Anorexia nervosa

Anorexia nervosa (AN), often referred to simply as anorexia,^[12] is an eating disorder characterized by food restriction, body image disturbance, fear of gaining weight, and an overpowering desire to be thin.^[1]

Individuals with anorexia nervosa have a fear of being

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.[19] 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.^[4][19] Often it begins during the teen years or young adulthood.^[1] While anorexia became more commonly diagnosed during the 20th century, it is unclear if this was due to an increase in its frequency or simply due to improved diagnostic capabilities.^[3] In 2013, it directly resulted in about 600 deaths globally, up from 400 deaths in 1990.^[20] Eating disorders also increase a person's risk of death from a wide range of other causes, including suicide.^[1][19] About 5% of people with anorexia die from complications over a ten-year period.^[4][9]

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.^[21] Though anorexia is typically recognized by the physical manifestations of the illness, it is a mental disorder that can be present at any weight.

Anorexia nervosa, and the associated

• A low body mass index for one's age and height (except in cases of "atypical anorexia")^[26]
• Irregular or absent menstrual^[27] periods
• Dry hair and skin, hair thinning, as well as hair loss^[28]
• Feeling cold all the time (hypothermia)^[29]
• Rapid, continuous weight loss^[30]
• Gastrointestinal disease^[31]
• Hypotension or orthostatic hypotension
• Bradycardia or tachycardia
• Russell's Sign; can be a tell-tale sign of self-induced vomiting with scratches on the back of the hand
• Chronic fatigue^[32]
• Infertility
• Halitosis (from vomiting or starvation-induced ketosis
  )
• Having severe
  muscle tension
  , aches and pains
• Insomnia
• Abdominal distension
• Lanugo: soft, fine hair growing over the face and body^[33]
• Orange discoloration of the skin, particularly the feet (Carotenosis)

Cognitive symptoms

• An obsession with counting calories and monitoring fat 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.
• 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^[34]
• 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

• Food / energy restrictions despite being underweight or at a healthy weight.
• Food rituals, such as cutting food into tiny pieces, refusing to eat around others, and hiding or discarding of food.
• Purging (only in the
  diuretics to flush food out of their system after eating or engage in self-induced vomiting. Anorexia purging is a subtype of anorexia, wherein the person severely restricts most of the time but has recurring episodes of binge eating. After bingeing they engage in purging behaviors. This is different from bulimia nervosa.^[35]
• Excessive exercise,[36] including micro-exercising, for example making small persistent movements of fingers or toes.^[37]
• Self harming
  or self-loathing.
• Solitude: may avoid friends and family and become more withdrawn and secretive.

Perceptual symptoms

• Perception of self as overweight, in contradiction to a normal or underweight reality (namely "body image disturbance"^[13])
• Intolerance to cold and frequent complaints of being cold; body temperature may lower (hypothermia) in an effort to conserve energy due to malnutrition.^[38]
• Altered body schema (i.e. an implicit representation of the body evoked by acting)
• Altered interoception

Interoception

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.^[39] Aside from noticeable physiological dysfunction, interoceptive deficits also prompt individuals with anorexia to concentrate on distorted perceptions of multiple elements of their body image.^[40] This exists in both people with anorexia and in healthy individuals due to impairment in interoceptive sensitivity and interoceptive awareness.^[40]

Aside from weight gain and outer appearance, people with anorexia also report abnormal bodily functions such as indistinct feelings of fullness.^[41] 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.^[42] 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.^[41]

Interoceptive awareness and emotion are deeply intertwined, and could mutually impact each other in abnormalities.^[42] Anorexia patients also exhibit emotional regulation difficulties that ignite emotionally-cued eating behaviors, such as restricting food or excessive exercising.^[42] 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 (e.g., fullness).^[42] Combined, these interoceptive and emotional elements could together trigger maladaptive and negatively reinforced behavioral responses that assist in the maintenance of anorexia.^[42] In addition to metacognition, people with anorexia also have difficulty with social cognition including interpreting others' emotions, and demonstrating empathy.^[43] 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.^[41]

Comorbidity

Other psychological issues may factor into anorexia nervosa. Some pre-existing disorders can increase a person's likelihood to develop an eating disorder. Additionally, Anorexia Nervosa can contribute to the development of certain conditions.^[44] The presence of psychiatric comorbidity has been shown to affect the severity and type of anorexia nervosa symptoms in both adolescents and adults.^[45]

There is evidence for biological, psychological, developmental, and sociocultural risk factors, but the exact cause of eating disorders is unknown.^[60]

