Toronto Alexithymia Scale
Overview
The Toronto Alexithymia Scale (TAS) is the most widely used measure of alexithymia, a personality trait characterised by the difficulty in identifying and describing emotions. The scale provides a standardised, self-report method for assessing emotional awareness and has been used extensively in psychology research and clinical practice.{{Cite journal |last1=Bagby |first1=R. Michael |last2=Parker |first2=James D. A. |last3=Taylor |first3=Graeme J. |date=1994-01-01 |title=The twenty-item Toronto Alexithymia scale—I. Item selection and cross-validation of the factor structure |url=https://linkinghub.elsevier.com/retrieve/pii/0022399994900051 |journal=Journal of Psychosomatic Research |volume=38 |issue=1 |pages=23–32 |doi=10.1016/0022-3999(94)90005-1 |pmid=8126686 |issn=0022-3999}} The current version, the TAS-20, includes 20 items addressing three core dimensions of alexithymia .
The TAS-20 is useful for screening individuals for alexithymia, assisting with clinical formulation and predicting therapy outcomes. High alexithymia scores have been linked to premature termination of psychotherapy, difficulty establishing therapeutic alliances and poorer emotional insight.{{Cite journal |last1=Ogrodniczuk |first1=John S. |last2=Piper |first2=William E. |last3=Joyce |first3=Anthony S. |date=2011 |title=Effect of alexithymia on the process and outcome of psychotherapy: A programmatic review |url=https://linkinghub.elsevier.com/retrieve/pii/S016517811000185X |journal=Psychiatry Research |language=en |volume=190 |issue=1 |pages=43–48 |doi=10.1016/j.psychres.2010.04.026|pmid=20471096 }} The scale can act as an early indicator of therapy challenges, allowing clinicians to tailor interventions to address emotional deficits. Research suggests that improving emotional identification and awareness can lead to better emotional regulation and reduced psychological distress.{{Cite journal |last1=Bagby |first1=R. Michael |last2=Parker |first2=James D. A. |last3=Taylor |first3=Graeme J. |date=2020-04-01 |title=Twenty-five years with the 20-item Toronto Alexithymia Scale |url=https://linkinghub.elsevier.com/retrieve/pii/S002239991931178X |journal=Journal of Psychosomatic Research |volume=131 |pages=109940 |doi=10.1016/j.jpsychores.2020.109940 |pmid=32007790 |issn=0022-3999}}
Research using the TAS-20 has consistently shown elevated alexithymia scores in individuals with various mental health disorders, including eating disorders, depression, anxiety disorders, substance use disorders and somatoform disorders. These findings have been interpreted as evidence of the association between alexithymia and mental health conditions.{{Cite journal |last1=Leweke |first1=Frank |last2=Leichsenring |first2=Falk |last3=Kruse |first3=Johannes |last4=Hermes |first4=Sandra |date=2012 |title=Is Alexithymia Associated with Specific Mental Disorders |url=https://karger.com/article/doi/10.1159/000325170 |journal=Psychopathology |language=en |volume=45 |issue=1 |pages=22–28 |doi=10.1159/000325170 |pmid=22123513 |issn=0254-4962}}
The TAS-20 is also used in medical settings to explore links between alexithymia and psychosomatic symptoms, chronic pain and cardiovascular health. This highlights its broader relevance beyond mental health alone.
Development and History
The current version, known as the 20-item Toronto Alexithymia Scale (TAS-20), was developed in 1994 by Michael Bagby, James Parker and Graeme Taylor, after the previous 26-item Toronto Alexithymia Scale (TAS-26) was found to have psychometric limitations. The revised 20-item version (TAS-20) improved validity and reliability and established a three-factor structure.
In the years since its publication, the English version of the TAS-20 has been translated into more than 30 languages (pdfs of translated versions can be found [https://contextualscience.org/TAS_Measure here]) and there are many papers on their validity across diverse cultural contexts.{{Cite journal |last1=González-Arias |first1=Mauricio |last2=Martínez-Molina |first2=Agustín |last3=Galdames |first3=Susan |last4=Urzúa |first4=Alfonso |date=2018-06-12 |title=Psychometric Properties of the 20-Item Toronto Alexithymia Scale in the Chilean Population |journal=Frontiers in Psychology |language=English |volume=9 |page=963 |doi=10.3389/fpsyg.2018.00963 |doi-access=free |issn=1664-1078 |pmc=6005868 |pmid=29946289}}
The TAS-20 is primarily administered to adults as the developers advised caution in diagnosing alexithymia in individuals under 17 years old. A version for children, the Children Alexithymia Scale (CAS), was developed but has demonstrated weaker psychometric properties compared to the adult version.
Structure, Scoring and Interpretation
The TAS-20 is composed of 20 items assessing three different factors, each representing a different subscale:
- Difficulty Identifying Feelings (DIF): Items 1, 3, 6, 7, 9, 13, 14.
- Difficulty Describing Feelings (DDF): Items 2, 4, 11, 12, 17.
- Externally Oriented Thinking (EOT): Items 5, 8, 10, 15, 16, 18, 19, 20.
