Neuroanatomical profiles of alexithymia dimensions and subtypes

Basolateral Amygdala Functional Connectivity in Alexithymia: Linking Interoceptive Sensibility and Cognitive Empathy

Emotions rely on bodily states, and perceiving the emotions of others depends on awareness of one's own emotional state. However, the intercorrelations among interoception, alexithymia, and empathy are not well understood, and the neural mechanisms behind this connection are also largely unknown. To address these issues, 297 college students participated in this study, completing measures of interoceptive sensibility (IS), empathy and alexithymia and undergoing resting-state fMRI scans. The functional connectivity of the amygdala was analysed to identify the neural substrates of alexithymia, and mediation analyses were conducted to examine the mediation effect of alexithymia and alexithymia-specific amygdala functional connectivity on the relationship between IS and empathy. The results showed that higher levels of IS were associated with increased cognitive empathy through weakened alexithymia. Functional connectivity analysis indicated that right basolateral amygdala (BLA)-left precuneus connectivity was negatively related to alexithymia, while right BLA-left precentral gyrus connectivity was positively related to alexithymia. Furthermore, right BLA-left precuneus connectivity was found to mediate the impact of interoception on cognitive empathy. In conclusion, this study provides valuable insights into the relationships among IS, alexithymia, and empathy. The right BLA-left precuneus connectivity may serve as a shared neural substrate between interoception and cognitive empathy.

Personality traits related to cognitive functioning in patients with functional neurological disorder

Cognitive symptoms are prevalent in patients with functional neurological disorder (FND). Several studies have suggested that personality traits such as neuroticism may play a pivotal role in the development of FND. FND has also been associated with alexithymia: patients with FND report difficulties in identifying, analyzing, and verbalizing emotions. Whether or not alexithymia and other personality traits are associated with cognitive symptomatology in patients with FND is unknown. In the current study, we explored whether the Big Five personality model factors (neuroticism, extraversion, openness, agreeableness, and conscientiousness) and alexithymia were associated with cognitive functioning in FND. Twenty-three patients with FND were assessed using a neuropsychological assessment and questionnaire assessment to explore personality traits (Neuroticism-Extraversion-Openness Five-Factor Inventory) and alexithymia (Bermond-Vorst Alexithymia Questionnaire). The results indicated that high conscientiousness was associated with lower planning scores (ρ = -0.52, p = .012) and high scores on alexithymia were associated with lower scores on verbal memory scores (ρ = -0.46, p = .032) and lower sustained attention scores (ρ = -0.45, p = .046). The results did not remain significant after controlling for multiple testing. The preliminary results of our study suggest that personality and cognitive symptomatology in patients with FND are topics that should be further explored in future studies, as cognitive symptomology can affect treatment results.

Prevalence of alexithymia in cancer patients: a systematic review and meta-analysis

PURPOSE

To systematically evaluate the prevalence of alexithymia in cancer patients and to compare the prevalence of alexithymia in different countries, genders, and cancer types.

METHODS

We thoroughly searched PubMed, EMBASE, Web of Science, The Cochrane Library, CINAHL, PsychINFO, China Integrated Knowledge Resource Database, Wanfang Database, Weipu Database, and Chinese Biomedical Database for studies on the prevalence of alexithymia in cancer patients from the inception to April 2, 2023. Based on the Stata 15.0 software package, the prevalence of alexithymia in cancer patients was estimated using a random-effects model in this meta-analysis.

RESULTS

Eighteen studies with a total of 3,196 participants met the eligibility criteria for the meta-analysis. In 18 studies, 37.0% (95% CI: 28.0% - 46.0%) of cancer patients had alexithymia. 13 studies identified that the pooled mean score of alexithymia in cancer patients was 56.91 (95% CI: 54.44% to 59.37%). The prevalence of alexithymia was higher in cancer patients in developing countries (39.7%, 95% CI: 28.7% to 50.7%), males (40.0%, 95% CI: 24.0% to 55.9%), and colorectal cancer patients (47.3%, 95% CI: 21.3% to 93.3%).

CONCLUSIONS

Our study found that the pooled prevalence of alexithymia in cancer patients was 37.0%, and higher in developing countries, males, and patients with colorectal cancer. Understanding the current status of alexithymia in cancer patients, timely identification and treatment by medical practitioners can improve the prognosis of cancer patients.

CLINICAL TRIAL REGISTRATION

The protocol was registered in PROSPERO [CRD42023414665].

Bidirectional relationship between insular grey matter volume and alexithymia: Evidence from a longitudinal study

BACKGROUND

The insula is considered to be involved in emotional cognitive processes, and may be structurally altered in people with alexithymia. However, it remains unclear how the relationship between the insula and alexithymia changes over time. This study aimed to investigate whether alexithymia has longitudinal relationship with the insular structure.

METHODS

Having processed structural MRI data via FreeSurfer, the insula was divided into five sub-regions, and the Toronto Alexithymia Scale was administered to assess alexithymia in the general population. Subsequently, we established the latent change score models between insular sub-regions and the alexithymia (N = 252).

RESULTS

The TAS-20 mean value of the sample at Time 1 was not significantly different by sex (t = -0.993, df = 250, p = 0.321), while the TAS-20 mean value at Time 2 was slightly different by sex (t = 2.025, df = 250, p = 0.044). Most insular grey matter volumes at Time 1 and Time 2 were significantly associated with TAS-20 at Time 2. The baseline alexithymia and insular grey matter volume positively predicted the other's rate of change between Time 1 and Time 2 in a bidirectional way.

LIMITATIONS

This study had a limited number of measurement time points, potential bias due to smaller sample sizes and gender imbalance, as well as the potential for inaccuracy in the self-report measure of alexithymia.

CONCLUSIONS

Time-lagged alexithymia changes and insular grey matter volume changes occur in coupled manner over time, which might improve our understanding of the neurological underpinnings of alexithymia, and shed light on clinical and psychological treatment for alexithymia.

