Medical condition
Eating disorders refer to a group of conditions defined by abnormal eating habits that may involve either insufficient or excessive food intake to the detriment of an individual's physical and mental health. Bulimia nervosa, anorexia nervosa, and binge eating disorder are the most common specific forms in the United States.[1] Though primarily thought of as affecting females (an estimated 5–10 million being affected in the U.S.), eating disorders affect males as well (an estimated 1 million U.S. males being affected).[2][3][4] Although eating disorders are increasing all over the world among both men and women, there is evidence to suggest that it is women in the Western world who are at the highest risk of developing them and the degree of westernization increases the risk.[5]
The precise cause of eating disorders is not entirely understood, but there is evidence that it may be linked to other medical conditions and situations. One study showed that girls with ADHD have a greater chance of getting an eating disorder than those not affected by ADHD.[6][7] One study showed that foster girls are more likely to develop bulimia nervosa.[8] Some also think that peer pressure and idealized body-types seen in the media are also a significant factor. However, research shows that for some people there is a genetic reason why they may be prone to developing an eating disorder.[9]
While proper treatment can be highly effective for many of the specific types of eating disorder, the consequences of eating disorders can be severe, including death[10][10][11] (whether from direct medical effects of disturbed eating habits or from comorbid conditions such as suicidal thinking).[1][12]
Causes
The exact cause of Eating Disorders is unknown. However, it is believed to be due to a combination of biological, psychological and/or environmental abnormalities. A common belief is that "Genetics loads the gun, environment pulls the trigger."[citation needed]
This would mean that some people are born with a predisposition to it, which can be brought to the surface pending on environment and reactions to it. Many people with eating disorders suffer also from body dysmorphic disorder, altering the way a person sees themselves.[citation needed]
Biological
"We conclude that epigenetic mechanisms may contribute to the known alterations of ANP homeostasis in women with eating disorders."[20][21]
- Biochemical: Eating behavior is a complex process controlled by the neuroendocrine system of which the Hypothalamus-pituitary-adrenal-axis (HPA axis) is a major component. Dysregulation of the HPA axis has been associated with eating disorders,[22][23] such as irregularities in the manufacture, amount or transmission of certain neurotransmitters, hormones[24] or neuropeptides[25] and amino acids such as homocysteine, elevated levels of which are found in AN and BN as well as depression.[26]
- leptin and ghrelin: leptin is a hormone produced primarily by the fat cells in the body; it has an inhibitory effect on appetite by inducing a feeling of saiety. Ghrelin is an appetite inducing hormone produced in the stomach and the upper portion of the small intestine. Circulating levels of both hormones are an important factor in weight control. While often associated with obesity, both hormones and their respective effects have been implicated in the pathophysiology of anorexia nervosa and bulimia nervosa.[36]
- immune system: studies have shown that a majority of patients with anorexia and bulimia nervosa have elevated levels of autoantibodies that affect hormones and neuropeptides that regulate appetite control and the stress response. There may be a direct correlation between autoantibody levels and associated psychological traits.[37][38]
- infection: PANDAS, is an abbreviation for Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal Infections. Children with PANDAS "have obsessive-compulsive disorder (OCD) and/or tic disorders such as Tourette syndrome, and in whom symptoms worsen following infections such as "strep throat" and scarlet fever." (NIMH) There is a possibility that PANDAS may be a precipitating factor in the development of anorexia nervosa in some cases, (PANDAS AN).[39]
- lesions: studies have shown that lesions to the right frontal lobe or temporal lobe can cause the pathological symptoms of an eating disorder.[40][41][42]
- tumors: tumors in various regions of the brain have been implicated in the development of abnormal eating patterns.[43][44][45][46][47]
- brain calcification: a study highlights a case in which prior calcification of the right thalumus may have contributed to development of anorexia nervosa.[48]
- somatosensory homunculus: is the representation of the body located in the somatosensory cortex, first described by renowned neurosurgeon Wilder Penfield. The illustration was originally termed "Penfield's Homunculus", homunculus meaning little man. "In normal development this representation should adapt as the body goes through its pubertal growth spurt. However, in AN it is hypothesized that there is a lack of plasticity in this area, which may result in impairments of sensory processing and distortion of body image". (Bryan Lask, also proposed by VS Ramachandran)
