This study aimed to investigate the role of brain-behavioral systems and assertive behavior on impulsive behavior in individuals with attention deficit hyperactivity disorder with regard to the mediating role of frustration tolerance. The statistical population included all students with attention deficit hyperactivity disorder in 2021-2022. From the aforementioned population, 96 people were selected as samples using multi-stage cluster sampling. To collect information, the brain-behavioral systems questionnaire Carver and White (1994) , Gambrill and Richey Assertiveness Inventory (1975), Patton, Stanford, and Barratt Impulsiveness Scale (1995), and Harrington Frustration Tolerance Scale (2005), and the Conners Parents Rating Scale for Attention Deficit Hyperactivity Disorder (1973) were used.The data were analyzed using Pearson correlation and structural equation modeling in AMOS24.The findings of this study indicated that components of the behavioral brain systems (behavioral activation and behavioral inhibition) and assertive behavior significantly predict impulsive behavior in students with attention-deficit/hyperactivity disorder (ADHD). Moreover, frustration tolerance plays a key mediating role in explaining these relationships. These results suggest that educational and therapeutic interventions focused on enhancing assertiveness, increasing frustration tolerance, and modifying patterns of behavioral activation and inhibition may effectively reduce impulsivity and improve behavioral adjustment in this group of students.
