schizophrenia is a disorder of language?

Back in Sept 2007 Scientific American has an article on the potential evolution advantages of schizophrenia. The claim was that schizophrenia is a language disorder — hmm…
It’s No Delusion: Evolution May Favor Schizophrenia Genes: Scientific American
Co-author Crespi says that a number of theories have been floating around regarding the persistence of schizophrenia’s genetic underpinnings. One holds that schizophrenia is a "disorder of language" and that the illness is an unfortunate consequence of the development of human speech, expression and creativity. "Whenever you get strong selection, it’s like a big plus, and you can drag along a lot of minuses," he says. "You can think of schizophrenics as paying the price of all the cognitive and language skills that humans have—they have too many of the alleles that taken individually…might have positive effect, but together they are bad."