The Role of Early Diagnosis in Shaping Neurodevelopment, Social Integration, and Behavioral Outcomes in Children with Autism Spectrum Disorder: A Systematic Review

Abstract

Background: Autism Spectrum Disorder (ASD) is a neurodevelopmental disorder that includes arguments in favor of early diagnosis for improved results but also concerns about the early establishment of this diagnosis. The goal of this systematic review is to compare the results of early versus later diagnosis of ASD on neurodevelopment, social integration, and behavioral outcomes in children. Methods: A comprehensive literature search following the PRISMA guidelines was conducted in the PubMed, Scopus, Web of Science, and PsycINFO databases for themes surrounding the early detection of ASD, cognitive and language outcomes, and social adaptation. Results: Findings across the seven included studies comprising 1,047 children were mixed but revealed important trends. Earlier diagnosis of ASD (before the age of three but extending up to age seven in some studies) was often, though not universally, associated with improved cognitive development, language acquisition, school integration, and symptom reduction. However, outcomes varied by domain and intervention type. Conclusion: While heterogeneity exists in outcomes and age of early diagnosis, variations suggest that age, intervention type and individual variability may influence outcomes. Further studies are necessary to clarify the optimal age cutoffs for diagnosis, examine the interactions between diagnostic timing and intervention models, and track long-term outcomes across domains.