**6.2 Neurobiological explanations**

Neurobiological studies of AN focus on the brain areas, biological origins of symptoms, and neurochemical differences between people diagnosed with AN and healthy controls. Severe weight loss in anorexia causes a decrease in gray matter in several areas of the brain [56]. Moreover, a review of neuroimaging studies (PET, MRI, and fMRI) noted dysfunction in certain brain areas such as the amygdala, basal ganglia structures, and hippocampus [57]. On the other hand, research indicates dysfunctions in dopaminergic and serotonergic (5-HT) systems that are responsible for food, motivation, the reward system, executive function, emotion regulation, and impulse control [58]. Thus, food as a natural reward becomes a

source of both threat and anxiety, which makes it easier to avoid or restrict [59]. Neuroimaging studies also support this explanation. In one fMRI study with AN patients, an increase in amygdala activity (threat perception) and a decrease in inferior parietal lobe activity (food-related pleasure and interest) were evident while patients were looking at food pictures [60]. Furthermore, AN patients give different responses to body-related words and pictures than controls. They pay more attention to these words and pictures, focusing on the parts of the body rather than focusing on the body as a whole; they experience cognitive, perceptual, and emotional changes when they look at their own body [61, 62]. These changes can be explained through the decrease in occipital and prefrontal cortex activity.

Lastly, the "insula hypothesis" is proposed as a neurological model of anorexia nervosa that states that a dysfunction of the neural circuitry integrated by the insula can be responsible for the clinical presentation of AN [63, 64]. Symptoms arise because of disability in the insula, which establish a homeostatic balance by linking the brain's perception, emotional response, and memory-related regions to each other. Thus, it is assumed that this dysfunction causes changes in reactions to foods, internal and external bodily sensations, and emotional processing.

#### **6.3 Psychodynamic explanations**

Psychodynamic explanations usually offer a unique way to understand patients' experiences of AN. These models emphasize the meanings and functions of symptoms and early childhood experiences that may cause fixation or unconscious conflicts related to individualization, separation, dependency, and control. From a psychoanalytic perspective, restriction of food symbolizes an area of control and a denial of growing up or becoming a woman [65]. Thus, the patient can stay as a child and can be looked after. Furthermore, family dynamics play an important role in these psychodynamic models. Excessive involvement, rigidity, inability to resolve conflict, and excessive protectionism are common dynamics in families of AN sufferers [66]. Bruch [67] also stated that this overinvolvement by "perfect" mothers may cause ineffectiveness in the child, resulting in these children may be not being able to identify and understand their needs or internal states. When food becomes a way of self-soothing, relaxing, and communicating, this pattern may result in eating related symptoms. Nevertheless, psychodynamic explanations are important to understand patients as individuals. However, generalization and causality is always a problem within these explanations. Moreover, these models fail to explain why childhood relationships are expressed through eating behaviors. In addition, it is always difficult to test or evaluate these explanations.

#### **6.4 Cognitive behavioral explanations**

Behavioral models of anorexia nervosa regard the disorder as a behavior that has been learned and is maintained through reinforcement. Individuals reduce their food intake as a means to lose weight due to the social pressure to be thin or other experiences, and this behavior is reinforced by sociocultural norms, feelings of being in control. These first explanations were criticized for not focusing on causal factors, and therefore cognitive explanations were proposed to be linked with these behaviors. Slade [68] pointed out that interpersonal problems and family conflicts underlie the perfectionistic tendency in anorexia, and this tendency is a triggering factor for dieting. Cognitive explanations focus on patients' thoughts about food, eating, weight, and shape which parallel Beck's model on depression [69]. Moreover, predisposing factors for self-starvation such as perfectionism, self-criticizing, and control were specified [70]. Thus, once the dieting and weight loss begin, they are

**73**

social ones.

**6.6 Risk factors in etiology**

*Anorexia Nervosa*

and behaviors.

**6.5 Sociocultural explanations**

*DOI: http://dx.doi.org/10.5772/intechopen.91278*

reinforced and maintained easily as they become a way of gaining self-esteem. With the evidence-based studies, cognitive behavioral therapy (CBT) becomes the leading approach in both understanding and treating EDs in general [71]. CBT explains the etiology in AN as follows: dysfunctional thoughts of weight shape and body are influential in the development and persistence of symptoms, while weight control or compensatory methods (dieting, exercise, etc.) continue to reinforce the disorder. Symptoms are also conceptualized as a coping mechanism and a way of emotion regulation. Lately, Fairburn [6] has developed a transdiagnostic model of EDs that conceptualizes EDs beyond the diagnostic categories and targets the mechanism that is sustainable in all eating disorders. From Fairburn's transdiagnostic perspective, AN, BN, BED, and ED-NOS share the same core pathology that is cognitive in nature. For patients, the overvaluation of body shape and weight and their control is the most important part of life that defines and determines the worth of one's self. This pathology both causes and maintains eating and compensatory behaviors. In the case of anorexia, the consequences of malnutrition and hunger affect the cognitive ability of patients, which also causes rigidity in thoughts

