To the Editor.鈥�听
There is perhaps more diversity in the language used to describe "formal thought disorder" than in any other aspect of psychopathology. This diversity is confusing to students and residents, as well as their "superiors," and significantly impairs communication in both clinical work and research. The letter by Michael Taylor and the scale by Endicott and Spitzer1 to which he refers are fine illustrative examples. Endicott and Spitzer, working from a Kraepelinian and Bleulerian tradition, describe five types of formal thought disorder in the Research Diagnostic Criteria: incoherence, loosening of associations, illogical thinking, poverty of content of speech, and neologisms. Taylor, working from the German Phenomenological tradition, proposes such alternatives as paraphasias, drivelling, nonsequitive speech, verbigeration, and tangential speech. Other investigators, such as Harrow and Prozen or Chapman and Chapman, have emphasized bizarre associations or intermingling2 or illusory correlations.3The diversity is due to many factors. One major