Abnormal levels of a key brain chemical may predispose depressed people to commit suicide, and measuring levels of this chemical may enable doctors to identify those most likely to take their lives, researchers say.
Dr. J. John Mann of the Columbia Presbyterian Medical Center said Monday that studies by a number of researchers have shown that levels of serotonin, an important neurotransmitter protein in the brain, are 20 to 25 percent lower in patients who are at high risk of suicide.
Serotonin is particularly active in a part of the brain that controls inhibition, and a lack of the neurotransmitter, or its related chemicals, lowers the amount of control a person has over actions.
“This predisposes a person to act on suicide thoughts,” Mann said in an interview. “Serotonin is important for restraint. If serotonin is reduced, a person is more apt to act on powerful feelings.”
By identifying those most likely to kill themselves, such patients then could receive more aggressive care to help them control suicidal impulses through a variety of medications now available.
Mann delivered a lecture on the neurobiology of suicide on Monday at a national meeting of the Society for Neuroscience.
Identifying people who are seriously planning suicide has long been one of the most difficult challenges for doctors who work with depressed patients. People who have a dedicated plan to commit suicide often are able to hide their intentions.
Also, doctors often fail to accurately gauge how serious a patient’s suicide intentions are. For instance, studies in Finland and England show that about half of all people who commit suicide see a physician in the 90 days before they kill themselves, but only about 25 percent of them receive adequate care.
Suicide is the eighth leading cause of death in the United States.
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