From lumping to splitting and back again: Atypical social and language development in individuals with clinical-high-risk for psychosis, first episode schizophrenia, and autism spectrum disorders

Objective: Individuals with autism and schizophrenia exhibit atypical language and social symptoms. The extent to which these symptoms are evident during development and in current functioning is unclear. Method: Three groups of patients aged 11-20 diagnosed as clinical-high-risk for psychosis (CHR; n = 15), first episode psychosis (FEP; n = 16), and autism spectrum disorders (ASD; n = 20), plus typically developing individuals (TYP; n = 20) were compared on common autism parent-report questionnaires assessing social and language development and current functioning including the Social Communication Questionnaire, the Children's Communication Checklist, and the Social Reciprocity Scale. Results: All clinical groups demonstrated atypical social and language development, with social impairment highest in ASD. Twenty percent of participants with CHR and FEP met diagnostic criteria for ASD as assessed by parent-report. ASD exhibited greater current syntactic, and pragmatic language symptoms including delayed echolalia, pedantic speech, and deficits in appreciating irony and sarcasm. All clinical groups exhibited current deficits in social functioning. CHR and FE had similar and intermediate levels of functioning relative to ASD and TYP, with CHR generally scoring closer to TYP, providing construct validity for the CHR diagnostic label. Conclusions: The results of this study suggest that ASDs, CHR, and FEP share common features of atypical neurodevelopment of language and social function. Evidence of impaired social reciprocity across both disorders and distinct language symptoms in ASDs provides important information for differential diagnosis and psychosis prevention, as well as leads for future investigations of comparative genetics and pathophysiology.