Adolescents with childhood onset schizophrenia (COS) and adolescents with Asperger syndrome (AS) are characterized by impairments in pragmatics and in cognition.

The study of the specificity of pragmatic and cognitive deficits in COS and in AS is important to highlight some fundamental areas to each disorder and to refine behavioural phenotypes which may provide a link to gene-brain-behaviour.

The present study directly compares the pragmatic and cognitive functions in adolescents with COS and AS.

Twelve adolescents with COS and 14 adolescents with AS, matched on general IQ, verbal IQ and performance IQ, were compared. Pragmatics was explored by the Children's Communication Checklist, a parental report of language and communication in naturalistic context. Cognition was explored by Wechsler Intelligence Scale and by several specific tasks: Theory of Mind (ToM), Figurative Language Comprehension, executive functions (WCST), mental flexibility and working memory (TMT) and inhibition (Stroop).

Compared to adolescents with COS, adolescents with AS exhibited more severe pragmatic impairments in naturalistic context and had more reduced figurative comprehension. In contrast, compared to AS, adolescents with COS exhibited impaired inhibition and deficit in verbal reasoning (subtest “Similarities” of the Wechsler). Both groups had similar results on ToM, WCST and TMT tasks, and on the all other Wechsler’s subtests.

Despite some similarities, adolescents with AS and with COS differed when pragmatics was evaluated in naturalistic context. Cognitive impairments observed in inhibition and in verbal reasoning may be specifically related to thought disorder, a core feature of schizophrenia.