Objectives <p>This research examined both the direct and indirect influences of childhood trauma and negative emotional state on ADHD symptoms in adults, highlighting the mediating effect of executive cognitive functions.</p> Methods <p>The study comprised 182 adults diagnosed with ADHD, selected through purposive sampling within a cross-sectional design. Data collection utilized the Conners’ Adult ADHD Rating Scales Self-Report: Screening Version (CAARS-S: SV), the Childhood Trauma Questionnaire-Short Form (CTQ-SF), the Depression, Anxiety, and Stress Scale-21 (DASS-21), and the Amsterdam Executive Function Inventory (AEFI).</p> Results <p>To analyze the direct and indirect relationships of independent, mediating, and dependent variables, Partial Least Squares Structural Equation Modeling (PLS-SEM) was used. Findings indicated that both childhood trauma (<i>β</i> = .072; 95% CI = .009, .142; <i>p</i> = .049) and negative emotional state (<i>β</i> = .748; 95% CI = .642, .841; <i>p</i> = .0001) have significant direct positive associations with the symptoms of ADHD. But executive cognitive functions (<i>β</i> = −.163; 95% CI = −.261, −.093; <i>p</i> = .0001) have a significant direct negative association with the symptoms of ADHD. Furthermore, these constructs have a significant indirect role in ADHD symptoms mediated by executive cognitive functions. In this investigation, childhood trauma, negative emotional states, and executive cognitive functions collectively accounted for 92% of the variation in clinical features of ADHD. This study has established a conceptual model illustrating the direct and indirect relationships between childhood trauma, negative emotional state, and clinical features of ADHD in adults, mediated through executive cognitive functions.</p> Conclusions <p>The findings have implications for addressing the consequences of childhood trauma and reducing negative emotional state, as well as improving executive cognitive functions in adult ADHD patients.</p>