August 2, 2014
Genetic Biomarker Discovery Could Lead To Development Of Blood Test For Suicide
redOrbit Staff & Wire Reports - Your Universe Online
Newly discovered chemical changes in the body could ultimately lead to a blood test to help predict whether or not a person is at risk of committing suicide, according to new research appearing in the online edition of The American Journal of Psychiatry.
The discovery, which was made by scientists from the Johns Hopkins University School of Medicine Department of Psychiatry and Behavioral Sciences and the Johns Hopkins Bloomberg School of Public Health Department of Mental Health, centers around an alteration that occurs in a single human gene linked to stress reactions.
Changes occurring in this particular gene, which plays a role in how the brain responds to stress hormones, have a significant impact in determining if an individual has an unremarkable response to the strains of day-to-day life, or if those pressures become the catalyst for suicidal thoughts and actions. If confirmed in larger studies, this finding could provide doctors with a simple blood test to reliably predict whether or not a person is at risk of killing themselves.
"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,” Zachary Kaminsky, the lead study author and an assistant professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine, said in a statement. “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.”
Kaminsky, an assistant professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine, and his colleagues conducted a series of experiments focused on a genetic mutation the SKA2 gene, explained Bloomberg reporter Angela Zimm. SKA2 is expressed in the brain’s prefrontal cortex and is involved in inhibiting negative thoughts and controlling impulsive behaviors.
By analyzing brain samples of both healthy and mentally ill individuals, the authors discovered that those who had died as a result of suicide had reduced levels of SKA2, as well as elevated levels of methyl chemicals. The cause was attributed to an epigenetic modification that altered the way the SKA2 gene functioned without changing its underlying DNA sequence – an alternation which added methyl chemical groups to the gene.
In another portion of the study, Kaminsky’s team analyzed three different sets of blood samples, including one involving more than 300 participants in the Johns Hopkins Center for Prevention Research Study. That investigation revealed similar methylation increases at SKA2 in individuals with suicidal thoughts or attempts.
Using this data, the research team developed a model which successfully predicted which participants had tried to kill themselves or were experiencing suicidal thoughts. The model correctly identified 80 percent of those men and women, and predicted more severe suicide risk with 90 percent accuracy, the researchers said.
Furthermore, in the youngest data set, blood test results were 96 percent accurate in determining if a participant had attempted suicide. Kaminsky believes that a diagnostic test based on these findings could be used to predict potential suicide attempts in those who are ill, to help decide how intense potential intervention strategies should be, and to help doctors and hospitals determine if some patients should not receive medications linked to suicidal thoughts.
“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,” said Kaminsky. “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.”