Eating disorders - summary of chapter 11 of Abnormal Psychology by Kring, Davison, Neale & Johnson (12th edition)

Clinical psychology
Chapter 11
Eating disorders

Clinical description of eating disorders

Anorexia nervousa

DSM-5 criteria for anorexia nervousa

• Restriction of food that leads to very low body weight; bodyweight is significant below normal
• Intense fear of weight gain
• Body image disturbance

Amenorrhea: loss of menstrual period

Two types of anorexia nervosa:

• Restricting type
  Weight loss is achieved by severely limiting food intake
• Binge-eating/ purging type
  The person has also regularly engaged in binge eating and purging.

Typically begins in the early to middle teenage years, often after an episode of dieting and the occurrence of life stress.
Lifetime prevalence: less than one percent
10 time more frequent in women than in men.

• Women with anorexia are frequently diagnosed with depression, obsessive-compulsive disorder, phobias, panic disorder, substance use disorder, and various personality disorders.
• Men with anorexia nervosa are also likely to have a diagnoses of a mood disorder, schizophrenia, or substance use disorder.

Suicide rates are quite high for people with anorexia

Physical consequences of anorexia nervosa

Self-starvation and use of laxatives produce numerous undesirable biological consequences in people with anorexia nervosa.

• Blood pressure falls
• Heart rate slows
• Kidney and gastriontestinal problems
• Bone mass declines
• Skin dries out
• Nails become brittle
• Hormone levels change
• Mild anemia may occur
• some people loose hair, and they may develop lanugo, a fine, soft hair on their bodies.
• Levels of electrolytes are altered. These are essential to neural transmission, and lowered levels can lead to
  • Tiredness
  • Weakness
  • Cardiac arrhythmias
  • Sudden death

Prognosis

Between 50 and 70 percent of people with anorexia eventually recover.
Recovery often takes 6 to 7 years, and relapses are common before a stable pattern of eating and weight maintenance is achieved.

Anorexia nervosa is a life-threatening illness.

Bulimia nervosa

DSM-5 criteria for bulimia nervosa

• Recurrent episodes of binge eating
• Recurrent compensatory behaviors to prevent weight gain, for example, vomiting
• Body shape and weight are extremely important for self-evaluation

Involves episodes of rapid consumption of a large amount of food, followed by compensatory behavior, such as vomiting, fasting, or excessive exercise, to prevent weight gain.

Binge has two characteristics:

• It involves eating and excessive amount of food within a short period of time
• It involves a feeling of losing control over eating

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

The key difference between anorexia and bulimia is weight loss.
People with bulimia do not lose a tremendous amount of weight.

In bulimia, binges typically occur in secret. They may be triggered by stress and negative emotions they arouse, and they continue until the person is uncomfortably full.
There is wide variation in the caloric content consumed by people with bulimia nervosa during binges.

People report that they lose control during a binge, even to the point of experiencing something akin to a strancelike state. They are usually ashamed of their binges and try to conceal them.

After the binge is over, feelings of discomfort, disgust, and fear of weight gain lead to the second step of bulimia nervosa, the inappropriate compensatory behavior (purging) to attempt to undo the caloric effects of the binge.

Episodes of bingeing and compensatory behavior occur at least once a weak for 3 months.

People with bulimia nervosa are afraid of gaining weight, and their self-esteem depends heavily on maintaining normal weight.

Typically begins in late adolecence or early adulthood.
90% of the cases are women
1 to 2 percent 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.

Comorbid with numerous other episodes.

• Depression,
• Personality disorders
• Anxiety disorders
• Substance use disorders
• Conduct disorder
• Men are also likely to be diagnosed with mood disorder or substance use disorder.

Suicide rates are higher among people with bulimia nervosa than in the general population, but substantially lower than among people with anorexia.

Physical consequences of bulimia nervosa

Bulimia is associated with several physical side effects.

• Menstrual irrgeularities can occur, although people with bulimia typically have a normal body mass index (BMI)
• Frequent purging can cause postassium depletion.
• Heavy use of laxatives induces diarrhea, which can also lead to changes in electrolytes and cause irregularities in the heartbeat.
• Recurrent vomitting has been linked to menstrual problems and may lead to tearing of tissue in the stomach and throat and loss of dental enamel as stomach acids eat away the teeth, which become ragged
• The salivary glands may be swollen
• Death

Prognosis

75 percent recover, although about 10 to 20 percent remain fully symptomatic.
Intervening soon after diagnosis is made is linked with an even better prognosis.
People with bulimia nervosa who binge and vomit more and who have comorbid substance use or a history of depression have a poorer prognosis than people without these factors.

Binge eating disorder

DSM-5 criteria for Binge eating disorder:

• Recurrent binge eating episodes
• Binge episodes include at least three of the flowing:
  • Eating more quickly than usual
  • Eating until over full
  • Eating large amounts even if not hungry
  • Eating alone due to embarrassment about large food quantity
  • Feeling bad after the binge
• No compensatory behavior is present

Lack of control during the binges.
Absence of weight loss and compensatory behaviors.
Most often, people with binge eating disorder are obese.
Not all obese people meet criteria for binge eating disorder.

