Anorexia nervosa


Anorexia nervosa, often referred to simply as anorexia, is an eating disorder characterized by food restriction, body image disturbance, fear of gaining weight, and an overpowering desire to be thin.
Individuals with anorexia nervosa have a fear of being overweight or being seen as such, despite the fact that they are typically underweight. The DSM-5 describes this perceptual symptom as "disturbance in the way in which one's body weight or shape is experienced". In research and clinical settings, this symptom is called "body image disturbance" or body dysmorphia. Individuals with anorexia nervosa may also deny that their symptoms or behaviors are indicative of illness. They may weigh themselves frequently, eat small amounts, and only eat certain foods. Some patients with anorexia nervosa binge eat and purge to influence their weight or shape. Purging can manifest as induced vomiting, excessive exercise, and/or laxative abuse. Medical complications may include osteoporosis, infertility, and heart damage, along with the cessation of menstrual periods and death. Complications in men may include lowered testosterone. In cases where the patients with anorexia nervosa continually refuse significant dietary intake and weight restoration interventions, a psychiatrist can declare the patient to lack capacity to make decisions. Then, these patients' medical proxies decide that the patient needs to be fed by restraint via nasogastric tube.
Anorexia often develops during adolescence or young adulthood. One psychologist found multiple origins of anorexia nervosa in a typical female patient, but primarily sexual abuse and problematic familial relations, especially those of overprotecting parents showing excessive possessiveness over their children. The exacerbation of the mental illness is thought to follow a major life-change or stress-inducing events. Ultimately however, causes of anorexia are varied and differ from individual to individual. There is emerging evidence that there is a genetic component, with identical twins more often affected than fraternal twins. Cultural factors play a very significant role, with societies that value thinness having higher rates of the disease. Anorexia also commonly occurs in athletes who play sports where a low bodyweight is thought to be advantageous for aesthetics or performance, such as dance, cheerleading, gymnastics, running, figure skating and ski jumping.
Treatment of anorexia involves restoring the patient back to a healthy weight, treating their underlying psychological problems, and addressing underlying maladaptive behaviors. A daily low dose of olanzapine has been shown to increase appetite and assist with weight gain in anorexia nervosa patients. Psychiatrists may prescribe their anorexia nervosa patients medications to better manage their anxiety or depression. Different therapy methods may be useful, such as cognitive behavioral therapy or an approach where parents assume responsibility for feeding their child, known as Maudsley family therapy. Sometimes people require admission to a hospital to restore weight. Evidence for benefit from nasogastric tube feeding is unclear. Some people with anorexia will have a single episode and recover while others may have recurring episodes over years. The largest risk of relapse occurs within the first year post-discharge from eating disorder therapy treatment. Within the first two years post-discharge, approximately 31% of anorexia nervosa patients relapse. Many complications, both physical and psychological, improve or resolve with nutritional rehabilitation and adequate weight gain.
It is estimated to occur in 0.3% to 4.3% of women and 0.2% to 1% of men in Western countries at some point in their life. About 0.4% of young women are affected in a given year and it is estimated to occur ten times more commonly among women than men. It is unclear whether the increased incidence of anorexia observed in the 20th and 21st centuries is due to an actual increase in its frequency or simply due to improved diagnostic capabilities. In 2013, it directly resulted in about 600 deaths globally, up from 400 deaths in 1990. Eating disorders also increase a person's risk of death from a wide range of other causes, including suicide. About 5% of people with anorexia die from complications over a ten-year period with medical complications and suicide being the primary and secondary causes of death respectively. Anorexia has one of the highest death rates among mental illnesses, second only to opioid overdoses.

Signs and symptoms

Anorexia nervosa is an eating disorder characterized by attempts to lose weight by way of starvation. A person with anorexia nervosa may exhibit a number of signs and symptoms, the type and severity of which may vary and be present but not readily apparent. Although anorexia is often recognized by the physical signs, it is a mental disorder that can occur at any body weight.
Anorexia nervosa, and the associated malnutrition that results from self-imposed starvation, can cause complications in every major organ system in the body. Malnutrition can cause changes in the brain due to a lack of essential nutrients in the body. Hypokalemia, a drop in the level of potassium in the blood, is a sign of anorexia nervosa. A significant drop in potassium can cause abnormal heart rhythms, constipation, fatigue, muscle damage, and paralysis.
Signs and symptoms may be classified in various categories including: physical, cognitive, affective, behavioral and perceptual:

