At a recent press briefing on suicide prevention, J. John Mann, M.D., a professor of psychiatry at Columbia University College of Physicians and Surgeons and chief of the department of neuroscience at the New York State Psychiatric Institute, announced preliminary findings of documentable, biological differences in the brains of persons who have attempted suicide.

Since 1976 studies have indicated that levels of the neurotransmitter serotonin are different in the spinal fluid of persons who died by suicide. Recently Victoria Arango, M.D., of the Mental Health Clinical Research Center for the Study of Suicidal Behavior (MHCRC), identified differences in serotonergic neurons in specific regions of the frontal cortex of brains donated from suicide victims. Using positron emission tomography (PET) scanning, Mann, who also serves as the director of the MHCRC, looked for differences in serotonin-induced brain metabolic activity in the areas of the frontal cortex identified by Arango. Mann found that in patients with a clinical diagnosis of depression, serotonin activity was reduced throughout regions of the frontal cortex. This finding is consistent with the physiological basis of SSRI antidepressant therapy. When Mann used the same technique in patients who had attempted suicide, serotonin activity was again reduced; however, the pattern was markedly different. Serotonin activity was reduced in a small, specific area of the frontal cortex, immediately above the eyes, an area thought to be associated with control of impulsive behaviors. "It is interesting," noted Mann, "that we would find a difference in an area that is considered the emotional seat belt."

The PET scan results are the first report of imaging of regional serotonin response in living human brains. "Much work needs to be done," Mann cautioned. He is currently recruiting more patients with depression and suicidal ideation to expand his sample. "Research of this type will undoubtedly improve detection of patients who are at high risk for suicide," Mann said, "and, more importantly, lead to novel treatment options."