Associated with obesity and a history of dieting.
Linked to impaired work and social functioning, depression, low self-esteem, substance use disorders, and dissatisfaction with body shape.
Risk factors for developing binge eating disorder are:

• Childhood obesity
• Critical comments regarding body overweight
• Weight-loss attempts in childhood.
• Low self-concept
• Depression
• Childhood sexual abuse.

More prevalent than either anorexia nervosa or bulimia nervosa.
3,5 percent for women and 2, percent for men.
Comorbid with depression and anxiety disorders

Physical consequences of binge eating disorder

Many of the physical consequences are likely a function of associated obesity.

• Increased risk for type 2 diabetes
• Cardiovascular problems
• Breathing problems
• Insomnia
• Joint/muscle problems

Problems not associated with the obesity:

• Sleep problems
• Anxiety
• Depression
• Irritable bowel syndrome
• Early onset of menstruation

Prognosis

Between 25 and 82 percent of people recover.
People have binge eating much longer than anorexia or bulimia.

Etiology of eating disorders

Genetic factors

Both anorexia and bulimia run in families.
It has a genetic influence.

Nonshared environmental factors also contribute to the development of eating disorders.

Key features of the eating disorders, such as dissatisfaction with one’s body, a strong desire to be thin, binge eating, and preoccupation with weight, are heritable.
Common genetic factors may account for the relationship between certain personality characteristics.

Neurobiological factors

The hypothalamus is a key brain center for regulating hunger and eating.
The level of hormones regulated by the hypothalamus is abnormal in people with anorexia.
These hormonal abnormalities occur as a result of self-starvation, and levels return normal after weight gain.
A dysfunctional hypothalamus does not seem highly likely as a factor in anorexia nervosa.

Endogenous opioids are substances produced by the body that reduce pain sensations, enhance mood, and suppress appetite.
Starvation among people with anorexia may increase the levels of endogenous opioids, resulting in a positively reinforcing euphoric state.
Excessive exercise seen among some people with eating disorders would increase opioids and thus be reinforcing.
We don’t know if the low levels of opioids seen in people with bulimia are a cause or an effect of changes in food intake or purging.

Serotonin promotes satiety.
Binges of people with bulimia could result from a serotonin deficit that causes them to not feel satiated as they eat.
Food restriction interferes with serotonin synthesis in the brain. Among people with anorexia, the severe food intake restrictions could interfere with the serotonin system.
There are low levels of serotonin metaoblies among people with anorexia and bulimia.
Serotonin could also be linked to the comorbid depression often found in anorexia and bulimia.

Dopamine is linked to the motivation to obtain food and other pleasurable or rewarding things.
Restrained eaters may be more sensitive to food cues, since one of the functions of dopamine is to signal the salience of a particular stimuli.
Women with anorexia showed greater activation in the ventral stiratum, an area of the brain linked to dopamine and reward, than women without anorexia when viewing pictures of underweight women.

Women with either anorexia or bulimia had greater expression of the dopamine transporter gene DAT. DAT influences the release of a protein that regulates the reuptake of dopamine back into the synapse.

Brain activity or gene expression of certain dopamine genes is correlated with eating disorders.

Cognitive behavioral factors

People with eating disorders may have maladaptive schemata that narrow their attention toward thoughts and images related to weight, body shape, and food.

Anorexia nervosa

Cognitive behavioral theories of anorexia nervosa emphasize fear of fatness and body-image disturbance as the motivating factors that powerfully reinforce weight loss.

Many who develop anorexia nervosa symptoms report that the onset followed a period of weight loss and dieting.

• Behaviors that achieve or maintain thinness are negatively reinforced by the reduction of anxiety about becoming fat.
• Dieting and weight loss may be positively reinforced by the sense of mastery or self-control they create

Perfectionism and a sense of personal inadequacy may lead a person to become especially concerned with his or her appearance, making dieting a potent reinforcer.
Seeing portrayals in the media of thinness as an ideal, being overweight, and tending to compare oneself with especially attractive others all contribute to dissatisfaction with one’s body.

Criticism of peers and parents about being overweight is also important in producing a drive to thinness.

Bulimia nervosa and binge eating disorder

People with bulimia are also thought to be over-concerned with weight gain and body appearance.
They judge self-worth mainly by their weight and shape.

• Low self-esteem
  Because weight and shape are somewhat more controllable than are other features of the self, they tend to focus on weight and shape, hoping their efforts in this area will make them feel better generally.

They try to follow a pattern of restrictive eating that is very rigid, with strict rules regarding how much to eat, what kinds of food to eat, what kinds of food to eat, and when to eat.
These strict rules are inevitably broken, and the lapse escalates into a binge.
After the binge, feelings of disgust and fear of becoming fat build up, leading to compensatory actions such as vomiting.
Although purging temporarily reduces the anxiety from having eaten too much, this cycle lowers the person’s self-esteem, which triggers still more bingeing and purging, a vicious circle that maintains desired body weight but has serious medical consequences.

