Autism in schizophrenia and its original link to self-disorder: returning a borrowed concept

Autism was introduced by Eugen Bleuler in 1910 as a defining feature of schizophrenia, and it remained so for 80 years. However, the concept was borrowed by Leo Kanner and Hans Asperger to describe another condition (infantile autism) and eventually awareness of autistic features in schizophrenia declined. Today, autistic features are by default considered indicative of autism spectrum disorder, and patients with schizophrenia, who exhibit autistic features, risk being misdiagnosed with autism spectrum disorder and receiving inadequate treatment. To aid differential diagnosis and treatment, it is important to rediscover what autism in schizophrenia is, and how it differs from autism spectrum disorder. We present a reading of the seminal works that shaped the understanding of autism in schizophrenia and extract four key insights: autistic features are common in schizophrenia; autistic features are found both in behaviours and experiences; autism in schizophrenia can be defined as a frail immersion in the lifeworld, manifesting as a pervasive inability to take for granted what others consider matter of fact; and autism is hypothesised to be caused by self-disorder. Contemporary psychopathological research corroborates the idea that autism is caused by self-disorder, a concept that could substantially aid differential diagnostic resources.