Childhood trauma and social support affect symptom profiles through cortical thickness abnormalities in major depressive disorder: A structural equation modeling analysis

BACKGROUND

Childhood trauma, low social support, and alexithymia are recognized as risk factors for major depressive disorder (MDD). However, the mechanisms of risk factors, symptoms, and corresponding structural brain abnormalities in MDD are not fully understood. Structural equation modeling (SEM) has advantages in studying multivariate interrelationships. We aim to illustrate their relationships using SEM.

METHODS

313 MDD patients (213 female; mean age 42.49 years) underwent magnetic resonance imaging and completed assessments. We integrated childhood trauma, alexithymia, social support, anhedonia, depression, anxiety, suicidal ideation and cortical thickness into a multivariate SEM.

RESULTS

We first established the risk factors-clinical phenotype SEM with an adequate fit. Cortical thickness results show a negative correlation of childhood trauma with the left middle temporal gyrus (MTG) (p = 0.012), and social support was negatively correlated with the left posterior cingulate cortex (PCC) (p < 0.001). The final good fit SEM (χ2 = 32.92, df = 21, χ2/df = 1.57, CFI = 0.962, GFI = 0.978, RMSEA = 0.043) suggested two pathways, with left PCC thickness mediating the relationship between social support and suicidal ideation, and left MTG thickness mediating between childhood trauma and anhedonia/anxiety.

CONCLUSION

Our findings provide evidence for the impact of risk factor variables on the brain structure and clinical phenotype of MDD patients. Insufficient social support and childhood trauma might lead to corresponding cortical abnormalities in PCC and MTG, affecting the patient's mood and suicidal ideation. Future interventions should aim at these nodes.

Characteristics and correlation of gray matter volume and somatic symptoms in adolescent patients with depressive disorder

Background

Adolescent patients with depressive disorders commonly exhibit somatic symptoms, which have a significant negative impact on their treatment and prognosis. Despite this, specific brain imaging characteristics of these symptoms have been poorly studied.

Methods

The Hamilton Depression Rating scale (HAMD-17), Children's Functional Somatization scale (CSI), and Toronto Alexithymia scale (TAS) were used to evaluate the clinical symptoms of adolescent depression. We analyzed the correlation between brain gray matter volume (GMV) and clinical symptoms in adolescent patients with depression and somatic symptoms.

Results

The depression subgroups with and without functional somatic symptoms (FSS) had higher scores on the HAMD-17, CSI, and TAS than the normal control group. The group with FSS had higher HAMD-17, CSI, and TAS scores than the depression group without FSS (p < 0.05). CSI and TAS scores were positively correlated (r = 0.378, p < 0.05). The GMV of the right supplementary motor area was higher in the depression groups with and without FSSs than in the normal control group, and the GMV was higher in the group without FSS than in the group with FSS (F = 29.394, p < 0.05). The GMV of the right supplementary motor area was negatively correlated with CSI in the depressed group with FSS (r = -0.376, p < 0.05). In the group with depression exhibiting FSS, CSI scores were positively correlated with GMV of the middle occipital gyrus (pr = 0.665, p = 0.0001), and TAS scores were positively correlated with GMV of the caudate nucleus (pr = 0.551, p = 0.001).

Conclusion

Somatic symptoms of adolescent depressive disorder are associated with alexithymia; moreover, somatic symptoms and alexithymia in adolescent patients with depressive disorders are correlated with GMV changes in different brain regions.

The relationship between alexithymia, interoception, and neural functional connectivity during facial expression processing in autism spectrum disorder

Neural processing differences of emotional facial expressions, while common in autism spectrum disorder (ASD), may be related to co-occurring alexithymia and interoceptive processing differences rather than autism per se. Here, we investigate relationships between alexithymia, interoceptive awareness of emotions, and functional connectivity during observation of facial expressions in youth (aged 8-17) with ASD (n = 28) compared to typically developing peers (TD; n = 37). Behaviorally, we found no significant differences between ASD and TD groups in interoceptive awareness of emotions, though alexithymia severity was significantly higher in the ASD group. In the ASD group, increased alexithymia was significantly correlated with lower interoceptive sensation felt during emotion. Using psycho-physiological interaction (PPI) analysis, the ASD group showed higher functional connectivity between the left ventral anterior insula and the left lateral prefrontal cortex than the TD group when viewing facial expressions. Further, alexithymia was associated with reduced left anterior insula-right precuneus connectivity and reduced right dorsal anterior insula-left ventral anterior insula connectivity when viewing facial expressions. In the ASD group, the degree of interoceptive sensation felt during emotion was positively correlated with left ventral anterior insula-right IFG connectivity when viewing facial expressions. However, across all participants, neither alexithymia nor interoceptive awareness of emotions predicted connectivity between emotion-related brain regions when viewing emotional facial expressions. To summarize, we found that in ASD compared to TD: 1) there is stronger connectivity between the insula and lateral prefrontal cortex; and 2) differences in interhemispheric and within left hemisphere connectivity between the insula and other emotion-related brain regions are related to individual differences in interoceptive processing and alexithymia. These results highlight complex relationships between alexithymia, interoception, and brain processing in ASD.

Alexithymia, depression, and cognition in patients with Parkinson's disease

BACKGROUND

Basal ganglia are connected to dorsal prefrontal and orbitofrontal structures, which have an important role in emotional experience. Alexithymia is defined as the inability to recognize and verbalize emotions. There is little known about alexithymia and cognitive dysfunction and its relationship with depression. In this study, we examined the relation of alexithymia with cognition and depression in non-demented patients with Parkinson's disease (PD).

MATERIALS AND METHODS

Fort-two consecutive non-demented patients PD and 40 healthy controls were enrolled in the study. The Turkish version of the Montreal Cognitive Assessment scale (MOCA-TR), 20-item Toronto Alexithymia Scale (TAS-20) (F1, F2, F3 subgroups), and Beck Depression Inventory (BDI-I) were used to evaluate cognitive functions, alexithymia, and depression, respectively, in both groups.

