Science: Cooperation Impaired in People with Borderline Personality Disorder

A new study in Science suggests that borderline personality disorder may arise partly through abnormalities in a brain region involved in cooperation and social exchange.

These findings, published in the journal’s 8 August issue, may be a step toward improved behavioral therapies or drug treatments for the disorder, which is more common than schizophrenia or bipolar disorder and disproportionately affects young women.

Estimated to effect 6 million people in the United States, individuals affected by the disorder, also known as BPD, typically have unstable interpersonal relationships and difficulty controlling their impulses and emotions.

For the study, lead author Brooks King-Casas, a neuroscientist at the Baylor College of Medicine in Houston, Texas, and his colleagues monitored the brain activity of BPD patients and healthy individuals while they played a multi-round “trust game” designed by the research team.

In the activity, money was exchanged between an investor, who decides how much money to invest, and a trustee, who decides how much of the investment to repay. The investment is tripled during the transfer, so the players benefit more from cooperating than if the investor keeps most of the money.

The researchers found that the BPD patients were less likely to maintain the level of trust required for both parties to profit maximally in the multi-round simulation, and they were less likely to repair breaches of trust by repaying larger amounts of money.

In a related Perspective, Andreas Meyer-Lindenberg, a researcher at the University of Heidelberg in Germany, says that the findings imply that individuals with BPD may have difficulty cooperating because they lack the “gut feeling” that the relationship is in jeopardy. Meyer-Lindenberg also discusses how exchange games and game theory offers a new paradigm for studying other severe mental illnesses.

Kathy Wren

8 August 2008