Parent-Reported Developmental Regression in Autism: Epilepsy, IQ, Schizophrenia Spectrum Symptoms, and Special Education.

Examined the psychiatric and clinical correlates of loss of previously acquired skills (regression) as reported by parents of youth with autism spectrum disorder (ASD). Study sample comprised 6- to 18-year old (N = 213) children and adolescents with ASD. Parents reported regression in 77 (36%) youth. A more homogeneous subgroup with regression between 18 and 36 months (n = 48) had higher rates of intellectual disability, epilepsy, and special education, more socially restrictive educational settings, and more severe ASD communication deficits and schizophrenia spectrum symptoms than non-regressed youth (n = 136). Similar results were obtained for a more inclusive definition of regression (n = 77). A brief parent report of developmental regression may be a useful clinical indicator of later general functioning.