title: Factorial validity and measurement invariance of the 20-item Toronto Alexithymia Scale in clinical and nonclinical samples.
abstract: The most widely used instrument to measure alexithymia is the 20-item Toronto Alexithymia Scale (TAS-20). However, different factor structures have been found in different languages. This study tests six published factor models and metric invariance across clinical and nonclinical samples. It also investigated whether there is a method effect of the negatively keyed items. Second-order models with alexithymia as a higher order factor are tested. Confirmatory factor analyses showed that the original factor model with three factors-difficulty identifying feelings (DIF); difficulty describing feelings (DDF) and externally oriented thinking (EOT)-is the best fitting model. Partial measurement invariance across samples was illustrated but requires further study. A weakness of the model is the low internal consistency of the third factor. Because models with a method factor had a better fit, future reconsideration of the negatively formulated items seems necessary. No evidence was found for the second-order models.
authors.affiliation: Ghent University, Faculty of Psychology and Educational Services, Department of Psychoanalysis and Clinical Consulting, Ghent, Belgium. Reitske.Meganck@UGent.be
authors.forename: Reitske
authors.initials: R
authors.lastname: Meganck
authors.forename: Stijn
authors.initials: S
authors.lastname: Vanheule
authors.forename: Mattias
authors.initials: M
authors.lastname: Desmet
mesh_terms: D000328:Adult; D000342:Affective Symptoms / Q000523:psychology*; D005260:Female; D006801:Humans; D008297:Male; D008960:Models, Psychological; D010556:Personality Tests