Thought disorder in schizophrenia. Testing models through confirmatory factor analysis

Theoretical and empirical models of thought disorder (ThD) were tested through Confirmatory factor analysis (CFA). A sample of 253 DSM-III-R acute schizophrenic patients consecutively admitted was studied. PI semistructured interview for schizophrenia was used for diagnosis, and ThD was assessed by means of the Thought, Language, and Communication scale (TLC). Nine ThD models comprising the 18 symptoms of the TLC were tested (ranging from a null model to a six-factor model). The six-dimension model achieved the best fit to the data, although no perfect fit was found. ThD dimensions included in this model were Disorganization, Negative, Idiosyncratic, Semantic, Attentional, and Referential dimensions. The TLC was close to capture adequately these underlying constructs. The Disorganization and the Negative dimensions received more validity on conceptual and psychometric grounds than the remaining dimensions. Thought Disorder multidimensional models fitted the data better than one-dimension models. Thought Disorder dimensions would be potential markers for biological, neurophysiological, and neuropsychological studies of schizophrenic disorder.