- Obstetric complications: There have been studies done which show maternal smoking, obstetric and perinatal complications such as maternal anemia, very pre-term birth (32<wks.), being born small for gestational age, neonatal cardiac problems, preeclampsia, placental infarction and sustaining a cephalhematoma at birth increase the risk factor for developing either anorexia nervosa or bulimia nervosa. Some of this developmental risk as in the case of placental infarction, maternal anemia and cardiac problems may cause intrauterine hypoxia, umbilical cord occlusion or cord prolapse may cause ischemia, resulting in cerebral injury, the prefrontal cortex in the fetus and neonate is highly susceptible to damage as a result of oxygen deprivation which has been shown to contribute to executive dysfunction, ADHD, and may affect personality traits associated with both eating disorders and comorbid disorders such as impulsivity, mental rigidity and obsessionality. The problem of perinatal brain injury, in terms of the costs to society and to the affected individuals and their families, is extraordinary. (Yafeng Dong, PhD)[49][50][51][52][53][54][55][56][57][58][59]
Psychological
Eating disorders are classified as Axis I[60] disorders in the Diagnostic and Statistical Manual of Mental Health Disorders (DSM-IV) published by the American Psychiatric Association. There are various other psychological issues that may factor into eating disorders, some fulfill the criteria for a separate Axis I diagnosis or a personality disorder which is coded Axis II and thus are considered comorbid to the diagnosed eating disorder. Axis II disorders are subtyped into 3 "clusters", A, B and C. The causality between personality disorders and eating disorders has yet to be fully established.[61] Some people have a previous disorder which may increase their vulnerability to developing an eating disorder.[62][63][64] Some develop them afterwards.[65] The severity and type of eating disorder symptoms have been shown to affect comorbidity.[66] The DSM-IV should not be used by laypersons to diagnose themselves, even when used by professionals there has been considerable controversy over the diagnostic criteria used for various diagnoses, including eating disorders. There has been controversy over various editions of the DSM including the latest edition, DSM-V, due in May 2013.[67][68][69][70][71]
Personality traits
There are various childhood personality traits associated with the development of eating disorders.[86] During adolescence these traits may become intensified due to a variety of physiological and cultural influences such as the hormonal changes associated with puberty, stress related to the approaching demands of maturity and socio-cultural influences and perceived expectations, especially in areas that concern body image. Many personality traits have a genetic component and are highly heritable. Maladaptive levels of certain traits may be acquired as a result of anoxic or traumatic brain injury, neurodegenerative diseases such as Parkinson's disease, neurotoxicity such as lead exposure, bacterial infection such as Lyme disease or viral infection such as Toxoplasma gondii as well as hormonal influences. While studies are still continuing via the use of various imaging techniques such as fMRI; these traits have been shown to originate in various regions of the brain[87] such as the amygdala[88][89] and the prefrontal cortex[90] Disorders in the prefrontal cortex and the executive functioning system have been shown to affect eating behavior.[91][92]
Environmental
Child maltreatment
Child abuse which encompasses physical, psychological and sexual abuse, as well as neglect has been shown by innumerable studies to be a precipitating factor in a wide variety of psychiatric disorders, including eating disorders. Children who are subjugated to abuse may develop a disordered eating in an effort to gain some sense of control or for a sense of comfort. Or they may be in an environment where the diet is unhealthy or insufficient. Child abuse and neglect can cause profound changes in both the physiological structure and the neurochemistry of the developing brain. Children who, as wards of the state, were placed in orphanages or foster homes are especially susceptible to developing a disordered eating pattern. In a study done in New Zealand 25% of the study subjects in foster care exhibited an eating disorder (Tarren-Sweeney M. 2006). An unstable home environment is detrimental to the emotional well-being of children, even in the absence of blatant abuse or neglect the stress of an unstable home can contribute to the development of an eating disorder.[93][94][95][96][97][98][99][100][101]
Social isolation
Social isolation has been shown to have a deleterious effect on an individuals' physical and emotional well-being. Those that are socially isolated have a higher mortality rate in general as compared to individuals that have established social relationships. This effect on mortality is markedly increased in those with pre-existing medical or psychiatric conditions, and has been especially noted in cases of coronary heart disease. "The magnitude of risk associated with social isolation is comparable with that of cigarette smoking and other major biomedical and psychosocial risk factors." (Brummett et al.)
