Is a condition in which people lack the ability to understand describe and process?

ABSTRACT

Background

Alexithymia is a risk factor for major depressive disorder (MDD) and has been associated with diminished treatment response. Neuroimaging studies have revealed structural aberrations of the anterior cingulate cortex and the fusiform gyrus in healthy controls with high levels of alexithymia. The present study tried to corroborate and extend these results to patients with MDD compared with healthy controls.

Methods

We investigated the relationship between alexithymia, depression and grey matter volume in 63 patients with MDD (mean age ± standard deviation = 42.43 yr ± 11.91; 33 female) and 46 healthy controls (45.35 yr ± 8.37; 22 female).. We assessed alexithymia using the Toronto Alexithymia Scale. We conducted an alexithymia × group analysis of covariance; we used a region-of-interest approach, including the fusiform gyrus and anterior cingulate cortex, and conducted whole brain analysis using voxel-based morphometry.

Results

Our analysis revealed a significant alexithymia × group interaction in the fusiform gyrus (left,pFWE = 0.031; right,pFWE = 0.010). Higher alexithymia scores were associated with decreased grey matter volume in patients with MDD (pFWE = 0.009), but with increased grey matter volume of the fusiform gyrus in healthy controls (pFWE = 0.044). We found no significant main effects in the region-of-interest analysis.

Limitations

Owing to the naturalistic nature of our study, patients with MDD and healthy controls differed significantly in their alexithymia scores.

Conclusion

Our results showed the fusiform gyrus as a correlate of alexithymia. We also found differences related to alexithymia between patients with MDD and healthy controls in the fusiform gyrus. Our study encourages research related to the transition from risk to MDD in people with alexithymia.

Trait Versus State Alexithymia

Alexithymia has been proposed as a personality dimension, and validation of the construct comes through the work of Taylor and colleagues on the TAS and TAS-20. Both of these scales have been validated by examining their relationships with scales that would tap into deficits observed among people with alexithymia (e.g., access to one's feelings). Concomitantly, there are studies that support the idea that alexithymia could also be a state reaction to different mental and physical conditions. Longitudinal studies have looked at the stability of alexithymia in the context of different levels of stress. Overall, these studies supported the trait view by demonstrating the long-term stability of alexithymia, thus supporting Taylor's conceptualization of alexithymia as a stable personality trait. In contrast, studies on clinical populations have suggested that when connected to psychopathology, alexithymia is viewed as state dependent, or as an outcome of the experienced vulnerability during stressful situations that subsides with the alleviation of symptoms.

To reconcile these two views, it was proposed that when speaking of personality traits a distinction between relative and absolute stability is warranted. Absolute stability is reached if people with alexithymia score the same on an alexithymia scale over time. Relative stability refers to temporal stability or people's relative position on levels of alexithymia, even though their absolute score may change. Similar trends are seen in other personality dimensions such as neuroticism and extraversion. Saarijärvia and colleagues offer empirical support for the idea that the two views don't have to be mutually exclusive, but that they can complement each other for a more complex understanding of alexithymia. In their study, while alexithymia scores decreased as depression decreased, overall, subjects remained high in this trait even after reduction of depression. In conclusion, a temporary increase in negative affect may exacerbate alexithymia traits, but this change was not found to explain the entire trait in any given person; hence, those scoring high on alexithymia most likely possess this trait.

Conclusion

Alexithymia is an intriguing topic, one that in 40 years has generated voluminous research. Although researchers and clinicians have made gains in conceptualizing and assessing alexithymia, considerable construct validity work remains. Debates about the definition and measurement of alexithymia continue, its etiology has not been established firmly, understanding of its links to physical disease (origins and treatment) is incomplete, and its neural correlates remain uncertain. Although these gaps are sobering, alexithymia work, nevertheless, holds promise. Thus, this entry ends with suggestions for creating more certainty and, perhaps, wider acceptance of the construct.

Functional consequences of alexithymia in neurological disorders

Alexithymia has a disruptive effect on a variety of important outcomes in patients with neurologic disorders. In both PD and cTBI, clinically significant alexithymia is associated with reduced quality of life and increased caregiver burden with a disruptive impact on interpersonal relationships (Williams and Wood, 2013; Klietz et al., 2020). The negative impact of alexithymia on functional outcomes has been particularly well demonstrated in a series of cTBI studies by Williams, Wood, and colleagues, suggesting that alexithymia in cTBI is associated with decreased emotional empathy (Williams and Wood, 2010), increased somatic complaints and personal distress (Wood et al., 2009; Wood and Doughty, 2013), as well as increased suicidal ideation (Wood et al., 2010). In each of these studies, alexithymia—and most frequently the difficulty identifying feelings subscale—was found to account for variance in these outcomes above that accounted for by anxiety and depression. The disruptive impact of alexithymia on emotional empathy in cTBI has been replicated by an independent group (Neumann et al., 2014). An association between alexithymia and degraded interpersonal relationships has also been demonstrated in patients with neurodegenerative disorders (Sturm and Levenson, 2011). Finally, pathological reward-guided decision making has been linked to increased alexithymia in patients with neurological disorders. For example, in penetrating TBI, alexithymia has been associated with impaired value-based decision making (Hogeveen et al., 2021) and alexithymia in PD has been associated with impulsivity–compulsivity disorders (Goerlich-Dobre et al., 2014). These studies indicate the importance of intact emotional awareness for making adaptive value-based decisions. Collectively, studies of patients with psychiatric and neurological disorders provide evidence that feelings are not a mere epiphenomenon of human emotion. Instead, emotional awareness plays a functional role in shaping adaptive behaviors and, when disrupted by alexithymia, can drive a host of negative affective and interpersonal outcomes.

