Toronto Alexithymia Scale

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.^[1] 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.^[2] 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.^[3]

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.^[4]  

The TAS-20 is also used in medical settings to explore links between alexithymia and psychosomatic symptoms, chronic pain and cardiovascular health.^[3] 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.^[1] 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 ^[3] (pdfs of translated versions can be found here) and there are many papers on their validity across diverse cultural contexts.^[5]

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.^[3]

Structure, Scoring and Interpretation

The TAS-20 is composed of 20 items assessing three different factors, each representing a different subscale:

1. Difficulty Identifying Feelings (DIF): Items 1, 3, 6, 7, 9, 13, 14.
2. Difficulty Describing Feelings (DDF): Items 2, 4, 11, 12, 17.
3. 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).^[1][3]

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.^[3]

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.^[6][7] This limitation was also acknowledged by the original authors early on.^[8] To address this, the developers suggested supplementing the TAS-20 with interviews and developed the Toronto Structured Interview for Alexithymia.^[3][9]

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.^[10] While the BVAQ offers a broader theoretical scope, the TAS-20 remains more widely used due to its brevity and validated structure.