Social isolation can be inherently stressful, depressing and anxiety provoking. In an attempt to ameliorate these distressful feelings an individual may engage in emotional eating in which food serves as a source of comfort. The loneliness of social isolation and the inherent stressors thus associated have been implicated as triggering factors in binge eating as well.[102][103][104][105]
Parental influence
Parental influence has been shown to be an intrinsic component in developing the eating behaviors of children. This influence is manifested and shaped by a variety of diverse factors such as familial genetic predisposition, dietary choices as dictated by cultural or ethnic preferences, the parents' own body shape and eating patterns, the degree of involvement and expectations of their children's eating behavior as well as the interpersonal relationship of parent and child. This is in addition to the general psychosocial climate of the home and the presence or absence of a nurturing stable environment. It has been shown that maladaptive parental behavior has an important role in the development of eating disorders. As to the more subtle aspects of parental influence it has been shown that eating patterns are established in early childhood and that children should be allowed to decide when their appetite is satisfied as early as the age of two. A direct link has been shown between obesity and parental pressure to eat more.
Coercive tactics in regard to diet have not been proven to be efficacious in controlling a child's eating behavior. Affection and attention have been shown to affect the degree of a childs' finickiness and their acceptance of a more varied diet.[106][107][108][109][110][111]
Peer pressure
In various studies such as one conducted by The McKnight Investigators, peer pressure was shown to be a significant contributor to body image concerns and attitudes toward eating among subjects in their teens and early twenties.
Eleanor Mackey and co-author, Annette M. La Greca of the University of Miami, studied 236 teen girls from public high schools in southeast Florida. "Teen girls' concerns about their own weight, about how they appear to others and their perceptions that their peers want them to be thin are significantly related to weight-control behavior," says psychologist Eleanor Mackey of the Children's National Medical Center in Washington and lead author of the study. "Those are really important."
According to one study, 40% of 9- and 10-year-old girls are already trying to lose weight.[112] Such dieting is reported to being influenced by peer behavior, with many of those individuals on a diet reporting that their friends also were dieting. The number of friends dieting and the number of friends who pressured them to diet also played a significant role in their own choices.[113][114][115][116]
Cultural pressure
There is a cultural emphasis on thinness which is especially pervasive in western society. There is an unrealistic stereotype of what constitutes beauty and the ideal body type as portrayed by the media, fashion and entertainment industries. "The cultural pressure on men and women to be "[perfect]" is an important predisposing factor for the development of eating disorders" (Prof. Bryan Lask).[117][118]
In men
It is estimated that 8 million people in the United States are suffering from an Eating Disorder, and of that number 10% are men. Professionals suggest that the percentage suffering that are men is much higher, but because of the old fashioned idea that this illness strikes only women, few men come forward to find the help they deserve.
To date, the evidence suggests that the gender bias of clinicians means that diagnosing either bulimia or anorexia in men is less likely despite identical behavior. Men are more likely to be diagnosed as suffering depression with associated appetite changes than receive a primary diagnosis of an eating disorder.
