Being able to identify those at high risk for suicide
is vital for prevention, but there is not currently a
reliable way to predict this risk. Now, researchers
from Johns Hopkins University School of Medicine
in Baltimore, MD, say they have found a chemical
alteration in a gene linked to stress responses
that could enable the creation of a blood test to
predict a person’s risk of suicide consistently.
The study, led by Zachary Kaminsky, assistant
professor of psychiatry and behavioral sciences at
Johns Hopkins, is published in The American
Journal of Psychiatry.
According to the Centers for Disease Control and
Prevention (CDC), in 2009, suicide was the 10th
leading cause of death in the US among persons
aged 10 and older, resulting in 36,891 deaths
overall.
“Suicide is a major preventable public health
problem,” says Kaminsky, “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.”
He adds that their test could help them “stem
suicide rates by identifying those people and
intervening early enough to head off a
catastrophe.”
Their findings suggest that alterations in a gene
that plays a role in the brain’s response to stress
hormones is involved in turning ordinary reactions
to everyday stresses into suicidal tendencies.
To conduct their study, Kaminsky and his team
aimed their attention at a genetic mutation in a
gene called SKA2. They analyzed brain samples
from deceased people, some of whom had been
mentally ill and some of whom had been healthy.
They found that the samples of people who died
by suicide had significantly reduced levels of this
gene.
Model analysis predicts suicide risk with 80%
accuracy
Investigating further, the researchers found that
some subjects had an epigenetic alteration that
changed the way SKA2 operated – without
changing the gene’s DNA sequence. This
modification added chemicals – called methyl
groups – to the gene, they say.
These higher methylation levels were found in the
study subjects who had committed suicide, and
the team explains that these findings were
replicated in two independent brain cohorts.
The researchers next tested three different sets of
blood samples, the largest of which involved 325
living participants, and found comparable
increases in methylation in SKA2 in those
participants who reportedsuicidal thoughts or
attempts.
Based on this, the team designed a model
analysis that predicted with 80% certainty which of
the participants were experiencing suicidal
thoughts or had attempted suicide.
And in those with a more severe risk of suicide,
the model analysis was able to predict with 90%
accuracy. Based on blood results, the team was
able to identify – with 96% accuracy – whether or
not a participant had attempted suicide in the
youngest data set.
According to the researchers, SKA2 is expressed
in the prefrontal cortex, which plays a role in
inhibiting negative thoughts and controlling
impulsive behaviors. This gene is also
responsible for guiding stresshormone receptors
into the nuclei of cells so they can function.
However, if there is not enough SKA2 or if it
changes in some way, the stress hormone
receptor becomes unable to stop the release of
cortisol in the brain.
Potential applications
Kaminsky and his team are hopeful that a test
based on their findings might be used to predict
future suicide attempts in those at highest risk,
which could help facilitate interventions.
Potential applications include in the military,
where members could be tested for the gene
mutation, and if found, could be more closely
monitored upon their return home. Additionally, a
test would be useful in a psychiatric emergency
room, where doctors could assess suicide level
risks.
Commenting on their findings, Kaminsky says:
“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.”
He adds that – though it needs further study –
the test could potentially be used to inform
treatment arrangements, including whether or not
to administer certain medications linked with
suicidal thoughts.


http://www.punchng.com/health/foreign-health/blood-test-could-predict-risk-of-suicide/