Psychometric evaluation of the Norwegian Toronto Alexithymia Scale (TAS-20) in a multisite clinical sample of patients with personality disorders and personality problems

OBJECTIVE

Psychometric properties of 20-item Toronto Alexithymia Scale (TAS-20) have been widely analyzed, but the validity and psychometric qualities of the TAS-20 in populations with personality disorders are still poorly understood. The aim of the current study was to analyze the factor structure and validity of TAS-20.

METHOD

Data were extracted from a multisite clinical sample of patients with personality disorders or personality-related problems referred to specialist mental health services in Norway.

RESULTS

With one exception, TAS-20 revealed acceptable psychometric properties. Variations of TAS-20 are associated with other clinical measures of distress and severity. Anxiety disorders, borderline, and avoidant personality disorders were all highly related to levels of TAS-20. The TAS-20 also revealed unique variance not accounted for by subjective distress, symptom disorders, or dysfunctional personality traits.

CONCLUSION

The TAS-20 is a relevant instrument for use in assessment of personality disorders, but one subscale should be improved.

Psychometric Properties of the 20-Item Toronto Alexithymia Scale in the Chilean Population

Alexithymia can be defined as inability to identify and describe emotions in the self. Has shown to be related to several psychological and pathological processes that can result in unsatisfactory interpersonal relationships and decreased social adjustment. Advances in research of alexithymia require the development and validation of assessment instruments, and its application to different population. With this aim, we studied the psychometric properties of the Twenty-Item Toronto Alexithymia Scale (TAS-20) in Chilean population using various modeling procedures (e.g., CFA, ESEM) in different structures (i.e., Correlated, Unidimensional, Hierarchical or Wording factors). Among the 10 models tested, the four-dimensional structure offered the best fit but with item-loading problems in the last factor (Pragmatic Thinking). We suggest that the studied version of the scale needs improvement (theoretical and empirical) to ensure optimal indices of validation for Chilean population.

Factorial validity and measurement invariance of the 20-item Toronto Alexithymia Scale in clinical and nonclinical samples

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.