Background: Bipolar disorder is a debilitating psychiatric disorder characterized by recurrent depression, manic and hippomanic episodes. The effect of a dialectical behavior therapy on executive functions in bipolar disorders has not been addressed so far. The aim of this study was to determine the effect of the dialectical behavior therapy on executive function in the bipolar disorder. Materials and Methods: Sixty patients with a bipolar disorder were randomly assigned to the intervention (the dialectical behavior therapy combined with medication) and control (only medication) groups. The questionnaires and tests were used at baseline, after 12 weeks intervention, and three months after the intervention. Participants in the intervention group received twelve 90-min sessions of the standard dialectical behavior therapy for the bipolar disorder. Results: The results showed that the intervention group had a lower score in mania, and depression. Also, the intervention group had a higher score in executive functions after three months intervention and three months follow-up. Conclusion: The dialectical behavior therapy in combination with medication can lead to reduce manic and depression symptoms, and improve performance of the patients in planning and problem-solving
