Personality Disorders: Theory, Research, and Treatment Vol. 9, Iss. 4,  (Jul 2018): 390-396. Concomitant substance misuse in adults with borderline personality disorder (BPD) is associated with a more severe course of illness and poorer outcomes. Previous research has found an association between the number of borderline personality features and substance misuse in community samples. This study examined the relationship between substance use and severity of BPD in youth presenting for the first time for treatment (first presentation) of BPD. . To read the full article, log in using your NHS OpenAthens details.