Suicide Check

By Christine Gorman

It is a crisis that few in the emergency room are equipped to handle. Concerned friends have just arrived with a frightened man in his 20s. He is not bleeding. Nothing's broken. Yet he cannot stop crying, and his companions are worried that he might kill himself. Is he just having a bad night, or is he likely to do himself harm? When it comes to determining an individual's desire to commit suicide, physicians rely heavily on experience and intuition. There has never been a laboratory test that doctors could order that would help them measure the risk more precisely.

That predicament seems likely to change in the next few years, as scientists learn more about the biochemistry of behavior. Some of the latest research -- parts of which were presented at last week's meeting of the Society for Neuroscience in Miami -- suggests that measuring the levels of certain chemicals in the brain can identify those people with a biological predisposition to self-destruction. "More than 95% of the people who commit suicide show these changes in the brain ((at autopsy))," says Dr. John Mann of the Columbia University College of Physicians and Surgeons in New York City. "But the biochemical abnormality is there even in those who attempt to kill themselves. And it is most pronounced in those who make the most dangerous attempts."

A lab test for suicide -- the eighth leading cause of death in the U.S. -- sounds incredible. Yet it is only one of the promising developments being pursued in the hot new field of biological psychiatry. What was once the purview of priests and analysts, who try to probe the mind by listening and observing, is now a frontier for neuroscientists, who use blood tests, brain scans and spinal taps. Psychiatrists at some research centers are already using these tools to distinguish among types of depression and schizophrenia, and predict with some degree of certainty the best course of treatment for their patients.

There have been setbacks. Despite compelling evidence that manic depression, a mental illness characterized by extreme mood swings, runs in families, no one has isolated the genes responsible for the disorder. Several candidates have been identified, only to be discarded. But while the geneticists have hit a snag, the brain chemists are moving faster than anyone thought possible, and have produced an impressive array of practical results.

Nowhere is this bonanza more apparent than with the research into the brain chemical called serotonin. One of the many signaling chemicals used by nerve cells to communicate with one another, serotonin is intricately linked to those parts of the brain that affect mood and impulse control. Nerve cells manufacture, release and absorb serotonin in quick bursts that ripple throughout the cerebrum. Although no one understands quite why, low levels of the chemical are associated with clinical depression. As a result, serotonin has become the target for a whole new genre of antidepressant drugs -- the most popular of which is Prozac -- that keep it active in the brain longer than usual.

Not everyone who is depressed attempts suicide; nor does a low serotonin level automatically doom a person to self-destruction. According to Mann and his colleagues at Columbia and the New York State Psychiatric Institute, changes must occur in specific regions of the brain to create that danger. Their research, presented at last week's Neuroscience meeting, focuses on a section of white matter -- the orbital cortex -- that sits just above the eyes and modulates impulse control. In autopsies of 20 suicide victims, Mann's group found that in almost every case, not enough serotonin had reached that key portion of the brain. The neurological fail-safes that normally prevent people from hurting themselves seem to have been disabled. "Having the biochemical deficiency alone is not enough to make you commit suicide," Mann says. "Stress alone is not enough. But if you have the pre-existing condition and you pile on a major depression or a substance-abuse problem, then the chances go up."

Other research on people who have survived suicide attempts suggests that some of the biochemical changes are temporary and may peak in the weeks prior to the act. If that finding holds up, it could lead to a lab test that would identify those who are most immediately vulnerable. Studies show that half of all people who commit suicide visit their doctor in the month prior to their death. Most of the time the physician finds nothing medically wrong with them and sends them home. Doctors may someday be able to give these people a blood test that measures their body's ability to manufacture serotonin. Those whose capacity is impaired would be considered at greatest risk of hurting themselves.

The swift pace of biopsychiatric research has led to new tests for other mental illnesses. Leslie Prichep and her colleagues at the New York University Medical Center in Manhattan have retooled the electroencephalogram, or EEG, which measures the electrical activity of the brain, to identify various subtypes of schizophrenia, depression and other disorders. Their goal is to eliminate some of the trial and error that psychiatrists typically have to go through when prescribing pills for their patients. They have already seen results with obsessive-compulsive disorder, or OCD, a condition in which people continuously repeat the same sequence of thoughts or behaviors. By performing sophisticated computer analyses of patients' EEG readings, they have been able to describe distinct patterns that distinguish those who are more likely to respond to drugs from those who are not.

The rush to embrace biological explanations of human behavior is not without its critics. "We have some links, but they don't prove cause and effect," says Dr. Donald Mender, author of The Myth of Neuropsychiatry. It's the same statistical quandary that basketball coaches face all the time. Nearly all great male hoopsters tower over 6 ft. 5 in. But that does not mean that all tall men are great basketball players. Says Mender: "The danger lies in seeing people as if they were machines."

There is also a risk that research results could be abused. If suicide is linked to low serotonin levels, does that mean that violence against others can also be tied to depleted stores of the brain chemical? Scientists who are looking into that possibility are worried that their work could be used to label troubled children as incorrigible and excuse the lack of services designed to help them. "It's almost impossible to discuss scientifically," says Dr. Frederick Goodwin, former director of the National Institute of Mental Health. "People always overinterpret the science in this area."

Despite these concerns, the push to discover the biological markers of behavior shows no signs of abating. No lab test will ever solve the suicide crisis. But by raising the question -- and by giving doctors another way to verify their suspicions -- it could save lives.

With reporting by Dick Thompson/Washington