Emerging research suggests suicidal tendencies may be the result of genetic mutations. This finding could help to develop future genetic tests to identify predisposition to suicide, without ignoring the importance of social and cultural factors.

New studies by Spanish researchers at Mount Sinai Hospital and Columbia University in New York found multiple mutations among three genes.

“There is ever-increasing evidence pointing to the important role played by genes in predisposing people to suicidal behavior,” Mercedes Pérez-Rodríguez, co-author of the study and a researcher at Mount Sinai Hospital, said.

Research carried out to date shows that around 40 percent of the variability in suicidal behavior could have a genetic basis.

The objective of the study published in the American Journal of Medical Genetics was to identify a model able to differentiate between people with and without a background of suicide attempts. Instead of focusing on a few traditional candidate genes, the scientists examined a range of 840 functional single nucleotide polymorphisms (SNPs) present in 312 genes expressed in the brain.

“The SNPs were analyzed in men with diagnosed psychiatric illnesses, and the results are promising,” says Pérez-Rodríguez, who describes how her team was able to correctly classify 69 percent of the patients by using an algorithm based on three SNPs from three different genes.

“The predictive features of this algorithm for estimating suicide risk outperform those of all other models developed to date,” stresses the researcher. In addition, the new model identifies three different neurobiological systems that could play a role in diathesis (organic predisposition) to suicidal behavior.

The authors have suggested that the outcomes of this study could be used to create simple genetic tests for diagnosing and identifying patients prone to attempting suicide.

Aside from the sociological and psychological causes, scientists have also started to use genetics over the past 20 years to analyze the causes of suicidal behavior, which has continued to increase, above all in industrialized Western countries.

The latest data from the World Health Organization show that nearly one million people committed suicide in 2000, and it estimates that by 2020 this figure will have risen to 1.5 million.

Currently there are no reliable clinical tests to identify people who may be more predisposed to suicide.

To date, studies have focused on parameters related to serotonin function, such as 5-hydroxyindoleacetic acid (5-HIAA) of the cerebrospinal fluid (CSF) or measurements of the hypothalamic-pituitary-adrenal axis (HPA) such as the dexamethasone suppression test. However, these models are difficult to apply in a clinical setting.

Researchers hope the new finding will lead to new investigation of the genetic underpinning for suicidal behavior.

Source: FECYT – Spanish Foundation for Science and Technology