Convergent/Concurrent

The PTI-AS correlated positively with the TAS-20 and BVAQ-COG, but not with the BVAQ-AFF as follows: PTI-AS/TAS-20 (.74), PTI-AS/TAS-DIF (.70), PTI-AS/TAS-DDF (.55), and PTI-AS/TAS-EOT (.32) and PTI-AS/BVAQ (.40), PTI-AS/BVAQ-COG (.63), PTI-AS/BVAQ-AFF –.12, PTI-AS/BVAQ subscale ANA (.29), PTI-AS/BVAQ-AS/BVAQ-VERB (.65), PTI-AS/BVAQ-IDENT (.44), PTI-AS/BVAQ-FAN –.07, and PTI-AS/BVAQ-EMO –.12.

Impoverished Dreaming in Alexithymia

Alexithymia refers to a difficulty in verbalizing emotions, literally, to a lack of a lexicon for describing feelings. Early investigations of patients who have psychosomatic disorders linked an alexithymic response style with diminished dream recall11 and an absence of affect in dreams.12 Reduced dream recall among alexithymic patients has since been replicated and linked with the difficulty identifying feelings subscale.13,14,14a One study of subjects with nocturnal asthma15—a population in whom comorbid alexithymia is common—revealed that REM sleep awakenings produced an elevated incidence of impoverished dreaming, especially dreams reported with short sentences and the frequent impression of dreaming but without recall of specific contents.

Studies have reported evidence that specific sensory and structural features in dreams are impoverished among alexithymic patients. One study found that alexithymic patients reported colorless dreams16 and a second found that subjects with nonclinical alexithymia had less fantastic dream content than did controls but did not differ on other measures of dream recall and emotion.17

Sleep studies have not yet identified a consistent pattern of changes that might explain dream impoverishment. In one study,18 higher alexithymia scores were associated with more frequent REM episodes, shorter REM latencies, and more stage 1 sleep during and immediately after REM sleep. However, alexithymia was also related to increased NREM stage 1 and decreased NREM stages 3 and 4. In a second study,19 alexithymia scores did not correlate with any polysomnographic variable or with REM density; however, an association with shortened REM latencies was observed. Finally, alexithymia is reliably associated with certain sleep disorders, including chronic insomnia and parasomnias.16

In sum, although converging evidence indicates that dream impoverishment is associated with alexithymia, more research is needed to clarify relationships between alexithymic factors and various attributes of dream recall, content, and emotion and sleep polysomnography. It also bears noting that other patterns of disturbed dreaming characterize some alexithymic patients, such as dreams that are extremely macabre, nightmarish, or lacking in ego and emotional control.20 A similar paradoxical combination of both impoverished and nightmarish dreams is also found among some PTSD patients.

6.24.5.1.3 Deficits in emotion processing (alexithymia)

Alexithymia literally means “no words for feelings.” The concept refers to a hypothesized communicative function of somatic symptoms. Its key features are a relative constriction of emotional functioning, poverty of fantasy life, and inability to find appropriate words to describe one's emotions (Taylor, Bagby, & Parker, 1991). Alexithymic individuals seem to be vulnerable to mounting tension from undifferentiated states of unpleasant emotional arousal. This vulnerability is presumably caused by a disturbance in the processing of emotional awareness that is believed to interfere with the subject's ability to experience and express emotions. For example, in a sample of normal volunteers, Vingerhoets, Van Heck, Grim, and Bermond (1995) found strong negative correlations between alexithymia and the expression of emotions, daydreams, and fantasies, and planful and rational actions. Bach and Bach (1995) found high alexithymia scores to be predictive of persistent somatization. More recently, the concept of alexithymia has also been discussed in relation to a variety of psychological traumata (Salminen, Saarijävi, & Äärelä, 1995).

Impoverished Dreaming in Alexithymia

Alexithymia refers to a difficulty in verbalizing emotions, literally, to a lack of a lexicon for describing feelings. Early investigations of psychosomatic patients1011 linked an alexithymic response style with diminished dream recall and an impoverished imaginal life more generally. An absence of affect in dreams was also frequently noted. Levitan12 described dreams from many psychosomatic patients with alexithymia in which either the protagonists in the dreams failed to fully perceive their own feelings or their feelings were minimized by attributing them to other characters.

A study13 of patients with nocturnal asthma—a population with a high incidence of alexithymia14—revealed that rapid eye movement (REM) sleep awakenings produced an elevated incidence of dreams with short sentences and impressions of having dreamed but with no specific recall.

