Pervasive developmental disorder and childhood-onset schizophrenia: comorbid disorder or a phenotypic variant of a very early onset illness?

Formal Thought Disorder and the Autism Spectrum: Relationship with Symptoms, Executive Control, and Anxiety

“…Consistent with this view, multiple studies have documented premorbid childhood social difficulties and oddness in individuals later diagnosed with schizophrenia (Schiffman et al 2004;Walker et al 1993);and Sporn et al (2004) found that ASD was present in 25% of a cohort of children diagnosed with early onset schizophrenia.…”

“…While the vast majority of individuals with autism do not have schizophrenia, it is noteworthy that approximately 25% of individuals with childhood onset schizophrenia meet lifetime diagnostic criteria for PDD (Sporn et al 2004). Future comparative studies of individuals with schizophrenia spectrum disorders and ASDs may further understanding of the relationships between context processing, disordered communication, restricted and repetitive behaviors, and the social impairment that is part of both disorders.…”

“…Initially, it was believed that autism was the earliest manifestation of schizophrenia, which then presented fully in late adolescence or early adulthood (Bender 1947). Later, Kolvin (1971) and Rutter (1972) suggested the two disorders were functionally distinct, and empirical research demonstrated that individuals diagnosed with autism did not develop schizophrenia at a rate higher than the general population (Mouridsen et al 1999;Sporn et al 2004;Volkmar and Cohen 1991).…”

“…Initially, it was believed that autism was the earliest manifestation of schizophrenia, which then presented fully in late adolescence or early adulthood (Bender 1947). Later, Kolvin (1971) and Rutter (1972) suggested the two disorders were functionally distinct, and empirical research demonstrated that individuals diagnosed with autism did not develop schizophrenia at a rate higher than the general population (Mouridsen et al 1999;Sporn et al 2004;Volkmar and Cohen 1991).More recently, it has been proposed that the presence of an autism spectrum disorder (ASD), including high functioning autism, Asperger's Disorder, and Pervasive Developmental Disorder Not Otherwise Specified (PDDNOS), may be a nonspecific marker of severe early abnormal neurodevelopment present in disorders including schizophrenia. Consistent with this view, multiple studies have documented premorbid childhood social difficulties and oddness in individuals later diagnosed with schizophrenia (Schiffman et al 2004;Walker et al 1993);and Sporn et al (2004) found that ASD was present in 25% of a cohort of children diagnosed with early onset schizophrenia.…”

“…When aspects of FTD are present in ASDs, they are not necessarily co-morbid schizophrenia spectrum symptoms, but likely are evidence of symptomatic overlap with the pragmatic language abnormalities inherent in Tager-Flusberg et al 2005). In this sample, in individuals with ASDs, impairments in cognitive control appear to be related to making illogical statements, whereas anxiety and autism symptoms appear to be more related to making loose and tangential statements.While the vast majority of individuals with autism do not have schizophrenia, it is noteworthy that approximately 25% of individuals with childhood onset schizophrenia meet lifetime diagnostic criteria for PDD (Sporn et al 2004). Future comparative studies of individuals with schizophrenia spectrum disorders and ASDs may further understanding of the relationships between context processing, disordered communication, restricted and repetitive behaviors, and the social impairment that is part of both disorders.…”