Étude des relations entre alexithymie et anhédonie chez des femmes présentant des troubles du comportement alimentaire et chez des témoins

The mediating role of alexithymia and cognitive flexibility in the relationship between behavioral inhibition system/behavioral activation system and depression in Turkish population

This study aims to examine the relationships between the behavioral inhibition system (BIS)/behavioral activation system (BAS), depression, cognitive flexibility, and alexithymia, and to determine the mediator role of cognitive flexibility and alexithymia in the relationship between BIS/BAS and depression. Data were collected from a community sample, consisting of 1,275 people, 904 women (70.90%) and 371 (29.10%) men, aged 18-65 years. It was detected that the whole variables in this research were interrelated. Additionally, for the mediation analyses, two significant models in which were determined the mediator role of cognitive flexibility and alexithymia in the relationship between the dimensions of BIS-Fear and BAS-Reward and depression were created. Consequently, high BIS-Fear and low BAS-Reward were associated with susceptibility to depression through decreased cognitive flexibility and increased alexithymia. Moreover, it may be possible to identify which subdimensions of alexithymia and cognitive flexibility play a role in the relationship between depression and reward/punishment systems and which of these are risk factors via the models tested in this study. In this way, clinical interventions for the factors that are both associated with depressive symptoms and mediators for depression can be planned and this can help to achieve effective results in the therapy process.

Anhedonia in Eating Disorders

Anhedonia is frequently observed among individuals with eating disorders (ED), though its relevance to ED pathology and clinical outcomes remain poorly understood. This chapter will present the latest findings regarding anhedonia in ED, with the majority of data available for anorexia nervosa (AN) and bulimia nervosa (BN). We consider anhedonia from the mechanistic lens of altered reward processing, with attention given to subjective experience, neurotransmitter function, neural correlates, and cognitive performance corresponding to distinct components of reward (i.e., liking, wanting, and learning). Findings from animal models are also highlighted. The chapter concludes with a discussion of implications for treatment and future directions aimed at better understanding anhedonia in ED.

A Transdiagnostic Perspective on Social Anhedonia

Humans are highly social beings, yet people with social anhedonia experience reduced interest in or reward from social situations. Social anhedonia is a key facet of schizotypal personality, an important symptom of schizophrenia, and increasingly recognized as an important feature in a range of other psychological disorders. However, to date, there has been little examination of the similarities and differences in social anhedonia across diagnostic borders. Here, our goal was to conduct a selective review of social anhedonia in different psychological and life course contexts, including the psychosis continuum, depressive disorder, posttraumatic stress disorder, eating disorders, and autism spectrum disorders, along with developmental and neurobiological factors. Current evidence suggests that the nature and expression of social anhedonia vary across psychological disorders with some groups showing deficient learning about, enjoyment from, and anticipation of the pleasurable aspects of social interactions, while for others, some of these components appear to remain intact. However, study designs and methodologies are diverse, the roles of developmental and neurobiological factors are not routinely considered, and direct comparisons between diagnostic groups are rare-which prevents a more nuanced understanding of the underlying mechanisms involved. Future studies, parsing the wanting, liking, and learning components of social reward, will help to fill gaps in the current knowledge base. Consistent across disorders is diminished pleasure from social situations, subsequent withdrawal, and poorer social functioning in those who express social anhedonia. Nonetheless, feelings of loneliness often remain, which suggests the need for social connection is not entirely absent. Adolescence is a particularly important period of social and neural development and may provide a valuable window on the developmental origins of social anhedonia. Adaptive social functioning is key to recovery from mental health disorders; therefore, understanding the intricacies of social anhedonia will help to inform treatment and prevention strategies for a range of diagnostic categories.

High levels of alexithymia in patients with multiple sclerosis

Alexithymia is a personality trait characterized by difficulties identifying and describing feelings. Some researchers describe high levels of alexithymia among patients with multiple sclerosis (MS) but literature data on this subject are scarce.

