Can the Stroop Test be useful in differentiating specific learning disorder from attention deficit hyperactivity disorder in medication-free children?

Introduction: Specific learning disorder (SLD) is a significant comorbidity in children with attention deficit hyperactivity disorder (ADHD). Identifying SLD in patients with ADHD is crucial because individualized educational interventions are the primary treatment for SLD. This study aimed to evaluate the utility of the Stroop Test (ST) in differentiating SLD from ADHD. Methods: A total of 79 patients (42 with ADHD and 37 with ADHD and SLD) participated in the study. ST performance metrics (completion time, errors, and corrections) were collected by a child and adolescent psychiatrist. Additionally, parents completed the Turgay Diagnostic and Statistical Manual of Mental Disorders ADHD Rating Scale to assess the severity of ADHD symptoms. Results: The ADHD+SLD group exhibited longer completion times across all sections of the ST. Errors in the third, fourth, and fifth sections were significantly higher in the ADHD+SLD group. After adjusting for age, gender, and ADHD symptom severity, the completion time in the fifth section remained significant. Receiver operating characteristic (ROC) analysis identified cut-off scores for the fifth section's completion time (42 seconds; sensitivity: 0.62, specificity: 0.66) and errors (1 error; sensitivity: 0.64, specificity: 0.61). Moreover, errors in the fifth section predicted being in the ADHD+SLD group (p =.006, odds ratio [OR] = 1.527). Conclusion: The findings suggest that the ST may be a valuable tool for diagnosing SLD in patients with ADHD. In particular, the completion time and errors in the fifth section of the ST may serve as useful tools in supporting the diagnostic process.