The alexithymia questionnaire for children (AQC): Psychometric properties in a sample of 105 adolescents hospitalized in an adolescent psychiatric department

The 20-item Toronto Alexithymia Scale (TAS-20) is the most widely used measure of alexithymia in non-clinical or clinical populations. The TAS-20 evaluates three dimensions of the alexithymia construct: the difficulty identifying feelings (DIF), the difficulty describing feelings (DDF) and externally oriented thinking (EOT). The TAS-20 is also used in adolescents or children, and the psychometric properties of the scale have not been systematically evaluated in these populations. Recently several studies have shown systematic age differences in the factor structure and a decrease of the quality of the measurement with age. Notably, low reliability measured by the Cronbach α coefficient has been found for the EOT factor. Taking into account the limitations of the TAS-20 in pre-adult populations the Alexithymia Questionnaire for Children (AQC), an adaptation of the TAS-20, has been proposed by a reformulation of the TAS-20 items (Rieffe et al., 2006). Two studies in healthy children found satisfactory psychometric properties with the three-factor structure demonstrating adequate parameters in the confirmatory factorial analyses (CFA). In the two studies low reliabilities of the EOT factor were reported, and recent studies in adolescents using the TAS-20 found that a two-factor model (DDF, DIF) had a better fit than the original three-factor model. Thus, the aim of the present study was firstly to verify the psychometric properties of the AQC in a sample of adolescents presenting various psychiatric disorders and secondly to test the adequacy of the bi- or tridimensional model of the scale. One hundred and five adolescents (27 males, 78 females) with a mean age of 15.06 years (sd=1.55, range: 12-18 years) were hospitalized in the adolescent psychiatric department of the Erasme Hospital (Bruxelles, Belgium) for various psychiatric disorders. The main diagnoses were: adjustment disorder (n=56, 53.5%), mood or anxiety disorders (n=17, 16.2%), impulse control disorder (n=11, 10.5%). The subjects completed the French version of the AQC. CFA were done testing the adequacy of the three or two-factor structure of the scale. Two indices were considered: the normed χ (ratio of χ and degrees of freedom) and the root mean square error of approximation (RMSEA). The values for acceptable fit were normed χ