Conditions that further increase the eating of restrained eaters after a preload,

• Various negative mood states, such as anxiety and depression
• When self-image is threatened and if they have low self-esteem

The binge may function as a means of regulating negative affect. But this is not successful.

Stress and negative affect are relieved by purging.

Concerns about body shape and weight predicted restrained eating, which in turn predicted an increase in binge eating.

There is a bias toward food and body image.

Sociocultural factors

Throughout history, the standards societies have set for the ideal body have varied greatly.

As society become more health and fat conscious, dieting to lose weight has become more common.
Social standards stressing the importance of thinness play a rile in the development of eating disorders.

Exposure to media portrayals of unrealistically thin models can influence reports of body dissatisfaction.
The sociocultural ideal of thinness is a likely vehicle through which people learn to fear being or even feeling fat.
Reducing the stigma associated with being overweight will be beneficial to those with eating disorders as well as those who are obese.

Gender influences

Western cultures reinforce the desirability of being thin for women more than men.
Women are defined more by their bodies, whereas men are esteemed more for their accomplishments. This led women to self-objectify.

Cross-cultural studies

Evidence for eating disorders across cultures depends on the disorder.
Cases of anorexia have been found in cultures with very little western influence. But, the anorexia observed in these diverse cultures does not always include the intense fear of gaining weight or being fat.

Bulimia nervosa appears to be more common in industrialized societies.

Other factors contributing to the etiology of eating disorders

Personality influences

An eating disorder itself can affect personality.

Personality traits

• Perfectionism
• Shy
• Complaint

additional for bulimia:

• Histrionic features
• Affective instability
• Outgoing social disposition

Characteristics of families

Family characteristics may contribute to the risk for developing an eating disorder, but, eating disorders also likely have an impact on family functioning.

Child abuse and eating disorders

Some studies have indicated that self-reports of childhood sexual abuse are higher among people with eating disorders than among people without eating disorders, especially those with bulimia nervosa.
Not especially for eating disorders.

Higher rates of childhood physical abuse among people with eating disorders.

Treatment of eating disorders

Hospitalization is frequently required to treat people with anorexia so that their ingestion of food can be gradually increased and carefully monitored.

Medications

Because bulimia nervosa is often comorbid with depression, it has been treated with various antidepressants.
Reduce purging and binge eating.
Big dropout.

Medications for anorexia have not shown to be successful.
Medication for binge eating disorder has not been well studied.

Psychological treatment of anorexia nervosa

Therapy for anorexia is generally believed to be a two-tiered process

• The immediate goal is to help the person gain weight
  The person is often so weak and physiological functioning is so disturbed that hospital treatment is medically imperative.
  Operant conditioning behavior therapy programs have been somewhat successful in achieving weight gain in the short term.
• The second goal is maintenance of weight gain.

Psychological treatment for anorexia can also involve cognitive behavior therapy (CBT)

Family therapy is the principle form of psychological treatment for anorexia.
Three major goals

• Changing the patient role of the person with anorexia
• Redefining the eating problem as an interpersonal problem
• Preventing the parents from using their child’s anorexia as a means of avoiding conflict

Psychological treatment of bulimia nervosa

Cognitive behavior therapy is the best-validated and most current standard for the treatment of bulimia.
In CBT, people with bulimia are encouraged to question society’s standards for physical attractiveness. People with bulimia must also uncover and then change beliefs that encourage them to starve themselves to avoid becoming overweight.
They must be helped to see that normal body weight can be maintained without severe dieting and that unrealistic restriction of food intake can often trigger a binge.
Altering all-or-nothing thinking can help people begin to eat more moderately.
They also learn assertiveness skills, which help them cope with unreasonable demands placed on them by others, as well as more satisfying ways of relating to people.

The overall goal of treatment in bulimia is to develop normal eating patterns.

ERP can help in the short-term.

People with bulimia who are successful in overcoming their urge to binge and purge also improve in associated problem areas.

CBT alone is more effective than any available drug treatment.

Self-help CBT is effective for people on the wait-list.

Family therapy is also affective for bulimia.

Psychological treatment for binge eating disorder

Cognitive behavior therapy has been shown to be effective for binge eating disorder.
CBT targets binges as well as restrained eating by emphasizing self-monitoring, self-control, and problem solving as regards eating.
IPT is also effective.

Preventive interventions for eating disorders

Three different types of preventive interventions have been developed and implemented:

• Psyhcoeducational approaches
  Educating children and adolescents about eating disorders in order to prevent them from developing symptoms
• Deemphasizing sociocultural factors
  Reject sociocultural pressures to be thin
• Risk factor approach
  Identifying people with known risk factors for developing eating disorders and intervening to alter these factors.