Eating Disorders: Anorexia Nervosa, Bulimia Nervosa, Binge-Eating Disorder, Night Eating Syndrome and Eating Disorders Not Otherwise Specified
Eating disorders are psychological illnesses associated with a host of adverse medical conditions, negative psychological affects, and substantial reductions in quality of life. This paper will explore some of the causes research has attributed to this behavior. According to Leslie Sim, et al. (2010) the main eating disorders are anorexia nervosa, bulimia nervosa, binge-eating disorder, night eating syndrome and eating disorders not otherwise specified.
Anorexia nervosa is described as abnormally low body weight of at least 15% below what would be expected and a corresponding fear of weight gain with an undue emphasis on weight and shape in self-evaluation. The incidence of anorexia nervosa is approximately 0.5% to 1% and is highest among adolescent girls and young women. Anorexia nervosa can be classified into 2 subtypes, the restricting subtype and the binge-eating/purging subtype. Patients with anorexia nervosa who rarely binge-eat or purge but maintain a fairly regular pattern of caloric restriction may be classified as having the restricting subtype. Those who regularly engage in binge eating and/or compensatory behavior to prevent weight gain may be diagnosed as having the binge-eating/purging subtype. Many of those with the restricting subtype will eventually develop binge eating, with at least one-third of patients' crossing over into bulimia nervosa. Cross over to binge eating and bulimia nervosa typically occurs within the first five years of the illness. Women with anorexia nervosa who develop bulimia nervosa are likely to relapse back into anorexia nervosa.
Unfortunately, outcomes for patients diagnosed with anorexia nervosa are poor. There is only a 35% to 85% recovery rate and a protracted recovery period that ranges from 57 to 79 months. Furthermore, anorexia nervosa may evolve into a chronic condition and is one of the most medically serious psychiatric disorders. Individuals with this condition are not only affected by the physical consequences of the severe weight loss, but also with psychological co-morbid conditions that contribute to mortality. Suicides represent a large portion of the deaths from anorexia nervosa. Depression, a consequence of poor caloric intake and low weight, is frequently observed with this condition. Anxiety symptoms are also common and often precede the development of the illness.
The negative effect of anorexia nervosa on patients' long-term physical health is well documented. This condition most commonly affects women during the period of development of peak bone mass and the effects on the skeletal system can be severe and debilitating (Sim et al., 2010).
Bulimia nervosa has a higher occurrence among woman than anorexia nervosa. Typically the disorder is found in women aged 16 to 22 years; however older individuals may be affected. Bulimia nervosa can also be classified into 2 subtypes. The purging type is characterized by episodes of binge-eating, followed by compensatory behavior, such as self-induced vomiting, laxative abuse, and diuretic abuse. The non-purging type is characterized by excessive exercise, fasting, and/or strict diets. As with anorexia nervosa, patients with bulimia nervosa may place undue emphasis on their body shape and live in fear of gaining weight.
Binge eating and purging occurring in the context of low weight and amenorrhea is an indication of anorexia nervosa. Even though crossover from anorexia nervosa to bulimia nervosa is common, crossover from bulimia nervosa to anorexia nervosa is relatively rare unless the patient was originally diagnosed as having anorexia nervosa. Findings during an initial physical examination may not establish the presence of bulimia nervosa. Most patients with bulimia nervosa will be of normal weight; however calluses, or abrasions on the dorsum of the hand caused by repeated contact with the incisors during self-induced vomiting, may indicate the presence of this condition. Other physical signs are unexpected frequency of dental caries and enamel erosion from repeated vomiting. Laboratory findings of hypokalemia, metabolic alkalosis, and/or hypochloremia in an otherwise healthy, young woman should also prompt inquiry (Sim et al., 2010).
Binge Eating Disorder
Binge-eating disorder is characterized by the consumption of large amounts of food in a two-hour time period accompanied by a perceived loss of control. Symptoms include feeling uncomfortably full, eating rapidly, eating alone, eating when not hungry, and a feeling of disgust afterward. Unlike bulimia nervosa, compensatory behavior, such as vomiting and laxative abuse, does not accompany these binge episodes.
