Examining the Construct Validity of Borderline Personality Traits Using Familial Aggregation and Other External...

Area of Science:

• Psychiatry and Psychology
• Mental Health Research
• Personality Disorders

Background:

• The categorical conceptualization of borderline personality disorder (BPD) faces ongoing questions regarding its reliability and validity.
• The Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) Section III introduced an alternative trait-based model for BPD, potentially offering a more nuanced understanding of the disorder.

Purpose of the Study:

• To investigate the construct validity of the DSM-5 Section III trait-based model of BPD.
• To examine familial aggregation of a latent BPD factor derived from Section III traits among siblings.
• To assess the association of this latent BPD factor with external constructs relevant to borderline pathology, and to test for gender moderation.

Main Methods:

• A total of 498 community-recruited adults completed the Personality Inventory for DSM-5, a risk-taking behavioral assessment, and reported on childhood maltreatment, substance use, nonsuicidal self-injury, and suicidal ideation.
• Familial aggregation was specifically assessed in 232 sibling pairs.
• Statistical analyses were performed to evaluate correlations between sibling BPD scores and associations with external validators, including gender as a potential moderator.

Main Results:

• Significant familial aggregation was found between siblings' BPD trait scores, indicating a genetic or shared environmental influence.
• Most external validators, including childhood maltreatment, substance use, nonsuicidal self-injury, and suicidal ideation, were significantly associated with the latent BPD factor.
• Risk-taking behavior did not show a significant association with the BPD factor, and results were consistent across genders.

Conclusions:

• The findings provide further empirical support for the construct validity of the DSM-5 Section III's trait-based profile for borderline personality disorder.
• The trait-based model demonstrates familial aggregation and links with key indicators of borderline pathology, suggesting its utility in clinical and research settings.
• The results underscore the potential of dimensional, trait-based approaches to better capture the complexity of borderline personality disorder.