Autism in Adults: A Survey - Part 3: Alexithymia
In this section, I will discuss a questionnaire about another common area of coexisting difficulty in autism - alexithymia.
Alexithymia, an impairment in the ability to recognize and analyze your own emotions, was assessed using the Toronto Alexithymia Scale - 20 (TAS-20), a 20-item self-report scale.
Scores on the TAS-20 ranged from 35-84, with a mean of 67.55+/-13.117. A score of 52-60 indicates possible alexithymia and 61 or higher indicates definite alexithymia. In this sample, 77.5% of participants showed definite alexithymia, 10% had possible alexithymia and 12.5% did not show alexithymia. Therefore, most of this sample had alexithymia. This is higher than both normal controls and addiction patients in Loas et (2001), who scored an average of 46.23+/-10.51 and 55.24+/-10.72, respectively. It is also higher than both the normal and HFA/AS samples in Silani et al (p < .001), who scored 43.7+/-12.7 and 55.6+/-9.7 respectively. In addition, it's significantly higher than Moriguchi et al (2007)'s non-alexithymic group (p < .001), who scored 34.1+/-3.7, but not significantly different from that study's alexithymic group (p = .489), who scored 66.1+/-4.5.
The TAS-20 items are divided into three subscales - difficulty describing feelings, difficulty identifying feelings, and externally-oriented. Difficulty describing items represented problems with talking about feelings to other people, difficulty identifying items represented confusion about your own internal emotional state, and externally-oriented represented a tendency to see feelings as unimportant and uninteresting.
On the 5-item difficulty describing scale, participants scored an average of 19.21+/-4.922. This is higher than the normal controls in Loas et al, who scored 13.67+/-4.35, the normal controls in Silani et al (p < .001), who scored 11.8+/-4.4, and the non-alexithymic group in Moriguchi et al (p < .001), who scored 9.6+/-3.9. It's also higher than Loas et al's addiction patients, who scored 16.12+/-4.19, and Silani et al's HFA/AS sample (p = .011), who scored 17.2+/-4.2. However, they did not significantly differ from Moriguchi's alexithymic group (p = .250), who scored 20.1+/-2.4. This suggests that most participants in my sample had a great deal of difficulty describing their feelings to other people, more even than most autistic people.
On the 7-item difficulty identifying scale, participants scored an average of 25.44+/-6.317. This is higher than both the normal controls in Loas et al, who scored 14.82+/-5.24, and in Silani et al (p < .001), who scored 14.3+/-5.3, as well as Moriguchi et al's non-alexithymic group (p < .001), who scored 10.6+/-3.7. It's also higher than Loas et al's addiction patients, who scored 21.11+/-5.96, and Silani et al's HFA/AS sample (p < .001), who scored 18.5+/-6.5. However, once again, they did not differ from Moriguchi et al's alexithymic group (p = .458), who scored 21.4+/-4.0. This suggests that most participants in my study also had a lot more difficulty identifying their emotions than most autistic people.
On the 8-item externally-oriented scale, participants scored an average of 22.40+/-4.904. This is higher than both the normal controls in the Loas et al, who scored 17.74+/-4.54, Silani et al's normal controls (p < .001), who scored 17.6+/-5.3, and Moriguchi et al's non-alexithymic group, who scored 13.9+/-3.3. It's also higher than Loas et al's addiction patients, who scored 18.09+/-4.78, and Silani et al's HFA/AS group (p = .002), who scored 19.9+/-3.1, but not significantly different from Moriguchi et al's alexithymic group (p = .192), who scored 21.4+/-4.0. This suggests that most participants in my study tended to undervalue the importance of emotional experiences more than most autistic people do.
The TAS-20 and its subscales did not significantly differ by age or gender.
The TAS-20 and all subscales correlated strongly positively with the AQ total (r ranging from .372 to .534, p = .013-.002), the AQ social subscale (r ranging from .476 to .544, p between .002 and <.001), and the AQ imagination subscale (r ranging from .350 to .455, p = .027-.003).
AQ attention to detail was positively correlated with the TAS-20 total and two subscales (r ranging from .335 to .435, p = .041-.006), as was AQ communication (r ranging from .371 to .473, p = .022-.002), but neither scale was correlated with TAS external.
The TAS-20 total was also significantly positively correlated with the FrSBe total (r = .428, p = .009) and FrSBe apathy (r = .378, p = .018). The difficulty identifying and difficulty describing subscales showed strong positive correlations between FrSBe total and all three FrSBe subscales (r ranging from .317 to .543, p = .047-.001). TAS external was correlated only with FrSBe apathy (r = .391, p = .011).
Overall, my sample seems to be biased towards higher alexithymia than is typical for autistic individuals. It's possible either that Wrong Planet attracts more alexithymic individuals (perhaps they're more likely to seek autism information online, due to their poorer self-understanding?), or that my study did. In any case, this limits the generalizability of my conclusions.
Interestingly, alexithymia appeared to be linked not only to autism severity, but also to executive dysfunction - particularly apathy. Another group at high risk of executive dysfunction, individuals with traumatic head injuries, are also at elevated risk of alexithymia (study, study and study), but this has not been linked with executive dysfunction or with particular brain regions. The possible link between alexithymia and executive dysfunction should be studied more in the future.