Genetic

Anorexia nervosa is highly

A 2019 study found a genetic relationship with mental disorders, such as schizophrenia, obsessive–compulsive disorder, anxiety disorder and depression; and metabolic functioning with a negative correlation with fat mass, type 2 diabetes and leptin.^[66]

The mutations of two particular genes, the estrogen-related receptor alpha (ESRRA) gene and histone deacetylase 4 (HDAC4) gene, have been linked to anorexia. While the ESRRA mutation decreases its transcriptional activity, the HDAC4 mutation increases ESRRA's transcription repression. This decreased ESRRA activity is associated with risks of anorexia nervosa.^[67] In some tissues, the ESRRA gene alters the ability of estrogen and estrogen receptors to interact with DNA and change the function of cells.^[68] Since estrogen has potent effects upon appetite and feeding, any genetic abnormality in the estrogen signaling pathway could contribute to the symptoms of anorexia and explain why anorexia typically appears in young women just after the onset of puberty.^[69]

Environmental

Neuroendocrine dysregulation: altered signaling of peptides that facilitate communication between the gut, brain and adipose tissue, such as ghrelin, leptin, neuropeptide Y and orexin, may contribute to the pathogenesis of anorexia nervosa by disrupting regulation of hunger and satiety.^[73][74]

Anorexia nervosa is more likely to occur in a person's pubertal years. Some explanatory hypotheses for the rising prevalence of eating disorders in adolescence are "increase of adipose tissue in girls, hormonal changes of puberty, societal expectations of increased independence and autonomy that are particularly difficult for anorexic adolescents to meet; [and] increased influence of the peer group and its values."[85]

Psychological

Early theories of the cause of anorexia linked it to childhood sexual abuse or dysfunctional families;^[86][87] evidence is conflicting, and well-designed research is needed.^[60] The fear of food is known as sitiophobia^[88] or cibophobia,^[89] and is part of the differential diagnosis.^[90][91] Other psychological causes of anorexia include low self-esteem, feeling like there is lack of control, depression, anxiety, and loneliness.^[92] People with anorexia are, in general, highly perfectionistic^[93] and most have obsessive compulsive personality traits^[94] which may facilitate sticking to a restricted diet.^[95] It has been suggested that patients with anorexia are rigid in their thought patterns, and place a high level of importance upon being thin.^[96][97]

A risk factor for anorexia is trauma. Although the prevalence rates vary greatly, between 37% and 100%,^[98] there appears to be a link between traumatic events and eating disorder diagnosis.^[99] Approximately 72% of individuals with anorexia report experiencing a traumatic event prior to the onset of eating disorder symptoms, with binge-purge subtype reporting the highest rates.^[98][99] There are many traumatic events that have been identified as possible risk factors for the development of anorexia, the first of which was childhood sexual abuse.^[100] However, other traumatic events, such as physical and emotional abuse have also been found to be risk factors. Interpersonal, as opposed to non-interpersonal trauma, has been seen as the most common type of traumatic event,^[98] which can encompass sexual, physical, and emotional abuse.^[100] Individuals who experience repeated trauma, like those who experience trauma perpetrated by a caregiver or loved one, have increased symptom severity of anorexia and a greater prevalence of comorbid psychiatric diagnoses.^[100]

In individuals with anorexia, the prevalence rates for those who also qualify for a PTSD diagnosis ranges from 4% to 52% in non-clinical samples to 10% to 47% in clinical samples.^[98][99] A complicated symptom profile develops when trauma and anorexia meld; the bodily experience of the individual is changed and intrusive thoughts and sensations may be experienced.^[100] Traumatic events can lead to intrusive and obsessive thoughts, and the symptom of anorexia that has been most closely linked to a PTSD diagnosis is increased obsessive thoughts pertaining to food.^[100] Similarly, impulsivity is linked to the purge and binge-purge subtypes of anorexia, trauma, and PTSD.^[99] Emotional trauma (e.g., invalidation, chaotic family environment in childhood) may lead to difficulty with emotions, particularly the identification of and how physical sensations contribute to the emotional response.^[100] Trauma and traumatic events can disturb an individual's sense of self and affect their ability to thrive, especially within their bodies.^[100][101]

