Network Analysis of Language Disorganization in Patients with Schizophrenia.

Language disorganization, an objective component of formal thought process abnormality, has been regarded as a core symptom of schizophrenia from an evolutionary psychopathology perspective. However, to the best of our knowledge, the network structure of language disorganization has rarely been examined in patients with schizophrenia. Thus, our preliminary study aimed to evaluate the network structure using the Clinical Language Disorder Rating Scale (CLANG) in 167 inpatients with schizophrenia. All 17 of the CLANG items were considered to be ordered categorical variables ranging from 0 to 3. Our results indicated that disclosure failure, excess syntactic constraints, abnormal prosody, and aprosodic speech rank among the top five central domains within the network structure. We deemed that disclosure failure and prosody problems are the most important symptoms of language disorder in schizophrenia. Thus, reduced top-down processing of linguistic information may be a core neurobiological underpinning of language disorganization in schizophrenia. Further studies controlling for the potential effects of confounding factors (i.e., duration of illness) on network analyses of language disorder and formal thought disorder are warranted in patients with schizophrenia.