(PS12-A14) The Effect of Skills Group Attendance on Patient Outcomes in DBT

Background

Dialectical Behaviour Therapy (DBT; Linehan, 1993) is a well-established treatment for individuals with borderline personality disorder (BPD). However, less is known about the specific variables which may affect treatment outcomes. Higher attendance to DBT skills group has been found to have positive effects on treatment (Yin et al., 2022; Blackford & Love, 2011), although data on skills group attendance is not often reported.  This study sought to examine the relationships between attendance at skills groups and treatment outcomes for DBT patients over the duration of their program.

Methods

A naturalistic within-subjects design was used to examine the relationships. Participants (N = 214) were patients completing comprehensive DBT treatment in an outpatient clinic in Southern California. The sample was 65% cisgender women with a mean age of 27.65 years (SD = 11.06). Measures included the BSL-23, PHQ-9, GAD-7, WSAS and MHC-SF-14, and were collected every two months. Mixed Linear Effects were used to test hypotheses in R Studio.

Results

As predicted, significant improvements were found over the course of treatment for all measures. Uniquely, the BSL-23 displayed a significant interaction between months in treatment and average skills group attendance (b = .18, se = .08, p = .029), suggesting those who attended a greater average number of group sessions reported less improvement per month than those who attended fewer sessions. No other significant interactions were found between attendance at DBT skills group and change in symptoms over time.

Discussion

Our findings follow the expected trend of observed improvements over the course of treatment. Interestingly, the data suggests that participants who attended more DBT group sessions were likely to report slower improvement. This finding may imply that a longer-term program may slow symptom recovery which is in line with McMain et al’s (2022) finding that patients in 6-month – compared to 12 month – DBT programmes displayed more rapid reductions in BPD symptomatology. Alternatively, this may be explained by a selection effect; as patients were excluded if they did not report their attendance, we may be missing data for those who attended fewer sessions and dropped out due to poor progress. Furthermore, data on attendance was self-reported retrospectively by clients. Additional limitations to this study include: the sample was predominantly white, women and well-educated, which may potentially affect the generalisability of findings. Future studies could longitudinally re-evaluate the relationship between skills attendance and treatment outcomes for DBT participants by tracking attendance throughout treatment rather than through self-report post-treatment.