A rating scale for the assessment of objective and subjective formal Thought and Language Disorder (TALD)

Abstract

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.

Distinct Neuropsychological Correlates in Positive and Negative Formal Thought Disorder Syndromes: The Thought and Language Disorder Scale in Endogenous Psychoses

“…The TALD scale was found to be a reliable and nosologically open instrument to account for the multidimensionality of FTD in different diagnostic study samples [9]. Neuroimaging investigations may further help to identify a differential neurobiological basis of these clinical phenotypes.…”

“…TALD scores were calculated according to the following 4 dimensions [9]: factor I = objective positive (OP); factor II = subjective negative (SN); factor III = objective negative (ON), and factor IV = subjective positive (SP). Mean scores for each dimension were individually calculated and used for the subsequent correlation analysis.…”

“…These assessment procedures differ with respect to interview length, the number of FTD phenomena, and nosological openness among different patient groups. The nosologically open Rating Scale for the Assessment of Objective and Subjective Formal Thought and Language Disorder (TALD) [9] revealed excellent psychometric properties covering the full variety of FTD symptoms. The scale encompasses operationalized definitions, descriptions of symptom severity, exemplary questions allowing exact coding and separation from other phenomena, examples and particularly the inclusion of subtle subjective FTD symptoms.…”

Systems Neuroscience of Psychosis: Mapping Schizophrenia Symptoms onto Brain Systems

“…This operational definition has been systematically realized in the BPS. It is also consistently reflected in other modern instruments for assessing FTDs, including the Scale for the Assessment of Thought, Language and Communication (TLC) [75], the Thought and Language Index (TLI) [76], or the rating scale for the assessment of objective and subjective formal Thought and Language Disorder (TALD) [77]. However, only the BPS and the TALD include different dimensions of FTDs.…”

The impact of thought disorder on therapeutic alliance and personal recovery in schizophrenia and schizoaffective disorder: An exploratory study

“…The study had some shortcomings which are important to consider: First, thought disorder was assessed by a general psychopathology scale (Wallwork et al, 2012) and not a symptom specific measure, such as the Thought, Language, and Communication (TLC) scale (Andreasen, 1979) or the Thought and Language Disorder (TALD) scale (Kircher et al, 2014). However, the PANSS Disorganization/Concrete subscale has been successfully used in other empirical studies investigating thought and language disorder in patients with psychosis (e.g.…”