Suicide risk can be hard to measure. But a brain's reaction to words like 'carefree' may offer clues

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% of patients who took their own lives denied they were contemplating suicide in their last contact with a mental healthcare 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?