Differences in regional grey matter volumes in currently ill patients with anorexia nervosa

Neurobiological findings in anorexia nervosa (AN) are inconsistent, including differences in regional grey matter volumes. Methodological limitations often contribute to the inconsistencies reported. The aim of this study was to improve on these methodologies by utilising voxel-based morphometry (VBM) analysis with the use of diffeomorphic anatomic registration through an exponentiated lie algebra algorithm (DARTEL), in a relatively large group of individuals with AN. Twenty-six individuals with AN and 27 healthy controls underwent a T1-weighted magnetic resonance imaging (MRI) scan. AN participants were found to have reduced grey matter volumes in a number of areas including regions of the basal ganglia (including the ventral striatum), and parietal and temporal cortices. Body mass index (BMI) and global scores on the Eating Disorder Examination Questionnaire (EDE-Q) were also found to correlate with grey matter volumes in a region of the brainstem (including the substantia nigra and ventral tegmental area) in AN, and predicted 56% of the variance in grey matter volumes in this area. The brain regions associated with grey matter reductions in AN are consistent with regions responsible for cognitive deficits associated with the illness including anhedonia, deficits in affect perception and saccadic eye movement abnormalities. Overall, the findings suggest reduced grey matter volumes in AN that are associated with eating disorder symptomatology.

Deranged endocannabinoid responses to hedonic eating in underweight and recently weight-restored patients with anorexia nervosa

BACKGROUND

A dysregulation of reward mechanisms was suggested in the pathophysiology of anorexia nervosa (AN), but the role of the endogenous mediators of reward has been poorly investigated. Endocannabinoids, including anandamide and 2-arachidonoylglycerol, and the endocannabinoid-related compounds oleoylethanolamide and palmitoylethanolamide modulate food-related and unrelated reward. Hedonic eating, which is the consumption of food just for pleasure and not homeostatic need, is a suitable paradigm to explore food-related reward.

OBJECTIVE

We investigated responses of endocannabinoids and endocannabinoid-related compounds to hedonic eating in AN.

DESIGN

Peripheral concentrations of anandamide, 2-arachidonoylglycerol, oleoylethanolamide, and palmitoylethanolamide were measured in 7 underweight and 7 weight-restored AN patients after eating favorite and nonfavorite foods in the condition of no homeostatic needs, and these measurements were compared with those of previously studied healthy control subjects.

RESULTS

1) In healthy controls, plasma 2-arachidonoylglycerol concentrations decreased after both types of meals but were significantly higher in hedonic eating; in underweight AN patients, 2-arachidonoylglycerol concentrations did not show specific time patterns after eating either favorite or nonfavorite foods, whereas in weight-restored patients, 2-arachidonoylglycerol concentrations showed similar increases with both types of meals. 2) Anandamide plasma concentrations exhibited no differences in their response patterns to hedonic eating in the groups. 3) Compared with 2-arachidonoylglycerol, palmitoylethanolamide concentrations exhibited an opposite response pattern to hedonic eating in healthy controls; this pattern was partially preserved in underweight AN patients but not in weight-restored ones. 4) Like palmitoylethanolamide, oleoylethanolamide plasma concentrations tended to be higher in nonhedonic eating than in hedonic eating in healthy controls; moreover, no difference between healthy subjects and AN patients was observed for food-intake-induced changes in oleoylethanolamide concentrations.

CONCLUSION

These data confirm that endocannabinoids and endocannabinoid-related compounds are involved in food-related reward and suggest a dysregulation of their physiology in AN. This trial was registered at ISRCTN.org as ISRCTN64683774.

Alexithymia in anorexia nervosa: the mediating role of depression

The role of depression in the expression of alexithymia in anorexia nervosa (AN) has been controversially explained and several variables that may mask or increase the presence of emotional difficulties have scant examination in previous studies. This study aims to analyze the associations between alexithymia and state variables, such as age, BMI, illness duration, treatment duration, and medication status in AN participants, and to test the mediating role of depression in emotional difficulties. The Toronto Alexithymia Scale (TAS-20) and the Zung Self-Rating Depression Scale were administrated to 160 females: 80 participants with AN and 80 healthy controls. High levels of alexithymia were not a function of state variables. The mediating role of depression differed by the alexithymia dimension, with total mediation found for the TAS-DDF and partial mediation found for the TAS-DIF. Alexithymia is a relevant feature throughout the spectrum of AN and does not seem to be related to developmental maturation and some clinical features. Depression is probably the variable that best accounts for the variance in alexithymia, but is not a complete explanation for the known cognitive-affective disturbances in AN. Specific emotional competencies require scrutiny during psychiatric treatment.

