Discourse cohesion in the verbal interactions of individuals diagnosed with autistic disorder or schizotypal personality disorder

Autistic disorder and schizotypal personality disorder have been characterised as social communication spectrum disorders. However, it is not clear whether, or by what parameters, the two disorders differ with regard to social use of language. This study compares highfunctioning adolescents with autism and cognitively similar adolescents with schizotypal personality disorder in one aspect of social language use, namely referencing. Cohesion analysis is used to examine pronominal, demonstrative, and comparative references in dialogue from semi-structured interviews. The study finds that adolescents with schizotypal personality disorder use cohesiveties of reference more often and more correctly than do the adolescents with autism. However, both groups have similar rates, types, and patterns of cohesive reference errors. These results indicate that referencing skills in individuals with autism and schizotypal personality disorder are faulty in similar ways, producing similar disruptive effects on the smooth flow of discourse. The results lend support to the concept of a continuity of deficits in social language use in autism and schizotypal personality disorder.