Studies have reported evidence of impoverishment in dream sensory and structural features in alexithymia. One study of the general Finnish population15 found that alexithymic subjects reported colorless dreams, and a second16 found that the dreams of nonclinical alexithymic subjects were less fantastic than those of controls; these groups did not differ on other measures of dream recall and emotion, however.

Sleep studies have not yet identified a consistent pattern of changes that might explain dream impoverishment. In one study,17 higher alexithymia scores were related to several REM sleep variables: more frequent REM sleep episodes, shorter REM sleep latency, and more stage 1 sleep during and immediately after REM. However, alexithymia was also related to non-REM sleep variables: increased stage 1 and decreased stage 3/4. In a second study,18 alexithymia scores did not correlate with any polysomnographic (PSG) variable or with rapid eye movement density; however, there was an association with shortened REM sleep latency. Finally, a survey study15 indicated that alexithymia is reliably associated with certain sleep disorders, such as chronic insomnia and parasomnias.

In sum, although converging evidence indicates that dream impoverishment is associated with alexithymia, more research is needed to clarify relationships between alexithymic subcomponents and various attributes of dream recall, dream content, and dream emotion. Sleep measures also require further clarification.

It is also noteworthy that other patterns of disturbed dreaming characterize some alexithymic patients—for example, dreams that are extremely macabre, nightmarish, or lacking in ego and emotional control.19 A similar manifestation of both impoverished and nightmarish dreams also characterizes patients with PTSD.

3.4.2 Alexithymia

Alexithymia is a subclinical cognitive-affective impairment affecting the ability to interpret one’s own emotional experiences.125 Alexithymia is present in approximately 10% of the general population,126,127 with significantly higher incidence levels within autistic populations (∼50%).121,124 Recent work suggests that comorbidity with alexithymia may be a fundamental factor in some of the social impairments (including empathy and emotion perception) exhibited by autistic individuals.128 Prior research has demonstrated that, relative to low alexithymia controls, individuals with high alexithymia ratings tend to score lower on trait empathy measures and exhibit reduced activation of the dorsal ACC, DLPFC, and cerebellum during the experience of empathy.91,92 Silani et al.92 found evidence of a positive correlation between AI activation during an interoceptive task and the extent to which individuals were able to correctly interpret their own emotional states. Interestingly, this correlation was consistent across autistic individuals and healthy controls, suggesting that the severe empathy deficits associated with autism may be mediated, at least to some extent, by comorbid alexithymia commonly observed with autism. This assertion is supported by another neuroimaging investigation, which found that activity within the self-pain network in response to the perceived pain of others correlated with alexithymia scores but was not associated with the presence of autism per se.129

As many of the studies that have identified empathy deficits in alexithymia used cue-based paradigms (which do not require participants to accurately infer the affective states of others based on perceptual cues), the atypical empathic outcomes are presumably not the result of impairments in perceptual input systems.5 Consistent with this interpretation, a recent pictorial-based investigation found that while alexithymic individuals were able to distinguish between expressions depicting anger and disgust, they were unable to correctly classify these expressions.128

Based upon such findings, indicating that individuals with alexithymia are aware of the presence of their own emotions but unable to correctly classify them, Bird and Viding5 propose that the atypical empathic outcomes observed in alexithymia are likely associated with impairments in the affective representation system. Dysfunction of the affective representation system would be expected to result in such deficits, as one’s ability to form a representation of internal affective states that are accessible to conscious introspection would be impeded. Furthermore, such a deficit in classifying one’s own internal affective states would be likely to affect the ability to develop the appropriate learned associations between internal and external emotion cues (which is a critical process in the development of emotional contagion as proposed by learning-based models).104 Thus, while the affective cue classification system may be functioning correctly in alexithymic individuals (allowing for correct classification of perceptual affective cues), dysfunction of the affective representation system would result in an inability to form a consciously accessible internal representation of the perceived emotion and to correctly classify external affective cues based upon learned associations with the corresponding internal affective state.5

Mini-dictionary of terms

Alexithymia

The cognitive inability to encode, identify, and describe one’s own and another person’s emotions.

A form of nonverbal psychotherapy that uses creative art-making processes to allow clients to express personal feelings and experience a sense of healing. This allows art psychotherapists to understand and analyze clients’ mental state through their artwork.

An explanation of how human perception processing begins from physical/sensory stimulation and gradually becomes cognitive representation in the mind.

A type of art therapy utilizing clay as media. The tactile property of clay can induce intense haptic sensations that, along with visual stimulation, is believed to soothe emotions and promote emotion regulation.

The process of turning inner abstract values, emotions, and thoughts into concrete clay representations.

The autonomic use of cognitive strategies to rectify optimal and adaptive expression, tension, frequency, and duration of an emotional response.

The theoretical model describing how people engage in, process, and express information when they interact with art media.

The haptic perception of one’s spatial position within the body’s “built-in” sensors in the muscles, joints, tendons, ligaments, and skin.

The sense of optimal coordination between one’s bodily state and one’s mental state, which produces a sense of pleasure.