Alexithymia May Explain the Genetic Relationship Between Autism and Sensory Sensitivity

Alexithymia May Explain the Genetic Relationship Between Autism and Sensory Sensitivity

Alexithymia

Isabel Yorke, Jennifer Murphy, Fruhling Rijsdijk, Emma Colvert, Stephanie Lietz, Francesca Happé, Geoffrey Bird

Translational Psychiatry

Vol. 15

No. 75

2025

Nature Publishing Group

Journal article

English

21583188

England, Wales

Open Access

Sensory symptoms are highly prevalent amongst autistic individuals and are now considered in the diagnostic criteria. Whilst evidence suggests a genetic relationship between autism and sensory symptoms, sensory symptoms are neither universal within autism nor unique to autism. One explanation for the heterogeneity within autism and commonality across conditions with respect to sensory symptoms, is that it is alexithymia (a condition associated with difficulties identifying and describing one’s own emotions) that has a genetic relationship with sensory symptoms, and that alexithymia commonly co-occurs with autism and with several other conditions. Using parent-reports of symptoms in a sample of adolescent twins, we sought to examine the genetic association between autism, alexithymia and sensory symptoms. Results showed that the genetic correlation between autism and sensory symptoms was not significant after controlling for alexithymia. In contrast, after controlling for variance in alexithymia explained by autism, the genetic correlation between alexithymia and sensory symptoms was significant (and the proportion of variance explained by genetic factors remained consistent after controlling for autism). These results suggest that 1) alexithymia and sensory symptoms share aetiology that is not accounted for by their association with autism and 2) that the genetic association between sensory symptoms and autism may be, in part or wholly, a product of alexithymia. Future research should seek to examine the contribution of alexithymia to sensory symptoms across other conditions.

Robin Cole