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Chapter

Eating Disorders

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Department
Psychology
Course
PSYC 3140
Professor
Gerry Goldberg
Semester
Winter

Description
Chapter 9 – Eating Disorders - 0.5% of Canadians 15 years of age or older reported that they had been diagnosed wit an eating disorder in the preceding 12 months - women are more likely than men to report an eating disorder - eating disorders can cause long-term psychological, social, and health problems - hospitalization is sometimes necessary; hospitalization rates are highest among young women in the 15- 24 range; rates are also high among those aged 10-14 and 20-24 Clinical Description - anorexia nervosa and bulimia nervosa both share features; the most important being an intense fear of being overweight Anorexia Nervosa anorexia nervosa (AN) – a disorder in which a person refuses to eat or to retain any food or suffers a prolonged and severe decrease of appetite; the individual has an intense fear of becoming obese, feels fat even when emaciated, refuses to maintain a minimal body weight, and loses at least 25% of his/her original weight - anorexia refers to loss of appetite and nervosa indicates that this is for emotional reasons - there are 4 features required for the diagnosis:  the person must refuse to maintain a normal body weight this is usually taken to mean that the person weighs less than 85% of what is considered normal for that person’s age and height; weight loss is typically achieved through dieting, although purging (self-induced vomiting, heavy use of laxatives or diuretics) and excessive exercise can also be part of the picture  the person has an intense fear of gaining weight and the fear is not reduced by weight loss; they can never be thin enough  patients with AN have a distorted sense of their body shape their self-esteem is closely linked to maintaining thinness; the tendency to link self esteem and self-evaluation with thinness is known as over-evaluation of appearance  in females, the extreme emaciation causes amenorrhea, the loss of the menstrual period of the 4 diagnostic criteria, amenorrhea seems least important to determining a diagnosis of anorexia; comparisons conducted in Canada show few differences between women who meet all 4 criteria and women who meet the other 3 but not amenorrhea; amenorrhea occurs in a significant minority of women before any significant weight loss and the symptom can persist after weight gain amenorrhea – loss of menstrual period that is sometimes caused by eating disorders - the distorted body image that accompanies AN has been assessed in several ways, most frequently by questionnaires such as the Eating Disorders Inventory (EDI) - the EDI is one of the most widely used measures to assess self-reported aspects of eating disorders - patients with AN overestimate their own body size and choose a thin figure as their ideal - DSM-IV-TR distinguishes 2 types of AN - in the restricting type, weight loss is achieved by severely limiting food intake - in the binge eating-purging type, the person also regularly engages in binge eating and purging - the binging-purging subtype appears to be more psychopathological; patients exhibit more personality disorders, impulsive behavior, stealing, alcohol and drug abuse, social withdrawal, and suicide attempts than do patients with the restricting type of anorexia - also, relative to the restricting type, binging-purging patients tend to weigh more in childhood, come from heavier families with greater familial obesity, and use more extreme weight-control methods - AN typically begins in the early to middle teenage years, often after an episode of dieting and exposure to life stress - it’s about 3-10 times more frequent in women than in men, with a lifetime prevalence of 1% in women - it was found that males had lower levels of drive for thinness and body dissatisfaction, but there were many more similarities than differences between the males and females - patients with AN are diagnosed frequently with depression, OCD, phobias, panic disorder, alcoholism, oppositional defiant disorder, and various personality disorders - comorbidity is higher in clinical samples than community samples Physical Changes in Anorexia Nervosa - self-starvation and use of laxatives produce numerous undesirable biological consequences in patients with AN - blood pressure often falls, heart rate slows, kidney and gastrointestinal problems develop, bone mass declines, the skin dries out, nails become brittle, hormone levels change, and mild anemia may occur - some patients lose hair from the scalp, and they may develop laguna, a fine, soft hair, on the bodies - levels of electrolytes, such as K and Na are altered; these are essential for the process of neural transmission, and lowered levels can lead to tiredness, weakness, cardiac arrhythmias, and even sudden death - brain size declines in patients with AN, and EEG abnormalities and neurological impairments are frequent - deficits in white matter volumes in the brain are restored upon recovery from AN, but deficits in grey-matter volumes appear irreversible, at least in the short term Prognosis - about 70% of patients with AN eventually recover; recovery often takes 6-7 years, and relapses are common before a stable pattern of eating and maintenance of weight is achieved - AN is a life-threatening illness; death rates are about 10 times higher among patients with the disorder than among the general population and twice as high among patients with other psychological disorders - suicide rates are not elevated in bulimia nervosa like they are in AN, though people with BN are more likely to have suicide ideation Bulimia Nervosa bulimia nervosa (BN) – a disorder characterized by episodic uncontrollable eating binges followed by purging either by vomiting or by taking laxatives - this disorder involves episodes of rapid consumption of a large amount of food, followed by compensatory behaviors, such as vomiting, fasting, or excessive exercise, to prevent weight gain - the DSM defines a binge as eating an excessive amount of food within less than 2 hours - BN is not diagnosed if the binging and purging occur only in the context of AN and its extreme weight loss; the diagnosis in such a case is AN, binge eating-purging type - binges typically occur in secret, may be triggered by stress and the negative emotions it arouses, and continue until the person feels uncomfortably full - the person who is engaged in