Abstract
Despite the centrality of adult romantic relationships to the conceptualization of borderline personality disorder (BPD), little is known about the earlier development of this interdependency during adolescence. Thus, we examined the co-development of romantic relationships and BPD symptoms from ages 15 to 19 in a large urban sample of girls (N = 2310) in the Pittsburgh Girls Study. We had two major aims. First, we sought to examine associations between BPD symptoms and romantic relationship involvement (number of partners, importance of relationship) and relational insecurity (concerns about infidelity and tactics to maintain relationship) during adolescence. Second, we investigated mutual influences and temporal precedence of BPD symptoms and four specific romantic relationship characteristics (perceived support and antagonism, verbal and physical aggression) during adolescence using latent growth curve models (LGCMs). Results indicated that BPD symptoms were associated with increased involvement in romantic relationships and heightened relational insecurity across adolescence. Furthermore, higher BPD symptoms at age 15 predicted increases in antagonism, verbal aggression, and physical aggression across ages 15 to 19. Conversely, perceptions of higher levels of relationship support at age 15 predicted steeper increases in BPD symptoms across ages 15 to 19, suggesting a potential negative influence of early involvement in close romantic relationships. These findings demonstrate the reciprocal nature of romantic relationship functioning and BPD symptoms during adolescence and suggest novel prevention targets for youth at risk for BPD.