The burden of BPD on public mental health services is high. While DBT is the gold standard treatment for BPD and is widely offered, dissociation has been identified as a barrier to its effectiveness. Unfortunately dissociation is not well understood nor routinely assessed in community mental health services which may limit the effectiveness of the DBT programs offered.
This study sought to examine the nature, extent, and impact of dissociative experiences on outcomes among adult BPD patients (mean age 27.65 years, SD = 8.07) receiving DBT treatment in a community mental health service. N=65 participants completed measures prior to commencing DBT and n = 18 completed measures after completing six months of treatment.
On the Dissociative Experiences Scale (DES), over half (57.6%) of the participants scored above the cut-off for probable dissociative identity disorder. On a subset of DES items measuring pathological dissociation (Dissociative Taxon), 63.6% of mean scores were above 20, indicating a probable dissociative disorder. There was a strong positive correlation between Borderline Symptom List (BSL-23) scores (items measuring dissociation removed) and total DES scores (r = .45; rc = .52), suggesting shared common underlying processes. The impact of dissociative experiences on DBT outcomes was explored using multiple regression. Contrary to expectations, results did not support the hypothesis that the relationship between pre- and post-treatment borderline symptom scores depended on the level of pre-treatment dissociative experiences scores, but the analysis was underpowered and so results must be interpreted with caution.
The high variability in dissociative experiences and large proportion of individuals with BPD who experience pathological levels of dissociation in community mental health services underscore the importance of screening for dissociation in this cohort of individuals and calls for more education and training for mental health professionals. Future studies with larger sample sizes are needed to clarify the impact of dissociative experiences on treatment outcomes.