a binge often feels a loss of control over the amount of food being consumed; foods that can be rapidly consumed, especially sweets such as ice cream or cake, are usually part of a binge - patients are usually ashamed of their binges and try to conceal them; they report that they lose control during a binge, even to the point of experiencing something akin to a dissociative state, perhaps losing awareness of what they’re doing or feeling that it is not really they who are binging nd - after the binge is over, disgust, feelings of discomfort, and fear of weight gain lead to the 2 step of BN – purging to undo the caloric effects of the binge - purging can involve induced vomiting and excessive exercise; the use of laxatives and diuretics is common, even though this does not actually result in weight loss - although many people binge occasionally and some people also experiment with purging, the DSM diagnosis of BN requires that the episodes of binging and purging occur at least twice a week for 3 months - there is a continuum of severity rather than a sharp distinction with BN; there’s some people who binge/purge less frequently with twice a week but they can still have BN - like patients with AN, patients with BN are afraid of gaining weight, and their self-esteem depends heavily on maintaining normal weight - 2 subtypes of BN are distinguished: a purging type and a non-purging type in which the compensatory behaviors are fasting or excessive exercise - BN typically begins in late adolescence or early adulthood - about 90% of cases are women, and prevalence among women is thought to be about 1-2% of the population - Canadian studies of rates of eating disorders in community samples find that lifetime rates for females are about 1.1% of the population for BN and 0.5% of the population for AN - research conducted in Canadian schools also suggests that bulimia is more common than anorexia among adolescents - comparisons across time suggest that the frequency of BN may be increasing - BN is associated with numerous other diagnoses, notably depression, personality disorders (especially borderline personality disorder), anxiety disorders, substance abuse, and conduct disorder - suicide rates are much higher among people with BN than in the general population - a twin study has found that BN and depression are genetically related; BN has been associated with stealing and patients with BN who steal tend also to be illicit drug users and promiscuous - like AN, BN is associated with several physical side effects; frequent purging can cause K depletion; heavy use of laxatives induces diarrhea, which can also lead to changes in electrolytes and cause irregularities in the heartbeat; recurrent vomiting may lead to tearing of tissue in the stomach and throat and to loss of dental enamel as stomach acids eat away at the teeth, making them ragged; the salivary glands may become swollen - mortality tends to be much less common in BN than in AN Binge Eating Disorders binge eating disorder (BED) – categorized in DSM-IV as a diagnosis in need of further study; include recurrent episodes of unrestrained eating - this disorder includes recurrent binges (2 times per week for at least 6 months), lack of control during the binding episode, and distress about binging, as well as other characteristics, such as rapid eating and eating alone - it is distinguished from AN by the absence of weight loss and from BN by the absence of compensatory behaviors (purging, fasting, or excessive exercise) - BED appears to be more prevalent than either AN or BN - while it did not meet the threshold for inclusion in DSM-IV, BED has several features that support its validity - it occurs more often in women than in men and is associated with obesity and a history of dieting - it’s linked with impaired work and social functioning, depression, low self-esteem, substance abuse, and dissatisfaction with body shape - risk factors for developing BED include childhood obesity, critical comments regarding being overweight, low self-concept, depression, and childhood physical or sexual abuse - the average life-term duration may be greater than the duration of AN or BN Etiology of Eating Disorders - eating disorders result when several influences converge in a person’s life Biological Factors Genetics - both AN and BN run in families - 1 degree relatives of young women with AN are about 4 times more likely than average to have the disorder themselves - twin studies of eating disorders also suggest a genetic influence; most studies of both AN and BN report higher identical than fraternal concordance rates - research has also shown that key features of the eating disorders, such as dissatisfaction with one’s body and a strong desire to be thin, appear to be heritable Eating Disorders and the Brain - the hypothalamus is a key brain center in regulating hunger and eating lateral hypothalamus – a section of the brain that, if lesioned, is associated with a dramatic loss of appetite - research on animals with lesions to the lateral hypothalamus indicates that they lose weight and have no appetite; thus, the hypothalamus has been proposed to play a role in anorexia but it does not seem a highly likely factor in AN - the paraventricular nucleus has also been implicate - the level of some hormones regulated by the hypothalamus, such as cortisol, are indeed abnormal in patients with anorexia rather than causing the disorder, however, these abnormal abnormalities occur as a result of self-starvation, and levels return to normal following weight gain - endogenous opioids are substances produced by the body that reduce pain sensations, enhance mood, and suppress appetite, at least among those with low body weight - opioids are released during starvation and have been viewed as playing a role in both AN and BN - the excessive exercise seen among some patients with eating disorders would increase opioids and thus be reinforcing - it has been hypothesized that BN is mediated by low levels of endogenous opioids, which are thought to promote craving; a euphoric state is then produced by the ingestion of food, thus reinforcing binging - some data support the theory that endogenous opioids do play a role in eating disorders, at least in BN - animal research has shown that serotonin promotes satiety (feeling full); therefore, it could be that the binges of patients with BN result from a serotonin deficit, which would cause them not to feel full as they eat - patients with bulimia also show smaller responses to serotonin