Formal Thought Disorder in Schizophrenia: A Problematic History

It appears that some features of communication in schizophrenia, but not others, have been selected at different points in time for clinical and research use without realizing that by carrying out that selection, the phenomenon under study itself is changed. Remarkably, some theories of FTD remained in use, despite being empirically disproved (eg, word association disorder, concrete thinking, paralogical thinking) or despite its highly problematic and discriminatory nature. We would suggest that studies of FTD should explicitly consider which and why some of its features are included or excluded when assessing it. Furthermore, we would suggest that the study of FTD should incorporate the complexity of human communication, including the pragmatic, paralinguistic, non-verbal, and cognitive dimensions of the localized and unique situation where it takes place.