Scientists at Johns Hopkins University say they have uncovered a chemical change in a single human gene which could lead to a simple blood test for suicide risk.
The gene, known as SKA2, is involved in the way the brain responds to stress hormones, according to the research published in The American Journal of Psychiatry (Guintivano et al., 2014).
Zachary Kaminsky, who lead the study, explained:
“Suicide is a major preventable public health problem, but we have been stymied in our prevention efforts because we have no consistent way to predict those who are at increased risk of killing themselves.
With a test like ours, we may be able to stem suicide rates by identifying those people and intervening early enough to head off a catastrophe.”
In the research, samples were taken from those with mental illness, as well as healthy people.
Genetic analysis showed that amongst those who had died of suicide, the SKA2 gene had genetically mutated.
Although the DNA sequence remained the same, the SKA2 gene had a chemical added to it called a methyl group.
People who had killed themselves had higher levels of methylation on this gene.
The researchers tested the predictive power of the test by running it on hundreds of blood samples of people whose suicide risk was known, partly because some had already attempted it.
For those at the most severe risk of suicide, they found the test was 90% accurate.
Amongst young people, the test was 96% accurate.
The accuracy dropped to 80%, however, when people at less severe risk were included.
Kaminsky thinks the result is significant:
“We have found a gene that we think could be really important for consistently identifying a range of behaviors from suicidal thoughts to attempts to completions.
We need to study this in a larger sample but we believe that we might be able to monitor the blood to identify those at risk of suicide.”
If refined, the test could have all kinds of applications:
- Helping to predict the suicide risk of those being assessed in psychiatric emergency rooms.
- Military personnel returning from active duty who are at high risk could be carefully monitored.
- To inform the prescription of certain medications that are known to increase suicide risk.
Image credit: Chapendra