When a person's distress, depression or discouragement appears to have taken a sharp turn for the worse, it's time to ask him or her a weighty question: Are you thinking of harming yourself?
If only the answer were a better guide. One study has found that nearly 80 percent of patients who took their own lives denied they were contemplating suicide in their last contact with a mental health care professional. Friends and family suffer the guilt and anguish of not having divined a loved one's intentions, but mental health professionals rarely fare much better at doing so.
But what if the brain's response to a series of questions -- never the question, but a more indirect probe of a person's feelings -- yielded a more accurate signal?
New research suggests it can.
In a study published Monday in the journal Nature Human Behavior, researchers found that patterns of brain activation in response to a set of written words could reliably distinguish between young adults who had contemplated suicide and young, healthy control subjects. These words included ones related to death and to both positive and negative emotions.
A further exercise -- gauging specific brain responses to clusters of highly emotional words -- made an even finer distinction: between subjects who had a history of suicide attempts and those who had pondered such a step but never acted on it.
"Suicidal ideation and attempt are associated with measurable alterations in the way a person thinks about 'death,' 'suicide,' and other positive and negative concepts," wrote the authors of the new study, led by Carnegie Mellon University neuroscientist Marcel Just.
The interactions are complex, but computer-learning programs can tease out patterns that allow predictions to be made -- or at least identify individuals most in need of immediate and intensive help.
After years of peering into the spectral images produced by a functional magnetic resonance imaging, or fMRI, scanner, Just said he and his colleagues have gotten pretty accurate at "reading" a subject's feelings of shame, sadness, anger and pride, among others.
We humans may vary widely in how we express our emotions, Just said. But when a given emotion is aroused in a number of experimental subjects, blood flows in predictable patterns to predictable structures of the brain. With all our individual variability, he said, some emotions have very identifiable "neural signatures."