The alexithymic brain: the neural pathways linking alexithymia to physical disorders

Abstract

Alexithymia is a personality trait characterized by difficulties in identifying and describing feelings and is associated with psychiatric and psychosomatic disorders. The mechanisms underlying the link between emotional dysregulation and psychosomatic disorders are unclear. Recent progress in neuroimaging has provided important information regarding emotional experience in alexithymia. We have conducted three brain imaging studies on alexithymia, which we describe herein. This article considers the role of emotion in the development of physical symptoms and discusses a possible pathway that we have identified in our neuroimaging studies linking alexithymia with psychosomatic disorders. In terms of socio-affective processing, alexithymics demonstrate lower reactivity in brain regions associated with emotion. Many studies have reported reduced activation in limbic areas (e.g., cingulate cortex, anterior insula, amygdala) and the prefrontal cortex when alexithymics attempt to feel other people’s feelings or retrieve their own emotional episodes, compared to nonalexithymics. With respect to primitive emotional reactions such as the response to pain, alexithymics show amplified activity in areas considered to be involved in physical sensation. In addition to greater hormonal arousal responses in alexithymics during visceral pain, increased activity has been reported in the insula, anterior cingulate cortex, and midbrain. Moreover, in complex social situations, alexithymics may not be able to use feelings to guide their behavior appropriately. The Iowa gambling task (IGT) was developed to assess decision-making processes based on emotion-guided evaluation. When alexithymics perform the IGT, they fail to learn an advantageous decision-making strategy and show reduced activity in the medial prefrontal cortex, a key area for successful performance of the IGT, and increased activity in the caudate, a region associated with impulsive choice. The neural machinery in alexithymia is therefore activated more on the physiologic, motor-expressive level and less in the cognitive-experiential domains of the emotional response system. Affects may play an important role in alleviating intrinsic physiologic reactions and adapting to the environment. Deficient development of emotional neural structures may lead to hypersensitivity to bodily sensations and unhealthy behaviors, a possible mechanism linking alexithymia to psychosomatic disorders.

Alexithymia, Depression, Inflammation, and Pain in Patients With Rheumatoid Arthritis

“…A high prevalence of alexithymia has been observed in patients with chronic pain (9), including those with RA (14,15). Numerous observational and some experimental studies revealed positive associations between alexithymia and pain intensity and sensitivity (16). However, there are some conflicting reports; alexithymia has been suggested to be associated with poor awareness of physical symptoms, such as cardiac pain, resulting in a delay of seeking treatment (17).…”

“…Another shortcoming of previous studies is that most of them evaluated the output of pain without considering the inputs of pain (13). According to recent experimental studies, those with alexithymia may be insensitive to their own physical sensation when the external stimuli are not strong enough (16,20).…”

“…Another shortcoming of previous studies is that most of them evaluated the output of pain without considering the inputs of pain (13). According to recent experimental studies, those with alexithymia may be insensitive to their own physical sensation when the external stimuli are not strong enough (16,20).The purpose of this study was to examine the independent impact of alexithymia on pain perception among patients with RA. From accumulating evidence, we hypothesized that the association of perceived pain severity is altered by the level of inflammation and by the presence of depression and alexithymia.…”

Do Patients with Somatoform Disorders Present with Illusory Mental Health?

“…In line with Lane [10], Kano and Fukudo [11] found evidence by reviewing brain imaging studies, that people who have deficits in the cognitive experience of emotions only experience rudimentary forms of emotional experience (high arousal of bodily sensations) and this may lead to disadaptive behaviours.…”

“…The present study however suggests that somatoform patients do report anxiety to a similar extent as other psychiatric patients do. Their anxiety may be related to an anxious preoccupation with illness symptoms [11].…”