Parents with borderline personality disorder (BPD) experience deficiencies in parenting skills leading to increased family burden, stress, mental health problems in children and even family violence. The present study evaluated a Dutch version of the parenting training based on Dialectical Behavior Therapy (DBT) for mothers with BPD. A multiple baseline single-case experimental design study was conducted with standardized and idiosyncratic assessments of parenting behavior and parental stress before, biweekly during, and after training. Participants (N = 10) were mothers with a BPD diagnosis with a child under the age of 6. Four participants discontinued the training. Among six training completers, clinically reliable improvements in parenting skills were most pronounced for inconsistent discipline, involvement, positive parenting and corporal punishment. Frequent, idiosyncratic assessments showed that for six mothers training had a positive effect on parenting skills, while for five mothers this effect was large. Overall, less improvement was found for parenting stress. DBT parenting training seems to have clinical value for mothers with BPD struggling with raising their children. Most prominent improvement was found in relation to mothers disciplining their child in a more consistent manner. The complexity and heterogeneity of mothers with BPD requires a more idiosyncratic, patient-centered approach. This study was registered (retrospectively) in ISRCTN (ID ISRCTN74447767). https://www.isrctn.com/ISRCTN74447767, March 2022.