Sociocultural models focus on the impact of culture and environment on body image and emphasize the importance of body image problems in the development of AN. Cultural expectations of thinness, usually termed "thin idealization," come from the media, family, friends, and peers [72]. Thinness is generalized within the scope of many positive meanings such as beauty, desirability, success, will, appreciation, charm, and control. Notably, exposure to images represented in the media that are often biologically unreachable for many women or even unreal (e.g., photoshopped) suggests thinness as a route to happiness, love, and success. Sociocultural models emphasize that the ideals of thinness are internalized through messages given by society, the media, peers, and family, resulting in eating and body problems and psychological symptoms in people who are dissatisfied with their body [73]. Lately, social media applications like Instagram and Tumblr and their impact on eating and body problems have become the focus of research in this area. Internalization of this thin ideal and an increase in body dissatisfaction are correlated with the prevalent pictures and the following of the accounts of thin people, celebrities, models, and actors [74]. Consequently, sociocultural factors play an important role in the thin idealization, but it is assumed that anorexia nervosa is developed through many factors including biological, cognitive, emotional, and

Several risk factors that include body dissatisfaction, dieting, being involved in body-related activities/sports/professions (dancing, ballet, athletics, modelling, acting, etc.), personality traits, family dynamics, and stress/trauma are stated as contributing to the etiology of anorexia [75]. Personality traits such as perfectionism, an obsessive-compulsive personality, and deficits in emotion regulation are prevalent in AN [76, 77]. These personality dimensions can be considered as both the predisposing and maintaining factors. Besides family dynamics, as we reviewed in the psychoanalytic model, are also important. Insecure attachment styles through stressful early childhood experiences and food-/body-related communications [78, 79] are the prominent factors related to the family. There is also some evidence of decreased family functioning in families of AN patients; however this might be a

#### *Anorexia Nervosa DOI: http://dx.doi.org/10.5772/intechopen.91278*

*Weight Management*

source of both threat and anxiety, which makes it easier to avoid or restrict [59]. Neuroimaging studies also support this explanation. In one fMRI study with AN patients, an increase in amygdala activity (threat perception) and a decrease in inferior parietal lobe activity (food-related pleasure and interest) were evident while patients were looking at food pictures [60]. Furthermore, AN patients give different responses to body-related words and pictures than controls. They pay more attention to these words and pictures, focusing on the parts of the body rather than focusing on the body as a whole; they experience cognitive, perceptual, and emotional changes when they look at their own body [61, 62]. These changes can be

explained through the decrease in occipital and prefrontal cortex activity.

internal and external bodily sensations, and emotional processing.

is always difficult to test or evaluate these explanations.

**6.4 Cognitive behavioral explanations**

**6.3 Psychodynamic explanations**

Lastly, the "insula hypothesis" is proposed as a neurological model of anorexia nervosa that states that a dysfunction of the neural circuitry integrated by the insula can be responsible for the clinical presentation of AN [63, 64]. Symptoms arise because of disability in the insula, which establish a homeostatic balance by linking the brain's perception, emotional response, and memory-related regions to each other. Thus, it is assumed that this dysfunction causes changes in reactions to foods,

Psychodynamic explanations usually offer a unique way to understand patients'

Behavioral models of anorexia nervosa regard the disorder as a behavior that has been learned and is maintained through reinforcement. Individuals reduce their food intake as a means to lose weight due to the social pressure to be thin or other experiences, and this behavior is reinforced by sociocultural norms, feelings of being in control. These first explanations were criticized for not focusing on causal factors, and therefore cognitive explanations were proposed to be linked with these behaviors. Slade [68] pointed out that interpersonal problems and family conflicts underlie the perfectionistic tendency in anorexia, and this tendency is a triggering factor for dieting. Cognitive explanations focus on patients' thoughts about food, eating, weight, and shape which parallel Beck's model on depression [69]. Moreover, predisposing factors for self-starvation such as perfectionism, self-criticizing, and control were specified [70]. Thus, once the dieting and weight loss begin, they are

experiences of AN. These models emphasize the meanings and functions of symptoms and early childhood experiences that may cause fixation or unconscious conflicts related to individualization, separation, dependency, and control. From a psychoanalytic perspective, restriction of food symbolizes an area of control and a denial of growing up or becoming a woman [65]. Thus, the patient can stay as a child and can be looked after. Furthermore, family dynamics play an important role in these psychodynamic models. Excessive involvement, rigidity, inability to resolve conflict, and excessive protectionism are common dynamics in families of AN sufferers [66]. Bruch [67] also stated that this overinvolvement by "perfect" mothers may cause ineffectiveness in the child, resulting in these children may be not being able to identify and understand their needs or internal states. When food becomes a way of self-soothing, relaxing, and communicating, this pattern may result in eating related symptoms. Nevertheless, psychodynamic explanations are important to understand patients as individuals. However, generalization and causality is always a problem within these explanations. Moreover, these models fail to explain why childhood relationships are expressed through eating behaviors. In addition, it

**72**

reinforced and maintained easily as they become a way of gaining self-esteem. With the evidence-based studies, cognitive behavioral therapy (CBT) becomes the leading approach in both understanding and treating EDs in general [71]. CBT explains the etiology in AN as follows: dysfunctional thoughts of weight shape and body are influential in the development and persistence of symptoms, while weight control or compensatory methods (dieting, exercise, etc.) continue to reinforce the disorder. Symptoms are also conceptualized as a coping mechanism and a way of emotion regulation. Lately, Fairburn [6] has developed a transdiagnostic model of EDs that conceptualizes EDs beyond the diagnostic categories and targets the mechanism that is sustainable in all eating disorders. From Fairburn's transdiagnostic perspective, AN, BN, BED, and ED-NOS share the same core pathology that is cognitive in nature. For patients, the overvaluation of body shape and weight and their control is the most important part of life that defines and determines the worth of one's self. This pathology both causes and maintains eating and compensatory behaviors. In the case of anorexia, the consequences of malnutrition and hunger affect the cognitive ability of patients, which also causes rigidity in thoughts and behaviors.