RESULTS

The total TAS-20 score was 55.71 ± 19 in the PD group and 46.33 ± 8.21 in the control group. There was a statistically significant difference in the total TAS-20 scores between the groups (p < 0.001). In subgroups of alexithymia, all mean scores of F1, F2, and F3 were higher in the PD group (p = 0.019, p < 0.001, and p = 0.005, respectively). In the MOCA-TR test, the mean scores in visuospatial and delayed recall of patients with PD were statistically lower than in the control group (p = 0.044 and p = 0.04, respectively). The MOCA-TR and BDI total scores were significantly correlated with TAS-20 total scores. In subgroup analysis, we only found an association between the visuospatial domain of MOCA-TR and the F3 subgroup of TAS-20 (r = - 0.22, p = 0.03). There was no relation between alexithymia and disease duration or total levodopa dose (p < 0.05).

CONCLUSION

Alexithymia is not a rare symptom in PD. It should be accepted as an independent non-motor symptom, and patients should be interrogated accordingly.

Constructing and Verifying an Alexithymia Risk-Prediction Model for Older Adults with Chronic Diseases Living in Nursing Homes: A Cross-Sectional Study in China

Alexithymia is a critical global public health concern. This questionnaire-based cross-sectional study explored the risk factors of alexithymia in older adults living in nursing homes with chronic diseases. It also developed and evaluated an alexithymia risk-prediction model. A total of 203 older adults with chronic diseases were selected from seven nursing homes in Changsha, China, using simple random and cluster sampling. The participants were surveyed using the Toronto Alexithymia Scale (TAS-20), Geriatric Depression Scale-15 (GDS-15), Connor-Davidson Resilience Scale (CD-RISC), Perceived Social Support Scale (PSSS), and a socio-demographic characteristics questionnaire. The alexithymia total score was 43.85 ± 9.570, with an incidence rate of 8.9%. Alexithymia had a partial mediating effect on the relationship between social support and psychological resilience (the effect value was 0.12), accounting for 19.04% of the total effect. Gender, depression, and psychological resilience were the main independent influencing factors of alexithymia (p < 0.05). The area under the receiver operating characteristic (AUC-ROC) curve of the risk-prediction model was 0.770. The participants, especially those who were male and depressed, exhibited a certain degree of alexithymia. Additionally, it partially mediated the association between social support and psychological resilience, which is a protective factor against alexithymia. The risk-prediction model showed good accuracy and discrimination. Hence, it can be used for preliminary screening of alexithymia in older adults with chronic diseases living in nursing homes.

The Association of White Matter Tracts with Alexithymia among Individuals with Major Depressive Disorder

Alexithymia is characterized by impairments in the processing of emotions. Although the disruptions in the white matter (WM) integrity in Major depressive disorder (MDD) has frequently been reported, the underlying relationship with alexithymia remains unclear. In the present study, we investigated WM tracts with Tracts Constrained by UnderLying Anatomy approach to discover potential associations between alexithymia and WM integrity to identify the neural basis of impaired emotional self-awareness in MDD. 101 patients with MDD and 99 healthy sex- and age-matched individuals underwent diffusion-weighted imaging. All participants were assessed with the 20-item Toronto Alexithymia Scale (TAS). TAS scores were significantly higher in MDD patients than in controls. Patients with MDD exhibited significantly lower FA values in the left inferior longitudinal fasciculus and it also showed negative associations with TAS. These results contribute to the neurobiological evidence on the association between MDD and alexithymia. Additionally, they suggest that reduced white matter integrity in the regions constitutes a principal pathophysiology underlying impaired emotional recognition and description in MDD.

White matter tracts associated with alexithymia and emotion regulation: A diffusion MRI study

BACKGROUND

Alexithymia is a cognitive-affective impairment, suggested to be associated with emotion regulation. Herein, we investigated white matter (WM) tracts with Diffusion Magnetic Resonance Imaging (DMRI) connectometry approach using quantitative anisotropy (QA) tractography to discover possible associations between the emotion identification and regulation patterns and WM tracts.

METHODS

DMRI data were acquired from 218 healthy subjects aging 39.15 ± 20.19 who filled the Toronto Alexithymia Scale (TAS) and emotion regulation questionnaire (ERQ) from the LEMON dataset. Connectometry analysis was applied on WM tracts in DMRI images.

RESULTS

DMRI connectometry analysis revealed a significant correlation between TAS identification score and increased microstructural connectivity in WM pathways, including the body of corpus callosum (CC), bilateral fornix, and left arcuate fasciculus (AF) in males (FDR = 0.028), and corticospinal and cingulum tracts in females (FDR = 0.026). Furthermore, we found a significant positive correlation between overall TAS score and fornix properties in men (FDR = 0.026) and corticospinal tracts in women (FDR = 0.028). Middle cerebellar peduncle negatively correlated with describing emotion (FDR = 0.025) and the splenium of the CC and corticospinal tracts negatively correlated with this subscale (FDR = 0.049) in male group. However, the splenium of the CC, corticospinal tracts, and left AF positively associated with this subscale (FDR = 0.029). The splenium of the CC was negatively related to externally-oriented thinking among men (FDR = 0.038). Our results showed marginally associations between ERQ and similar WM tracts.

CONCLUSION

Certain WM microstructures significantly correlate with emotion identification and regulation. These tracts are associated with specific somatosensory areas, language processing areas, and limbic area.

