From negative to positive and back again: polarized affective and relational experience in borderline personality disorder.

A core feature of borderline personality disorder (BPD) is the tendency to evaluate one's experience with extreme polarity (i.e., feeling all good or all bad; Beck, Freeman, & Davis, 2004; Kernberg, 1975; Linehan, 1993). In this investigation, we examined the polarity of within-person reports of experience in individuals with BPD and healthy adults over the course of a 21-day, experience-sampling diary. We applied multilevel modeling techniques (Rafaeli, Rogers, & Ravelle, 2007) to capture the within-person covariance of momentary reports of negative and positive features of experience, either affective or relational. Our data indicated significantly greater polarity in reports of affective and relational experiences in BPD that increased during heightened interpersonal stress. We also examined the association of affective and relational polarity to reports of impulsive behaviors (e.g., self-injury, substance use, etc.) and found evidence that increased polarity in reports of affective (in low-stress contexts) and relational experiences (in high-stress contexts) predicted increased rate of reports of impulsive behaviors. Together, these data present strong evidence for the role of polarized experiences in BPD, and have implications for the treatment of individuals with this disorder.