FTD can be subdivided into positive versus negative and objective versus subjective symptom clusters. Positive symptoms include derailment and loosening of associations, an increased amount of produced speech (e.g., logorrhoea, pressured speech), the use of new words (neologisms), and stilted speech phenomena (manneristic speech). Negative FTD has been conceptualized as a quantitative deficit in speech and thought production (e.g., poverty of speech, slowed thinking). Subjective positive FTDs include pressure of thoughts and thought interference. Subjective negative FTDs include inhibited thinking and dysfunction of thought initiative, respectively.1
Abbreviations: FTD=formal thought disorder
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