The objective of this study was to examine the psychometric properties and clinical correlates of the 20-item Toronto Alexithymia Scale (TAS-20) in patients with psoriasis.
Three hundred patients with psoriasis completed the TAS-20 and had the severity of their psoriasis clinically assessed. Test-retest reliability was assessed over 10 weeks in a subset of 71 patients receiving standard medical treatment for their psoriasis. Examination of the factor structure employed both exploratory (EFA) and confirmatory (CFA) factor analysis techniques.
The overall prevalence of alexithymia in this population of psoriasis patients, as indicated by the TAS-20, was 33%. The TAS-20 total score was not related to clinical severity, age, age at onset or duration of psoriasis. The 10-week test-retest reliability on a sample of 71 psoriasis patients, pre- and posttreatment with photochemotherapy, was found to be acceptable (r=.69; P<.001). EFA produced no stable solutions. The three-factor structure of the TAS-20 using CFA was also not replicable in this sample.
The findings of this study support the contention that alexithymia is not significantly influenced by either disease severity or chronicity in patients with psoriasis. It is recommended that when employing the TAS-20 in patients with psoriasis, caution is exercised in the interpretation of the scale scores and that further psychometric evaluation of the scale is undertaken as appropriate.