When trauma is perpetrated on an individual, it can lead to feelings of not being safe within their own body.^[100][102] Both physical and sexual abuse can lead to an individual seeing their body as belonging to an "other" and not to the "self".^[100] Individuals who feel as though they have no control over their bodies due to trauma may use food as a means of control because the choice to eat is an unmatched expression of control.^[100] By exerting control over food, individuals can choose when to eat and how much to eat. Individuals, particularly children experiencing abuse, may feel a loss of control over their life, circumstances, and their own bodies. Particularly sexual abuse, but also physical abuse, can make individuals feel that the body is not a safe place and an object over which another has control. Starvation, in the case of anorexia, may also lead to reduction in the body as a sexual object, making starvation a solution. Restriction may also be a means by which the pain an individual is experiencing can be communicated.^[100]

Sociological

Anorexia nervosa has been increasingly diagnosed since 1950;^[103] the increase has been linked to vulnerability and internalization of body ideals.^[85] People in professions where there is a particular social pressure to be thin (such as models and dancers) were more likely to develop anorexia,^[104] and those with anorexia have much higher contact with cultural sources that promote weight loss.^[105] This trend can also be observed for people who partake in certain sports, such as jockeys and wrestlers.^[106] There is a higher incidence and prevalence of anorexia nervosa in sports with an emphasis on aesthetics, where low body fat is advantageous, and sports in which one has to make weight for competition.^[107] Family group dynamics can play a role in the perpetuation of anorexia including negative expressed emotion in overprotective families where blame is frequently experienced among its members.^{[108][109][110]} When there is a constant pressure from people to be thin, teasing and bullying can cause low self-esteem and other psychological symptoms.^[92]

Media effects

Persistent exposure to media that present thin ideal may constitute a risk factor for body dissatisfaction and anorexia nervosa. Cultures that equate thinness with beauty often have higher rates of anorexia nervosa.^[111] The cultural ideal for body shape for men versus women continues to favor slender women and athletic, V-shaped muscular men. Media sources such as magazines, television shows, and social media can contribute to body dissatisfaction and disordered eating across the globe, by emphasizing Western ideals of slimness.^[112] A 2002 review found that, of the magazines most popular among people aged 18 to 24 years, those read by men, unlike those read by women, were more likely to feature ads and articles on shape than on diet.^[113] Body dissatisfaction and internalization of body ideals are risk factors for anorexia nervosa that threaten the health of both male and female populations.^[114]

Another online aspect contributing to higher rates of eating disorders such as anorexia nervosa are websites and communities on social media that stress the importance of attainment of body ideals extol. These communities promote anorexia nervosa through the use of religious metaphors, lifestyle descriptions, "thinspiration" or "fitspiration" (inspirational photo galleries and quotes that aim to serve as motivators for attainment of body ideals).^[115][116] Pro-anorexia websites reinforce internalization of body ideals and the importance of their attainment.^[116]

Media portrayal of idealized and unrealistic bodies contribute to AN prevalence. In magazines and movies and even on billboards most of the actors/models are digitally altered in multiple ways. People then strive to look like these "perfect" models who, in reality, are flawed themselves.^[117]

Cultural

Cultural attitudes towards body image, beauty, and health also significantly impact the incidence of anorexia nervosa. There is a stark contrast between Western societies that idolize slimness and certain Eastern traditions that worship gods depicted with larger bodies,^[118] and these varying cultural norms have varying influences on eating behaviors, self-perception, and anorexia in their respective cultures. For example, despite the fact that "fat phobia", or a fear of fat, is a key diagnostic criteria of anorexia by the DSM-5, anorexic patients in Asia rarely display this trait, as deep-rooted cultural values in Asian cultures praise larger bodies.^[119] Fat phobia appears to be intricately linked to Western culture, encompassing how various cultural perceptions impact anorexia in various ways. It calls on the need for greater, diverse cultural consideration when looking at the diagnosis and experience of anorexia. For instance, in a cross-sectional study done on British South Asian adolescent English adolescent anorexia patients, it was found that both patients' symptom profiles differed. South Asians were less likely to exhibit fat-phobia as a symptom versus their English counterparts, instead exhibiting loss of appetite. However, both kinds of patients had distorted body images, implying the possibility of disordered eating and highlighting the need for cultural sensitivity when diagnosing anorexia.^[120]

Notably, although these cultural distinctions persist, modernization and globalization slowly homogenize these attitudes.^[118] Anorexia is increasingly tied to the pressures of a global culture that celebrates Western ideals of thinness. The spread of Western media, fashion, and lifestyle ideals across the globe has begun to shift perceptions and standards of beauty in diverse cultures, contributing to a rise in the incidence of anorexia in places they were once rare in.^[121] Anorexia, once primarily associated with Western culture, seems more than ever to be linked to the cultures of modernity and globalization.