Atypical interoception as a common risk factor for psychopathology: A review

The inadequacy of a categorial approach to mental health diagnosis is now well-recognised, with many authors, diagnostic manuals and funding bodies advocating a dimensional, trans-diagnostic approach to mental health research. Variance in interoception, the ability to perceive one's internal bodily state, is reported across diagnostic boundaries, and is associated with atypical functioning across symptom categories. Drawing on behavioural and neuroscientific evidence, we outline current research on the contribution of interoception to numerous cognitive and affective abilities (in both typical and clinical populations), and describe the interoceptive atypicalities seen in a range of psychiatric conditions. We discuss the role that interoception may play in the development and maintenance of psychopathology, as well as the ways in which interoception may differ across clinical presentations. A number of important areas for further research on the role of interoception in psychopathology are highlighted.

Social-Specific Impairment of Negative Emotion Perception in Alexithymia

Alexithymia has been characterized as an impaired ability of emotion processing and regulation. The definition of alexithymia does not include a social component. However, there is some evidence that social cognition may be compromised in individuals with alexithymia. Hence, emotional impairments associated with alexithymia may extend to socially relevant information. Here, we recorded electrophysiological responses of individuals meeting the clinically relevant cutoff for alexithymia (ALEX; n = 24) and individuals without alexithymia (NonALEX; n = 23) while they viewed affective scenes that varied on the dimensions of sociality and emotional valence during a rapid serial visual presentation task. We found that ALEX exhibited lower accuracy and larger N2 than NonALEX in the perception of social negative scenes. Source reconstruction revealed that the group difference in N2 was localized at the dorsal anterior cingulate cortex. Irrespective of emotional valence, ALEX showed stronger alpha power than NonALEX in social but not non-social conditions. Our findings support the hypothesis of social processing being selectively affected by alexithymia, especially for stimuli with negative valence. Electrophysiological evidence suggests altered deployment of attentional resources in the perception of social-specific emotional information in alexithymia. This work sheds light on the neuropsychopathology of alexithymia and alexithymia-related disorders.

Alexithymia Is Linked with a Negative Bias for Past and Current Events in Healthy Humans

Although research provides a rich literature about the influence of emotional states on temporal cognition, evidence about the influence of the style of emotion processing, as a personality trait, on temporal cognition is extremely limited. We provide a novel contribution to the field by exploring the relationship between difficulties of identifying and describing feelings and emotions (alexithymia) and time perspective. One hundred and forty-two healthy participants completed an online version of the TAS-20 scale, which measures alexithymia, and the Zimbardo Time Perspective Inventory, which monitors individual differences in time-orientation regarding the past, present, and future. The results show greater attention to past negative aspects in participants whose TAS-20 score was indicating borderline or manifest alexithymia, as compared to non-alexithymic individuals. Moreover, the higher the TAS-20 score, the higher the tendency was to focus on negative aspects of the past and interpret the present fatalistically. These results suggest that difficulties in identifying and describing feelings and emotions are associated with a negative bias for past and present events. Theoretical and clinical implications of this finding are discussed.

Alexithymia and Somatization in Agenesis of the Corpus Callosum

Deficient communication between the cerebral hemispheres is one of several prevailing neurobiological explanations for alexithymia and has been strongly supported by research on patients with commissurotomy. We examined self-reported symptoms of alexithymia in adults with agenesis of the corpus callosum (AgCC), a condition characterized by more subtle reductions in interhemispheric transfer than in commissurotomy. 16 adults with AgCC and FSIQ > 80 were compared with 15 age- and IQ-matched neurotypical controls. The AgCC group endorsed greater difficulty identifying and describing feelings and more vague physical symptoms than controls, but similar levels of emotional experience and emotional coping. This finding of impaired emotional interpretation with intact emotional experience is consistent with findings in callosotomy patients, implicating the critical role of the corpus callosum in cognitive dimensions of emotion processing. Further study of alexithymia in AgCC using task-based measures may help clarify the nature of this relationship.

An evaluation of alexithymia subtypes using latent profile analysis

Four subtypes of the alexithymia construct have been proposed based on different response patterns to the Cognitive and Affective dimensions of the Bermond-Vorst Alexithymia Questionnaire (BVAQ). Previous studies investigating whether alexithymia subtypes can be statistically estimated have not found complete support for these specific subtypes. These previous studies, however, contained several methodological limitations such as relatively small sample sizes, and considerations of only a limited number of proposed subtypes. In the current investigation, we examined whether the four proposed subtypes could be statistically detected in a large sample of undergraduate students (N = 612) who completed the BVAQ, using latent profile analysis (LPA). Based on observed responses to the five BVAQ subscales, consistent with previous studies, our results did not find support for the four proposed alexithymia subtypes. Rather, our results suggested LPA solutions that correspond to individuals with various degrees of alexithymia 'severity'. Although further studies are needed, especially with clinical samples, these results question the idea of four alexithymia subtypes and suggest that the implementation of these subtypes into various research studies may be a premature endeavour.

Interoception and stress in patients with Functional Neurological Symptom Disorder

INTRODUCTION

Research suggests that patients with Functional Neurological Symptom Disorder (pwFND) struggle to identify their own emotions and associated physiological cues (interoceptive sensitivity, IS). However, it is not known how this deficit interacts with stress. This study aimed to assess IS in pwFND at baseline and following stress induction, and relate the findings to self-reported emotion processing difficulties.

METHODS

Twenty-six pwFND and 27 healthy controls performed the Heart Beat Detection Task pre- and post-stress induction with the Cold Pressor Test. Participants also completed questionnaires assessing anxiety (GAD-7) and depressive symptomology (PHQ-9), as well as emotion processing (EPS-25).

RESULTS

Patients reported deficits in emotion processing (p < . 001) and had lower IS (p = .032) than healthy controls. IS improved following stress induction across both groups (p = .003) but patients' IS was lower than that of healthy controls' pre-and post-stress induction. Exploratory analyses revealed that patients reporting sensory symptoms had lower IS at baseline than patients who did not.

CONCLUSION

Our findings suggest that pwFND are relatively impaired in the identification of their emotions at baseline and following stress induction. This may be related to the experience of functional sensory symptoms and has implications for the psychological treatment of emotion dysregulation in this population.

