Predicting change in borderline personality: Using neurobehavioral systems indicators within an individual growth curve framework

The natural history and course of borderline personality disorder (BPD) has long been the focus of speculation, typically guided by impressions from clinical work with BPD-affected individuals. Not unlike the other personality disorders (PDs), it has long been assumed that BPD is relatively stable, traitlike, and enduring in nature. The extent to which BPD is or is not a plastic construct has implications not only for understanding its longitudinal course, but also for understanding its development and, ultimately, its treatment and/or prevention. This paper consists of two parts. The first part reviews the longitudinal research corpus that bears directly upon the issue of stability of BPD in both adolescents and adults. The consistent trend in very nearly all studies, whether using a categorical or dimensional approach to assessment, is one of considerable change over time. This literature presents complexities, however, because most of the extant studies examine BPD-affected individuals who have been exposed to treatment. However, at least two large-scale longitudinal studies, which include both treated and untreated persons, also provide support for viewing BPD as a malleable disorder that declines in severity over time. The second part presents original data from the Longitudinal Study of Personality Disorders that specifically examine the predictors of change in BPD using a neurobehavioral model of personality within an individual growth curve (IGC) analytical framework. This IGC analysis revealed important predictors of both overall level of BPD features as well as rate of change in BPD features, with particularly important roles played by the agentic positive emotion (i.e., incentive motivation) and anxiety (negative emotion) systems. The benefits of the IGC approach for understanding the developmental psychopathology of BPD is also stressed.