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Researchers have identified a chemical alteration in a gene linked with suicide and believe the finding is a key step toward a blood test that could reliably predict a patient’s suicide risk.

“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,” said lead researcher Zachary Kaminsky, PhD, assistant professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine, Baltimore. “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.”

In the July 30 online American Journal of Psychiatry, Dr. Kaminsky and colleagues at Johns Hopkins University report on a mutation in the SKA2 gene they found in people who died by suicide.

Linked to stress reactions, SKA2 is expressed in the brain’s prefrontal cortex and involved in cortisol suppression.

When researchers compared brain samples from people who were mentally ill and people who were healthy, they found significantly reduced levels of SKA2 in people who had committed suicide. In a subset of subjects who died by suicide, researchers also found an epigenetic modification that caused higher levels of methylation at SKA2.

Based on the findings, they designed a model analysis to predict which participants had thought about or attempted suicide: its accuracy rate was 80%. Among people with more severe risk of suicide, the test’s accuracy rate jumped to 90%.

Researchers next seek to replicate their findings in larger studies.

“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,” Dr. Kaminsky said. “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.”

—Jolynn Tumolo

References
1. Guintivano J, Brown T, Newcomer A, et al. Identification and replication of a combined epigenetic and genetic biomarker predicting suicide and suicidal behaviors. American Journal of Psychiatry. 2014 July 30. [Epub ahead of print].
2. A blood test for suicide? Alterations to a single gene could predict risk of suicide attempt [press release]. Newswise: Charlottesville, VA; July 28, 2014.