Emotions in Eating Disorders: The Interplay of Emotion Regulation and Inhibitory Control in Appetite and Eating Behaviour

Abstract

OBJECTIVES: The main goals of this thesis were to examine the link between the regulation of emotions and disordered eating to obtain insights into the processes underlying ED psychopathology. More specifically, this work aimed to expand upon previous knowledge on emotion regulation in ED patients and upon the effects of these difficulties on eating patterns and craving. An additional aim was to advance the research regarding addiction-like eating and to contribute to the discussion about the validity and usefulness of the FA concept.

RESULTS: Study 1: A systematic review of a total of 39 studies showed alterations in emotional facial expression across different mental disorders (obsessive-compulsive disorder, depression, bipolar disorder, borderline personality disorder, AN, BN, autism spectrum disorder, and disruptive behaviour disorder). A meta-analysis showed decreased facial expressivity in response to positive and negative stimuli in patients with AN, with a higher summary effect size for positive (d=1.01) than for negative (d=.58) stimuli.

Study 2: ED patients had higher values than HC in the total score and in all subscales of difficulties in emotion regulation. Results furthermore showed that difficulties in emotion regulation mediate the influence of harm avoidance and self-directedness on ED severity. While for self-directedness an indirect and a direct effect on ED was found, the effect of harm avoidance was fully explained through the level of difficulties in emotion regulation.

Study 3: This study on predictors of FA in ED patients showed that those patients with higher levels of FA are characterized by lower self-directedness, more negative urgency and less perseverance. The probability of receiving an FA “diagnosis” was predicted by higher reward dependence, higher negative urgency and higher premeditation. Negative urgency was the strongest predictor of FA in patients with an ED.

Study 4: Results suggest that of the variables included the only independent predictor of FA might be negative urgency. Self-directedness and emotion regulation predicted negative urgency and were highly related to ED symptomatology in general, but not to FA.

Study 5: A systematic review of 26 studies on attentional processing of food stimuli as measured through electrophysiological potentials showed high motivated attention towards food pictures compared to neutral pictures in all participants. This review shows that the type of eating pathology and other factors such as the availability of food and the type of stimuli have an influence on the attentional processing of food cues; however, further research is needed for a better understanding of the subject.

Study 6: In this study on stimulus-induced chocolate craving patients with binge-eating pathology reported higher craving than controls; both groups experienced a significant increase in craving when exposed to the smell and sight of chocolate. Amplitudes of electrophysiological event-related potentials were higher for chocolate than for neutral pictures. The Late Positive Potential as measure of motivated attention did not differ between groups. Patients compared to HC had lower baseline amplitudes of an electrophysiological potential related to inhibitory control (N2) in neutral trials but showed a higher relative increase in N2 amplitudes related to chocolate pictures. Priming chocolate pictures by chocolate odour compared to neutral odour led to a slightly increased craving response and to an increased activation of inhibitory control resources in binge-eating patients.

CONCLUSIONS: Alterations in facial emotional expressivity and self-reported difficulties in emotion regulation point towards emotional problems underlying ED psychopathology. Unregulated affect and decreased facial emotional expressivity might explain difficulties to recognize own and other’s emotions and thus constrain satisfactory social relations. Negative urgency is a form of impulsivity related to negative affect and is shown to be specifically associated to addictive eating patterns in patients with EDs. There is a possible incentive sensitization of food cues, which is seen in that food stimuli lead to more motivated attention than neutral stimuli.

Los objetivos principales de esta tesis doctoral fueron el análisis de la relación entre la regulación emocional y los TCA, para incrementar el entendimiento de los procesos que subyacen a la psicopatología del TCA. Más concretamente, este trabajo tuvo como objetivo ampliar los conocimientos sobre la regulación emocional, en los pacientes con TCA, y sobre los efectos de estas dificultades en los patrones de alimentación y el deseo por la comida. Otro objetivo fue avanzar en la investigación relacionada con hábitos alimentarios similares a la adicción, contribuyendo a la discusión sobre la validez y la utilidad del concepto de la AC. Teniendo en cuenta que la sensibilización incentivada está relacionada con la atribución de significado motivacional a los estímulos potencialmente adictivos, otro objetivo fue investigar si la prominencia de incentivación de alimentos claves, está alterada en pacientes con TCA en comparación con individuos sanos.

Los resultados demostraron que las alteraciones en la regulación emocional, identificadas a través de la expresión facial y de las medidas de autoinforme apuntan a los problemas emocionales que subyacen la psicopatología de los TCA. El afecto mal regulado y la disminución de la expresividad emocional facial, podrían explicar las dificultades para reconocer las propias emociones y los emociones de otros, limitando el establecimiento y mantenimiento de relaciones sociales satisfactorias. La urgencia negativa es una forma de impulsividad relacionada a las emociones negativas, demostrándose que está específicamente asociada a los patrones de alimentación adictivos, en los pacientes con TCA. Existe una posible sensibilización a los incentivos ante determinados estímulos alimentarios. Cuando éstos se comparan con estímulos neutros se identifica la presencia de una atención motivacional alterada. Se confirmó un elevado sesgo atencional frente a la comida, en distintos patrones de alimentación anormal, principalmente referente a la orientación atencional. Además, los intervalos de tiempo posteriores parecían estar afectados por estrategias cognitivas que los individuos utilizarían con el fin de controlar su conducta alimentaria. El olor del chocolate es un potente estímulo para inducir deseo de comer y podría aumentar la respuesta a los estímulos visuales.