Toronto Alexithymia Scale-20: Examining 18 Competing Factor Structure Solutions in a U.S. Sample and a Philippines Sample

What is the relationship between alexithymia and experiential avoidance? A latent analysis using three alexithymia questionnaires

Alexithymia is a clinically relevant personality trait characterized by poor emotional awareness and associated with several psychological and physical health concerns. Individuals with high alexithymia tend to engage in experiential avoidance and this may mediate psychological distress. However, little is known about what specific processes of experiential avoidance are involved, and the nature of the relation between alexithymia, experiential avoidance, and psychological distress remains unclear at a latent construct level. To examine this relationship at the latent construct level, a representative sample of 693 U.S. adults completed alexithymia (TAS-20, BVAQ, PAQ), general distress (DASS-21), multi-dimensional experiential avoidance (MEAQ), and general health (PROMIS-G-10) questionnaires. Structural equation modeling revealed that alexithymia significantly predicted experiential avoidance (β = 0.966, t = 82.383, p < .01), experiential avoidance significantly predicted general distress (β = 0.810, t = 2.017, p < .05), and experiential avoidance fully mediated the relationship between alexithymia and general distress (βindirect = -0.159, t = -0.398, p > .05). Correlations between alexithymia and experiential avoidance subfactors revealed a strong relationship to the repression and denial subfactor. Experiential avoidance is a promising target for clinical interventions, though longitudinal research is necessary to elucidate how the relationship between alexithymia and experiential avoidance unfolds over time.

Alexithymia and Impulsivity in Combat Sports - A Tale of Three Measures

The purpose of this study was to compare the psychometric properties of two measures of alexithymia - the Toronto Alexithymia Scale (TAS-20) and the Perth Alexithymia Questionnaire (PAQ) - as well as the Barratt Impulsiveness Scale 11 measure of behavioural impulsivity because the psychometric properties of these scales have not been established in athletes. As part of a larger study, 298 participants completed an online survey that included the TAS-20, PAQ, and BIS 11, as well personal- (age and gender) and sport-specific (primary combat sport and level of competition) demographic measures. A unidimensional model was retained for the TAS-20. A unidimensional model with the possibility of multidimensional measure was retained for the PAQ, with the viability of a subscale for Generalised Externally Orientated Thinking supported. The only versions of the BIS that were retainable were unidimensional models for the BIS-15 (a 15-item version of the BIS 11) and the BIS-Brief (an 8-item version of the BIS 11). As expected, the measures of alexithymia were highly correlated. The associations between impulsivity and alexithymia as well as age and alexithymia were small in nature, with none these associations moderated by level of gender, level of competition, or primary sport for the participants. No differences in alexithymia or impulsivity according to gender, level of competition, or primary sport were noted for the participants. Implications of these findings for the measures of alexithymia - the TAS-20 and PAQ - and impulsivity - the BIS-15 and BIS-Brief - examined in the present study with athletes (as well as with other populations) are discussed.

Bi-factor and Second-Order Copula Models for Item Response Data

Bi-factor and second-order models based on copulas are proposed for item response data, where the items are sampled from identified subdomains of some larger domain such that there is a homogeneous dependence within each domain. Our general models include the Gaussian bi-factor and second-order models as special cases and can lead to more probability in the joint upper or lower tail compared with the Gaussian bi-factor and second-order models. Details on maximum likelihood estimation of parameters for the bi-factor and second-order copula models are given, as well as model selection and goodness-of-fit techniques. Our general methodology is demonstrated with an extensive simulation study and illustrated for the Toronto Alexithymia Scale. Our studies suggest that there can be a substantial improvement over the Gaussian bi-factor and second-order models both conceptually, as the items can have interpretations of discretized maxima/minima or mixtures of discretized means in comparison with discretized means, and in fit to data.

