Given the similarities between bulimia nervosa
and anorexia nervosa, binge-eating/purging type, there's room for
confusion when making a diagnosis, whether on the ASWB exam or in
real life. Let's take a look at what the DSM says about each.
What is anorexia nervosa?
Criteria for anorexia nervosa are as follows:
A. Restriction of energy intake leading to significantly low
body weight.
B. Intense fear of gaining weight despite significantly low
weight.
C. Disturbance in the way one's body weight or shape is
experienced, undue influence of body weight shape on
self-evaluation, or persistent lack of recognition of the
seriousness of current low body weight.
What are the types of anorexia nervosa?
There are two subtypes in anorexia nervosa:
Restricting type. Weight loss accomplished
primarily through dieting, fasting, and/or excessive exercise (not
recurrent binging or purging).
Binge-eating/purging type.
Recurrent episodes of binge eating or purging
(self-induced vomiting or the misuse of laxatives, diuretics, or
enemas).
What is bulimia
nervosa?
Criteria for bulimia nervosa are as
follows:
A. Recurrent episodes of binge eating
(overeating in a discrete period of time with a sensed lack of
control regarding the eating).
B. Recurrent inappropriate compensatory
behaviors to prevent weight gain (e.g., self-induced vomiting,
misuse of laxatives, diuretics, or other medications; fasting;
excessive exercise).
C. Lasts once a week for three
months.
D. Self-evaluation is unduly influenced
by body shape and weight.
E. Does not occur exclusively during
episodes of anorexia nervosa.
What's the difference between
anorexia nervosa, binge/purging-type and bulimia
nervosa?
Both anorexia nervosa and bulimia
nervosa involve negative self-evaluation of body shape and weight.
Both involve behaviors to avoid weight gain such as self-induced
vomiting. However, in anorexia nervosa, the disorder leads to
significantly low body weight, where bulimia nervosa does
not.
The difference is the ways severity is
coded for anorexia and bulimia helps highlight the essential
difference between the two diagnoses.
For anorexia nervosa, severity is
based on body mass index (BMI). For example, "mild"
indicates a BMI less than or equal to 17 kilograms per square
meter. "Extreme" indicates a BMI of less than fifteen kilograms per
square meter.
For bulimia nervosa, severity is based
on the frequency of behaviors. For 1-3 episodes per week,
a specifier of "mild" is applied. "Extreme" is used for 14 or more
episodes per week.
The difference is not the behavior
itself, it's the result.
Free ASWB Exam
Practice
The ASWB exam often tests to assess
knowledge of differentials between commonly occurring DSM disorders
like anorexia and bulimia. A sample question:
A 17-year-old client who appears noticeably underweight reports
frequently forcing herself to vomit after meals in order to "stay
skinny for cheerleading." The MOST likely DSM diagnosis for this
client is a type of:
A. Bulimia nervosa
B. Body dysmorphic disorder
C. Rumination disorder
D. Anorexia nervosa
Unless you're caught by the
distractors, body dysmorphic disorder (which is not diagnosed when
an eating disorder is present) and rumination disorder (not
described here), knowing the difference between anorexia and
bulimia quickly gets you to the correct answer. The client is
"noticeably underweight." You have your essential information. The
phrase "a type of" at the end of the question stem is an additional
clue. The client is most likely suffering from anorexia nervosa,
binge/purging-type. The answer is D.