I. Anorexia Nervosa
Diagnostic Criteria
A. Refusal to maintain body weight at or above
a minimally normal weight for age and height (e.g., weight loss leading
to maintenance of body weight less than 85% of that expected; or failure
to make expected weight gain during period of growth, leading to body weight
less than 85% of that expected).
B. Intense fear of gaining weight or becoming
fat, even though underweight.
C. Disturbance in the way in which one's body
weight or shape is experienced, undue influence of body weight or shape
on self-evaluation, or denial of the seriousness of the current low body
weight.
D. In postmenarcheal females, amenorrhea, i.e.,
the absence of three consecutive menstrual cycles.
Types:
Restricting Type: during the current episode of Anorexia
Nervosa, the person has not engaged in binge-eating or purging behavior
(i.e., self-induced vomiting or the misuse of laxatives, diuretics, or
enemas)
Binge-Eating/Purging Type: during the current episode of Anorexia Nervosa, the person has engaged in binge-eating or purging behavior (i.e., self-induced vomiting or the misuse of laxatives, diuretics, or enemas)
II. Bulimia Nervosa
A. Recurrent episodes of binge eating. An episode
of binge eating is characterized by the following:
(1) eating, in a discrete
period of time (e.g., within any 2-hour period), an amount of food that
is definitely larger than most people would eat during a similar period
of time under similar circumstances.
(2) a sense of lack of
control over eating during the episode (e.g., a feeling that one cannot
stop eating or control what or how much one is eating)
B. Recurrent inappropriate compensatory behavior in order to prevent weight gain, such as self-induced vomiting; the misuse of laxatives, diuretics, or enemas, or other medications; fasting; or excessive exercise.
C. The binge eating and inappropriate compensatory behaviors both occur, on average, at least twice a week for 3 months.
D. Self-evaluation is unduly influenced by body shape and weight.
E. The disturbance does not occur exclusively during episodes of Anorexia Nervosa.
Types:
Purging Type: during the current episode of Bulimia Nervosa, the
person has regularly engaged in self-induced vomiting or the misuse of
laxatives, diuretics, or enemas.
Nonpurging Type: during the current episode of Bulimia Nervosa, the person has used other inappropriate compensatory behaviors, such as fasting or excessive exercise, but has not regularly engaged in self-induced vomiting or the misuse of laxatives, diuretics, or enemas.
III. Other eating disorders:
A. Pica- pica is a disorder where children repeatedly
eat nonnutritive substances, such as paint, plaster, animal droppings,
or small rocks.
B. Rumination disorder- the infant regurgitates
partially digested food. The food may then be spit out, or chewed and reswallowed.
IV. Comorbidity
A. Most often seen with depression.
B. The differences between Anorexia and Bulimia
1. Bulimics are usually
within 10% of their normal body weight
2. Anorexics that purge
usually eat relatively small amounts of food and purge more often.
3. Bulimia is far more
common than Anorexia.
4. Bulimics tend to binge
on forbidden food and then purge to control their weight.
5. Only anorexics show
an "intense drive for thinness" and a disturbance in their perception of
body image.
V. Course of the disorder
A. Anorexia Nervosa
1. Average age of first
onset is about 17, with 68% of the cases beginning between ages 14 and
20.
2. Anorexia is a chronic
disorder with a lot of relapse, though there is a trend toward gradual
improvement over several years.
3. Anorexia leads to
death about 6%-10% of the time.
B. Bulimia Nervosa
1. Average age of onset
is about age 21.
2. Bulimia tends to alternatively
worsen and abate over several years if left untreated.
VI. Causes of the disorder
A. Sociocultural Factors-
1. Western culture values
thinness.
2. Dieting appears to
have a key causal role.
B. Familial Contributions
1. Enmeshment
2. More hostility and
difficulty resolving conflict, less support and nurturance, and more of
a sense of isolation and noncohesiveness within the family.
C. Psychophysiological and Genetic Influences
1. Anorexia nervosa occurs
in both of nonidentical fraternal twins about 7% of the time, which is
about the same rate as for nontwin sisters.
2. For identical twins,
both had bulimia nervosa 29% of the time.
3. It is estimated that
55% of the risk for bulimia comes from genetic rather than sociocultural
or psychological factors.
VII. Current Treatments
A. Cognitive-Behavioral
1. Exposure and Response
Prevention (ERP)