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.This research was supported in part by NIMH Grant MH 45448 to
Mark F. Lenzenweger for the Longitudinal Study of Personality
Disorders.