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.