Wk 7 Eating disorders

  1. Anorexia nervosa DSM 5
    DSM-5 criteria for anorexia nervosa

    • People with anorexia nervosa undertake a restriction of food that leads to very low body weight; their body weight is significantly below normal. (Usually means having a BMI less than 18.5)
    • People with anorexia nervosa have an intense fear of weight gain or repeat behaviours that interfere with weight gain.
    • People with anorexia nervosa experience body image disturbance.

    • Two subtypes:(research calls into question the validity of these types)
    • 1. restricting type: weight loss is achieved by severely limiting food
    • 2. Binge-eating/purging type: a person also regularly engages in binge eating and purging behaviour. 
    • A review of the subtype literature for the preparation of DSM-5 concluded that subtypes had limited predictive validity even though clinicians found them useful.
  2. Anorexia nervosa information
    Severity ratings based on BMI

    • Mild: ≤ 17
    • Moderate: 16–16.99
    • Severe: 15–15.99
    • Extreme: < 15

    Assessed through self-report questionnaires such as the Eating Disorders Inventory.

    • In another type of assessment, people with anorexia nervosa are shown line drawings of women (or men) with varying body weights and asked to pick the one closest to their own and the one that represents their ideal shape.
    • People with anorexia nervosa overestimate their own body size and choose a thin figure as their ideal. 
    • Despite this distortion in body size, people with anorexia nervosa are fairly accurate when reporting their actual weight.

    Key differences between female and male body disturbances: whereas females often report a strong ‘drive for thinness’, males often want to be ‘bigger’, more muscular.
  3. Anorexia nervosa prevalence and comorbity
    • Typically begins in early to middle teen years, often after an episode of dieting and the occurrence of life stress. 
    • Community studies from Western countries report lifetime prevalence rates of 0.9 for anorexia nervosa among adult females.
    • While the overall rate has been stable for several decades, there has been an increase in the high-risk group of 15- to 19-year-old girls.
    • Risen also in Asian countries, due to westernised thin ideal.
    • Anorexia nervosa is at least 10 times more frequent in women than in men.

    • For both men and women, anorexia nervosa is frequently comorbid with depression, obsessive–compulsive disorder, specific phobias, panic disorder and various personality disorders.
    • Mortality rates for individuals with anorexia nervosa are high; suicide rates are also high with one in five individuals with anorexia nervosa who died committing suicide.
  4. Physical consequences of anorexia nervosa
    • 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 anaemia (i.e., decrease in red blood cells) may occur. 
    •  Some people lose hair from the scalp and they may develop lanugo — a fine, soft hair — on their bodies as a means of keeping body temperature due to loss of fat tissue.
    •  Levels of electrolytes, such as potassium and sodium, are altered. These ionised salts, present in various bodily fluids, are essential to neural transmission and lowered levels can lead to tiredness, weakness, cardiac arrhythmias and even sudden death.
  5. Anorexia nervosa prognosis
    • Although approximately 50 percent of people with anorexia nervosa eventually recover, a substantial proportion will still experience some symptoms or remain chronically ill.
    • Recovery often takes more than six years and relapses are common before a stable pattern of eating and weight maintenance is achieved. 
    • Death rates are 10 times higher among people with the disorder than among the general population and twice as high as among people with other psychological disorders.
    • Mortality rates among women with anorexia nervosa range from 3 to 5 percent.
    • Death most often results from physical complications of the illness — for example, congestive heart failure — and from suicide.
    • A recent longitudinal study found that death was more likely to occur among those who had anorexia nervosa the longest.
  6. Bulimia nervosa DSM
    • DSM-5 criteria for bulimia nervosa
    • People with bulimia nervosa experience recurrent episodes of binge eating. (Involves not being able to stop/losing control over eating)
    • People with bulimia nervosa experience recurrent compensatory behaviours to prevent weight gain, for example, vomiting.
    • Body shape and weight are extremely important for self-evaluation.

    the DSM-5 diagnosis of bulimia nervosa requires that the episodes of binge eating and compensatory behaviour occur at least once a week for three months

    Bulimia nervosa is not diagnosed if the binge eating and purging occur only in the context of anorexia nervosa and its extreme weight loss; the diagnosis in such a case is anorexia nervosa, binge-eating/purging type.

