A – 63 Clinical Differentiation of Child Attention-Deficit/Hyperactivity Disorder and Autism Spectrum Disorder

Abstract Objective To examine key differentiating features between Attention-Deficit/Hyperactivity Disorder and Autism Spectrum Disorder across cognitive, behavioral, and neurobiological domains, with a focus on clinical assessment tools utilizing the diagnostic criteria outlined in the DSM-5-TR. Method A systematic literature review following PRISMA guidelines was conducted within PubMed, MDPI and PsychInfo databases. Documents were sourced using keywords “ADHD and ASD comorbidity”, “Cognitive Profiles in Neurodevelopmental Disorders, “ADOS Sensitivity” published between 2013 and 2024. The 37 articles meeting inclusion criteria examined the diagnostic process, cognitive and behavioral distinctions, or the clinical utility of standardized assessment tools. Priority was given to meta-analyses, systematic reviews, and empirical studies involving children. Results Age of first diagnosis is a strong predictor for comorbid conditions, and comorbidities may increase the likelihood of an ASD diagnosis. These factors contribute to higher rates of false positives, where symptoms of mood disorders, psychosis, eating disorders and other conditions are mistaken for ASD. The Autism Diagnostic Observation Schedule, Second Edition (ADOS-2) includes sensitivity which measures true positives, who test positive included as positive predictive value, and specificity which is a portion of true negatives who test negative included as negative predictive value. Diagnosing comorbid presentations in children and adolescents remains challenging, particularly when symptom overlap is not carefully evaluated. Conclusion Implications include the need for comprehensive, multidisciplinary assessments and the use of standardized measures that can distinguish between attentional and social communication impairments. Recognizing the nuances between ADHD and ASD is critical for accurate diagnosis, effective treatment planning, and improved developmental outcomes.