Middle Eastern Journal of Disability Studies

Abstract
Background & Objectives: Borderline personality disorder is a complex mental disorder characterized by pervasive instability of self–concept, emotions, and behavior. The inability to regulate emotion in this disorder may be related to cognitive impairment because cognitive function modulates emotional reactions as a response to environmental stimuli. Studies that have been conducted to investigate the effect of transcranial direct current stimulation (tDCS) on borderline personality disorder have reported conflicting results on the impact of this type of stimulation. Studies that investigate the effect of tDCS on borderline personality disorder are rare. Of course, no study has been reported to investigate the effect of this type of treatment on emotion regulation in borderline personality disorder. So, the purpose of this study is to determine the effectiveness of tDCS on emotion regulation in patients with borderline personality disorder.
Methods: This study method was a quasi–experimental intervention type with a pretest–posttest design and a control group. The statistical population included patients with borderline personality disorder aged 30 to 45 from Taft City, Iran, who were referred to psychiatric clinics in Yazd City, Iran. Among the community members, 30 available qualified volunteers entered the study, and 15 of them were randomly assigned to the intervention group and 15 to the control group. The inclusion criteria were having a borderline personality disorder and psychiatrist's approval, an age range of 30 to 45 years, not using other treatment methods such as drug therapy and psychotherapy. The exclusion criteria included absence from a session of tDCS and failure to complete the questionnaire during the study. Each person completed the consent form to participate in the research. The Difficulties in Emotion Regulation Scale (DERS) (Gratz & Romer, 2004) compared emotion regulation variable scores before and after tDCS. Data analysis was done using covariance analysis in SPSS version 17. The significance level of the tests was set at 0.05.
Results: The analysis of covariance by adjusting the effect of the pretest showed a significant difference in the average emotion regulation between the intervention group receiving tDCS and the control group without any intervention in the posttest (p<0.001). Also, the results related to the effect size indicated that 61% of the difference between the intervention and control groups in the emotion regulation variable was due to the implementation of tDCS.
Conclusion: According to the findings, tDCS has a significant effect on the improvement of emotion regulation of patients with borderline personality disorder. So, tDCS can be used as a complementary treatment to improve emotion regulation in patients with borderline personality disorder.