Alexithymia, a compounding factor for eating and social avoidance symptoms in anorexia nervosa

Socio-affective difficulties, in particular difficulties in representing, communicating and feeling emotions, may play a critical role in anorexia nervosa (AN). The aim of this longitudinal study was to explore the links between alexithymia and two types of difficulties in AN: eating symptoms and social avoidance. Sixty adolescent girls with AN were recruited following hospitalisation in a specialised department. They completed self-administered questionnaires of alexithymia (TAS-20), of central symptoms of the eating disorders (EDI), and of anxious and depressive affects (SCL-90). Anxiety and social avoidance were assessed in the course of a standardised interview (LSAS). These measures were performed at inclusion, and at 6-, 12- and 18-months' follow-up. The relationship between TAS-20 and EDI or LSAS total scale scores across the four time points was assessed using mixed-effects models, including anxiety, depression, BMI, anorexia subtype, and age as co-factors. Partial least square regression was used to refine this multivariate analysis at subscale level, at inclusion and 18 months. Robust associations between TAS-20 and EDI scores were found, independently from anxious and depressive scores, nutritional state and AN subtype. These effects appeared more particularly linked to the implication of the dimensions difficulties identifying and describing feelings, interpersonal mistrust, feelings of inadequacy and interoceptive awareness deficit. There was also a durable association between alexithymia and social anxiety and avoidance, after adjusting for the confounding effects of depression, and anxiety, and the state of starvation. Difficulties in describing feelings appeared particularly involved here. Thus alexithymia does appear as a factor in the persistence of disorders in AN, and difficulties identifying and describing feelings could compound the social difficulties and major the relational isolation of these patients.

Why study positive emotions in the context of eating disorders?

Experimental research, supported by systematic reviews, establishes that people with eating disorders have emotional difficulties in terms of recognising, regulating and expressing their emotions. These emotional difficulties contribute to poor social functioning and problems with relationships. The existing literature includes a broad range of studies, many of which have utilised self-report measures, but experimental studies of emotions in eating disorders are still limited. The primary aim of this paper is to highlight gaps in the clinical research on emotions in eating disorders, focusing on experimental investigations from our lab and highlighting potentially useful future directions for further basic research and its translation into new developments in treatment and prevention. Recent findings using experimental paradigms to study the expression of emotions along with neuroimaging research exploring differences in facial emotion processing are discussed, and clinical implications are presented.

Social anhedonia and work and social functioning in the acute and recovered phases of eating disorders

Interpersonal difficulties are proposed to maintain eating disorders (EDs). This study explored whether social anhedonia (SA) was an additional social emotional maintenance factor which might also explain work/social problems in EDs. Additionally, the study explored SA and work and social adjustment in recovered participants. Women with anorexia nervosa (AN; n=105), bulimia nervosa (BN; n=46), recovered from AN (RAN; n=30) and non-ED controls (n=136) completed the Work and Social Adjustment Scale (WSAS) and the Revised Social Anhedonia Scale. ED participants reported greater SA and WSAS scores than non-ED controls; the RAN group reported an intermediate profile. AN participants had poorer work/social adjustment than BN participants. SA was associated with longer illness duration. SA, current severity (BMI) and lifetime severity (lowest adult BMI) significantly predicted work/social difficulties. Recovered participants scoring in the clinical range for SA experienced significantly greater work/social difficulties than recovered participants scoring outside the clinical range for SA. EDs are associated with clinical levels of SA and poor work/social functioning which reduce in recovery. SA may maintain the interpersonal functioning difficulties.

