the characteristics described in kanner's first paper on the subject, notably "autistic aloneness" and "insistence on sameness", are still regarded as typical of the autistic spectrum of disorders. starting in the late 1960s, classic autism was established as a separate syndrome. it took until 1980 for the dsm-iii to differentiate autism from childhood schizophrenia. in 1987, the dsm-iii-r provided a checklist for diagnosing autism. in may 2013, the dsm-5 was released, updating the classification for pervasive developmental disorders. the grouping of disorders, including pdd-nos, autism, asperger syndrome, rett syndrome, and cdd, has been removed and replaced with the general term of autism spectrum disorder.