Alexithymia (2): Subtypes, Comorbidity, Prevalence

The growing evidence suggests that alexithymia is a heterogeneous and dimensional phenomenon.

Alexithymia Subtypes

Several studies have identified alexithymia subtypes. Here are some of the most recent ones:

Lane et al. (2015) distinguished anomic (problems naming emotions but intact theory of mind) and agnostic (problems forming conceptual representations of emotions and impaired theory of mind) forms.

Kajanoja et al. (2017) compared depressive and anxiety symptoms, self-reported psychiatric medical history, and self-reported early life adversity and identified two alexithymia subtypes (A & B). Type B alexithymia was associated with higher levels of difficulties in identifying feelings and was more strongly associated with current depressive and anxiety symptoms and self-reported early life adversity. Compared to type A, type B alexithymia was also associated with a higher prevalence of self-reported diagnosis of major depressive- and anxiety disorder.

Jakobson & Rigby (2021) used a latent profile analysis[1] that revealed five classes of individuals distinguished by the relative strength of different alexithymic traits and by differences in interoceptive accuracy, certain aspects of sensory processing and self-regulation: 1) Lexithymic Orchids, 2) Lexithymic Dandelions, 3) Modal, 4) Alexithymic Tulips, 5) Alexithymic Orchids.

Comorbidity

Originally observed in clinical settings with psychosomatic[2] patients (Nemiah et al. 1976), current research indicates that alexithymia not only frequently co-occurs with various medical and psychiatric disorders (Kano & Fukudo 2013; Lumley, Neely, Burger 2017; Lee et al. 2022), such as, for example, anxiety, depression, and post-traumatic stress disorder (PTSD) (Albantakis et al., 2020; Preece et al., 2022; Spitzer et al., 2007) but also it is seen in general population as well. Research shows that alexithymia (not autistic traits) can be considered the better predictor for anxiety in general population (Fietz, Valencia, Silani 2018).

Alexithymia is also linked to:   

eating disorders (anorexia nervosa, bulimia nervosa)

Individuals with eating disorders may find emotions unacceptable and/or frightening and may use their eating disorder symptoms (i.e., restricting food intake, binge eating, and/or purging) as a way to avoid or cope with their feelings (Nowakowski, McFarlane, Cassin 2013).

schizophrenia, substance abuse (Bird & Cook 2013, Grynberg et al. 2012);

suicidality (Hintikka et al. 2004);

increased psychosomatic complaints (Lane 2008);

elevated mortality rates (Tolmunen et al. 2010).

Prevalence of alexithymia 

In his 1973 study, Sifneos examined the frequency of alexithymia in patients with different psychosomatic diseases. The research revealed that psychosomatic patients were more than twice as likely as controls to exhibit ‘alexithymic’ traits.

In general population:

The prevalence of alexithymia in general population is 13%. Men are alexithymic almost twice (17%) as often as women (10%). Alexithymia was associated with male gender, advanced age, low educational level, and low socioeconomic status (Salminen et al. 1999).

In multiple sclerosis (MS):

The prevalence of alexithymia in MS ranges from 10% to 53%. It seems to be associated with anxiety, depression, fatigue, and some social cognitive aspects (Chalah, Ayache 2017).  

In autism:

The prevalence of alexithymia is significantly higher among ASD individuals: 55% of ASD adolescents compared to 16% non-ASD adolescents (Milosavljevic et al. 2016); 49.93% of autistic adults have alexithymia, in contrast to 4.89% in NT adults (Kinnaird et al. 2019).

Other studies indicate that at least 40–65% of autistic people experience severe alexithymia (Bird & Cook, 2013; Hobson et al., 2020). In a study involving people with autism and alexithymia, 47.3% of the participants were female and 21.0% were male (Oakley et al. 2022).

It is also more prevalent in relatives of individuals with ASD, potentially constituting an element of the broader autism phenotype (BAP) found in such relatives, e.g., within the ASD group, children of fathers with high alexithymia score higher on repetitive behaviour symptoms compared to children of fathers with low alexithymia. The alexithymia trait appears to be one of the many building blocks that make up the BAP (Szatmari et al. 2008).

It has been suggested that alexithymia is a transdiagnostic condition that plays a role in the emotional challenges and affective psychopathology seen in various psychiatric disorders (Albantakis et al. 2020; Brewer et al. 2021; Preece et al. 2022).

The co-occurrence of alexithymia and other mental health conditions can complicate diagnosis and treatment, as individuals with alexithymia may have difficulty expressing or identifying their emotional and psychological symptoms.

Understanding the relationship between alexithymia and these comorbid conditions is crucial for developing effective interventions for individuals struggling with emotional regulation difficulties.

By addressing both alexithymia and its comorbidities, we can better support individuals in developing healthy emotional coping skills and improving overall mental health outcomes.

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[1] The goal of latent profile analysis is to classify individuals from a heterogeneous population into smaller, more homogenous subgroups based on individuals’ based on their responses to continuous variables (Berlin, Williams, Parra 2014).

[2] Psychosomatic diseases are physical conditions that are influenced by psychological and social factors, such as stress. The disorders resulting from stress may manifest as hypertension, respiratory ailments, gastrointestinal disturbances, migraine and tension headaches, pelvic pain, sexual dysfunction, dermatitis, and ulcers. Despite the absence of an identifiable medical cause, these disorders can cause real, debilitating physical symptoms.

In 1950, Alexander introduced the term "psychosomatic" to highlight how psychological factors can either trigger or exacerbate seven specific diseases, known as the "holy seven." These diseases include peptic ulcer, bronchial asthma, rheumatoid arthritis, ulcerative colitis, essential hypertension, neurodermatitis, and thyrotoxicosis.