Assessing Alexithymia across Asian and Western Cultures: Psychometric Properties of the Perth Alexithymia Questionnaire and Toronto Alexithymia Scale-20 in Singaporean and Australian Samples

Alexithymia refers to difficulties identifying feelings (DIF), describing feelings (DDF), and externally orientated thinking (EOT). Originally conceptualized by American psychiatrists, some researchers have since questioned the validity and application of this construct in Asian cultures. However, to date, there is little empirical work formally assessing the invariance of alexithymia across Asian and Western cultures. The present study aimed to help address this gap, by examining the psychometric properties and measurement invariance of two alexithymia measures, the Perth Alexithymia Questionnaire (PAQ) and Toronto Alexithymia Scale-20 (TAS-20), across samples from Singapore (n = 434) or Australia (n = 489). The same theoretically congruent factor structure was supported across both samples; this structure was fully invariant across samples for the PAQ, and partially invariant for the TAS-20. Both measures had good internal consistency and concurrent validity across samples, except the TAS-20 EOT subscale which had low internal consistency and factor loadings in both samples. The Singaporean sample reported higher DIF and DDF for positive emotions than the Australian sample. Overall, our results support the cross-cultural validity and application of the alexithymia construct. The PAQ and TAS-20 both appear to have good utility in this respect, though the PAQ may provide a more detailed facet-level profile.

Validation of the Affect Integration Inventory in a sample of patients with personality disorders: A cross-sectional study

Affect integration is defined as the capacity to comprehend emotional experiences as meaningful and to convert this knowledge into well-adjusted motivation, communication and behavior. Thus, affect integration is considered essential for personal adjustment and well-being, and it has been operationalized through the Affect Integration Inventory. However, the validity of this questionnaire has been examined only in non-clinical respondents. Therefore, the purpose of this study was to investigate the psychometric properties of the questionnaire in a sample of patients with personality disorders (n = 87). The internal structure and consistency were addressed using Cronbach's alpha and confirmatory factor analysis. To determine aspects of convergent and discriminant validity, the correlations between the scores on the questionnaire and the scores on content-related questionnaires and scales were examined. Finally, scores from the clinical respondents and existing data from a previously collected non-clinical sample (n = 157) were compared to evaluate the external validity. The overall results demonstrated satisfactory internal consistency, a consistent factor structure, and systematic patterns of convergent and discriminant validity. Additionally, the findings indicated that the instrument clearly differentiated the clinical sample from the non-clinical sample.

Psychometric evaluation of the Norwegian Toronto Alexithymia Scale (TAS-20) in a multisite clinical sample of patients with personality disorders and personality problems

OBJECTIVE

Psychometric properties of 20-item Toronto Alexithymia Scale (TAS-20) have been widely analyzed, but the validity and psychometric qualities of the TAS-20 in populations with personality disorders are still poorly understood. The aim of the current study was to analyze the factor structure and validity of TAS-20.

METHOD

Data were extracted from a multisite clinical sample of patients with personality disorders or personality-related problems referred to specialist mental health services in Norway.

RESULTS

With one exception, TAS-20 revealed acceptable psychometric properties. Variations of TAS-20 are associated with other clinical measures of distress and severity. Anxiety disorders, borderline, and avoidant personality disorders were all highly related to levels of TAS-20. The TAS-20 also revealed unique variance not accounted for by subjective distress, symptom disorders, or dysfunctional personality traits.

CONCLUSION

The TAS-20 is a relevant instrument for use in assessment of personality disorders, but one subscale should be improved.

Improving the measurement of alexithymia in autistic adults: a psychometric investigation of the 20-item Toronto Alexithymia Scale and generation of a general alexithymia factor score using item response theory

BACKGROUND

Alexithymia, a personality trait characterized by difficulties interpreting emotional states, is commonly elevated in autistic adults, and a growing body of literature suggests that this trait underlies several cognitive and emotional differences previously attributed to autism. Although questionnaires such as the 20-item Toronto Alexithymia Scale (TAS-20) are frequently used to measure alexithymia in the autistic population, few studies have investigated the psychometric properties of these questionnaires in autistic adults, including whether differential item functioning (I-DIF) exists between autistic and general population adults.

