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A rating scale for the assessment of objective and subjective formal Thought and Language Disorder (TALD)
Schizophrenia Research, Volume 160, Issue 1-3, December 2014, Pages 216 - 221
Formal thought disorder (FTD) is a core syndrome of schizophrenia. However, patients with other diagnoses, such as mania and depression amongst others, also present with FTD. We introduce a novel, comprehensive clinical rating scale, capturing the full variety of FTD phenomenology including subjective experiences.
The 30-item Thought and Language Disorder (TALD) scale is based on a detailed review of the literature, encompassing all formal thought disorder symptoms reported from the early 20th century onwards. Objectively observable symptoms as well as subjective phenomena were included. Two hundred and ten participants (146 patients ICD-10 diagnoses: depression n = 63, schizophrenia n = 63, mania n = 20; 64 healthy control subjects) were interviewed and symptoms rated with the TALD, TLC, HAMD, YMRS and SAPS/SANS. A principal component analyses was performed for the TALD to differentiate sub-syndromes.
The principal component analysis revealed four FTD factors; objective and subjective as well as positive and negative factor dimensions. The correlation analyses with the TLC and the SAPS/SANS FTD sub-scores demonstrated the factor validity for the objective factors. The different diagnoses showed a distinct pattern of symptom severity in each of the factors, with mania patients exhibiting the highest value in the positive, objective dimension.
The scale showed good psychometric results, which makes it a practicable, nosologically-open instrument for the detailed assessment of all FTD dimensions. The results strengthen the importance of subjective symptom assessment reported by the patient.
Keywords: Formal thought disorder, Schizophrenia, Mania, Depression, Principal component analyses.
a Department of Psychiatry and Psychotherapy, Philipps-University Marburg, Rudolf-Bultmann-Str. 8, 35039 Marburg, Germany
b Department of Neurology, University of Freiburg, Hauptstr. 5, 79104 Freiburg, Germany
c Department of English Literature & Linguistics, College of Arts & Sciences, Qatar University, PO Box 2713, Doha, Qatar
d Vitos Haina Forensic Psychiatric Hospital, Landgraf-Philipp-Platz 3, 35114 Haina, Germany
⁎ Corresponding author. Tel.: + 49 6421 58 66218; fax: + 49 6421 58 6893.
© 2014 Published by Elsevier B.V.