Chapter 6: Autism Spectrum Disorder and Childhood-Onset Schizophrenia

Autism Spectrum Disorder is characterized by persistent difficulties in social communication and interaction combined with restricted and repetitive behavioral patterns, with symptom presentation varying considerably across individuals along a spectrum. The DSM-5-TR diagnostic framework emphasizes these core features while recognizing different support levels, and contemporary discussions highlight the tension between identity-first and person-first language preferences, reflecting broader conversations within the autistic and clinical communities about how to appropriately describe lived experience. The etiology of ASD involves significant genetic contributions alongside environmental factors such as prenatal exposures and maternal health conditions, with cognitive mechanisms including deficits in Theory of Mind, executive function differences, and atypical central coherence contributing to the observed symptomatology. Interventions prioritize behavioral approaches, speech-language pathology, and educational supports aimed at building communication skills and social competence rather than eliminating autistic characteristics. Childhood-Onset Schizophrenia represents a rare and severe psychotic disorder emerging in early childhood, fundamentally distinct from ASD in its symptom profile, which includes prominent hallucinations, delusions, disorganized thinking, and progressive deterioration in academic and social functioning. With incidence rates below one per ten thousand children, COS involves a gradual onset pattern frequently preceded by early warning signs and is understood through a neurodevelopmental lens emphasizing gene-environment interactions, including genetic vulnerabilities, structural brain abnormalities, and prenatal or early childhood risk factors. Treatment approaches for COS incorporate antipsychotic medications, cognitive-behavioral interventions, social skills development, and family-based support to address psychotic symptoms and functional decline. Understanding the distinctions between these disorders in terms of cognitive presentation, symptom trajectories, and treatment responsiveness is essential for accurate differential diagnosis and appropriate clinical intervention.