    The key difference between anorexia nervosa and bulimia nervosa is weight loss: people with ­anorexia nervosa lose a tremendous amount of weight, whereas people with bulimia nervosa do not.
  7. Bulimia nervosa information
    Binge eating typically occurs in secret; it may be triggered by stress and negative emotions, and it continues until the person is uncomfortably full.

    • There is wide variation in the caloric content consumed during these episode.
    •  People report that they lose control during a binge, even to the point of experiencing something akin to what happens in addiction.
    • They are usually ashamed of their behaviour and try to conceal it.
    • People with bulimia nervosa most often induce vomiting, take laxatives or diuretics (these behaviours are known as purging), fast or exercise excessively in order to prevent weight gain.
    • Bulimia more accurate on weight self report and are also likely to be highly dissatisfied with their bodies.

    • Severity ratings based on number of compensatory behaviours/week
    • Mild: 1–3
    • Moderate: 4–7
    • Severe: 8–13
    • Extreme: 14 or more
  8. Bulimia nervosa prevalence and comorbity
    • Typically begins in late adolescence or early adulthood.
    • About 90 percent of people with bulimia nervosa are women and according to recent evidence the prevalence among women is thought to be about 1-2% of the population.
    • Many people with bulimia nervosa were somewhat overweight before the onset of the disorder and the binge eating often started during an episode of dieting.

    • Bulimia nervosa is comorbid with numerous other diagnoses, notably depression, anxiety disorders, substance use, conduct disorder and personality disorders.
    • Suicide rates are higher among people with bulimia nervosa than in the general population, but substantially lower among people with anorexia nervosa.

    Found that symptoms of bulimia nervosa predicted the onset of depression symptoms. However, the converse was also true: depression symptoms predicted the onset of bulimia nervosa symptoms.
  9. Physical consequences of bulimia nervosa
    • Frequent purging can cause potassium depletion.
    • Heavy use of laxatives induces diarrhoea, which can also lead to changes in electrolytes and cause irregularities in the heartbeat.
    • Recurrent vomiting has been linked to menstrual problems and 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.
    • The salivary glands may become swollen.
  10. Prognosis
    Long-term follow-ups of people with bulimia nervosa reveal that around 45 percent fully recover, although nearly one-quarter remain symptomatic and have a chronic course.
  11. Binge-eating disorder DSM
    First included as a diagnosis in DSM-5.

    DSM-5 criteria for binge-eating disorder

    • People with binge-eating disorder experience recurrent binge-eating episodes.
    • Binge-eating episodes include at least three of the following:
    • – eating more quickly than usual
    • – eating until overly full
    • – eating large amounts even if not hungry
    • – eating alone due to embarrassment about large food quantity
    • feeling bad (e.g., disgusted, guilty or depressed) after the binge-eating episode.
    • No compensatory behaviour is present.
  12. Binge-eating information
    • It is distinguished from anorexia nervosa by the absence of weight loss and from bulimia nervosa by the absence of compensatory behaviours.
    • Often, people with binge-eating disorder are obese (i.e., have a BMI greater than 30).
    • Recent research suggests that anywhere from 5 to 30 percent of obese people meet the criteria for binge-eating disorders.
  13. Obesity
    • It is estimated that the total direct cost for obesity and being overweight in 2005 in Australia was $21 billion.
    • Obesity is linked to many health problems, including diabetes, hypertension, cardiovascular disease and several forms of cancer.
    • almost two in three Australian adults are overweight or obese (almost 28 percent of the adult population are obese)
    • More than one in four children aged 5–17 years are overweight or obese (ABS, 2015).
    • There is a global trend that overweight and obesity in children and adolescents is on the rise but has paused in Aus in the last decade.