Neurocognitive impairment and social cognition in multiple sclerosis

PURPOSE/AIM OF THE STUDY

The impairment of neurocognitive functions occurs in all subtypes of multiple sclerosis, even from the earliest stages of the disease. Commonly reported manifestations of cognitive impairment include deficits in attention, conceptual reasoning, processing efficiency, information processing speed, memory (episodic and working), verbal fluency (language), and executive functions. Multiple sclerosis patients also suffer from social cognition impairment, which affects their social functioning. The objective of the current paper is to assess the effect of neurocognitive impairment and its potential correlation with social cognition performance and impairment in multiple sclerosis patients.

MATERIALS AND METHODS

An overview of the available-to-date literature on neurocognitive impairment and social cognition performance in multiple sclerosis patients by disease subtype was performed.

RESULTS

It is not clear if social cognition impairment occurs independently or secondarily to neurocognitive impairment. There are associations of variable strengths between neurocognitive and social cognition deficits and their neural basis is increasingly investigated.

CONCLUSIONS

The prompt detection of neurocognitive predictors of social cognition impairment that may be applicable to all multiple sclerosis subtypes and intervention are crucial to prevent further neural and social cognition decline in multiple sclerosis patients.

Alexithymia

Humans are highly adept at differentiating, regulating, and responding to their emotions. At the core of all these functions is emotional awareness: the conscious feeling states that are central to human mental life. Disrupted emotional awareness-a subclinical construct commonly referred to as alexithymia-is present in a range of psychiatric and neurological disorders and can have a deleterious impact on functional outcomes and treatment response. This chapter is a selective review of the current state of the science on alexithymia. We focus on two separate but related issues: (i) the functional deficits associated with alexithymia and what they reveal about the importance of emotional awareness for shaping normative human functioning, and (ii) the neural correlates of alexithymia and what they can inform us about the biological bases of emotional awareness. Lastly, we outline challenges and opportunities for alexithymia research, focusing on measurement issues and the potential utility of formal computational models of emotional awareness for advancing the fields of clinical and affective science.

Determinants and impact of alexithymia on quality of life in Parkinson's disease

INTRODUCTION

Alexithymia is a neuropsychiatric symptom conceptualized as difficulty identifying and describing feelings. Although associated with other non-motor symptoms, mainly neuropsychiatric, alexithymia may present as an isolated symptom in persons with Parkinson's Disease (PwP). The objective of the study is to identify determinants of alexithymia and its association with quality of life (QoL) in Parkinson's disease.

METHODS

Subjects with Parkinson's disease were recruited. The following instruments were applied: Movement Disorders Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS), Non-Motor Symptoms Scale (NMSS), Montreal Cognitive Assessment (MoCA), Toronto alexithymia scale (TAS-20) and Parkinson's Disease Questionnaire (PDQ-8). Matched healthy controls were screened using TAS-20. Clinical and demographical variables were compared between alexithymic and non-alexithymic. Regression models were used to find determinants of alexithymia. Impact of alexithymia on QoL was estimated with a linear regression model.

RESULTS

98 patients were included. 56.1% PwP and 28.8% controls were alexithymic (p<0.001). Education level (OR 0.86) and NMSS urinary score (OR 1.09) determined alexithymia as well as TAS-20 score. Alexithymia was an independent determinant of QoL.

CONCLUSIONS

Alexithymia is a prevalent independent non-motor symptom in PwP with impact on QoL. Low education level and urinary symptoms are important determinants of alexithymia.

Cognitive and brain micro-structural correlates of alexithymia in essential tremor patients

Essential tremor (ET) is the most common movement disorder which has both motor and non-motor findings such as neuropsychiatic symptoms. Alexithymia is defined as inability to identify and describe emotions experienced by one's self or others. In our study, we aimed to evaluate the neurocognitive and brain micro-structural correlates of alexithymia in ET. 40 ET patients (mean age = 53.05 ± 19.74 years), were included. Fahn-Tolosa-Marin Tremor Rating Scale, Toronto Alexithymia Scale (TAS), Beck Depression Inventory, Beck Anxiety Inventory and detailed neurocognitive evaluation were applied to all patients. The patients were divided into three groups based on their TAS scores: no alexithymia, probable alexithymia, definite alexithymia. Diffusion Tensor Imaging (DTI) was performed in all patients. The mean TAS score was 50.05 ± 10.06. Depressive symptoms and anxiety levels were higher in definite alexithymia (p < 0.001, p < 0.01). Partial correlation controlling for age, gender and educational level between alexithymia scores and each cognitive test showed significant association between similarities (p < 0.001) and phonemic verbal fluency (p = 0.04). Left orbitofrontal cortex average diffusion coefficient (ADC) value (p = 0.05), left anterior cingulate cortex fractional anisotropy (FA) value (p = 0.04), right cuneus FA value (p = 0.04), left amygdala ADC value (p = 0.01) and left insula ADC value (p = 0.02) were differed between groups. TAS and DTImetrics were not found to be independently associated with the level of anxiety (p < 0.001) and depressive symptoms (p < 0.01). As a conclusion, impairments in executive function and complex attention were correlated with higher levels of alexithymia in ET. Many micro-structural alterations were determined to be correlated with alexithymia levels.

