Gender-specific effectiveness of dialectic-behavioral therapy for patients with complex post-traumatic stress disorder (DBT-PTSD) – results of an observational single center study

<b>Background:</b> Complex post-traumatic stress disorder (cPTSD) was recently included in the ICD-11, extending the PTSD symptom profile to encompass disturbances in self-organization (DSO). Trauma-focused Dialectical Behavior Therapy (DBT-PTSD) is an effective psychotherapeutic treatment, particularly among women. However, empirical data on DBT-PTSD's gender-specific effectiveness in naturalistic settings remains limited.<b>Objective:</b> The present study examined whether DBT-PTSD is similarly effective in reducing symptoms of cPTSD among women, men, and gender minority (GM) individuals under routine clinical conditions.<b>Method:</b> This observational single-center study included 215 patients (women = 78.1%, men = 18.6%, GM = 3.3%; 44.6+/-11.5 years) with cPTSD treated with DBT-PTSD at a psychosomatic inpatient clinic in Austria. Primary outcome was mean change in symptom severity assessed by the International Trauma Questionnaire (ITQ) before (T1) and after treatment (T2) and secondary assessment included anxiety and depression, somatization, dissociation, assessment of functioning, personality traits, emotion regulation, locus of control and borderline symptomatology. Repeated measures ANOVAs were used to evaluate treatment outcomes. Baseline predictors (T1) for ITQ score at T2 were identified by machine learning models and validated with mixed linear models.<b>Results:</b> While DBT-PTSD overall led to significant reductions in cPTSD symptoms with large effect size (<i>p</i> < .001, <i>η</i>²= 0.17), no significant difference was observed between men and women neither for the ITQ (<i>p</i> = .90, <i>η</i>² < 0.01), nor for any of the secondary outcomes (<i>p</i> = .08-.86; <i>η</i>² ≤ 0.01). Secondary outcomes showed statistically significant improvements in depression, anxiety, somatization emotion regulation and the locus of control (<i>p</i> < .001-.012). Higher negative affectivity was associated with worse outcomes in both men and women, while higher antagonism was associated with better outcomes in women and worse outcomes in men.<b>Conclusions:</b> DBT-PTSD is effective in reducing cPTSD symptoms among men and women in real-world clinical settings. However, larger samples of men are needed to validate the findings of this study.