Personality Disorders: Theory, Research, and Treatment, Vol 17(4), Jul 2026, 266-276; doi:10.1037/per0000766
Fewer men than women with borderline personality disorder (BPD) may be found in clinical and research settings, and so the majority of dialectical behavior therapy (DBT) treatment studies have focused on women. Because of this, DBT has not been sufficiently studied for treating BPD in men. The aim of this study was to examine the influence of gender on symptom trajectory differences and on the frequency and reasons for premature termination of treatment during a 3-month certified inpatient DBT program. The treatment-seeking sample included n = 1,991 women and n = 295 men with BPD who received treatment in a psychosomatic care hospital. Self-rated BPD symptoms were the primary outcome. There was no substantial moderating effect of sex on symptom trajectories from pre- to posttreatment. The effect sizes for borderline symptoms were g = .16 for men and g = .37 for women, respectively. According to the reliable change index, 26.1% of men and 17.9% of women experienced a deterioration in borderline symptoms; conversely, 42.1% of the women reliably improved compared with 35.9% of the men. No differences were observed in either the frequency of premature treatment discontinuation or the reasons for it. Due to symptom deterioration or the absence of improvement, a larger subgroup of men seemed to benefit less from therapy compared with women. (PsycInfo Database Record (c) 2026 APA, all rights reserved)