In addition, there may often be shrouds of secrecy because of the lack of therapy groups and treatment centers offering groups specifically designed for men. They may feel very alone at the thought of having to sit in a group of women, to be part of a program designed for women, and even at the prospect that a treatment facility will turn them down because of their sex.
Men who participate in low-weight oriented sports such as jockeys, wrestlers and runners are at an increased risk of developing an Eating Disorder such as Anorexia or Bulimia. The pressure to succeed, to be the best, to be competitive and to win at all costs, combined with any non-athletic pressures in their lives (relationship issues, family problems, abuse, etc.) can help to contribute the onset of their disordered eating.
It is not uncommon for men suffering with an Eating Disorder also to suffer with alcohol abuse and/or substance abuse simultaneously (though many women also suffer both disordered eating and substance abuse problems, combined). This may be due to the addictive nature of their psychological health, combined with the strong images put out by society of men's overindulgence in alcohol.
There may also be a link between ADHD, with male sufferers of Anorexia, Bulimia, and self-injury. More research is still needing to be done in this area.
For all those who suffer, men and women alike, there are many possible co-existing psychological illnesses that can be present, including depression, anxiety, PTSD, self-injury behaviors, substance abuse, OCD, borderline personality disorder, and Multiple Personality Disorders.
It is important to remember that most of the underlying psychological factors that lead to an Eating Disorder are the same for both men and women; low self-esteem, a need to be accepted, depression, anxiety, an inability to cope with emotions & personal issues, and other existing psychological illnesses. All of the physical dangers and complications associated with being the sufferer of an Eating Disorder are the same. A great number of the causes are the same or very similar (family problems, relationship issues, alcoholic/addictive parent, abuse, societal pressure).
Diagnosis
The initial diagnosis should be made by a competent medical professional. "The medical history is the most powerful tool for diagnosing eating disorders"(American Family Physician).[133] There are many medical disorders that mimic eating disorders and comorbid psychiatric disorders. All organic causes should be ruled out prior to a diagnosis of an eating disorder or any other psychiatric disorder is made.
Medical
The diagnostic workup typically includes complete medical and psychosocial history and follows a rational and formulaic approach to the diagnosis. Neuroimaging using fMRI, MRI, PET and SPECT scans have been used to detect cases in which a lesion, tumor or other organic condition has been either the sole causative or contributory factor in an eating disorder. "Right frontal intracerebral lesions with their close relationship to the limbic system could be causative for eating disorders, we therefore recommend performing a cranial MRI in all patients with suspected eating disorders" (Trummer M et al. 2002), "intracranial pathology should also be considered however certain is the diagnosis of early-onset anorexia nervosa. Second, neuroimaging plays an important part in diagnosing early-onset anorexia nervosa, both from a clinical and a research prospective".(O'Brien et al. 2001).[42][134]
Psychological
After ruling out organic causes and the initial diagnosis of an eating disorder being made by a medical professional, a trained mental health professional aids in the assessment and treatment of the underlying psychological components of the eating disorder and any comorbid psychological conditions. The clinician conducts a clinical interview and may employ various psychometric tests. Some are general in nature while others were devised specifically for use in the assessment of eating disorders. Some of the general tests that may be used are the Hamilton Depression Rating Scale[141] and the Beck Depression Inventory.[142][143]
Differential diagnoses
There are a variety of medical conditions which may be misdiagnosed as an eating disorder such as Lyme disease which is known as the "great imitator", as it may present as a variety of psychiatric or neurologic disorders including anorexia nervosa.[144][145]
- Addison's Disease is a disorder of the adrenal cortex which results in decreased hormonal production. Addison's disease, even in subclinical form may mimic many of the symptoms of anorexia nervosa.[146]
- gastric adenocarcinoma is one of the most common forms of cancer in the world. Complications due to this condition have been misdiagnosed as an eating disorder.[147]
- helicobacter pylori is a bacterium which causes stomach ulcers and gastritis and has been shown to be a precipitating factor in the development of gastric carcinomas. It also has an effect on circulating levels of leptin and ghrelin, two hormones which help regulate appetite. Upon successful treatment of helicobacter pylori associated gastritis in pre-pubertal children they showed "significant increase in BMI, lean and fat mass along with a significant decrease in circulating ghrelin levels and an increase in leptin levels" (Pacifico, L)."SUMMARY: H. pylori has an influence on the release of gastric hormones and therefore plays a role in the regulation of body weight, hunger and satiety,"(Weigt J, Malfertheiner P).[148][149]
- hypothyroidism, hyperthyroidism, hypoparathyroidism and hyperparathyroidism may mimic some of the symptoms of, can occur concurrently with, be masked by or exacerbate an eating disorder.[150][151][152][153][154][155][156][157]
There are multiple medical conditions which may be misdiagnosed as a primary psychiatric disorder. These may have a synergistic effect on conditions which mimic an eating disorder or on a properly diagnosed ED. They also may make it more difficult to diagnose and treat an ED.
