BILLY SMITH II CHRONICLE
Baylor neuroscientists Read Montague, left, and Brooks King-Casas write equations dealing with personality disorders.
Using brain imaging devices and a computer game, Houston researchers have developed an objective test for borderline personality disorder, a serious mental illness whose sufferers are unable to form and maintain stable relationships.
The brain malfunction found by Baylor College of Medicine neuroscientists is thought to be the first identified for any personality disorder.
"I'm hopeful this will mark a new approach for mental illness," said Read Montague, director of Baylor's Human Neuroimaging Lab and the project's leader. "It should provide a tool to diagnose the condition and test therapy's effectiveness."
The research, published in Friday's edition of the journal Science, is part of an ongoing effort to understand the neurobiology behind mental illnesses and to develop objective diagnostic tests for them, similar to the bloodwork, biopsies and x-rays used to diagnose other ailments. Baylor has been a leader in the effort.
As many as one in five psychiatric inpatients have borderline personality disorder, a formidable toll on not just those afflicted but on their social network and the health-care system.
Among the characteristics of the disorder are a chaotic self-image, black-and-white thinking, outbursts of rage, impulsive behavior and fear of abandonment. The Glenn Close character in the movie Fatal Attraction is sometimes cited as an extreme example.
The Baylor research paired people with the disorder and people without it, 110 in all, in what the scientists call a "trust game." The game involved the exchange of money between two players who could maximize profits by cooperating with each other. Functional magnetic resonance imaging devices measured the blood flow in participants' brains while they played.
Baylor researchers found that people with borderline personality disorder didn't pick up on certain social cues of their partners. In people with the disorder, an area of the brain that responds when norms are violated didn't activate when their partners showed signs of distrust.
In the 10-round computer game, a player known as the investor gives money, which automatically triples, to a player in another room. That player, known as the trustee, decides how to split the profits with the investor — decisions that motivate the investor to give more or less.
For instance, the investor hands over $20, which triples to $60. If the trustee gives back $40 to the investor, both players would be up $20, and the investor would presumably be motivated to continue giving generous amounts. If the trustee gives back a small amount, the investor might become stingy in subsequent rounds.
"Most people actually become a little generous when the other player sends a stingy amount, trying to coax cooperation back," said Brooks King-Casas, an assistant professor of neuroscience and psychiatry at Baylor and the lead author of the study. "But players with borderline personality disorder did that half as often. They were less likely to try to repair the problem."
The brain imaging devices confirmed the missed cues. When people without borderline personality disorder received a stingy amount, the brain region called the anterior insula lit up. But there was no change in the region of those with the condition.
The anterior insula responds to breakdowns in normal body function, from pain to high or low temperatures to emotional well-being. King-Casas described it as sending "a red flag" that something's wrong.
Baylor has used the trust game and brain imagers on more than 600 study participants, including the most functional autistics. Subjects with borderline personality disorder were the only ones whose anterior insula didn't activate during the game.
Montague said the next step in developing the test as a diagnostic tool will be to set up a large clinical trial in which the brain imagers measure blood flow in the anterior insula among borderline personality disorder patients on medication, among those in behavior therapy and among healthy people. He said if such a trial confirms the device's diagnostic value, there would be no obstacle to psychiatrists using it in practice.
Borderline personality disorder is one of 10 personality disorders listed in the DSM, the psychiatric diagnostic manual. It can be a controversial diagnosis, sometimes criticized as a catch-all category for patients whose symptoms don't snugly fit another classification.
Dr. Stuart Yudofsky, Baylor's chair of psychiatry and behavior sciences, acknowledged that diagnosis of the disorder would benefit from a more precise understanding of the brain biology involved and said the Baylor research advances the effort. He also said it gives hope for eliminating the stigma associated with personality disorders.
The Baylor researchers, excited about the discovery's boost to the field, said they couldn't remember the lead study in Science concerning a personality disorder before. The journal is known for its emphasis on biology, physics and chemistry.
The study was conducted in partnership with the Menninger Clinic, the legendary psychiatric institute that moved to Houston in 2003. Funding came from Menninger and the National Institutes of Health.