Mechanisms

Evidence from physiological, pharmacological and neuroimaging studies suggest serotonin (also called 5-HT) may play a role in anorexia. While acutely ill, metabolic changes may produce a number of biological findings in people with anorexia that are not necessarily causative of the anorexic behavior. For example, abnormal hormonal responses to challenges with serotonergic agents have been observed during acute illness, but not recovery. Nevertheless, increased cerebrospinal fluid concentrations of 5-hydroxyindoleacetic acid (a metabolite of serotonin), and changes in anorectic behavior in response to acute tryptophan depletion (tryptophan is a metabolic precursor to serotonin) support a role in anorexia. The activity of the 5-HT_2A receptors has been reported to be lower in patients with anorexia in a number of cortical regions, evidenced by lower binding potential of this receptor as measured by PET or SPECT, independent of the state of illness. While these findings may be confounded by comorbid psychiatric disorders, taken as a whole they indicate serotonin in anorexia.^[122][123] These alterations in serotonin have been linked to traits characteristic of anorexia such as obsessiveness, anxiety, and appetite dysregulation.^[84]

Neuroimaging studies investigating the functional connectivity between brain regions have observed a number of alterations in networks related to cognitive control, introspection, and sensory function. Alterations in networks related to the dorsal anterior cingulate cortex may be related to excessive cognitive control of eating related behaviors. Similarly, altered somatosensory integration and introspection may relate to abnormal body image.^[124] A review of functional neuroimaging studies reported reduced activations in "bottom up" limbic region and increased activations in "top down" cortical regions which may play a role in restrictive eating.^[125]

Compared to controls, people who have recovered from anorexia show reduced activation in the reward system in response to food, and reduced correlation between self reported liking of a sugary drink and activity in the striatum and anterior cingulate cortex. Increased binding potential of ¹¹C radiolabelled raclopride in the striatum, interpreted as reflecting decreased endogenous dopamine due to competitive displacement, has also been observed.^[126]

Structural neuroimaging studies have found global reductions in both gray matter and white matter, as well as increased cerebrospinal fluid volumes. Regional decreases in the left hypothalamus, left inferior parietal lobe, right lentiform nucleus and right caudate have also been reported^[127] in acutely ill patients. However, these alterations seem to be associated with acute malnutrition and largely reversible with weight restoration, at least in nonchronic cases in younger people.^[128] In contrast, some studies have reported increased orbitofrontal cortex volume in currently ill and in recovered patients, although findings are inconsistent. Reduced white matter integrity in the fornix has also been reported.^[129]

Diagnosis

A diagnostic assessment includes the person's current circumstances, biographical history, current symptoms, and family history. The assessment also includes a

DSM-5

Anorexia nervosa is classified under the Feeding and Eating Disorders in the latest revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM 5). There is no specific BMI cut-off that defines low weight required for the diagnosis of anorexia nervosa.^[130][4]

The diagnostic criteria for anorexia nervosa (all of which needing to be met for diagnosis) are:^[8][131]

• Restriction of energy intake relative to requirements leading to a low body weight. (Criterion A)
• Intense fear of gaining weight or persistent behaviors that interfere with gaining weight. (Criterion B)
• Disturbance in the way a person's weight or body shape is experienced or a lack of recognition about the risks of the low body weight. (Criterion C)

Relative to the previous version of the DSM (

There are two subtypes of AN:[22]^[133]

• Binge-eating/purging type: patients with anorexia could show binge eating and purging behavior.^[133] It is different from bulimia nervosa in terms of the individual's weight. An individual with binge-eating/purging type anorexia is usually significantly underweight. People with bulimia nervosa on the other hand can sometimes be normal-weight or overweight.^[32]
• Restricting type: the individual uses restricting food intake, fasting, diet pills, or exercise as a means for losing weight;^[22] they may exercise excessively to keep off weight or prevent weight gain, and some individuals eat only enough to stay alive.^[22][32] In the restrictive type, there are no recurrent episodes of binge-eating or purging present.^[130]

Levels of severity

Body mass index (BMI) is used by the DSM-5 as an indicator of the level of severity of anorexia nervosa. The DSM-5 states these as follows:^[134]

• Mild: BMI of greater than 17
• Moderate: BMI of 16–16.99
• Severe: BMI of 15–15.99
• Extreme: BMI of less than 15