    Factors: high availability of food, cheap junk food, larger portion sizes, marketing junk, sedentary lifestyle, hereditary.
  14. Physical consequences of binge-eating disorder
    • Many of them are likely a function of associated obesity, including increased risk of type 2 diabetes, cardiovascular problems, chronic back pain and headaches, even after controlling for the independent effects of other comorbid disorders.
    • Physical problems are present among people with binge-eating disorder that are independent from co-occurring obesity, including sleep problems, anxiety, depression, irritable bowel syndrome and, for women, early onset of menstruation.
  15. Binge eating prognosis
    • Perhaps because it is a relatively new diagnosis, fewer studies have assessed the prognosis of binge-eating disorder. 
    • Research so far suggests that between 25 and 82 percent of people recover.
  16. Aetiology of eating disorders- Genetic
    • Hereditary
    • First-degree relatives of women with anorexia nervosa are more than 10 times more likely than average to have the disorder themselves.
    • Similar results are found for bulimia nervosa, where first-degree relatives of women with bulimia nervosa are about four times more likely.

    • Twin studies of eating disorders also suggest a genetic influence.
    • Most studies of both anorexia nervosa and bulimia nervosa report higher monozygotic (MZ) than dizygotic (DZ) concordance rates.
    •  62 percent of the variance in symptoms of bulimia nervosa was attributable to genetic factors compared to 38 percent attributable to unique environmental factors.
  17. Aetiology of eating disorders- neurobiological factors
    • The hypothalamus is a key brain centre for regulating hunger and eating.
    • The level of some hormones regulated by the hypothalamus, such as cortisol, is indeed different in people with anorexia nervosa. However, rather than causing the disorder, these hormonal differences occur as a result of self-starvation and levels return to normal after weight gain.

    • Also, some endogenous opioids (e.g., beta-endorphin) have been hypothesised to play a role in eating disorders.
    • Endogenous opioids are substances produced by the body that reduce pain sensations, enhance mood and suppress appetite, and are also released during starvation. 
    • Starvation among people with anorexia nervosa may increase the levels of endogenous opioids, resulting in a positively reinforced mood state.
    • Furthermore, the excessive exercise seen among some people with eating disorders increase opioids and might thus be reinforcing.
    •  In contrast to anorexia nervosa, studies of people with bulimia nervosa found low levels of the endogenous opioid beta-endorphin.
    • We cannot conclude that low levels of opioids are a cause of bulimia nervosa or an effect of changes in food intake or purging.

    •  some research has focused on two neurotransmitters : serotonin, which is related to eating and satiety (feeling full), and dopamine, which is related to the rewarding/pleasing aspects of food.
    • Animal research has shown that serotonin promotes satiety.
    • Therefore, the binge-eating episodes in people with bulimia nervosa or binge-eating disorder could result from a serotonin deficit that causes them not to feel full after eating.
    • Several studies have found low levels of serotonin metabolites among people with anorexia nervosa.

    Another study found that women with either anorexia nervosa or bulimia nervosa had greater expression of the dopamine transporter gene DAT.
  18. Aetiology Anorexia Cognitive-behvaioural factors
    • Cognitive–behavioural theories of anorexia nervosa emphasise fear of weight gain and body-image disturbance as the motivating factors that powerfully reinforce weight loss.
    • Behaviours that achieve or maintain thinness are negatively reinforced by the reduction of anxiety about gaining weight as well as positively reinforced by comments from others.
    • Dieting and weight loss may also be positively reinforced by the sense of mastery or self-control they create.
    • Another important factor in producing a strong drive for thinness and a disturbed body image is criticism from peers and parents about being overweight.
    • One study found that low positive emotion differentiation prospectively predicted eating disorder behaviours.
    • Feeling more strong negative emotions also predicted these behaviours.
  19. Aetiology Bulimia and binge-eating disorder cognitive-behavioural factors
    • People with bulimia nervosa are also thought to be overconcerned with weight gain and body appearance; indeed, they often view their self-worth in terms of their weight and shape. 
    • They also have low self-esteem.
    • Although purging temporarily reduces the anxiety from having eaten too much, this cycle lowers the person’s self-esteem, which triggers more binge eating and purging to maintain desired body weight, which then leads to serious medical consequences.
    • Given the similarities between people who score high on the Restraint Scale and people with bulimia nervosa, restrained eating might play a central role in bulimia nervosa.

