Researchers have uncovered a marker in the brain that could help identify people at a higher risk of suicide.
Every day in the United States, an average of 130 people take their own lives. In 2021, 12.1 million Americans seriously considered suicide, according to the Centers for Disease Control and Prevention; 3.5 million of them even made a plan.
For the loved ones left behind after a suicide, grief is often clouded with regret and guilt: Why didn’t they know things were so bad? Could they have stopped it?
Although many of suicide’s risk factors are well known—depression, chronic pain, family violence, presence of guns—it’s not always clear why some people, and not others, slip from ideation to planning to attempt.
As reported in the paper published in the Journal of Affective Disorders, researchers found important connections in the brain differed among veterans with a history of suicide attempts—even before they tried to end their lives—and those with similar levels of psychiatric symptoms, but without a suicide history.
The differences were in the functional connectivity between brain networks involved in cognitive control (adjusting our behavior or choices to fit a certain task or goal) and self-referential thought processing (reflecting on what we’ve done today or something embarrassing that happened years ago or thinking about what we need to do tomorrow).
“Our study provides evidence that this brain connectivity marker may be identifiable before a suicide attempt, suggesting that it could help identify those at risk for suicide,” says lead author Audreyana Jagger-Rickels, assistant professor of psychiatry a Boston University Chobanian & Avedisian School of Medicine assistant professor of psychiatry. “This could also lead to new treatments that target these brain regions and their underlying functions.”
To look for indicators of suicide risk in the brain’s inner workings, researchers turned to post-9/11 veterans who’d been exposed to trauma. Participants were given a resting functional MRI scan, which tracks communication between brain regions and networks when no specific task is being performed—a common way of mapping the brain and how different areas interact.
The researchers then zeroed in on those who reported a suicide attempt at a one- to two-year follow-up assessment, but who had not reported any prior attempts. They examined brain connectivity before and after the suicide attempt and compared it to a matched control group of veterans with equivalent symptoms of depression and post-traumatic stress disorder (PTSD), but no reported suicide attempts.
The comparison revealed that brain connectivity between cognitive control and self-referential processing networks was dysregulated in veterans in the suicide attempt group, who were all part of a VA Boston Translational Research Center for Traumatic Brain Injury and Stress Disorders (TRACTS) longitudinal study measuring brain, cognitive, physical, and psychological heath. Critically, this brain connectivity signature was present both before and after the attempt, suggesting that the marker may be a novel suicide-specific risk factor.
The findings may eventually help clinicians overcome one of the major challenges in suicide risk assessment—its reliance on self-reporting, Jagger-Rickels says.
“Interventions to reduce suicide risk are limited to people who feel comfortable enough to disclose—self-report—suicidal thoughts and behaviors,” she says. “Identifying measures that do not require self-disclosure of suicidal thoughts and behaviors may help us identify people who are overlooked, and may also aid in the development of novel treatments targeting the brain mechanisms underlying suicidal thoughts and behaviors.”
The study also indicated that connectivity of the right amygdala, a brain region important for fear learning and trauma, differed between the suicide attempt and the control groups, but only after the reporting of a suicide attempt.
“This suggests that there are brain changes that occur after a suicide attempt, which could be related to the stressors surrounding a suicide attempt or due to the trauma of the suicide attempt itself,” says Jagger-Rickels, who’s also a principal investigator in the National Center for PTSD at the VA Boston Healthcare System. “This would indicate that suicide attempts themselves impact the brain, which could increase future suicide risk.”
The Department of Veterans Affairs and the National Institute of Mental Health supported the work.
Source: Gina DiGravio and Andrew Thurston for Boston University