Prevalence of autism in first-episode psychosis in two Hong Kong teaching hospitals
Authors: Kwok Terence TY , Chan Melody MY , Mo Flora YM , Hung Se-Fong , Leung Patrick WL , Lai Kelly YC , Shea Caroline KS 
Published: June 2024

This study estimated the prevalence of autism spectrum disorder in a 5-year inpatient cohort of children and adolescents diagnosed with first-episode psychosis in two Hong Kong teaching hospitals, and explored the clinical characteristics predicting first-episode psychosis–autism spectrum disorder comorbidity. The autism spectrum disorder diagnoses of 103 patients with first-episode psychosis were confirmed by Autism Diagnostic Interview–Revised. Based on the (1) Diagnostic and Statistical Manual of Mental Disorders (5th ed.) diagnostic checklist and (2) Autism Diagnostic Interview–Revised, three major observations were reported: (1) the prevalence of autism spectrum disorder among children and adolescents with first-episode psychosis was 28.2% (95% confidence interval = (19.7%, 37.9%)); (2) after administering the Autism Diagnostic Interview–Revised, an additional 31.0% of first-episode psychosis patients met the clinical diagnostic cut-off for autism spectrum disorder; and (3) multivariate binary logistic regression analysis showed that first-episode psychosis patients with a comorbid autism spectrum disorder diagnosis were more likely to be a male than a female (adjusted odds ratio = 3.57, 95% confidence interval = (1.29, 9.86), p = 0.014). Adding to the current literature, this study examined first-episode psychosis–autism spectrum disorder comorbidity with a large Chinese, inpatient sample with first-episode psychosis. Consistent with studies conducted overseas, we show that autism spectrum disorder is a common comorbidity among Chinese first-episode psychosis patients. A comprehensive autism spectrum disorder assessment that incorporates both observation-based and parent-report diagnostic tools is warranted for children and adolescents, especially boys, with psychosis. Lay abstract Autistic features are commonly observed in children and adolescents with first-episode psychosis, but they are sometimes overlooked by clinicians and caregivers. By comprehensively examining the clinical profiles of 103 children and adolescents (below 18 years old) with first-episode psychosis and conducting the Autism Diagnostic Interview–Revised (the ‘gold standard’ autism diagnostic tool) with their primary caregivers, we showed that around 28% of patients with first-episode psychosis had a comorbid autism diagnosis, and boys were 3.57 times more likely to have first-episode psychosis–autism spectrum disorder comorbidity than girls. After administering the Autism Diagnostic Interview–Revised, we also observed that an additional 30% of patients with first-episode psychosis met the autism spectrum disorder diagnostic cut-off; their autism spectrum disorder symptoms were probably overshadowed by prodromal psychotic symptoms and left undetected before this study. The co-occurrence of autism and first-episode psychosis might be more common than we previously thought. Careful autism screening and assessment is highly recommended for clinicians working with patients with psychosis.