased amounts of a particular protein in the bloodstream of those contemplating killing themselves. The test was conducted on only a few people, however, and given that such “biomarkers” often prove unreliable in the long run, it’s far from ready for clinical use.

Gustavo Turecki, a psychiatrist at McGill University in Montreal, Canada, was "particularly happy" when he read the study's results because it fits well with his own lab's previously published work, which has also found evidence that the production of SAT1’s protein is elevated in the brains of suicidal individuals after they die. Although he's hopeful that the findings will eventually illuminate the biological processes that underlie suicidal behavior, Turecki doubts that these biomarkers will ultimately help predict suicide in the clinic. The small sample sizes in Niculescu’s studies and the fact that all the patients were male and had bipolar disorder or schizophrenia means that the study is "not representative of the universe of people with suicidal behavior," he says. More important, he says, is that the vast majority of people who die by suicide don’t see a doctor first.

"Any one test isn't going to be a perfect predictor," agrees psychologist Matthew Nock of Harvard University, an expert in developing behavioral exams to predict suicide. However, looking for biological warning signs of suicide is "an important piece of the puzzle," he says. "Hopefully we'll see a lot more in this line of research.

Conclusion

This study raises the possibility that a test for suicide could be developed. However, the research is still in its preliminary stages.
The current study was small and only included men. It also only involved men with bipolar disorder or psychosis. The findings of this study need to be replicated in other studies, but even then it is difficult to see what the practical applications of such a test would be.
The reasons why a person thinks about or attempts suicide or self-harm are highly complex. Being at risk of suicide may involve a combination of various life events and genetics. Financial concerns, loss of work, relationship breakdown or bereavement, as well as health factors, can all influence a person's mental health.
A person's risk may also be increased when more than one negative life event occurs at the same time or there is a trigger event, such as losing a job or a relationship coming to an end.
People with a mental health illness such as depression, bipolar disorder or schizophrenia may be at an increased risk of suicide, particularly if they have a history of attempting suicide or self-harm.
But suicide does not only occur in people with a diagnosed mental health illness. People may have suicidal thoughts but have not been formally diagnosed with a mental health illness, or those who have received a diagnosis may not be receiving care and treatment.
Overall, even if further studies gave positive results, the possible application of such a blood test as a screening tool for suicide risk raises extensive questions.
The main issue is whether the results of a blood test, which does not take account of the many psychosocial factors that may be involved in a person's thoughts about harm or suicide, could ever provide a reliable indication of a their actual feelings or intent.    
The most important thing is that people who have thoughts about self-harm or suicide immediately receive the support and care that they need. People who are having these thoughts should talk to someone they trust, such as a loved one or their GP.