Borderline personality disorder (BPD) is a complex condition whose severity is compounded by the heterogeneous psychological functioning of those who suffer from the disorder. These differences have made the identification of a unified treatment difficult. Attempts have been made to reduce the effect of this variation within the disorder by investigating subtypes of BPD. However, the clinical utility of this approach has not been examined. This book investigates the presence of subgroups of BPD and examines whether treatment effectiveness varies as a function of subtype. Using variables that...