agonists (chemicals that combine with receptors to initiate a reaction), again suggesting an underactive serotonin system - furthermore, when patients who had recovered from BN had their serotonin levels reduced, they showed an increase in cognitions related to eating disorders, such as feeling fat - these data all suggest that a serotonin deficit may well be related to BN Socio-Cultural Variables - in Playboy, the findings for female body sizes showed increasing thinness, in keeping with unrealistic cultural pressures; in contrast, the body sizes of male Playgirl models had grown due to increases in muscularity, and the body sizes of typical males had also grown, but because of increases in body fat - the researchers concluded that these pressures may be contributing to the increases in body dissatisfaction among males that have been reported in more recent studies - when it comes to the promotion of unrealistic images, female still feel more pressure than males - even toys reflect the unrealistic pressures on females: the Barbie doll - researchers have advanced the theory that women respond to these socio-cultural pressures by eating lightly in an attempt to project images of femininity - research has confirmed that women who are portrayed as eating heavily are indeed seen as more masculine and less feminine than women who are portrayed as eating light meals - Pliner and Chaiken have coined the term the Scarlett O’Hara effect to refer to this phenomenon of eating lightly to project femininity Scarlett O’Hara effect – a tendency to eat lightly in an attempt to project an image of femininity - while cultural standards and pressures to be thin were increasing, more and more people were becoming overweight; the prevalence of obesity has doubled since 1900 - a study found that weight dissatisfaction was associated negatively with age among women (i.e. younger women were more dissatisfied with their weight) but this association wasn’t evident among men - it was found that women were more likely than men to wish they weighed less and were actually doing something to try to lose weight; this tendency was found regardless of whether their actual weight was in the acceptable range, as prescribed by the BMI tables; also, women place greater importance on appearance than men do, and this difference exists across the lifespan - it has been recognized that there are differences among females and males in the extent of their internalization and acceptance of prescribed body image standards - as society has become more health and fat conscious, dieting to lose weight has become more common - the diet industry (books, pills, videos, special foods), is valued at more than $50 billion/year - liposuction (vacuuming out fat deposits just under the skin) is a very common (and sometimes risky) procedure in plastic surgery - a study of 12-year olds girls in Western Canada found that increases in eating disorder symptoms were associated with increased exposure to fashion magazines and these increases weren’t associated with amount of television viewed - another Australian study found that the amount of TV watched was unrelated to body image variables for either girls or boys - but, watching soap operas was associated with increased drive for thinness in girls and boys - in addition to creating an undesired physical shape, fat has negative connotations, such as being unsuccessful and having little self-control - obese people are viewed by others as less smart and are stereotypes as being lazy - a new study suggests that this anti-fat bias exists across the age spectrum so that even the most obese people tend to endorse those views; however, the bias seems more automatic among thinner people - even worse than the media’s promotion of thinness is the proliferation in the last 5 years of pro-anorexia websites; these websites glorify starvation and reinforce irrational beliefs about the importance of thinness and the perceived rewards of being dangerously thin - regarding thinness in athletes, it has been suggested that some people become anorexic because of a pursuit of fitness rather than a pursuit of thinness activity anorexia – the loss of appetite that results from being engaged in extreme physical activity; activity anorexia could apply to ballet dancers or athletes, for example - activity anorexia refers to the loss of appetite when engaged in physical activity - it was found that dancers, relative to models, had higher rates of anorexia and more disturbed eating attitudes; models and dancers share a pressure to maintain ideal appearance, but dancers also engage in much more strenuous physical activity - it has been suggested that 2 interrelated motivational factors account for activity anorexia: food deprivation increases the reinforcement effectiveness of physical activity, and physical activity decreases the reinforcement effectiveness of food Gender Influences - the primary reason for the greater prevalence of eating disorders among women than among men is that women appear to have been more heavily influenced by the cultural idea of thinness - women are typically valued more for their appearance, whereas men gain esteem more for their accomplishments - women are more concerned than men about being thin, are more likely to diet, and are thus more vulnerable to eating disorders Focus on Discovery 9.1 – To Diet or Not to Diet - Lowe and Levine noted that eating is motivated not only by the homeostasis system (which operates according to the presence or absence of actual energy deficits) but also by the hedonic system of the brain - the hedonic system is activated by the presence of highly palatable (appetizing), tasty food, an not getting enough highly palatable food to satisfy the hedonic system can result in a sense of perceived food deprivation despite having enough actual food - between 20-50% of variability in obesity phenotypes is attributable to genetic factors - heredity could produce its effects by regulating metabolic rate or through the hypothalamus and its impact on insulin level or the production of enzymes that make it easier to store fat and gain weight - dieting may be of little use to people whose obesity is principally genetically caused - stress and its associated negative moods can induce eating in some people - also, people are all subject to the continuing impact of ads, especially those promoting high fat, high calorie products such as snack foods, desserts, and meals at fast food res
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