    • research shows that people with anorexia nervosa and bulimia nervosa focus their attention on food-related words or images more than other images.
    • This bias towards food and body image may make it harder for women with eating disorders to change their thinking patterns.
  20. Aetiology socicultural factors
    • Over the past decades, the Western cultural ideal has progressed steadily towards increasing thinness.
    • For men, They found that the centrefolds’ BMI increased over the period and that their muscularity.
    • Finally, exposure to media portrayals of unrealistically thin models can influence reports of body ­dissatisfaction.
    • Being fat is stigmatised and has negative connotations.

    • Gender influences: objectification of women’s bodies. Led women to ‘self-­objectify’, which means that they see their own bodies through the eyes of others.
    • Decreased over age for women

    Cultural and ethnic:
  21. Aetiology personality
    • important to keep in mind that an eating disorder itself can affect personality.
    •  Being overly perfectionistic has been found to be a risk and maintenance factor for both anorexia nervosa and bulimia nervosa
    • here is also a strong overlap between obsessive–­compulsive disorder and anorexia nervosa, which is at least in part due to shared genetic factors
  22. Aetiology characteristics of families
    • Studies of the characteristics of families of people with eating disorders are scarce and have yielded variable results. 
    • retrospective self-reports of people with eating disorders frequently reveal high levels of conflict in the family.
    • while one study found that maladaptive parental behaviour (e.g., guilt to control the child or verbal abuse) during childhood increased the risk for eating ­disorders.
    •  For example, in a large population-based sample of boys and girls from Western Australia, parents’ ­perceptions of their child being overweight at age 8 or 10 years was a strong factor in predicting eating disorders in children aged 14 years.
  23. Child abuse and eating disorders
    • Studies have consistently found that child sexual abuse leads to an increased risk for mental disorders.
    • However, women who have been sexually abused as children are also more likely to develop depression and anxiety, which suggests that sexual abuse during childhood makes individuals more vulnerable for mental disorder in general.
    • other forms of child abuse such as physical and emotional abuse and neglect, also contribute to the later development of mental health problems and eating disorders
  24. Psychological treatment of anorexia nervosa
    • Psychological treatments for anorexia nervosa can be divided into individual and family-based interventions.
    •  CBT focuses primarily on the maintaining processes of anorexia nervosa by directly challenging cognitions and patterns of thinking.
    • Specialist supportive clinical management (SSCM), which primarily focuses on the resumption of normal eating and restoration of weight, is another recommended treatment option for adults with anorexia nervosa.

    • Family therapy is another form of psychological treatment for anorexia nervosa and is based on the notion that interactions among members of the patient’s family can play a role in treating the disorder.
    • However, more girls receiving FBT were in full remission (49 percent) one year after treatment than girls receiving individual therapy (23 percent).
  25. Psychological treatment of bulimia nervosa
    • CBT is the best-validated and current standard for the treatment of bulimia nervosa.
    •  In CBT, they learn that all is not lost with just one bite of high-calorie food; occasional snacking does not need to trigger binge eating.

    Interpersonal therapy (IPT) 

    Family therapy is also effective for bulimia nervosa
  26. Medications
    • Medications have also been used to treat anorexia nervosa with little success in improving weight or other core features of anorexia nervosa.
    • Because bulimia nervosa is often comorbid with depression, it has been treated with various antidepressants.
  27. Preventive interventions for eating disorder
    • Psychoeducational approaches. The focus is on educating children and adolescents about eating disorders in order to prevent them from developing the symptoms.
    • Deemphasising sociocultural influences. The focus here is on helping children and adolescents resist or reject sociocultural pressures to be thin.
    • Risk factor approach. The focus here is on identifying people with known risk factors for developing eating disorders (e.g., weight and body-image concern, dietary restraint) and intervening to alter these factors.

    numerous internet-based programs have been developed over the past few years. Such programs offer easily accessible, convenient and anonymous services, which is crucial as many people are ashamed about their problems.
Card Set
Wk 7 Eating disorders
Wk 7 Eating disorders 8.1 describe the symptoms associated with anorexia nervosa, bulimia nervosa and binge-eating disorder and be able to distinguish between the different eating disorders 8.2 describe the genetic, neurobiological, sociocultural and psychological factors implicated in the aetiology of eating disorders 8.3 describe the treatments for eating disorders and the evidence supporting their effectiveness.