The inability to recognise and interpret emotional states in other people – often called emotional blindness – which is commonly identified as a symptom of autism, is actually caused by a co-occurring condition called alexithymia, according to a new study.

The research, co-authored by Dr Richard Cook from City University London’s Department of Psychology, could have significant implications for the diagnosis of autistic spectrum conditions (ASCs), and may necessitate the development of new diagnostic criteria that do not include emotional impairment.

This also raises the possibility of targeted interventions for autism, tailored to those individuals with and without co-occurring alexithymia, reflecting their different needs and abilities.

The research team, a collaboration between Dr Cook and researchers from The Institute of Psychiatry, tested 32 participants with varying degrees of alexithymia, 16 of whom also had a diagnosis of autism. They found that alexithymia, rather than autism, predicted subjects’ ability to recognise facial expressions.

These findings provide evidence of sub-groups within the autistic population, defined by the presence or absence of alexithymia, and will allow for intervention strategies that can be tailored to meet the specific needs of each subgroup.

The report suggests that therapeutic approaches could address the emotional problems of individuals with alexithymia, and build on the emotional abilities of those autistic individuals without alexithymia, to help their social interaction.

“The study shows impaired emotion recognition – currently considered a feature of autism – is in fact caused by alexithymia, a condition that is more common in individuals with autism than in the general population,” said Dr Cook.

“Many practitioners currently regard impaired emotion recognition, together with reduced empathy and subjective experience of emotion as diagnostic markers of autism. However, if these difficulties are in fact due to co-occurring alexithymia, autistic individuals without alexithymia may not receive the support they need to build on their emotional abilities.

“Our findings represent a significant step toward helping researchers and clinicians understand the traits of ASC and we hope that it will prompt more research into alexithymia by cognitive scientists.”