Acceptance without judgment — 1 of 4 mindfulness components of Dialectical Behavior Therapy group skills training (DBT-ST) — was associated with a reduction in non-suicidal self-injury (NSSI) in patients with Borderline Personality Disorder (BPD). Results from a secondary analysis of prior research were published in Behaviour Research and Therapy.
DBT-ST has found success in mitigating suicidality, which prompted curiosity regarding its effectiveness in reducing NSSI. Mindfulness deficits may help explain avoidance of aversive internal experiences, leading to NSSI as a form of self-punishment. However, sparse literature has left it unclear which aspect of mindfulness — observing, describing, acting with awareness, or acceptance without judgment — was most responsible.
A total of 84 patients with BPD (78.6% female) were randomly assigned to either 20 weeks of DBT-ST or a waitlist control group. The Lifetime Suicide Attempt Self-Injury Interview was used to assess NSSI at baseline and after treatment, while the Kentucky Inventory of Mindfulness Skills (KIMS) was used to evaluate the 4 subscales of mindfulness at the same points. Investigators offered 2 hypotheses: of the four dimensions, only acceptance without judgment will predict NSSI baseline frequency, and only acceptance without judgment will have an impact on NSSI reductions via DBT-ST.
Contrary to their first hypothesis, none of the 4 KIMS subscales demonstrated a significant relationship with NSSI baseline frequency. However, in line with the second hypothesis, the researchers found that NSSI was uniquely affected directly and indirectly by acceptance without judgment vs the other three subscales.
Post-treatment NSSI rates were lower overall for DBT-ST participants, with a statistically significant total treatment effect (β = −1.22; z = 2.21; P =.04), and DBT-ST outperformed the control group in terms of pre-post treatment change scores for acceptance without judgment (β = 3.83, t = 2.28, P =.03). This change score increase was linked to significantly lower NSSI frequency post-treatment (β = −.10, z = −3.50, P <.001), and was estimated to mediate 63.3% of the total treatment effect on NSSI rates. None of the other subscale change scores was significantly associated, either directly or indirectly, with NSSI following treatment.
Study limitations included not being powered for mediation analysis, possibly affecting validity and reliability; inability to control for external treatments; and substantially shorter treatment duration than standard DBT.
While the investigators recommended further exploration of the mechanism connecting improvements in acceptance without judgment and NSSI reductions, they also acknowledged the important clinical and research implications of their findings, especially as a springboard to more refined interventions in the future. Learning to accept experiences without judgment can help patients with BPD reduce rates of NSSI, and streamlining therapeutic approaches will likely improve these results going forward.
Krantz LH, Mcmain S, Kuo JR. The unique contribution of acceptance without judgment in predicting nonsuicidal self-injury after 20-weeks of dialectical behaviour therapy group skills training. Behav Res Ther. 2018;104:44-50. doi:10.1016/j.brat.2018.02.006