Respondents rate each item on a five-point Likert scale, ranging from “strongly disagree” to “strongly agree”. Five items are reversed scored: 4, 5, 10, 18 and 19. The TAS-20 takes approximately 5-10 minutes to complete and can be administered online or in paper form.
Examples of TAS-20 items include:
- “I am often confused about what emotions I am feeling” (Item 1).
- “It is difficult for me to find the right words for my feelings” (Item 2).
- “I prefer to analyse problems rather than just describe them” (Item 5).
Scores range from 20 to 100, with the higher scores indicating greater levels of alexithymia. Interpretation follows these cut-offs:
- 0 – 51 = No alexithymia
- 52 – 60 = Possible alexithymia
- 61 – 100 = Present alexithymia
Subscale scores can provide insight into specific areas of emotional difficulty. The subscale with the higher score indicates the area where the individual experiences the greatest challenge. However, the total score is considered the most reliable estimate of alexithymia.
Psychometric properties
The TAS-20 has demonstrated good psychometric properties in both clinical and non-clinical populations. Research has shown that the scale has good levels of internal consistency, indicating that the items reliably measure the construct of alexithymia. Studies also support its test-retest reliability, suggesting that individuals’ scores remain relatively stable over short intervals of time.
Research supports the three-factor structure for the scale, reflecting the alexithymia construct. The TAS-20 scale also shows evidence of convergent validity and concurrent validity.
Additionally, a small statistically significant difference was found between the mean TAS-20 score for men (51.14) and women (48.99).
Limitations
Despite its widespread use, the TAS-20 has been criticised for several limitations. Research has shown that the Externally Oriented Thinking (EOT) subscale often demonstrates weaker internal consistency and factor loading compared to the other subscales. This issue is especially prevalent in many of the translated versions of the TAS-20 and leads to questioning this factor scale as a subscale.
Another limitation is the reliance on self-reported data to assess alexithymia. Critics argue that individuals high in alexithymia may lack the self-awareness necessary to accurately complete a questionnaire measuring their emotional difficulties.{{Cite journal |last1=Müller |first1=Jochen |last2=Bühner |first2=Markus |last3=Ziegler |first3=Matthias |last4=Şahin |first4=Lâle |date=2008-03-01 |title=Are alexithymia, ambivalence over emotional expression, and social insecurity overlapping constructs? |url=https://linkinghub.elsevier.com/retrieve/pii/S002239990700387X |journal=Journal of Psychosomatic Research |volume=64 |issue=3 |pages=319–325 |doi=10.1016/j.jpsychores.2007.10.005 |pmid=18291248 |issn=0022-3999}}{{Cite journal |last1=Lane |first1=Richard D |last2=Sechrest |first2=Lee |last3=Riedel |first3=Robert |date=1998-11-01 |title=Sociodemographic correlates of alexithymia |url=https://linkinghub.elsevier.com/retrieve/pii/S0010440X98900517 |journal=Comprehensive Psychiatry |volume=39 |issue=6 |pages=377–385 |doi=10.1016/S0010-440X(98)90051-7 |pmid=9829146 |issn=0010-440X}} This limitation was also acknowledged by the original authors early on.{{Cite book |last1=Taylor |first1=Graeme J. |url=https://www.cambridge.org/core/books/disorders-of-affect-regulation/4CF72A99726CDAC32080ACE36065E730 |title=Disorders of Affect Regulation: Alexithymia in Medical and Psychiatric Illness |last2=Bagby |first2=R. Michael |last3=Parker |first3=James D. A. |date=1997 |publisher=Cambridge University Press |isbn=978-0-521-77850-3 |location=Cambridge |doi=10.1017/cbo9780511526831}} To address this, the developers suggested supplementing the TAS-20 with interviews and developed the Toronto Structured Interview for Alexithymia.{{Cite journal |last1=Bagby |first1=R. Michael |last2=Taylor |first2=Graeme J. |last3=Parker |first3=James D.A. |last4=Dickens |first4=Susan E. |date=2005-12-16 |title=The Development of the Toronto Structured Interview for Alexithymia: Item Selection, Factor Structure, Reliability and Concurrent Validity |url=https://karger.com/pps/article-abstract/75/1/25/282172/The-Development-of-the-Toronto-Structured?redirectedFrom=fulltext |journal=Psychotherapy and Psychosomatics |volume=75 |issue=1 |pages=25–39 |doi=10.1159/000089224 |pmid=16361872 |issn=0033-3190}}
Related Measures
Other measures of alexithymia have been developed as alternatives or complements to the TAS-20. The Bermond-Vorst Alexithymia Questionnaire (BVAQ) assesses alexithymia across five dimensions and includes cognitive and affective components.{{Cite journal |last1=Vorst |first1=Harrie C. M |last2=Bermond |first2=Bob |date=2001-02-01 |title=Validity and reliability of the Bermond–Vorst Alexithymia Questionnaire |url=https://linkinghub.elsevier.com/retrieve/pii/S0191886900000337 |journal=Personality and Individual Differences |volume=30 |issue=3 |pages=413–434 |doi=10.1016/S0191-8869(00)00033-7 |issn=0191-8869}} While the BVAQ offers a broader theoretical scope, the TAS-20 remains more widely used due to its brevity and validated structure.