METHODS

This study is a revised version of a previous article that was retracted due to copyright concerns (Williams and Gotham in Mol Autism 12:1-40). We conducted an in-depth psychometric analysis of the TAS-20 in a large sample of 743 cognitively able autistic adults recruited from the Simons Foundation SPARK participant pool and 721 general population controls enrolled in a large international psychological study. The factor structure of the TAS-20 was examined using confirmatory factor analysis, and item response theory was used to generate a subset of the items that were strong indicators of a "general alexithymia" factor. Correlations between alexithymia and other clinical outcomes were used to assess the nomological validity of the new alexithymia score in the SPARK sample.

RESULTS

The TAS-20 did not exhibit adequate model fit in either the autistic or general population samples. Empirically driven item reduction was undertaken, resulting in an 8-item general alexithymia factor score (GAFS-8, with "TAS" no longer referenced due to copyright) with sound psychometric properties and practically ignorable I-DIF between diagnostic groups. Correlational analyses indicated that GAFS-8 scores, as derived from the TAS-20, meaningfully predict autistic trait levels, repetitive behaviors, and depression symptoms, even after controlling for trait neuroticism. The GAFS-8 also presented no meaningful decrement in nomological validity over the full TAS-20 in autistic participants.

LIMITATIONS

Limitations of the current study include a sample of autistic adults that was majority female, later diagnosed, and well educated; clinical and control groups drawn from different studies with variable measures; only 16 of the TAS-20 items being administered to the non-autistic sample; and an inability to test several other important psychometric characteristics of the GAFS-8, including sensitivity to change and I-DIF across multiple administrations.

CONCLUSIONS

These results indicate the potential of the GAFS-8 to robustly measure alexithymia in both autistic and non-autistic adults. A free online score calculator has been created to facilitate the use of norm-referenced GAFS-8 latent trait scores in research applications (available at https://asdmeasures.shinyapps.io/alexithymia ).

Improving the measurement of alexithymia in autistic adults: a psychometric investigation and refinement of the twenty-item Toronto Alexithymia Scale

BACKGROUND

Alexithymia, a personality trait characterized by difficulties interpreting one's own emotional states, is commonly elevated in autistic adults, and a growing body of literature suggests that this trait underlies a number of cognitive and emotional differences previously attributed to autism, such as difficulties in facial emotion recognition and reduced empathy. Although questionnaires such as the twenty-item Toronto Alexithymia Scale (TAS-20) are frequently used to measure alexithymia in the autistic population, few studies have attempted to determine the psychometric properties of these questionnaires in autistic adults, including whether differential item functioning (I-DIF) exists between autistic and general population adults.

METHODS

We conducted an in-depth psychometric analysis of the TAS-20 in a large sample of 743 verbal autistic adults recruited from the Simons Foundation SPARK participant pool and 721 general population controls enrolled in a large international psychological study (the Human Penguin Project). The factor structure of the TAS-20 was examined using confirmatory factor analysis, and item response theory was used to further refine the scale based on local model misfit and I-DIF between the groups. Correlations between alexithymia and other clinical outcomes such as autistic traits, anxiety, and quality-of-life were used to assess the nomological validity of the revised alexithymia scale in the SPARK sample.

RESULTS

The TAS-20 did not exhibit adequate global model fit in either the autistic or general population samples. Empirically driven item reduction was undertaken, resulting in an eight-item unidimensional scale (TAS-8) with sound psychometric properties and practically ignorable I-DIF between diagnostic groups. Correlational analyses indicated that TAS-8 scores meaningfully predict autistic trait levels, anxiety and depression symptoms, and quality of life, even after controlling for trait neuroticism.

LIMITATIONS

Limitations of the current study include a sample of autistic adults that was overwhelmingly female, later-diagnosed, and well-educated; clinical and control groups drawn from different studies with variable measures; and an inability to test several other important psychometric characteristics of the TAS-8, including sensitivity to change and I-DIF across multiple administrations.

