Abnormally low levels of metabolic activity in areas of the brain associated with decision-making and planning identify depressed people who make serious suicide attempts. Researchers at Columbia University found significantly reduced blood flow to the prefrontal cortex, the region of executive functions, among those whose suicide attempts were most medically damaging.
Reduced blood flow, observed in PET scans, was also linked to diminished serotonin activity in the prefrontal cortex. By contrast, depressed persons making suicide attempts that were less lethal had greater blood flow to the prefrontal cortex. And their actions were more impulsive.
Previous studies by the group have shown that depressed persons making serious suicide attempts have impaired verbal fluency. Language fluency is an executive function that may be a marker for metabolism in the prefrontal cortex.
The researchers suggest that impaired verbal fluency reflects executive function deficiencies that limit the suicide attempter's ability to devise solutions to a crisis, leaving them prey to suicidal thoughts. So perhaps one day soon a simple test of verbal fluency can spot those people most intent on taking their own life.