Investigations

Medical tests to check for signs of physical deterioration in anorexia nervosa may be performed by a general physician or psychiatrist, including:

• thrombocytosis and anemia which may result from malnutrition.^[135]
• Urinalysis: a variety of tests performed on the urine used in the diagnosis of medical disorders, to test for substance abuse, and as an indicator of overall health^[136]
• electrolytes such as potassium, chlorine and sodium and tests specific to liver and kidney function.^[137]
• Cushing's Syndrome, hypoglycemia and polycystic ovary syndrome.^[138]
• triglycerides.^[139]
• Serum cholinesterase test: a test of liver enzymes (acetylcholinesterase and pseudocholinesterase) useful as a test of liver function and to assess the effects of malnutrition.^[140]
• protein deficiency, kidney function, bleeding disorders, and Crohn's Disease.^[141]
• Luteinizing hormone (LH) response to gonadotropin-releasing hormone (GnRH): Tests the pituitary glands' response to GnRh, a hormone produced in the hypothalamus. Hypogonadism is often seen in anorexia nervosa cases.^[23]
• CK-MB), brain (CK-BB) and skeletal muscle (CK-MM).^[142]
• Blood urea nitrogen (BUN) test: urea nitrogen is the byproduct of protein metabolism first formed in the liver then removed from the body by the kidneys. The BUN test is primarily used to test kidney function. A low BUN level may indicate the effects of malnutrition.^[143]
• celiac disease, rhabdomyolysis, or cirrhosis of the liver.^[144][145]
• Electrocardiogram (EKG or ECG): measures electrical activity of the heart. It can be used to detect various disorders such as hyperkalemia.^[146]
• Electroencephalogram (EEG): measures the electrical activity of the brain. It can be used to detect abnormalities such as those associated with pituitary tumors.^[147]
• Thyroid function tests: tests used to assess thyroid functioning by checking levels of thyroid-stimulating hormone (TSH), thyroxine (T4), and triiodothyronine (T3).^[148]

Differential diagnoses

A variety of medical and psychological conditions have been misdiagnosed as anorexia nervosa; in some cases the correct diagnosis was not made for more than ten years.

The distinction between binge purging anorexia, bulimia nervosa and Other Specified Feeding or Eating Disorders (OSFED) is often difficult for non-specialist clinicians. A main factor differentiating binge-purge anorexia from bulimia is the gap in physical weight. Patients with bulimia nervosa are ordinarily at a healthy weight, or slightly overweight. Patients with binge-purge anorexia are commonly underweight.^[149] Moreover, patients with the binge-purging subtype may be significantly underweight and typically do not binge-eat large amounts of food.^[149] In contrast, those with bulimia nervosa tend to binge large amounts of food.^[149] It is not unusual for patients with an eating disorder to "move through" various diagnoses as their behavior and beliefs change over time.^[59]

Gender difference

While anorexia nervosa is commonly associated with women, it can also affect men. However, the diagnosis and awareness of eating disorders and associated health risks in men are frequently underrepresented. A survey conducted among a randomly selected sample of individuals aged 18–35 reveals that females are more inclined to report behaviors such as fasting, body checking, and body avoidance, whereas males are more prone to report overeating.^[150] 0.3% of men may experience anorexia nervosa in their life time.^[151]

Treatment

There is no conclusive evidence that any particular treatment for anorexia nervosa works better than others.^[12][152]

Treatment for anorexia nervosa tries to address three main areas.

• Restoring the person to a healthy weight;
• Treating the psychological disorders related to the illness;
• Reducing or eliminating behaviors or thoughts that originally led to the disordered eating.^[153]

In some clinical settings a specific body image intervention is performed to reduce body dissatisfaction and body image disturbance. Although restoring the person's weight is the primary task at hand, optimal treatment also includes and monitors behavioral change in the individual as well.^[18] There is some evidence that hospitalization might adversely affect long term outcome, but sometimes is necessary.^[154] Psychotherapy for individuals with AN is challenging as they may value being thin and may seek to maintain control and resist change.^[155] Initially, developing a desire to change is fundamental.^[156] Despite no evidence for better treatment in adults patients, research stated that family based therapy is the primary choice for adolescents with AN.^[12][157]

Therapy

Family-based treatment (FBT) has been shown to be more successful than individual therapy for adolescents with AN.

