Abnormal Psychology

Eating Disorders 471

the nonpurging type (which involves fasting or

excessive exercise). Bulimia is twice as preva-

lent as anorexia, and much more common

among women than men.

All purging methods can cause dehydration,

which lead to electrolyte imbalances and possi-

bly death. Chronic vomiting can lead to enlarged

parotid and salivary glands, and can erode dental

enamel. Chronic laxative use can lead to perma-

nent loss of intestinal functioning.

Aspects of the DSM-IV-TR criteria for a

diagnosis of bulimia have been criticized:

The defi nition of “binge eating” is subjective, the

purging/nonpurging distinction does not corre-

late meaningfully with course or prognosis, and

bulimia and anorexia do not appear to be distinct

disorders but rather may be different phases of

the same disorder. Problems with the criteria for

anorexia and bulimia are apparent in the preva-

lence of eating disorder not otherwise speci-

fi ed (EDNOS), which has a higher prevalence than

anorexia and bulimia combined. One subset of

patients with EDNOS have binge-eating disorder.

Thinking like a clinician

Tanya had been dieting, but after a month or

so, she began to pig out toward bedtime. After

the fi rst few of these gorging sessions, she felt

both physically uncomfortable and ashamed

of herself, and she would make herself vomit.

After about a week, though, she stopped

throwing up; instead she began exercising for

about an hour each day. This pattern of daily

exercising and pigging out in the evening has

persisted for about 6 months. Does Tanya have

bulimia nervosa, EDNOS, or just disordered

eating but no DSM-IV-TR diagnosis? What were

the key factors that determined your answer?

Summary of

Understanding Eating

Disorders

It is particularly difficult for researchers to

establish cause-and-effect relationships among

the factors associated with eating disorders be-

cause the symptoms themselves— restricting,

bingeing, purging, excessive exercise, mal-

nourishment—create neurological (and other

biological), psychological, and social changes.

Neurological factors associated with eat-

ing disorders include unusually low activity in

the frontal, temporal, and parietal lobes, as

well as the anterior cingulate cortex, the basal

ganglia, and the cerebellum. However, these

neural patterns may vary for specific types

of anorexia, and may be affected by dieting.

Patients with anorexia also have reduced gray

and white matter. People with anorexia and

bulimia are not as responsive to serotonin, a

neurotransmitter involved in mood, anxiety,

and binge eating. Eating disorders tend to run

in families and have substantial heritability,

which indicates a role for genes.

Psychological factors related to eating

disorders include: irrational thoughts and

excessive concerns about weight, appear-

ance, and food; binge eating as a result of

the abstinence violation effect; positive and

negative reinforcement of symptoms of eating

disorders (restricting, bingeing, and purging);

certain personality traits (perfectionism, harm

avoidance, neuroticism, and low self-esteem);

disinhibited eating triggered by the last sup-

per effect, especially in restrained eaters; and

comorbid disorders in female adolescents,

particularly depression.

Social factors related to eating disorders

include: Family members and friends who pro-

vide a model for eating, concern about weight,

and focus on appearance through their own

behaviors and responses to others. Cultural

factors play a key role, as evidenced by the

increased prevalence over time of bulimia and

concern about weight that is part of anorexia.

Specific cultural factors include a cultural

ideal of thinness and repeated exposure—

through the media—to this ideal, as well as

the individual’s assimilation of this ideal.

Thinking like a clinician

Suppose scientists discover genes that are

associated with eating disorders. What

could—and couldn’t—you infer about the

role of genetics in eating disorders? How

could genes contribute to eating disorders if

bulimia is a relatively recent phenomenon? In

what ways does the environment influence

the development of eating disorders? Why do

only some people who are exposed to familial

and cultural emphases on weight, food, and

appearance develop an eating disorder?

Summary of Treating

Eating Disorders

The treatments that target neurological and

other biological factors include: nutritional

counseling; medical hospitalization for signifi -

cant medical problems related to the disorder;

and medication to address symptoms of the

disorder and of anxiety and depression. Specif-

ically, SSRIs may help prevent relapse in those

with anorexia and can decrease symptoms of

bingeing and purging in those with bulimia.

The primary treatment that targets

psychological factors is CBT, which is the

treatment of choice for eating disorders. CBT

addresses maladaptive thoughts, feelings,

and behaviors that impede normal eating,

promote bingeing and purging, and lead to

body image dissatisfaction. CBT may include

exposure with response prevention and help

patients develop new coping strategies.

Treatments that target social factors include

IPT, which is designed to improve the patient’s

relationships; as relationships become more

satisfying, the eating disorder symptoms di-

minish. Family therapy, particularly with the

Maudsley approach, can be helpful for ado-

lescents with anorexia who live at home. Psy-

chiatric hospitalization provides supervised

mealtimes to increase normal eating and a

range of therapeutic groups to address various

psychological and social factors. Prevention

programs have the goal of preventing eat-

ing disorders from developing, particularly in

high-risk individuals.

Thinking like a clinician

Suppose your local hospital establishes an

eating disorders treatment program. Based

on what you have learned in this chapter,

what services should they offer, and why?

If your friend, who has bulimia nervosa, asked

your advice about what type of treatment she

should get, how would you respond, and why?

Key Terms

Bulimia nervosa (p. 435)

Anorexia nervosa (p. 435)

Eating disorders (p. 436)

Amenorrhea (p. 437)

Binge eating (p. 439)

Purging (p. 439)

Eating disorder not otherwise specifi ed

(EDNOS) (p. 446)

Partial cases (p. 446)

Subthreshold cases (p. 446)

Binge-eating disorder (p. 446)

Abstinence violation effect (p. 451)

Restrained eating (p. 454)

Objectifi cation theory (p. 458)

Maudsley approach (p. 467)

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