CONCLUSIONS

These results indicate the potential of the TAS-8 as a psychometrically robust tool to measure alexithymia in both autistic and non-autistic adults. A free online score calculator has been created to facilitate the use of norm-referenced TAS-8 latent trait scores in research applications (available at http://asdmeasures.shinyapps.io/TAS8_Score ).

Assessing alexithymia in forensic settings: Psychometric properties of the 20-item Toronto Alexithymia Scale among incarcerated adult offenders

BACKGROUND

Alexithymia is a trait involving difficulty identifying feelings (DIF), difficulty describing feelings (DDF) and externally orientated thinking (EOT). It is a risk factor for criminal behaviour. It is commonly assessed with the Toronto Alexithymia Scale (TAS-20), but the psychometrics of the TAS-20 have not been tested across the range of offender populations, and it has been suggested it might be unsuitable in incarcerated offenders.

AIM

To establish the psychometrics of the TAS-20 among incarcerated offenders.

METHODS

Factorial validity was examined using confirmatory factor analyses, and the invariance of this factor structure was tested against a published community sample. Reliability coefficients were calculated.

RESULTS

One hundred and forty six incarcerated offenders were recruited. The factor structure of the TAS-20 was invariant across the samples. The intended factor structure composed of DIF, DDF and EOT factors performed well overall (with a reverse-scored method factor added), but six EOT items had low factor loadings. The total scale score and DIF and DDF subscales had acceptable reliability, but EOT did not.

CONCLUSIONS

Our results suggest that the TAS-20 functions similarly in offender and community samples. Its total scale score, and DIF and DDF subscale scores can be used confidently, but the assessment of externally oriented thinking may not be adequate with this scale alone. In sum, the TAS-20 can facilitate robust assessment of alexithymia in closed criminal justice settings as well as in the wider community.

Interoceptive Abilities in Inflammatory Bowel Diseases and Irritable Bowel Syndrome

Alexithymia is usually described by three main dimensions difficulty identifying feelings (DIF), difficulty describing feelings (DDF), and externally oriented thinking (EOT). The most commonly used questionnaire investigating alexithymia, the Toronto Alexithymia Scale (TAS-20), supports this three-factor structure. One important assumption is that alexithymia severity is associated to vulnerability to somatic diseases, among them gastrointestinal disorders. However, the association between alexithymia and gastrointestinal disorders is not systematic, thus questioning the role of alexithymia as a vulnerability factor for those illnesses. A recent factor analysis suggested another four-factor structure for the TAS-20: difficulties in awareness of feelings (DAF), difficulties in interoceptive abilities (DIA), externally oriented thinking (EOT), and poor affective sharing (PAS). We assume that DIA and DAF might be more relevant to investigate the association between alexithymia and gastrointestinal disorders. The rationale is that DIA and DAF reflect impairments in emotion regulation that could contribute to an inappropriate autonomic and HPA axis homeostasis in irritable bowel syndrome (IBS), ulcerative colitis (UC), or Crohn's disease (CD). The aim of this study was to investigate whether DIA and DAF are associated with the presence of IBS, UC or CD, while checking for anxiety, depression, parasympathetic (vagus nerve) activity and cortisol levels. We recruited control participants (n=26), and patients in remission who were diagnosed with IBS (n=24), UC (n=18), or CD (n=21). Participants completed questionnaires to assess anxiety, depression, and alexithymia. A blood sample and an electrocardiogram were used to measure the level of cortisol and parasympathetic activity, respectively. Logistic regressions with the four-factor structure of the TAS-20 revealed that DIA was a significant predictor of IBS (W(1)=6.27, p=.01). Conversely, DIA and DAF were not significant predictors in CD and UC patients. However, low cortisol level was a significant predictor of UC (W(1)=4.67, p=.035). Additional logistic regressions based on the original 3-factor structure of TAS-20 (DIF, DDF, and EOT) showed that only DDF was a significant predictor of CD [W(1)=6.16, p < .001]. The present study suggests that DIA is an important dimension for assessing potential risk for gastrointestinal diseases, in particular for IBS.