Alexithymia and Autism (1): Intersections of two distinct conditions

The connection between alexithymia and ASD was initially explored in the 1990s through clinical studies on individuals with eating disorders, specifically anorexia nervosa (AN). The studies revealed the co-occurrence of eating disorders with deficiencies in social competence and identified some traits that were considered typical of ASD,[1] such as empathy problems, as well as some features considered typical of alexithymia, such as difficulty verbalising emotions, identifying feelings and distinguishing emotions from somatic sensations (Gillberg et al. 1995; Rastam et al. 1997).[2]

Subsequent research broadened the scope of investigation into the relationship between alexithymia and ASD, uncovering additional commonalities, such as disorders of cognitive functioning, impaired self-awareness and mentalisation, poor emotional lexicon and difficulties in behaviour control (Poquérusse et al. 2018). Earlier research studies explored the relationship between alexithymia and what is now known as ASD-1 by comparing alexithymic traits with those seen in individuals with Asperger syndrome (e.g., Shriberg et al. 2001; Corcos 2003; Tani et al. 2004; Fitzgerald & Bellgrove 2006; Hill & Berthoz 2006.

Etiological connections

The descriptions of alexithymia focusing on etiology and treatment all are similar to the literature on Asperger syndrome. Research suggests shared overlap in genetic and neurobiological factors, including activation in the oxytocinergic and serotonergic systems, and similar dysfunctions in brain regions such as amygdala, cingulate, and prefrontal cortex functioning (Fitzgerald & Belligrove 2006). Understanding these shared etiologies can clarify the relationship between alexithymia and ASD, including the potential association of certain subtypes of alexithymia with ASD (Poquérusse et al. 2018). 

Clinical Presentation and Cognitive Challenges

There is considerable overlap in the clinical presentation of persons with a diagnosis of alexithymia and ASD.

Individuals with alexithymia have problems with introspection, a poor capacity for fantasy, and they show a stimulus bound, externally orientated and rather factual based, excessively utilitarian thinking style that seen in individuals with Asperger syndrome as well (Taylor et al. 1997; Fitzgerald & Belligrove 2006; Patil et al. 2016).

Emotional Dysregulation and Expression Difficulties

Alexithymia involves altered emotional awareness, which is often present in people with ASD (Hill, Berthoz 2006). 

Individuals with alexithymia struggle with both verbal and nonverbal identification of emotions. They find it challenging to articulate their feelings, use emotion-related vocabulary, or interpret emotions conveyed through facial expressions, tones of voice, or emotionally charged situations. They often confuse emotions with somatic sensations. Similarly, ASD individuals encounter difficulties with the cognitive processing of their emotions, identifying, and describing feelings (Hill et al. 2004; Shah et al, 2016). More specifically, they have difficulty with general emotional competence, including emotion perception, regulation and recognition, particularly facial emotion recognition, but also recognition of emotional tones of speech and prosody, verbal content, and body movement (Gaigg et al. 2018; Serafini et al. 2017). These affect the ability of individuals with both conditions to communicate their needs and preferences to others, form relationships, and engage in social interactions. This, in turn, can further isolate them, as they may feel misunderstood or disconnected from others.

Social Relationship Dynamics

Difficulties with social relationships are common to both alexithymia and Asperger syndrome (Asperger 1944; Wing 1981; Taylor et al. 1997).

Individuals with ASD and alexithymia both have problems with affective interaction (including difficulties with cognitive and affective empathy), difficulty interpreting the non-verbal cues other people demonstrate in social interaction (Bird et al. 2011), reduced levels of enjoyment of prosocial interactions (Gebauer et al. 2014), and decreased levels of empathy (Luminet et al. 2006; Lartseva et al. 2015),[3] possibly linked to neurobiological deficits in limbic and paralimbic neural activity responses to emotionally salient stimuli Moriguchi, Komaki 2013).

Language and communication

Alexithymia and ASD are characterised by disturbances in speech, language and communication.  Alexithymic individuals use speech as an act rather than a symbolic means of communication of ideas or affect (McDougall 1978).  They often exhibit a monotone voice, decreased use of the pronoun "I," and a lack of nuanced communication. They can learn approximately socially appropriate responses but these are often excessively formal and pedantic, lacking nuance and proper prosody (Krystal 1998). Similarly, speech and prosodic issues are widely reported in high-functioning autism and Asperger syndrome (Fitzgerald, Bellgrove 2006).  

Distinct Yet Overlapping Conditions

While alexithymia and ASD share overlapping symptoms, they are distinct conditions. However, alexithymia is more prevalent in autistic individuals than in the neurotypical population, presenting unique challenges to those affected by both conditions in emotional, social, cognitive (verbal and non-verbal) domains, with varying degrees of convergent consequences for their individual and social behaviour and lives.

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[1] Recent research has confirmed a significant association between AN and autistic traits, suggesting a potential link between these conditions (e.g., Inal-Kaleli et al. 2024). The nature and cause of this overlap is currently poorly understood. Alexithymia has been recently proposed as a potential key to explain the presence of the so-called ASD signs, in patients with AN. However, the specific load of alexithymia in explaining the link between AN and ASD is still in debate. Interoception deficit has been proposed as having a crucial role (Miniati, Marazziti, Palagini 2022).

Concerningly, where Feeding and Eating Disorders (FEDs) and autism co-occur, clinical outcomes of FEDs are significantly worse, and treatment less effective, than when the FEDs occur in neurotypical individuals (Adams et al. 2024).

[2] Earlier research studies explored the relationship between alexithymia and what is now known as ASD-1 by comparing alexithymic traits with those seen in individuals with Asperger syndrome (e.g., Shriberg et al. 2001; Corcos 2003; Tani et al. 2004; Fitzgerald & Bellgrove 2006; Hill & Berthoz 2006.

[3] However, ‘sensory-based empathy’ is strong in many autistic people.