When diagnosing binge eating disorder care should be taken to differentiate it from overeating. Overeating episodes often occur at social functions, where abundant food is readily available, the mood is relaxed or positive, and other people are also overeating. Binge eating episodes typically are secretive and occur in the context of negative mood and all-or-nothing thinking. Primary care physicians may elect to screen for binge eating disorder using the Eating Attitudes Test, the most widely used eating disorder screening tool.
Binge eating disorder occurs in 2% to 3% of the general population. However, occurrences are much higher in weight management settings, 30%, and among those who are severely obese, 50%. Binge-eating disorder occurs in both men and women and affects many diverse populations. Patients range from 25-50 years of age. Physical complications associated with binge eating disorder are usually secondary to attendant obesity. Some studies show that binge eating disorder may be an indicator of those who will have a poor outcome in a weight loss program; however the findings on this topic are mixed.
Many patients with binge eating disorder are overweight or obese. Some disagreement exists about whether to first refer these patients to a behavioral weight loss program or to a binge eating disorder treatment program. Empirical evidence suggests that binge eating disorder treatment pre-behavioral weight loss is associated with greater long-term weight loss success (Sim et al., 2010).
Night Eating Syndrome
Night-eating syndrome was initially described as early as the 1950s as a syndrome consisting of morning anorexia, evening hyperphagia, and insomnia. Prevalence rates increase with increasing adiposity and have been estimated at 1.5% to 5.2% in the general population, 6% to 14% in obese outpatients, and 8% to 42% in patients seeking bariatric surgery. This syndrome is usually seen as a long-term circadian shift in eating behaviors. Night eating syndrome may be aggravated by stress. It should be distinguished from nocturnal sleep-related eating disorder, a parasomnia that occurs much less frequently in this population, is characterized by eating unusual foods or nonfood substances associated with a semiconscious state or sleep walking, and can be associated with the use of hypnotic agents.
A recent evaluation of the diagnostic criteria for night eating syndrome identified three features of the disorder, evening hyperphagia and/or nocturnal eating, initial insomnia, and awakenings from sleep. The first two criteria must both be present to indicate a diagnosis of night eating syndrome. Night eaters typically, engage in more frequent eating episodes, consume a larger percentage of their daily calories between 8 pm and 6 am, and experience more frequent nighttime awakenings. However, their overall caloric intake does not differ from that of the general population. They tend toward carbohydrate-rich nighttime snacks with a high carbohydrate-to-protein ratio. Night-eating syndrome has also been associated with low mood, depression, life stress, and low self-esteem, although to a lesser degree than binge eating disorder. Up to 40% of night eaters may engage in binge-eating episodes, especially those in obesity treatment-seeking programs. The primary physical complications related to night eating syndrome are obesity and a limited ability to lose weight (Sim et al., 2010).
Eating Disorder Not Otherwise Specified
Patients presenting to clinical settings would be classified as having an eating disorder not otherwise specified, a category designated in the DSM, for eating disorders of clinical severity that fall outside the specified diagnostic criteria of anorexia nervosa or bulimia nervosa. Because it is currently classified a category for further study, eating disorder not otherwise specified would also be used to formally diagnose binge eating disorder. In addition, eating disorder not otherwise specified would be the formal diagnostic label to identify night eating syndrome in patients for whom the behavior is particularly problematic.
Other examples of eating disorder not otherwise specified include female patients who meet all criteria for anorexia nervosa but who continue to menstruate, patients who meet all criteria for bulimia nervosa with less than twice weekly frequency of binge eating, or people of normal weight who use compensatory behaviors after ingesting small amounts of food.
Failure to meet the criteria for anorexia nervosa or bulimia nervosa does not rule put the existence of an eating disorder. In fact, those with eating disorder not otherwise specified have been found to have a high level of general psychiatric symptoms and a degree of illness severity and core psychopathology that is comparable to that of those with anorexia nervosa and bulimia nervosa (Sim et al., 2010).
According to Erguner-Tekinalp & Gillespie (2010) mental health practitioners agree that a general common definition of eating disorders is eating or not eating for emotional instead of physical reasons. Furthermore, the primary causes of eating disorders are body dissatisfaction, cultural ideal of thinness, and…