ABSTRACT
This study examined whether DBT treatment intensity predicts clinically significant change (CSC) in suicidal ideation, whether maladaptive personality traits moderate this relationship and whether early symptom improvements in suicidal ideation from baseline to midtreatment predicted CSC at post-treatment, above and beyond the effects of treatment intensity and personality traits. Adults (n = 105) in a hospital-based DBT day treatment programme were triaged into three DBT intensity tracks over 12 weeks: low intensity (weekly DBT skills group), mid intensity (weekly skills group plus individual therapy) and high intensity (two weekly skills groups, individual therapy). Suicidal ideation was assessed using the Beck Scale for Suicidal Ideation (BSSI), and maladaptive personality traits were assessed using the Personality Inventory for ICD-11 at baseline, Week 6 and Week 12. Early symptom improvement was operationalized as change in BSSI scores from baseline to Week 6. CSC at Week 12 was defined as a reliable improvement from baseline to Week 12 and a BSSI score of ≤ 6 at Week 12. Suicidal ideation decreased significantly over time, with no differences across treatment intensity levels or maladaptive personality traits. Early symptom improvement predicted higher odds of achieving CSC at Week 12, whereas Disinhibition predicted lower odds of achieving CSC. Suicidal ideation improved across DBT intensity levels, with early reductions in suicidal ideation and Disinhibition, but not treatment intensity, emerging as key predictors of clinically significant recovery at post-treatment.