Factor Structure of the Greek Translation of the Scale for the Assessment of Thought, Language and Communication

Abstract

The Scale for the Assessment of Thought, Language and Communication (TLC) is a widely used instrument for the assessment of formal thought disorder. TLC disorders were initially conceptualized as having only two underlying dimensions, a negative and a positive one. But studies of the factorial structure of the TLC have not provided confirmation for the positive-versus-negative distinction. The aim of the present study was to assess the factorial structure of the Greek translation of the TLC. Subjects were 103 patients (69 male, 34 female) with psychotic disorders randomly recruited from both inpatient and outpatient facilities. The TLC was assessed by two raters based on a 20 min clinical interview. Principal component analysis with varimax rotation yielded a three-factor structure; the three factors consisted off items reflecting (i) disorganization of speech; (ii) peculiarities of speech; and (iii) verbosity. The disorganization factor could be further divided into two dimensions reflecting disturbances in the flow of ideas and in the structure of speech. The investigation of the factorial structure of the Greek translation of the TLC scale found no support for the positive-versus-negative distinction of TLC disorders. Three factors (disorganization, speech peculiarities, and verbal productivity) were found to underlie the variance of the scale.