RESEARCHERS may have found a biomarker for suicidal thoughts in the brains of people with posttraumatic stress disorder (PTSD), a new study suggests. The study found that people with PTSD had higher levels of a certain receptor on the surface of their brain cells, compared with people without PTSD. And among people with PTSD, those who reported experiencing some suicidal thoughts on the day of their brain scan had even higher levels of this receptor, compared with those that did not report suicidal thoughts on the day of the scan.
The findings, published May 13 in the journal Proceedings of the National Academy of Sciences (PNAS), are preliminary, and more research is needed to better understand the connection between this receptor, PTSD and suicidal thoughts.
But the findings point to the receptor as a possible target for future drug therapies for PTSD, the authors said. Currently, there are only two drugs approved by the Food and Drug Administration for treating PTSD symptoms. But these drugs were initially developed for depression rather than PTSD; and they don’t work for everyone and can take weeks or months to have any benefits.
“We don’t have anything right now in PTSD [that] we can give people to alleviate suicidal thinking rapidly,” said study senior author Irina Esterlis, a neuroscientist at Yale University School of Medicine. “If we have a biomarker that is specific to PTSD,” that may pave the way for the development of a drug specifically for symptoms of suicidal thoughts tied to PTSD, Esterlis told Live Science.
People with PTSD are at increased risk for suicidal thoughts, suicide attempts and death by suicide. But there is limited understanding of the biological mechanisms that underly suicide risk in PTSD.
Previously, the same group of researchers found that people with PTSD had higher levels of a brain receptor called metabotropic glutamatergic receptor, or mGluR5, on the surface of brain cells, compared with healthy people who didn’t have PTSD. Thisreceptor is for glutamate, a neurotransmitter, or chemical messenger, that’s thought to play a role in numerous brain processes — ranging from learning and memory to sleep and cognitive functioning. However, whether this receptor is linked with suicidal thinking was previously unclear.
In the new study, the researchers scanned the brains of 29 people with PTSD, 29 people with depression who did not have PTSD, and 29 people (controls) who had not been diagnosed with any psychiatric disorder. On the day of the scan, participants were asked whether they had experienced suicidal thoughts.