Impulsivity in borderline personality disorder: reward-based decision-making and its relationship to emotional distress.

Impulsivity in Borderline Personality Disorder (BPD) has been defined as rapid and unplanned action. However, a preference for immediate gratification and discounting of delayed rewards might better account for the impulsive behaviors that appear to regulate emotional distress in BPD. To investigate this, a delay discounting task was administered to 30 outpatients diagnosed with BPD and 28 healthy community controls (all aged 15-24) before and after a mood induction. Trait impulsivity was measured with the Barratt Impulsiveness Scale. The results showed that the BPD group had a greater preference for immediate gratification and higher rate of discounting the delayed reward than the control group. Although the mood induction resulted in increased feelings of rejection and anger in all participants, and the rate of delay discounting changed significantly in the control group, the rate of discounting did not change for the BPD group. There was no evidence of rapid decision-making in the BPD group as response times were similar between the two groups during both trials. Finally, greater general impulsiveness and nonplanning impulsiveness were associated with greater rates of discounting in the BPD group. Together these findings suggest that BPD is characterized by a preference for immediate gratification and tendency to discount longer-term rewards. This characteristic appears to exist independent of feelings of rejection and anger, rather than being reactive to this, and to be related to trait impulsivity.