Defining Eating Disorders

Eating disorders are mental disorders defined by abnormal eating habits. These abnormal habits may involve either insufficient or excessive food intake to the detriment of an individual's physical and mental health. People with eating disorders can appear underweight, of healthy weight, or overweight. Symptoms of these disorders are culturally influenced, being found primarily in young Caucasian women; however, eating disorders occur across populations of all genders, races, ages, and socioeconomic status. Furthermore, one person can have multiple types of disorder.

There are four types of eating disorders that are recognized in the DSM-5: anorexia nervosa, bulimia nervosa, binge eating disorder, and eating disorder not otherwise specified (NOS). Some people with eating disorders suffer also from body dysmorphic disorder, a disorder which alters the way a person sees themselves.

Anorexia Nervosa

Anorexia nervosa is characterized by extreme food restriction and excessive weight loss, accompanied by the fear of being fat. An anorexic person often perceives himself or herself as fat even if they are severely underweight. Anorexia is further characterized by refusal to maintain a healthy body weight, an obsessive fear of gaining weight, and an unrealistic perception of current body weight. 

Anorexia can cause menstruation to stop in females, and often leads to bone loss and loss of skin integrity. It greatly stresses the heart, increasing the risk of heart attacks and related heart problems. The risk of death is greatly increased in individuals with this disease. Complications consistent with this malnourished physical state include bradycardia, hypotension, hypothermia, and leuhopenia. Physical symptoms include hair loss; development of downy hair growth on the face, neck, and extremities; salivary gland enlargement; indigestion; and constipation, among others.

DSM-5 Diagnostic Criteria

To be diagnosed with anorexia nervosa, a person must engage in a restriction of food to the point of a significantly low body mass index; must experience an intense fear of gaining weight, even though they are underweight; and must experience a disturbance in their self-image or self-experience (for example, perceiving themselves as overweight even if they are significantly underweight). Relative to the previous version of the DSM (DSM-IV-TR) the 2013 revision (DSM-5) reflects changes in the criteria for anorexia nervosa, most notably that of the amenorrhea criterion being removed. Amenorrhea was removed for several reasons: it doesn't apply to males, it isn't applicable for females before or after the age of menstruation or taking birth control pills, and some women who meet the other criteria for AN still report some menstrual activity.

Bulimia Nervosa

Bulimia nervosa is characterized by recurrent binge eating followed by compensatory behaviors for the intake of food, such as purging. Bingeing is characterized by eating a large amount of food in a short period of time (relative to a person's normal eating habits). A purge can include self-induced vomiting, excessive use of laxatives/diuretics, fasting, or excessive exercise.

BN affects predominantly adolescents and young adults in industrialized societies, but has also been described in a variety of non-Western cultures as well. The frequency and intensity of binge-purge episodes tends to escalate over time, enough so that many patients develop the ability to induce vomiting without mechanically triggering the gag reflex. 

DSM-5 Diagnostic Criteria

Bulimia nervosa can be difficult to detect compared to anorexia nervosa, because people with bulimia tend to be of average or slightly above or below average weight. Many people with bulimia may also engage in significantly disordered eating and exercising patterns without meeting the full diagnostic criteria for bulimia nervosa. The diagnostic criteria utilized by the DSM-5 includes repetitive episodes of binge eating compensated for by excessive or inappropriate measures taken to avoid gaining weight. The diagnosis requires the episodes of compensatory behaviors and binge eating to happen a minimum of once a week for a consistent time period of 3 months. The diagnosis is made only when the behavior is not a part of the symptom complex of anorexia nervosa and when the behavior reflects an overemphasis on physical mass or appearance. 

Binge Eating Disorder

Binge eating disorder, also referred to as "compulsive overeating," is characterized by uncontrollably eating a large amount of food in a short period of time; after a bingeing episode a person will not purge and will feel an extreme sense of guilt. Episodes of bingeing may be a method of self-soothing in the face of emotional stressors; social isolation and loneliness, in particular, have been implicated as triggering factors in binge eating. BED is seen most commonly in middle-aged individuals, and is evenly distributed across gender and racial demographics, though there is some evidence to suggest that women may be more likely to seek treatment. 

DSM-5 Diagnostic Criteria

Previously considered a topic for further research exploration, binge eating disorder was included in the eating disorders section of the DSM-5 in 2013. In order to be diagnosed, a person must experience recurrent episodes of binge eating together with distress about the binges, on a frequency of at least once a week over a time period of 3 months. The binges must not be accompanied by compensatory purging behavior seen in bulimia nervosa.

Eating Disorder Not Otherwise Specified 

Eating disorders not otherwise specified (EDNOS) is an eating disorder that does not meet the DSM criteria for anorexia, bulimia, or binge eating disorder. Examples include someone who may be at a "healthy weight" but who has anorexic thought patterns and behaviors. Individuals with EDNOS usually fall into one of three groups: sub-threshold symptoms of another eating disorder, mixed features of different eating disorders, or extremely atypical eating behaviors that are not characterized by any of the other established disorders.

Poor Self-Image

Sufferers of eating disorders may also suffer from body dysmorphic disorder (BDD), a mental illness characterized by obsession with perceived body defects that are unnoticeable to the public or do not exist at all, such as being overweight.

Etiology

The precise causes of eating disorders are not entirely understood, but there is evidence that they may be linked to other medical conditions and are often a combination of circumstances. These circumstances may include biological contexts, genetic predispositions, psychological factors (such as depression or obsessive-compulsive disorder), and environmental influences (such as social isolation, parental influence, peer pressure, and cultural pressure).

There is evidence that genetics may predispose certain individuals, as well as neuro-chemical abnormalities. Depression, anxiety disorders, and low self-esteem have been described as possible predisposing factors. There are also many other possibilities such as environmental, social, and interpersonal issues that could promote and sustain these illnesses. Cultural idealizations of thinness and youthfulness in the United States have contributed to eating disorders affecting diverse populations. Peer pressure and idealized body types seen in the media may be significant factors. The media is often blamed for the rise in the incidences of eating disorders due to the fact that media images of idealized slim physical shape of people such as models and celebrities motivate or even force people to attempt to achieve slimness themselves. Cultural influences are accused of distorting reality, in the sense that people portrayed in the media are unnaturally thin by putting excessive pressure on themselves (often through eating disorders), or thin by means of editing and airbrushing photos to make them look thinner and blemish-free.

Cultural Ideal of Perfection

The common practice of editing photos before publishing leads many women of all ages to strive towards an unrealistic ideal.

Child abuse (such as neglect or physical, psychological, or sexual abuse) has been shown by many studies to be a precipitating factor in a wide variety of psychiatric disorders, including eating disorders. Children who are subjected to abuse may develop eating disorders 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.

Treatment

Treatment varies according to type and severity of eating disorder, and usually more than one treatment option is utilized. However, there is lack of good evidence about treatment and management, which means that current views about treatment are based mainly on clinical experience. Treatment can take place in a variety of different settings such as community programs, hospitals, day programs, and groups. Some of the treatment methods include cognitive-behavioral therapy (CBT), dialectical behavioral therapy (DBT), family therapy, nutritional counseling, and medication to treat comorbid (co-occurring) disorders (such as anxiety, depression, obsessive-compulsive disorder, bipolar disorder, etc.).