[Emotion regulation in adolescents with conduct disorder and controls]

OBJECTIVES

Although many authors have highlighted similarities between conduct disorder (CD) and alexithymia, little empirical research has actually investigated the contribution of emotion processing to CD. The purpose of this study was to explore the relationships between CD and scores on affect regulation scales among 75 adolescents: a group of 30 adolescents with CD and a group of 45 controls, ranging in age from 13 to 18.

METHOD

All participants filled in a socio-demographic questionnaire. CD diagnosis was assessed in regard to DSM-IV criteria using the specific CD section of the Kiddie-Sads. Affect regulation was measured with two self-reports: TAS-20 (Toronto Alexithymia Scale), known as the gold standard for alexithymia measurement, and DERS (Difficulties in Emotion Regulation Scale), a recently validated scale. In addition, since depression may influence the correlations between CD and alexithymia, it was also measured with the BDI. In order to have more information on the CD group, the CTQ was also used. One way analyses of variance adjusting for age were used for mean score comparisons. Partial correlations adjusting for age were used to investigate the link between the CD severity (the severity index was calculated from the Kiddie-Sads) and affect regulation scores. Finally, discriminant analyses were conducted to explore whether affect regulation could correctly categorize controls and adolescents with CD.

RESULTS

These results provided some additional data in order to understand the relationship between affect regulation and CD. Controls and adolescents with CD had significantly different emotion regulation scales scores at both scales (TAS-20 and DERS) and in most of their dimensions. Moreover, they also point out the positive correlation between difficulties in affect regulation and CD severity. To our knowledge, this is the first study to have investigated relationships between CD and alexithymia using a severity index of CD. Finally, discriminant analyses showed that the two emotion regulation scales permitted the significant discrimination of both groups. These results are consistent with previous works highlighting the theoretical relationship between deficit in mental elaboration and acting-out. They point to the need to develop therapeutic programs in order to improve emotion regulation of teenagers with CD. Finally, an additional analysis showed a relationship between emotional neglect in childhood (measured with CTQ) and the CD severity. A task for future research would be to study the relationships between attachment, emotional regulation and CD in adolescence.

Increased BOLD signal in the fusiform gyrus during implicit emotion processing in anorexia nervosa

Background

The behavioural literature in anorexia nervosa (AN) has suggested impairments in psychosocial functioning and studies using facial expression processing tasks (FEPT) have reported poorer recognition and slower identification of emotions.

Methods

Functional magnetic resonance imaging (fMRI) was used alongside a FEPT, depicting neutral, mildly happy and happy faces, to examine the neural correlates of implicit emotion processing in AN. Participants were instructed to specify the gender of the faces. Levels of depression, anxiety, obsessive–compulsive symptoms and eating disorder behaviour were obtained and principal component analysis (PCA) was performed to acquire uncorrelated variables.

Results

fMRI analysis revealed a greater blood-oxygenation level dependent (BOLD) response in AN in the right fusiform gyrus to all facial expressions. This response showed a linear increase with the happiness of the facial expression and was found to be stronger in those not taking medication. PCA analysis revealed a single component indicating a greater level of general clinical symptoms.

Conclusion

Neuroimaging findings would suggest that alterations in implicit emotion processing in AN occur during early perceptual processing of social signals and illustrate greater engagement on the FEPT. The lack of separate components using PCA suggests that the questionnaires used might not be suited as predictive measures.

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Greater BOLD response in AN in the right fusiform gyrus to all facial expressions.

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The BOLD response showed a linear increase with the happiness of the expression

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The BOLD response was stronger in those not taking psychotropic medication

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These alterations occur during early perceptual processing of social signals

Emotional aspects of anorexia nervosa: results of prospective naturalistic cognitive behavioral group therapy

BACKGROUND

Anorexic girls have difficulties in handling their emotions. We examined emotional problems of adolescent girls with anorexia nervosa (AN) during the course of cognitive behavioral group therapy (G-CBT).