Getting lost in a story: how narrative engagement emerges from narrative perspective and individual differences in alexithymia

The present research examines how narrative engagement, or the extent to which people immerse themselves into the world of a story, varies as a function of narrative perspective and individual differences in alexithymia. The authors hypothesised that narrative engagement would be higher when people assume a first-person (rather than third-person) perspective and for people lower (rather than higher) on alexithymia. In an online study (N = 541) and a lab study (N = 55), participants with varying levels of alexithymia read first- and/or third-person narrated texts and then rated their narrative engagement. As expected, first-person stories evoked more narrative engagement than third-person stories, and global alexithymia was negatively correlated with narrative engagement. Narrative perspective did not interact with cognitive facets of alexithymia (i.e. difficulties identifying, verbalising, and understanding feelings). However, narrative perspective did interact with affective facets of alexithymia (i.e. emotionalising and fantasising): First-person (rather than third-person) stories elicited more narrative engagement at lower levels of affective alexithymia, but not at higher levels of affective alexithymia. The interaction effect was significant in Study 1; the interaction was significant in Study 2 after controlling for trait absorption. Together, these findings suggest that alexithymia is linked to difficulties in mentally simulating narrative worlds.

Deciphering the neural underpinnings of alexithymia in multiple sclerosis

OBJECTIVES

Alexithymia is a personality construct that could occur in up to 53 % of patients with multiple sclerosis (MS). It entails difficulties in identifying and describing one's feelings and an externally oriented thinking. The current work aims to assess the neural underpinnings of alexithymia in this population.

METHODS

Forty-five patients with MS filled in the Toronto Alexithymia Scale (n = 17 with high alexithymia and n = 28 with low alexithymia). Brain magnetic resonance imaging was obtained for each patient and a morphometry algorithm (MorphoBox) was applied to calculate regional brain volumes. All patients underwent a clinical and neuropsychological evaluation which included measures for anxiety, depression, fatigue, daytime sleepiness, and basic and social cognition.

RESULTS

Compared to patients with low alexithymia, patients with high alexithymia had significantly higher fatigue and depression ratings, and lower empathy scores. In addition, they had lower volumes of corpus callosum, deep white matter, pallidum bilaterally, and left thalamus. In the whole cohort, alexithymia scores were inversely correlated with gray matter (thalamus and pallidum bilaterally) and white matter volumes (corpus callosum and bilateral deep white matter) after controlling for covariates (ps<0.05).

CONCLUSION

This study offers insights on the neuropsychological and neural substrates of alexithymia in MS. The current findings are consistent with alexithymia reports in other clinical populations, and suggest an association between alexithymia and atrophy of thalami, pallidum, corpus callosum and deep white matter in MS. Further research is needed to enhance the understanding of alexithymia mechanisms in this clinical context.

Alexithymic traits predict the speed of classifying non-literal statements using nonverbal cues

There is increasing interest in exploring the impact of alexithymia on interpersonal interactions. This study explored relationships between alexithymia and the complex mentalising skills needed to infer how a speaker intended a non-literal statement to be understood. A sample of university students (N = 70) viewed videotaped exchanges and attempted to classify remarks as literal, sarcastic, jocular, or white lies. Alexithymia was not associated with less consistent labelling of statement types. However, after accounting for variance due to verbal intelligence and sex, we found that those who reported more difficulties identifying their own feelings needed more time to distinguish between different statement types on the basis of the speaker's nonverbal cues. These findings highlight the value of examining response times, and of accounting for individual differences in specific alexithymic traits, when assessing social perception and cognition.

Negative valence specific deficits in judgements of musical affective quality in alexithymia

Alexithymia is characterised by a lack of words for emotional experiences and it has been implicated in deficits in emotion processing. Research in this area has typically focused on judgements of discrete emotions rather than of affect, which is a precursor to emotion construction. In the current study, higher alexithymia was predicted to be related to more neutral judgements of valence and arousal of music representing a range of emotions. Participants (N = 162) listened to ten 15-second musical pieces that represented five target emotions (happy, sad, tender, angry, and fearful) and rated the valence and arousal of each. Participants also listed emotion words they knew to be expressed in music. Analyses revealed that alexithymia was not related to the number of emotion words generated but was related to valence-specific affect judgements of music. Participants higher in alexithymia rated sad, angry, and fearful pieces as more neutral in valence and arousal. Alexithymia was not related to ratings of valence or arousal for happy and tender pieces. These findings suggest that perceptual deficits in alexithymia may be specific to negative emotions. Our results are consistent with the idea that alexithymia is related to the direction of attention away from negative stimuli.

Alexithymia and reactive aggression: The role of the amygdala

Past research suggests an association between reactive aggression and alexithymia, but neural mechanisms underlying this association remain unknown. Furthermore, the relationship between proactive aggression and alexithymia remains untested. This study aimed to: (1) test whether alexithymia is more related to reactive than proactive aggression; and (2) determine whether amygdala, insula, and/or anterior cingulate cortical (ACC) volume could be neurobiological mechanisms for this association. One hundred and fifty-six community males completed the Reactive-Proactive Aggression Questionnaire and the Toronto Alexithymia Scale. Amygdala, insula, and ACC volumes were assessed using MRI. Alexithymia was positively associated with reactive but not proactive aggression. Alexithymia was positively and bilaterally associated with amygdala and anterior cingulate volumes. Reactive aggression was positively associated with right amygdala volume. Controlling for right amygdala volume rendered the alexithymia-reactive aggression relationship non-significant. Results suggest that increased right amygdala volume is a common neurobiological denominator for both alexithymia and reactive aggression. Findings suggest that greater right hemisphere activation may reflect a vulnerability to negative affect, which in turn predisposes to experiencing negative emotions leading to increased aggression. Findings are among the first to explicate the nature of the alexithymia-aggression relationship, with potential clinical implications.

Emotion dysregulation in patients with psychogenic nonepileptic seizures: A systematic review based on the extended process model

Psychogenic nonepileptic seizures (PNES) are characterized by paroxysmal alterations in motor and sensory functions resembling epileptic seizures, but are not caused by epileptiform activity. In recent years, there has been increasing scientific interest in emotion dysregulation in patients with PNES (pwPNES), but the literature has not yet been interpreted within a broader model of emotion dysregulation. The aim of this review was therefore to synthesize the existing literature on emotion dysregulation in pwPNES within the extended process model (EPM) of emotion regulation.

