Differential diagnosis of autism spectrum disorder, intellectual disability and attention-deficit hyperactivity disorder (ADHD)

Purpose Professionals working with community populations are often presented with complicated cases where it is difficult to determine which diagnosis or diagnoses are appropriate. Differentiating among neurodevelopmental disorders such as autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder and intellectual disability can be a complex process, especially, as these disorders have some overlapping symptoms and often co-occur in young children. This series of case studies aims to present commonly overlapping symptoms in children who present to clinics with developmental concerns. Design/methodology/approach This paper presents three case studies that were completed at a free community ASD screening clinic in Southern California. Findings The case studies have common presenting behaviors and symptoms (e.g. social communication difficulties) that often co-occur across diagnoses; explanations for the final diagnoses are given in each case. Research limitations/implications Conclusions from these three cases cannot generalize to all children being seen in clinics for neurodevelopmental concerns. Practical implications This series of case studies highlights commonly overlapping symptoms in children who present for differential diagnosis with social and/or behavioral concerns. Implications for educational placement and intervention are discussed. Social implications These cases highlight the challenges involved in the differential and dual diagnostic process for young children with developmental concerns. Diagnostic considerations can affect later educational placement and opportunities for socialization. Originality/value This series of case studies provide practical information for clinicians about how to effectively differentiate between commonly occurring neurodevelopmental disorders, particularly given recent changes to the Diagnostic and Statistical Manual, 5th edition (DSM-5).