Biological mechanism involved in the suicidal behavior of people

Suicidal behavior is found to be linked to the glutamateResearchers have found the probable mechanism through which the glutamate is more active in the brains of the people who try to suicide.

This research has been published online in the journal Neuropsychopharmacology.

Glutamate is an amino acid involved in signaling between the nerve cells and has been found to be involved in depression.

“The findings are important because they show a mechanism of disease in patients,” Brundin, associate professor of translational science and molecular medicine in MSU’s College of Human Medicine, said in a statement. “There’s been a lot of focus on another neurotransmitter called serotonin for about 40 years now. The conclusion from our paper is that we need to turn some of that focus to glutamate.”

Researchers in this study worked on the spinal fluid of 100 patients in Sweden. They checked the glutamate activity by determining the quinolinic acid that is involved in chemical switch causing glutamate to send more signals to neighboring cells. In the patients, about 67% of the participants were admitted after attempting suicide while the rest were healthy.

Researchers found two times more quinolinic acid in the spinal fluid of the suicide attempters as compared to the healthy people showing elevated glutamate signaling between the nerve cells. Moreover, the highest levels of acid were found in the people with strongest desire to kill themselves. The patients also showed decreased levels of quinolinic acid in the patients after six months, when the suicidal behavior stopped.

This research also pointed to the mechanism for inflammation in the brain that would be caused by quinolinic acid that is the immune response. Recently, the NMDA-receptor antagonist ketamine has been found to be efficient in removing suicidal behavior.

“In the future, it’s likely that blood samples from suicidal and depressive patients will be screened for inflammation,” Brundin said. “It is important that primary health care physicians and psychiatrists work closely together on this.”

Reference:

Sophie Erhardt, Chai K Lim, Klas R Linderholm, Shorena Janelidze, Daniel Lindqvist, Martin Samuelsson, Kristina Lundberg, Teodor T Postolache, Lil Träskman-Bendz, Gilles J Guillemin, Lena Brundin, (2012). Connecting Inflammation with Glutamate Agonism in Suicidality. Neuropsychopharmacology, doi: 10.1038/npp.2012.248