The extent of dissociation in borderline personality disorder: A meta-analytic review.

Several authors have studied dissociation within the borderline personality disorder (BPD) population and postulated 3 dissociative subgroups. Conversely, other authors suggest that dissociation may play a central role in the development of trauma-related disorders and specifically in BPD. Nevertheless, the role of dissociation in BPD seems to be controversial. Our aim is to perform a meta-analytic review of the literature to evaluate the extent of dissociation in BPD compared to other psychopathological disorders to clarify its role in this specific condition. Ten eligible studies resulted in a total of 2,035 subjects. Results show that levels of dissociation are higher in BPD than in other psychiatric disorders in general, although this difference is moderate and the heterogeneity of effect sizes is large. In particular, individuals with BPD seem to show higher levels of dissociation than those with several psychiatric and personality disorders but not dissociative disorders or posttraumatic stress disorder. These findings support the fact that dissociation is not specifically a core feature of BPD and, in addition, sustain the existence of a continuum of severity within the psychiatric population. Nevertheless, the current work has several limitations related to the paucity of studies included, the heterogeneity of control groups, their clear definition, and the statistical robustness of the results. In addition, our conclusions require future research in order to explain the role of different forms of dissociation and their etiological factors among the psychiatric population. Eventually, we invite clinicians and researchers to systematically evaluate dissociation in order to reach a better diagnosis for a more specific treatment indication.