# Discriminant Validity of the 20-Item Toronto Alexithymia Scale and the Perth Alexithymia Questionnaire in Relation to Psychological Distress

## TL;DR

This study compares two alexithymia scales to see if they distinguish emotional difficulties from general psychological distress in a sample with psychiatric conditions.

## Contribution

The study challenges recent claims about the Toronto Alexithymia Scale's validity by replicating findings in a diverse sample.

## Key findings

- Both alexithymia measures showed moderate but distinct correlations with psychological distress.
- TAS-20 DIF items loaded exclusively on an emotional dysfunction factor, not distress.
- Findings support the discriminant validity of both scales against distress.

## Abstract

Recent investigations have questioned whether the Toronto Alexithymia Scale (TAS-20) distinguishes alexithymia from general psychological distress, with some researchers positioning the Perth Alexithymia Questionnaire (PAQ) as demonstrating superior discriminant validity. We evaluated both instruments in a community sample enriched with participants having psychiatric diagnoses or a treatment history (N = 681). Participants completed the TAS-20, PAQ, and Depression Anxiety Stress Scales-21 (DASS-21). Both alexithymia measures showed moderate correlations with the DASS-21, suggesting related but distinct constructs. Item-level exploratory factor analysis revealed a factor separation between general emotional dysfunction and distress, with no meaningful cross-loadings for TAS-20 Difficulty Identifying Feelings (DIF) items. At the subscale level, a two-factor solution supported distinct general emotional dysfunction and distress factors. In contrast to two recent investigations, the TAS-20 DIF subscale loaded exclusively on a general emotional dysfunction factor with negligible loading on a distress factor. These findings demonstrate that neither the TAS-20 nor the PAQ is compromised by distress, challenging recent claims of TAS-20 discriminant validity problems and underscoring the importance of replication across diverse samples and analytic methods.