Historically, practitioners have slowly increased calories at a measured pace from a starting point of around 1,200 kcal/day.[36]^[167] However, as understanding of the process of weight restoration has improved, an approach that favors a higher starting point and a more rapid rate of increase has become increasingly common. In either approach, the end goal is typically in the range of 3,000 to 3,500 kcal/day.^[167] Patients who experience hypermetabolism in response to refeeding have higher caloric intake needs.^[168]

Extreme hunger

People who have undergone significant caloric deficits often report experiencing

Treatment professionals tend to be conservative with refeeding in anorexic patients due to the risk of refeeding syndrome (RFS), which occurs when a malnourished person is refed too quickly for their body to be able to adapt. Two of the most common indicators that RFS is occurring are low phosophate levels and low potassium levels.^[171] RFS is most likely to happen in severely or extremely underweight anorexics, as well as when medical comorbidities, such as infection or cardiac failure, are present. In these circumstances, it is recommended to start refeeding more slowly but to build up rapidly as long as RFS does not occur. Recommendations on energy requirements in the most medically compromised patients vary, from 5–10 kcal/kg/day to 1900 kcal/day.^[172][173] This risk-averse approach can lead to underfeeding, which results in poorer outcomes for short- and long-term recovery.^[167]

Medication

Pharmaceuticals have limited benefit for anorexia itself.^[174][130] There is a lack of good information from which to make recommendations concerning the effectiveness of antidepressants in treating anorexia.^[175] Administration of olanzapine has been shown to result in a modest but statistically significant increase in body weight of anorexia nervosa patients.^[176]

Admission to hospital

Patients with AN may be deemed to have a lack of insight regarding the necessity of treatment, and thus may be involuntarily treated without their consent.^{[177]: 1038} AN has a high mortality^[178] and patients admitted in a severely ill state to medical units are at particularly high risk. Diagnosis can be challenging, risk assessment may not be performed accurately, consent and the need for compulsion may not be assessed appropriately, refeeding syndrome may be missed or poorly treated and the behavioural and family problems in AN may be missed or poorly managed.^[179] Guidelines published by the Royal College of Psychiatrists recommend that medical and psychiatric experts work together in managing severely ill people with AN.^[180]

Experience of treatment

Patients involved in treatment sometimes felt that treatment focused on biological aspects of body weight and eating behaviour change rather than their perceptions or emotional state.^[181]: 8 Patients felt that a therapists trust in them shown by being treated as a complete person with their own capacities was significant.^[181]: 9 Some patients defined recovery from AN in terms of reclaiming a lost identity.^[181]: 10 Additionally, access to timely treatment can be hindered by systemic challenges within the medical system. Some individuals have reported experiencing delays in treatment, particularly when transitioning from adolescence to adulthood.^[182] It has been noted that once patients reach the age of 17, they may encounter obstacles in receiving continued care, with treatment resuming only after they turn 18. This delay can exacerbate the severity of the disorder.

Healthcare workers involved in the treatment of anorexia reported frustration and anger to set backs in treatment and noncompliance and were afraid of patients dying. Some healthcare workers felt that they did not understand the treatment and that medical doctors were making decisions.

AN has the highest mortality rate of any psychological disorder.^[9] The mortality rate is 11 to 12 times greater than in the general population, and the suicide risk is 56 times higher.^[23] Half of women with AN achieve a full recovery, while an additional 20–30% may partially recover.^[9][23] Not all people with anorexia recover completely: about 20% develop anorexia nervosa as a chronic disorder.^[152] If anorexia nervosa is not treated, serious complications such as heart conditions^[21] and kidney failure can arise and eventually lead to death.^[184] The average number of years from onset to remission of AN is seven for women and three for men. After ten to fifteen years, 70% of people no longer meet the diagnostic criteria, but many still continue to have eating-related problems.^[185]

Alexithymia (inability to identify and describe one's own emotions) influences treatment outcome.^[174] Recovery is also viewed on a spectrum rather than black and white. According to the Morgan-Russell criteria, individuals can have a good, intermediate, or poor outcome. Even when a person is classified as having a "good" outcome, weight only has to be within 15% of average, and normal menstruation must be present in females. The good outcome also excludes psychological health. Recovery for people with anorexia nervosa is undeniably positive, but recovery does not mean a return to normal.^[186]

