It’s a startling statistic: One American dies from suicide every 12.8 minutes, making suicide the 10th leading cause of death in the country.
A new analysis of existing studies has found that there are increased levels of chemicals, called cytokines, in the body and brain that promote inflammation in individuals who are contemplating or attempted suicide, even when compared to patients being treated for the same psychiatric disorders who are not suicidal.
Previous studies have shown that cytokines are released under conditions of psychological stress and that inflammation in the brain contributes to depression.
According to researchers, the new study suggests that suicide emerges in the context of a relatively greater activation of the immune system than typical stress or depression.
To conduct the latest work, Dr. Carmen Black and Dr. Brian Miller at Georgia Regents University collected data from 18 published studies, resulting in a combined total of 583 psychiatric patients with suicidality — the likelihood of committing suicide, 315 psychiatric patients without suicidality, and 845 healthy control subjects.
Their analysis revealed that patients with suicidality had significantly increased interleukin (IL)-1β and IL-6 levels in the blood and postmortem brain.
“Our findings contribute to a growing body of evidence that immune system dysfunction, including inflammation, may be involved in the pathophysiology of major psychiatric disorders in some individuals,” Miller said. “Specifically, cytokine levels may help distinguish patients with suicidality from patients without suicidality and controls.”
The limitation of this study is that the relationship between elevated cytokine levels and suicide may be non-specific, according to the researchers. They explain that increased cytokine levels may not determine whether a specific person is going to attempt suicide at a specific time. As a result, a specific suicide test is still a distant goal, they note.
“However, by identifying biological markers generally associated with suicide, we may be gradually approaching an era where simple blood tests might help doctors predict long-term risk, much in the way that increased blood pressure may predict medical problems years or decades later,” the researcher noted in the study, which was published in Biological Psychiatry.
Studies are still needed to evaluate whether controlling inflammation earlier in life has a long-term protective effect, the researchers said. They added that “rigorously designed studies of large and diverse patient samples are still needed to confirm the presence of these cytokine alterations, but if replicated, such findings could contribute to more personalized medicine for patients.”
“Inflammation affects every organ in the body. It is increasingly evident that we need to take a long-term perspective on the effects of inflammation on the brain,” said Dr. John Krystal, editor of Biological Psychiatry.
“The path to preventing suicide may be to intervene early in long-term processes that increase the risk for suicide rather than to focus solely on the elusive short-term predictors of suicide.”
Source: Biological Psychiatry