METHODS

PubMed and Web of Science were searched for studies relevant to emotion dysregulation as defined by the EPM. These studies were subjected to a bespoke quality appraisal tool. Studies of acceptable quality were categorized to the different stages of the EPM and critically appraised.

RESULTS

Studies of emotion regulation in pwPNES were generally of low quality - a finding largely driven by small sample sizes. However, there was evidence of emotion dysregulation characterized by deficits in the identification of patients' own emotional states, as well as the selection and implementation of maladaptive regulatory strategies, and altered exteroceptive emotional processing. However, heterogeneity in findings suggests that emotion dysregulation is likely linked to other psychological factors and not common to all pwPNES.

SIGNIFICANCE

This review suggests that while pwPNES are likely to experience emotion dysregulation as defined by the EPM, there is variability in the distribution of regulatory deficits in this patient population, and a person-centered approach should be taken when working with these patients. There is a need for more high quality and better-powered studies in this area.

The Multifaceted Nature of Alexithymia - A Neuroscientific Perspective

Neuroscientific studies have mostly employed the 20-item Toronto Alexithymia Scale (TAS-20; Bagby et al., 1994a) for the assessment of alexithymia, a self-report scale that assesses the alexithymia facets difficulty identifying feelings, difficulty describing feelings, and externally oriented thinking. These facets can be considered to capture difficulties in the cognitive processing of emotions associated with alexithymia. However, Nemiah and Sifneos' original conceptualization of alexithymia included also an affective component, a lack of imaginative capacities, which cannot be assessed using the TAS-20. Aiming to capture the entire alexithymia construct, the Bermond-Vorst Alexithymia Questionnaire (BVAQ; Vorst and Bermond, 2001) was developed, a self-report scale which assesses two affective facets (difficulty fantasizing and difficulty emotionalizing) in addition to three cognitive facets. Based on these facets, an affective and a cognitive dimension of alexithymia can be distinguished. By now, several neuroscientific studies have investigated the neural signatures of the different facets and dimensions of alexithymia. Here, I provide an overview of the history of the alexithymia facets and dimensions and review findings provided by functional and structural magnetic resonance imaging (MRI) studies that differentiated between the alexithymia facets and/or its affective and cognitive dimensions. I then provide a synopsis of the current neuroscientific evidence for dissociable substrates of alexithymia facets and dimensions. Finally, the scientific value and clinical implications of these findings are discussed.

Alexithymia as a Transdiagnostic Precursor to Empathy Abnormalities: The Functional Role of the Insula

Distorted empathic processing has been observed across multiple psychiatric disorders. Simulation theory provides a theoretical framework that proposes a mechanism through which empathy difficulties may arise. Specifically, introspection-centric simulation theory (IST) predicts that an inability to accurately interpret and describe internal affective states may lead to empathy difficulties. The purpose of this review is to synthesize and summarize an empirical literature suggesting that simulation theory provides insights into a cognitive and neurobiological mechanism (i.e., alexithymia and insula pathology) that negatively impacts empathic processing, in addition to how disruptions in these processes manifest across psychiatric disorders. Specifically, we review an emerging non-clinical literature suggesting that consistent with IST, alexithymia and associated insula pathology leads to empathy deficits. Subsequently, we highlight clinical research suggesting that a large number of disorders characterized by empathy pathology also feature alexithymia. Collectively, these findings motivate the importance for future work to establish the role of alexithymia in contributing to empathy deficits across clinical symptoms and disorders. The current review suggests that simulation theory provides a tractable conceptual platform for identifying a potential common cognitive and neural marker that is associated with empathy deficits across a wide array of diagnostic classes.

The role of ventromedial prefrontal cortex volume in the association of expressive suppression and externally oriented thinking

BACKGROUND

Studies have suggested that expressive suppression (ES) is linked to externally oriented thinking (EOT) through the ventromedial prefrontal cortex (vmPFC), and there are gender differences in their association. The present structural magnetic resonance imaging study was to investigate the neural bases of ES and EOT and their association in females versus males in a Chinese college sample.

METHODS

A total of 142 participants (83 females) were enrolled, and they completed the ES subscale of the Emotion Regulation Questionnaire, 20-item Toronto Alexithymia Scale, and anatomical scanning. Voxel-based morphometry, region of interest, and whole brain analyses with peak-level significance (family-wise error corrected at p < .05) were conducted to investigate the association of gray matter volume (GMV) variations with ES and EOT. A bootstrapping analysis was conducted to examine the role of vmPFC volume in the ES-EOT association.

RESULTS

The ES scores were positively linked to the GMV of the vmPFC in females and negatively related to right dorsolateral PFC volume in males. The EOT scores were positively correlated with the GMV of the vmPFC in females and supplementary motor area in males. Furthermore, vmPFC volume mediated the relationship between ES and EOT LIMITATIONS: The cross-sectional design limited causal conclusions.

CONCLUSIONS

The vmPFC may be the only neural base of ES and EOT and their association. In addition, these results were sex-specific.

Alexithymia and anesthetic bladder capacity in interstitial cystitis/bladder pain syndrome

OBJECTIVE

In contrast to the inconsistent results of organic causes, it has been found that psychological risk factors are reliably related to functional somatic syndromes (FSSs), including interstitial cystitis/bladder pain syndrome (IC/BPS). Compared to patients with acute cystitis, a subgroup of IC/BPS patients with a history of childhood relational trauma reported intensified unregulated affective states (i.e., anxiety and depression) and trauma-related psychopathology (i.e., dissociation). Nevertheless, it remains unknown whether psychosocial risk factors can be separated from bladder-centric factors. This study aimed to verify whether psychosocial factors such as alexithymia, which is a key psychological factor of FSSs, are less likely to be linked to a low bladder capacity in patients with IC/BPS.

METHODS

Ninety-four female IC/BPS patients were recruited from the outpatient departments of urology, obstetrics, and gynecology. Anxiety, depression, dissociation, childhood relational trauma, and alexithymia were assessed using standardized scales, and anesthetic bladder capacity was examined by cystoscopic hydrodistention.