Complications

Anorexia nervosa can have serious implications if its duration and severity are significant and if onset occurs before the completion of growth, pubertal maturation, or the attainment of peak bone mass.^{[187][medical citation needed]} Complications specific to adolescents and children with anorexia nervosa can include the following: Growth retardation may occur, as height gain may slow and can stop completely with severe weight loss or chronic malnutrition. In such cases, provided that growth potential is preserved, height increase can resume and reach full potential after normal intake is resumed.^[188] Height potential is normally preserved if the duration and severity of illness are not significant or if the illness is accompanied by delayed bone age (especially prior to a bone age of approximately 15 years), as hypogonadism may partially counteract the effects of undernutrition on height by allowing for a longer duration of growth compared to controls.^{[medical citation needed]} Appropriate early treatment can preserve height potential, and may even help to increase it in some post-anorexic subjects, due to factors such as long-term reduced estrogen-producing adipose tissue levels compared to premorbid levels.^{[medical citation needed]} In some cases, especially where onset is before puberty, complications such as stunted growth and pubertal delay are usually reversible.^[189]

Anorexia nervosa causes alterations in the female reproductive system; significant weight loss, as well as psychological stress and intense exercise, typically results in a

The most common gastrointestinal complications of anorexia nervosa are delayed stomach emptying and constipation, but also include elevated liver function tests, diarrhea, acute pancreatitis, heartburn, difficulty swallowing, and, rarely, superior mesenteric artery syndrome.^[195] Delayed stomach emptying, or gastroparesis, often develops following food restriction and weight loss; the most common symptom is bloating with gas and abdominal distension, and often occurs after eating. Other symptoms of gastroparesis include early satiety, fullness, nausea, and vomiting. The symptoms may inhibit efforts at eating and recovery, but can be managed by limiting high-fiber foods, using liquid nutritional supplements, or using metoclopramide to increase emptying of food from the stomach.^[195] Gastroparesis generally resolves when weight is regained.

Cardiac complications

Anorexia nervosa increases the risk of

Rates of relapse after treatment range 30-72% over a period of 2–26 months, with a rate of approximately 50% in 12 months after weight restoration.[199] Relapse occurs in approximately a third of people in hospital, and is greatest in the first six to eighteen months after release from an institution.^[200] BMI or measures of body fat and leptin levels at discharge were the strongest predictors of relapse, as well as signs of eating psychopathology at discharge.^[199] Duration of illness, age, severity, the proportion of AN binge-purge subtype, and presence of comorbidities are also contributing factors.

Epidemiology

Anorexia is estimated to occur in 0.9% to 4.3% of women and 0.2% to 0.3% of men in Western countries at some point in their life.^[19] About 0.4% of young females are affected in a given year and it is estimated to occur three to ten times less commonly in males.^{[4][19][200][201]} Rates in most of the developing world are unclear.^[4] Often it begins during the teen years or young adulthood.^[1] Medical students are a high risk group, with an overall estimated prevalence of 10.4% globally.^[202]

The lifetime rate of

While anorexia became more commonly diagnosed during the 20th century it is unclear if this was due to an increase in its frequency or simply better diagnosis.[3] Most studies show that since at least 1970 the incidence of AN in adult women is fairly constant, while there is some indication that the incidence may have been increasing for girls aged between 14 and 20.^[19]

Underrepresentation

In non-Westernized countries, including those in Africa (excluding South Africa), eating disorders are less frequently reported and studied compared to Western countries,^[205] with available data mostly limited to case reports and isolated studies rather than prevalence investigations. Theories to explain these lower rates of eating disorders, lower reporting and lower research rates in include the effects of westernisation, and culture change.^{[206][needs copy edit]}

Male and female athletes are often overlooked as anorexic.

Moreover, some individuals, particularly men, who exhibit symptoms of anorexia may not meet the BMI criteria outlined in the DSM-IV due to higher muscle weight and lower fat content.[207] Consequently, a subclinical diagnosis, such as Eating Disorder Not Otherwise Specified (ED-NOS) in DSM-IV or Other Specified Feeding or Eating Disorder/Unspecified Feeding or Eating Disorder in DSM-5, is often made instead though there is no significant difference.^[210]

An increasing trend of anorexia among the elderly, termed "Anorexia of Aging,"^[211] is observed, characterized by behaviors similar to those seen in typical anorexia nervosa but often accompanied by excessive laxative use.^[211] Most geriatric anorexia patients limit their food intake to dairy or grains, whereas an adolescent anorexic has a more general limitation.^[211]

This eating disorder that affects older adults has two types - early onset and late onset.^[211] Early onset refers to a recurrence of anorexia in late life in an individual who experienced the disease during their youth.^[211] Late onset describes instances where the eating disorder begins for the first time late in life.^[211]

