Development of borderline personality disorder in adolescence and young adulthood: introduction to the special section.

Recognizable symptoms and features of borderline personality disorder (BPD) appear during adolescence. However, there has been resistance to diagnose or research this disorder prior to adulthood because of clinical lore that BPD is a long-standing illness and that personality traits are not stable until adulthood. This has resulted in little information regarding the development of and risk factors for BPD in youth. The goal of this special section is to examine the development of BPD in adolescence and young adulthood using a broad collection of approaches, including a theoretical review paper, two prospective studies, and a multi-method cross-sectional study. This body of work provides new insights into vulnerabilities that may transact with early attachment relationships and experiences to predict the emergence of BPD in adolescence and young adulthood. These papers also point to future research that is needed to better understand the etiology, development, and course of BPD.