Background and Aim: Attention-deficit / hyperactivity disorder (ADHD) is one of the disorders that has adverse effects on the individual and society, and cognitive-behavioral third wave treatments are promising to treat these disorders.  The aim of the present study was to compare the effectiveness of Dialectical Behavior Therapy (DBT) with Acceptance and Commitment-Based Therapy (ACT) on emotion regulation and interpersonal relationships in adults with attention deficit / hyperactivity disorder (ADHD).
Materials and Methods: The present study was a pretest-posttest study with control group.  The statistical population of the study consisted of all students of Zanjan Central Azad University in the academic year of 1398-98.  Sample size consisted of 45 subjects who were divided into two experimental and one control group (15 subjects in each group).  Subjects in DBT group and ACT group received intervention while control group received no treatment.  Research instruments were Adult Attention Deficit / Hyperactivity Disorder Scale (ASRS), Emotion Regulation Questionnaire, and Interpersonal Relationships Questionnaire that were administered in the pre-test and post-test stages.  Descriptive statistics were used to analyze the data at multiple levels and multivariate analysis of variance (MANOVA) was used to analyze the data at inferential level and LSD test was used to compare the efficacy of treatments.  Data were analyzed in SPSS 25 software.
Results: The results showed that both treatment with Acceptance and Commitment Therapy and Dialectical Behavior Therapy were more effective on emotion regulation and interpersonal relationships than the control group (P <0.001).  In the comparison phase of the two treatments, the LSD test showed that dialectical behavior therapy was more effective in re-evaluating emotion regulation (P Conclusion: Overall, the results of this study showed that dialectical behavioral therapy is better for emotion regulation with interpersonal and acceptance-based therapy. Therefore, it can be used in clinical centers for attention deficit disorder, emotion regulation components and improvement.  Implement interpersonal and social relationships.