The stimulus for anorexia in elderly patients is typically a loss of control over their lives, which can be brought on by many events, including moving into an assisted living facility.^[212] This is also a time when most older individuals experience a rise in conflict with family members, such as limitations on driving or limitations on personal freedom, which increases the likelihood of an issue with anorexia.^[212] There can be physical issues in the elderly that leads to anorexia of aging, including a decline in chewing ability, a decline in taste and smell, and a decrease in appetite.^[213] Psychological reasons for the elderly to develop anorexia can include depression and bereavement, and even an indirect attempt at suicide.^[213] There are also common comorbid psychiatric conditions with aging anorexics, including major depression, anxiety disorder, obsessive compulsive disorder, bipolar disorder, schizophrenia, and dementia.^[214]

The signs and symptoms that go along with anorexia of aging are similar to what is observed in adolescent anorexia, including sudden weight loss, unexplained hair loss or dental problems, and a desire to eat alone.^[212]

There are also several medical conditions that can result from anorexia in the elderly. An increased risk of illness and death can be a result of anorexia.^[213] There is also a decline in muscle and bone mass as a result of a reduction in protein intake during anorexia.^[213] Another result of anorexia in the aging population is irreparable damage to kidneys, heart or colon and an imbalance of electrolytes.^[215]

Many assessments are available to diagnose anorexia in the aging community. These assessments include the Simplified Nutritional Assessment Questionnaire (SNAQ)^[216] and Functional Assessment of Anorexia/Cachexia Therapy (FAACT).^[217][211] Specific to the geriatric populace, the interRAI system^[218] identifies detrimental conditions in assisted living facilities and nursing homes.^[211] Even a simple screening for nutritional insufficiencies such as low levels of important vitamins, can help to identify someone who has anorexia of aging.^[211]

Anorexia in the elderly should be identified by the

The treatment for anorexia of aging is undifferentiated as anorexia for any other age group. Some of the treatment options include outpatient and inpatient facilities, antidepressant medication and behavioral therapy such as meal observation and discussing eating habits.[214]

History

The history of anorexia nervosa begins with descriptions of religious fasting dating from the

Etymologically, anorexia is a term of Greek origin: an- (ἀν-, prefix denoting negation) and orexis (ὄρεξις, "appetite"), translating literally to "a loss of appetite". In and of itself, this term does not have a harmful connotation, e.g., exercise-induced anorexia simply means that hunger is naturally suppressed during and after sufficiently intense exercise sessions.[223] It is the adjective nervosa that indicates the functional and non-organic nature of the disorder, but this adjective is also often omitted when the context is clear. Despite the literal translation of anorexia, the feeling of hunger in anorexia nervosa is frequently present and the pathological control of this instinct is a source of satisfaction for the patients.^[224]

The term "anorexia nervosa" was coined in 1873 by

In the late 19th century anorexia nervosa became widely accepted by the medical profession as a recognized condition. Awareness of the condition was largely limited to the medical profession until the latter part of the 20th century, when German-American psychoanalyst Hilde Bruch published The Golden Cage: the Enigma of Anorexia Nervosa in 1978. Despite major advances in neuroscience,^[227] Bruch's theories tend to dominate popular thinking. A further important event was the death of the popular singer and drummer Karen Carpenter in 1983, which prompted widespread ongoing media coverage of eating disorders.^[228]

See also

• Body image
• Eating recovery
• Evolutionary psychiatry
• Idée fixe
• Inedia
• List of people with anorexia nervosa
• National Association of Anorexia Nervosa and Associated Disorders
• Muscle dysmorphia
• Orthorexia nervosa
• Pro-ana

References

Further reading

• Bailey AP, Parker AG, Colautti LA, Hart LM, Liu P, Hetrick SE (2014). "Mapping the evidence for the prevention and treatment of eating disorders in young people". Journal of Eating Disorders. 2 (1): 5.
  PMID 24999427
  .
• Coelho GM, Gomes AI, Ribeiro BG, Soares E (2014). "Prevention of eating disorders in female athletes". Open Access Journal of Sports Medicine. 5: 105–113.
  PMID 24891817
  .
• Luca A, Luca M, Calandra C (February 2015). "Eating Disorders in Late-life". Aging and Disease. 6 (1): 48–55.
  PMID 25657852
  .

External links

Wikimedia Commons has media related to Anorexia nervosa.

Wikiquote has quotations related to Anorexia nervosa.

• National Association of Anorexia Nervosa and Associated Disorders
• Society of Clinical Psychology—Anorexia