Perth Alexithymia Questionnaire

Abstract: The level of alexithymia affects a person’s mental and physical health. Nevertheless, this trait is still measured using unreliable tools. The Perth Alexithymia Questionnaire (PAQ) is a promising measuring tool, but no study has examined its psychometric characteristics using Item Response Theory (IRT). Thus, we aimed to explore the psychometric features of the PAQ using IRT and Classical Test Theory. A sample of Czech adults ( n = 848, age: M = 34.95, SD = 11.90, females: 81.13%) participated in an online survey. We measured alexithymia, empathy, sensory processing sensitivity (SPS), neuroticism, anxiety, and depression. Confirmatory factor analysis provided evidence of the good fit of a five-factor solution: Reliability of the PAQ was good (omega = 0.70–0.96). Measurement invariance testing revealed that the PAQ measures alexithymia invariantly between people who are single and in partnership. Partial invariance was found in sex. The PAQ items had high discrimination, and their measurement precision was highest in individuals with above-average alexithymia. Higher alexithymia was present in males. Finally, alexithymia was positively associated with depression, anxiety, and neuroticism, and with SPS after neuroticism was taken into account. In conclusion, the PAQ represents a reliable and valid instrument for assessing alexithymia.