Self-report response style bias and borderline personality features.

Borderline personality disorder (BPD) is characterized by dichotomous thinking, biases in processing emotion-related information, impulsive responding, and identity disturbance - each of which may affect how individuals respond to assessment items. This study used item-response theory tree models to examine the association between number of self-reported BPD symptoms and response style bias on the NEO Five Factor Inventory-3, administered annually from ages 18 to 20 to 2196 community participants enrolled in the Pittsburgh Girls Study. Small to moderate negative correlations emerged between number of BPD symptoms and midpoint responding. Small correlations emerged between BPD symptoms and extremity responding. These patterns did not vary by age. Participants who endorsed higher initial BPD symptoms reported lower extraversion over time, whereas those initially endorsing midpoint extroversion reported greater decreases in BPD severity. Low initial agreeableness was associated with higher BPD symptom slopes. The current study found only small associations between response style biases and BPD symptoms among a sample with subthreshold symptoms for diagnosis.