Economic game provides fresh insights into borderline personality disorder

In the first study of its kind, psychologists have used an economic game to investigate the behaviour and brain processes of people diagnosed with a personality disorder.

Brooks King-Casas and colleagues recruited dozens of people with borderline personality disorder (BPD) to play the role of trustee in an economic game. People with this disorder tend to have unstable personal relationships and difficulty regulating their emotions. Healthy participants were recruited to play the part of investor and/or trustee.

Over several rounds, the game involved the investor choosing how much money to pass to the trustee. The investment was automatically tripled and then the trustee had to decide how much money to pass back to the investor. For maximum returns, both parties need to cooperate. If the trustee is unfair in the returns he gives back, the investor will likely reduce his investments on future rounds, meaning less profit for everyone.

The researchers found that cooperation broke down when a person with BPD played the role of trustee. They failed to recognise smaller investments as a sign that the investor was losing trust. Healthy trustees, by contrast, responded to a distrustful investor by increasing the returns they gave, thereby coaxing back the investor’s trust and provoking a return to larger investments.

Brain scans taken while the participants played the role of trustee showed that healthy participants, but not participants with BPD, showed greater activity in the anterior insula as investments reduced in size (this is a brain region known to be involved in fairness, as well as sensing the body’s internal states). Perhaps because of their low expectations for how others will treat them, the participants with BPD didn’t appear to recognise a low investment as unfair. Consequently, they didn’t attempt to restore the investor’s trust, thus leading to a collapse of cooperation.

In a commentary on the study, published in the same journal issue, Andreas Meyer-Lindenberg welcomed this pioneering use of an economic game for the study of mental health. “The correspondence of these brain findings to current psychotherapeutic practice is remarkable,” he also noted. “The most effective treatment of borderline personality disorder, dialectical behaviour therapy, is based on the assumption that patients lack skills in interpersonal regulation, and attempts to build these abilities.”

B. King-Casas, C. Sharp, L. Lomax-Bream, T. Lohrenz, P. Fonagy, P. R. Montague (2008). The Rupture and Repair of Cooperation in Borderline Personality Disorder Science, 321 (5890), 806-810 DOI: 10.1126/science.1156902

A. Meyer-Lindenberg (2008). PSYCHOLOGY: Trust Me on This Science, 321 (5890), 778-780 DOI: 10.1126/science.1162908

Christian Jarrett (@Psych_Writer) is Editor of BPS Research Digest

3 thoughts on “Economic game provides fresh insights into borderline personality disorder”

  1. This is very interesting research and I found the digest very clear. I have BPD and can really relate to these findings.I don’t think it is necessarily about not recognising signals from other’s that your behaviour needs to change, but feeling stuck in how to change without a)getting into more trouble b)loosing out too much c)being viewed as either a push over or bossy. Its the fear that you might get it wrong or might dig a bigger hole for yourself, which I guess is linked to the experiences in the past of being punished/ignored when trying to get needs met or show effective behaviour (e.g. the child owns up to breaking a plate and apologises nicely but is then scolded badly). In other words, once the situation has deteriorated past a certain point (e.g. become unfair) feelings of helplessness and hoplessness and distrust are triggered causing an emotional tidal wave to engulf my ability to think straight and problem solve, which is why some very smart people can have BPD. I wonder if one could use scenarios such as in this research to help BPD clients practice bringing themselves back from their feelings of powerlessness. Does this mean that I should never try to become a banker?Thanks Briony Petri-Dish

  2. Hi Briony – thanks so much for sharing your thoughts about this research. I think you’re right that these kinds of economic scenarios might well provide a useful way for BPD clients to practice certain skills. As regards banking — I’m sure you could have done a better job than the real bankers out there who have brought the current financial crisis upon the world!

  3. there seem to be a lot of variables in this kind of study. Each person has a different sense of what an economy is and how to succeed in said economy. i am sure the structure of the economic game was made clear, but there is no way a person can set aside all of their economic experiences from life, at least there is no way to prove they have or haven't.
    also especially since march of 2008 the word economy alone can cause a strong emotional reaction.
    All this really seems to say is that bad decision decision making is involved with having a lack of activity in the anterior insula. You can be a person that is hesitant or unskilled in making important decisions and not have bpd.

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