Physical symptoms

  • A low body mass index for one's age and height
  • Rapid, continuous weight loss
  • Dry hair and skin, hair thinning, as well as hair loss
  • Low body temperature
  • Raynaud Phenomenon
  • Hypotension or orthostatic hypotension
  • Bradycardia or tachycardia
  • Chronic fatigue
  • Insomnia
  • Having severe muscle tension, aches and pains
  • Irregular or absent menstrual periods
  • Infertility
  • Gastrointestinal disease
  • Halitosis
  • Abdominal distension
  • Russell's Sign; can be a tell-tale sign of self-induced vomiting with scratches on the back of the hand
  • Tooth erosion
  • Lanugo: soft, fine hair growing over the face and body
  • Orange discoloration of the skin, particularly the feet

    Cognitive symptoms

  • An obsession with counting calories and monitoring contents of food
  • Preoccupation with food, recipes, or cooking; may cook elaborate dinners for others, but not eat the food themselves or consume a very small portion; can do so in order to distract others from noticing the condition
  • Admiration of thinner people
  • Thoughts of being fat or not thin enough
  • An altered mental representation of one's body
  • Impaired theory of mind, exacerbated by lower BMI and depression
  • Memory impairment
  • Difficulty in abstract thinking and problem solving
  • Rigid and inflexible thinking
  • Poor self-esteem
  • Hypercriticism and perfectionism

    Affective symptoms

  • Depression
  • Ashamed of oneself or one's body
  • Anxiety disorders
  • Rapid mood swings
  • Emotional dysregulation
  • Alexithymia

    Behavioral symptoms

  • Compulsive weighing
  • Regular body checking
  • Food restriction, both in terms of caloric content and type
  • Food rituals, such as cutting food into tiny pieces and measuring it, refusing to eat around others, and hiding or discarding of food
  • Purging, which may be achieved through self-induced vomiting, laxatives, diet pills, emetics, diuretics, or exercise. The goals of purging are various, including the prevention of weight gain, discomfort with the physical sensation of being full or bloated, and feelings of guilt or impurity. Purging is not always present, with some patient behaviors focusing only on food restriction.
  • Excessive exercise or compulsive movement, such as pacing
  • Self harming or self-loathing
  • Social withdrawal and solitude, stemming from the avoidance of friends, family, and events where food may be present
  • Excessive water consumption to create a false impression of satiety
  • Excessive caffeine consumption

    Perceptual symptoms

  • Unawareness or denial of severity of condition, which may prevent some from seeking recovery
  • Perception of self as heavier or fatter than in reality, i.e., body image disturbance
  • Altered body schema, i.e., a distorted and unconscious perception of one's body size and shape that influences how the individual experiences their body during physical activities. For example, a patient with anorexia nervosa may genuinely fear that they cannot fit through a narrow passageway. However, due to their malnourished state, their body is significantly smaller than someone with a normal BMI who would actually struggle to fit through the same space. In spite of having a small frame, the patient's altered body schema leads them to perceive their body as larger than it is.

    Interoception

involves the conscious and unconscious sense of the internal state of the body, and it has an important role in homeostasis and regulation of emotions. Aside from noticeable physiological dysfunction, interoceptive deficits also prompt individuals with anorexia to concentrate on distorted perceptions of multiple elements of their body image. This exists in both people with anorexia and in healthy individuals due to impairment in interoceptive sensitivity and interoceptive awareness.
Aside from weight gain and outer appearance, people with anorexia also report abnormal bodily functions such as indistinct feelings of fullness. This provides an example of miscommunication between internal signals of the body and the brain. Due to impaired interoceptive sensitivity, powerful cues of fullness may be detected prematurely in highly sensitive individuals, which can result in decreased calorie consumption and generate anxiety surrounding food intake in anorexia patients. People with anorexia also report difficulty identifying and describing their emotional feelings and the inability to distinguish emotions from bodily sensations in general, called alexithymia.
Interoceptive awareness and emotion are deeply intertwined, and could mutually impact each other in abnormalities. Anorexia patients also exhibit emotional regulation difficulties that ignite emotionally cued eating behaviors, such as restricting food or excessive exercising. Impaired interoceptive sensitivity and interoceptive awareness can lead anorexia patients to adapt distorted interpretations of weight gain that are cued by physical sensations related to digestion. Combined, these interoceptive and emotional elements could together trigger maladaptive and negatively reinforced behavioral responses that assist in the maintenance of anorexia. In addition to metacognition, people with anorexia also have difficulty with social cognition including interpreting others' emotions, and demonstrating empathy. Abnormal interoceptive awareness and interoceptive sensitivity shown through all of these examples have been observed so frequently in anorexia that they have become key characteristics of the illness.