The purpose of this study was to assess alexithymia in adolescents and to compare the findings to previous findings for adults, taking into account the contribution of linguistic ability to alexithymic traits. We also sought to examine the criterion-related and discriminative validity of the self-reported TAS-20-based questionnaire, QAAA, for adolescents.
An exploratory factor analysis found the QAAA to be comprised of four factors: DIF, EOT, CIC, and DDF. These four factors correspond to the original four facets of the alexithymia construct : (a) difficulties in identifying feelings and in discriminating between emotions and physical sensations, (b) an externally oriented cognitive style, (c) constricted imaginal capacity, and (d) difficulties in describing feelings. In contrast to previous findings regarding EOT , we found that the factor loadings onto EOT were satisfactorily robust, thus confirming a four factor structure. This structure also has satisfactory reliability, although the MIC of DDF was slightly high, possibly because there were fewer DDF items in comparison with the other factors.
We found that DIF/DDF and EOT/CIC were negatively correlated: The higher scores should convey a deficit in cognition concerning emotions for all four factors related to alexithymia; DIF DDF, EOT and CIC. However, participants who had difficulties with identifying or describing their feelings had (paradoxically) a greater imaginal capacity and reported being more in tune with their inner experiences. These results were apparently different from the adult findings. Because positive correlations were reported between DIF/DDF and EOT among adults [8, 28], this striking contrast in the current study may reflect differences in the developmental process between DIF/DDF and EOT, as we recently reported in a community sample . It is possible that alexithymic adolescents, lacking skill at introspection, may overestimate their imaginal capabilities and ability to get in touch with their internal experiences. These findings, however, do not suggest that DIF and DDF scores are of no meaning; as would be the case if the items of the QAAA were not understood by the subjects, who would then answer in a more or less random way, but in fact were answered in an unexpected reverse way.
Higher Japanese linguistic ability was found to be associated with lower EOT and CIC scores but with higher DDF scores, suggesting that subjects with lower linguistic ability do not look much into their inner experiences or cultivate much imagination. In addition, positive correlations between linguistic scores and DDF scores indicated that those with higher linguistic ability attempt to describe their feelings with appropriate words. A positive correlation between DIF scores and emotional understanding [1, 19] was reported among primary school-age children; however, no such association was found in the present study, suggesting that this ability has no effect on the emotional awareness of adolescents. However, it is possible that this disparity may reflect the different educational system in Japan, or perhaps difficulties with the linguistic ability questionnaire itself.
Female students scored higher for difficulties in identifying and describing feelings than did males, but showed more interest in their internal experiences and greater self-reported imaginative ability. No linguistic abilities affected these gender differences. It presents, however, doubt about whether females were not as good at identifying inner emotions, as we recently found higher DIF scores for female adult subjects . These lines of evidence clearly support the validity issue of DIF/DDF factors in the self-reported questionnaire. Furthermore, regarding EOT, male adolescents were more externally-oriented, as previously reported in studies of adult males in Asian countries [10, 29]. Additional cross-cultural and developmental studies on gender differences will be needed to clarify possible cultural influences on alexithymic tendencies among adolescents.
As for criterion-related validity, the various factors of the multi-dimensional empathy scale for adolescents showed negative correlations with EOT and CIC scores, consistent with previous findings with adults . Students with lower levels of internal focus or with poor imaginations may have lower empathic abilities, and their attention toward psychological processes may be key in terms of the development of various aspects of emotional ability (e.g., emotional intelligence or emotional awareness) . This line of evidence suggests that the cultivation of interest in inner experiences or imagination during adolescence should not be neglected.
DIF and DDF scores were positively associated with scores on the multi-dimensional empathy scale for adolescents. Those who reported having difficulty identifying and describing their feelings were more empathic, inconsistent with earlier studies of adult subjects: While high 'personal distress' scores predicted high DIF and DDF scores, high 'empathic concern' predicted low DDF scores. High 'perspective taking' (corresponding to 'cognitive empathy' in the current study) predicted low DIF scores . Thus, the criterion-related validity of the DIF/DDF factors was not confirmed for early adolescent subjects using the present questionnaire, indicating that the present DIF/DDF items did not adequately assess difficulty in identifying/describing their feelings.
The items of the DIF and DDF subscales ask about one's meta-cognition: In this case, cognition about one's feelings . However, meta-cognitive skill is generally still developing during adolescence . Thus, as suggested by Müller et al. , it may be difficult to examine whether or not early adolescent subjects have identified and correctly described their feelings, especially by self-report. A high score on DIF may reflect a) actual difficulty identifying feelings that can be verified using objective measures, or b) subjective difficulty in identifying feelings that might be reported among those who have more objective talent. This view is supported by a previous report that alexithymia rates in general decreased from early to middle adolescence , consistent with the view that metacognitive ability develops during this time. The current unexpected results, such as the negative correlations between DIF/DDF and EOT/CIC, as well as the positive correlations between linguistic ability and DDF, may reflect inadequate metacognitive abilities among this age group. These results suggest that it is difficult to assess such characteristics in early adolescent subjects by self-reported questionnaire.
Test-retest reliability coefficients showed significant and high correlations, except for DDF. This is likely because this scale consisted of only two items. It will be necessary to develop further items for this scale for use in future studies.
The patients with psychosomatic and/or behavioral problems were significantly more likely to report difficulty in identifying feelings than the normative subjects, irrespective of linguistic ability. Consistent with previous studies, difficulty identifying feelings contributed in large part to the prediction of somatic complaints among children  and adults . These lines of evidence do appear to support the discriminative validity of the questionnaire. However, as noted earlier, the higher DIF scores for patients do not necessarily indicate that they are alexithymic. The number of somatic complaints reported was not associated with difficulty identifying emotions, but was instead associated with the content of reported emotion (e.g., fear) . Moreover, previous studies of adults and adolescents have suggested a relationship between DIF scores and depression and/or anxiety [28, 34], suggesting that somatic symptoms are affected by negative mood even when alexithymia scores are high [35–37]. The TAS questionnaire appears to reflect specific aspects of depression or general distress, and a tendency to access and express negative emotions [38–40]. The evidence suggests that our depressed patients were rather self-critical, and their responses on the questionnaires may have reflected this .
In summary, the present findings suggest that alexithymia in early adolescents is not adequately assessed by current self-report questionnaires based on the TAS-20. This is particularly the case for the DIF and DDF subscales. In the current study more than half of the items were eliminated after exploratory factor analysis due to low factor loadings, suggesting the necessity of modifying the content of these subscales or perhaps creating a new item pool.
On the basis of our observations, we conclude that self-report questionnaires for the measurement of alexithymia in early adolescents require further careful investigation; performance measures will be needed. Moreover, the present findings also suggest that the assessment of metacognitive ability and other emotional abilities (even among adult populations) merit further research attention. Finally, although alexithymia has been considered to be a universal characteristic, the present results suggest the possibility of different developmental trajectories of alexithymia as a function of culture.