METHODS

Overall, 29 girls with AN (age 13-17 years) participated in four groups of manual based G-CBT. We assessed the body mass index (BMI), eating behavior psychopathology, emotions, depression, hedonistic activities, self-care and-efficacy, social phobia, sense of coherence (SOC), and alexithymia before, during and up to 1 year after therapy.

RESULTS

Out of 29, 16 (55 %, intent to treat, or 76 %, per protocol) girls were successfully treated, 5 (17 or 24 %) had a "poor outcome", and 8 (28 %) dropped out. BMI, eating behavior, mood, social anxiety, self-care, and self-efficacy persistently improved. Anorexic girls had multiple emotional deficits, low self-confidence, and exaggerated needs of control and of being accepted. Emotional deficits were resistant to change. Hedonistic activities, social skills, and recovery from depression were positive, comorbid disorders and parental psychopathology negative prognostic factors.

Neuroanatomical correlates of trait anhedonia in patients with schizophrenia: a voxel-based morphometric study

The aim of this study was to characterize the association between trait anhedonia and regional gray matter volume in patients with schizophrenia. Forty-six patients with schizophrenia and 56 healthy controls underwent magnetic resonance imaging (MRI) to acquire high-resolution T1-weighted images. Trait anhedonia was measured using the Chapman Revised Physical Anhedonia Scale (PAS). Voxel-based morphometry was performed to investigate brain volume correlates of trait anhedonia. Several brain regions in the patient group, including the left precuneus and right posterior cingulate (PCC), were found to show significantly less correlation with PAS scores than those of the control group. Post-hoc analysis revealed that negative correlations between the regional gray matter volume and the PAS scores in the patient group were found at a trend level in the left precuneus and the right PCC. In conclusion, these findings suggest that trait anhedonia in patients with schizophrenia could possibly be associated with a volume deficit in brain regions related to default-mode, which reflects the impairment of self-referential processing and reward anticipation.

Pleasure for visual and olfactory stimuli evoking energy-dense foods is decreased in anorexia nervosa

Although patients with anorexia nervosa have been suggested to be anhedonic, few experiments have directly measured their sensory pleasure for a range of food and non-food stimuli. This study aimed to examine whether restrictive anorexia nervosa (AN-R) patients displayed: i) a generalized decline in sensory pleasure or only in food-related sensory pleasure; ii) a modification of hedonic responses to food cues (liking) and of the desire to eat foods (wanting) as a function of their motivational state (hunger vs. satiety) and energy density of foods (high vs. low). Forty-six female participants (AN-R n=17; healthy controls (HC) n=29) reported before/after lunch their pleasure for pictures/odorants representing foods of different energy density and non-food objects. They also reported their desire to eat the foods evoked by the sensory stimuli, and completed the Physical Anhedonia Scale and the Beck Depression Inventory. AN-R and HC participants did not differ on liking ratings when exposed to low energy-density food or to non-food stimuli. The two groups also had similar physical anhedonia scores. However, compared to HC, AN-R reported lower liking ratings for high energy food pictures regardless of their motivational state. Olfactory pleasure was reduced only during the pre-prandial state in the AN-R group. The wanting ratings showed a distinct pattern since AN-R participants reported less desire to eat the foods representing both low and high energy densities, but the effect was restricted to the pre-prandial state. Taken together these results reflect more the influence of core symptoms in anorexia nervosa (fear of gaining weight) than an overall inability to experience pleasure.

Odor perception in alexithymic patients

Alexithymia is characterized by a marked inability to identify feelings and emotional states and some studies have documented sensorial perception in response to visual or auditory cues in this disease. Although olfaction is well known for its emotional correlates, the perception of olfactory stimulations has not been previously investigated. This study compares with standard psychophysical methods the olfactory sensitivity and the self-ratings of intensity and hedonic valence of a panel of odorants in alexithymic patients, non-alexithymic patients and control subjects. Results show that alexithymics over-evaluate intensity and pleasantness of odorants compared to non-alexithymics or control subjects. This could be interpreted in the framework of a lack of inhibitory control including this particular sense.