RESULTS

Positive correlations were found between anesthetic bladder capacity and the psychosocial variables, including alexithymia. An increased bladder capacity was associated with anxiety, dissociation, and childhood relational trauma, and a combination of high cognitive and low affective alexithymia mediated the correlations between bladder capacity and the psychosocial variables.

CONCLUSIONS

Psychosocial variables that are associated with an aversive childhood relational environment and affect dysregulation may constitute a pathogenic trajectory that differs from bladder-centric defects such as a lower bladder capacity. The findings of this study support the notion that IC/BPS in some patients may be due to an FSS.

Illuminating the clinical significance of alexithymia subtypes: A cluster analysis of alexithymic traits and psychiatric symptoms

BACKGROUND

Alexithymia is a personality construct involving difficulties identifying and verbalizing feelings, and an externally oriented thinking style. There is preliminary evidence for alexithymia subtypes that may carry different risk profiles for psychiatric illness. The aim of this study was to gain support for the existence of alexithymia subtypes and further characterize their clinical relevance.

METHODS

To identify possible subtypes, a cluster analysis was conducted for individuals with high alexithymic traits (N=113). Current depressive and anxiety symptoms, self-reported psychiatric medical history, and self-reported early life adversity were compared between subtypes. The cluster analysis was replicated with the low (N=2471) and moderate (N=290) alexithymia groups.

RESULTS

We identified two alexithymia subtypes. Compared to type A, type B alexithymia was associated with higher levels of difficulties in identifying feelings, and was more strongly associated with current depressive (Cohen's d=0.77, p<0.001) and anxiety symptoms (Cohen's d=0.82, p<0.001), and self-reported early life adversity (Cohen's d 0.42, p=0.048). Compared to type A, type B alexithymia was also associated with a higher prevalence of self-reported diagnosis of major depressive- (30.2% vs. 8.3%) and anxiety disorder (18.9% vs. 3.3%).

CONCLUSIONS

The results of this study support the hypothesis of alexithymia subtypes, and add support to the growing evidence showing that alexithymia is likely a heterogeneous and dimensional phenomenon. The subtype (type B) with most pronounced difficulties in identifying feelings may be associated with a higher risk for psychiatric illness compared to type A alexithymia, and may exhibit a more severe history of early life adversity.

Autonomic Reactivity to Arousing Stimuli with Social and Non-social Relevance in Alexithymia

Emotional difficulties in alexithymia and their social consequences have been linked to alterations in autonomic nervous system. However, most of previous studies did not take into account the distinction between the affective and the cognitive dimensions of the alexithymia, leading to inconsistent results. Aim: In this study, we compared the effects of both dimensions of alexithymia on the autonomic arousal to emotional and social visual stimulations. Methods: Skin conductance responses (SCRs) to items of the International Affective Pictures System characterized by emotional (unpleasant, neutral, and pleasant), social (with humans) or non-social (without humans) content were recorded in non-alexithymic (NA), affective (AA) and cognitive alexithymic (CA) participants, selected on the basis of the Toronto Alexithymia Scale and the Bermond-Vorst Alexithymia Questionnaire. All participants responded to questionnaires of empathy, social phobia, depression, and anxiety before the experiment and evaluated the arousal of the pictures after it. Results: Cognitive alexithymic group showed lower amplitudes of SCRs to pictures with social than without social relevance whereas the opposite pattern was observed for the NA group. Arousal emotional effects of the pictures on SCRs did not differ among groups. In addition, CA participants showed lower scores than NA in the Personal Taking sub-scale of the empathy questionnaire, while AA showed lower scores than NA in the fantasy sub-scale. The CA group showed higher social phobia, depression and anxiety scores, than the other two groups. Conclusion: This work has two original outcomes: first, affective alexithymics expressed lower empathic affective scores than other groups; second, alexithymia modulated the impact of the social relevance of the stimuli on the autonomic reactivity, this impact vanishing in affective alexithymics and reversing in cognitive alexithymics. Thus, though the groups could not be distinguished on the basis of emotional effect on SCRs, they clearly differed when the empathic characteristics and the autonomic impact of social relevance were considered. Finally, the described autonomic signature to social relevant information could contribute to elucidate the difficulty of alexithymics to deal with emotions during social transactions.

Parental Praise Correlates with Posterior Insular Cortex Gray Matter Volume in Children and Adolescents

A positive parenting style affects psychological and cognitive development in children. Neuroimaging studies revealed that a positive parenting style influenced brain structure in children. Parental praise is a concrete behavior observed in positive parenting. Although previous psychological studies revealed a positive effect of parental praise on children, little is known about the relationship between parental praise and brain structure in children. Thus, the purpose of the present study was to determine whether there was a correlation between the parental attitude towards praising their child and gray matter volume in the children (116 boys and 109 girls; mean age, 10.6 years old). We examined the correlation between regional gray matter volume and parental praise using voxel-based morphometry (VBM) following magnetic resonance imaging (MRI). In addition, to confirm the positive effects of parental praise, we analyzed the correlation between the frequency of parental praise and personality traits in children. We showed that the parental attitude towards praising their child was significantly and positively correlated with the gray matter volume of the left posterior insular cortex in children. Moreover, we found a significant positive correlation between parental attitude towards praising their child and the personality traits of conscientiousness and openness to experience in the children. Prior studies said that gray matter volume in the posterior insula was correlated with empathy, and the functional connectivity between this area and the amygdala was associated with emotional regulation. Furthermore, the posterior insula relates to auditory function, and therefore, was likely involved in the processing of parental praise. Considering the possibility of experience-dependent plasticity, frequent parental praise would lead to increased posterior insular gray matter volume in children. Our study is the first to elucidate the relationship between a specific positive parenting behavior and brain structure in children.