- Lupus: 19 psychiatric conditions have been associated with systemic lupus erythematosus (SLE), including depression and bipolar disorder.[158]
- Toxoplasma seropositivity: even in the absence of symptomatic toxoplasmosis, toxoplasma gondii exposure has been linked to changes in human behavior and psychiatric disorders including those comorbid with eating disorders such as depression. In reported case studies the response to antidepressant treatment improved only after adequate treatment for toxoplasma.[159]
- neurosyphilis: It is estimated that there may be up to one million cases of untreated syphyilis in the US alone. "The disease can present with psychiatric symptoms alone, psychiatric symptoms that can mimic any other psychiatric illness". Many of the manifestations may appear atypical. Up to 1.3% of short term psychiatric admissions may be attributable to neurosyphilis, with a much higher rate in the general psychiatric population. Neurosyphilis like Lyme disease has been given the appellation the "great imitator" for it may present in various ways such as depression and chronic alcoholism. (Ritchie, M Perdigao J,)[160]
- dysautonomia: a term used to describe a wide variety of autonomic nervous system (ANS) disorders may cause a wide variety of psychiatric symptoms including anxiety, panic attacks and depression. Dysautonomia usually involves failure of sympathetic or parasympathetic components of the ANS system but may also include excessive ANS activity. Dysautonomia can occur in conditions such as diabetes and alcoholism.
There are separate psychological disorders which may be misdiagnosed as an eating disorder.
- Emetophobia is an anxiety disorder characterized by an intense fear of vomiting. A person so afflicted may develop rigorous standards of food hygiene, such as not touching food with their hands. They may become socially withdrawn to avoid situations which in their perception may make them vomit. Many who suffer from emetophobia are diagnosed with anorexia or self-starvation. In severe cases of emetophobia they may drastically reduce their food intake.[161][162]
- phagophobia is an anxiety disorder characterized by a fear of eating, it is usually initiated by an adverse experience while eating such as choking or vomiting. Persons with this disorder may present with complaints of pain while swallowing.[163]
- Body dysmorphic disorder (BDD) is listed as a somatoform disorder that affects up to 2% of the population. BDD is characterized by excessive rumination over an actual or perceived physical flaw. BDD has been diagnosed equally among men and women. While BDD has been misdiagnosed as anorexia nervosa, it also occurs comorbidly in 39% of eating disorder cases. BDD is a chronic and debilitating condition which may lead to social isolation, major depression and suicidal ideation and attempts. Neuroimaging studies to measure response to facial recognition have shown activity predominately in the left hemisphere in the left lateral prefrontal cortex, lateral temporal lobe and left parietal lobe showing hemispheric imbalance in information processing. There is a reported case of the development of BDD in a 21-year-old male following an inflammatory brain process. Neuroimaging showed the presence of a new atrophy in the frontotemporal region.[164][165][166][166][167]
