A better understanding of the genetic variants in individuals who have attempted suicide could lead to new treatments and preventions.
Genetic liability to depression increases an individual’s risk to attempt suicide, regardless of the psychiatric disorder they are affected by, according to the findings of a genome-wide association study published in The American Journal of Psychiatry.
The data-intensive effort has yielded insights that could eventually lead to new, more personalized treatments and preventions.
Researchers at the Icahn School of Medicine at Mount Sinai used data from the Psychiatric Genomics Consortium to compare the genomes of 6,569 individuals who attempted suicide and 17,232 who did not and have major depressive disorder, bipolar disorder or schizophrenia.
The researchers found that the polygenic risk scores for major depression were significantly associated with suicide attempt in major depressive disorder (0.25%), bipolar disorder (0.24%) and schizophrenia (0.40%).
“Our data showed that suicide attempters with major depressive disorder, bipolar disorder or a schizophrenia diagnosis carry a greater genetic liability for major depression than non-attempters,” said Niamh Mullins, Ph.D., postdoctoral fellow in psychiatric genomics.
The research team identified three genome-wide significant loci: one associated with suicide attempt in major depressive disorder, one associated with suicide attempt in bipolar disorder and one in the meta-analysis of suicide attempt in mood disorders. There were no significant associations in the meta-analysis of all three disorders.
The researchers combined samples across 46 individual cohorts from Europe, the U.S. and Australia. The research team then used polygenic risk scores to show that those who attempt suicide carry an increased genetic liability for depression, regardless of which psychiatric disorder they are affected by.
“These results indicate the existence of a shared genetic etiology between suicide attempt and major depression that is common to suicide attempt in different psychiatric disorders,” Mullins said.
More than 800,000 deaths each year are due to suicide.
The study authors suggest that increasing the sample size could help robustly identify specific genetic associations and variants and provide more biological insights into the cause of suicide attempt.
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