Bulimia nervosa is a complex disorder that does
not have a single cause. Research suggests that some
people have a predisposition toward bulimia and that
something then triggers the behavior, which then
becomes self-reinforcing. Hereditary, biological, psychological
and social factors all appear to play a role.
Causes
Heredity.
Twin studies suggest that there is an inherited
component to bulimia nervosa, but that it is
small. Having a close relative, usually a mother or a
sister, with bulimia slightly increases the likelihood
of other (usually female) family members developing
the disorder. However, when compared other inherited
diseases or even to anorexia nervosa, the genetic
contribution to developing this disorder appears less
important than many other factors. Family history
of depression, alcoholism, and obesity also increase
the risk of developing bulimia.
Biological factors.
There is some evidence that bulimia
is linked low levels of serotonin in the brain.
Serotonin is a neurotransmitter. One of its functions
is to help regulate the feeling of fullness or satiety
that tells a person to stop eating. Neurotransmitters
are also involved in other mental disorders such as
depression that often occur with bulimia. Other
research suggests that people with bulimia may
have abnormal levels of leptin, a protein that helps
regulate weight by telling the body to take in less
food. Research in this area is relatively new, and
the findings are still unclear.
Psychological factors.
Certain personality types
appear to be more vulnerable to developing bulimia.
People with bulimia tend to have poor impulse control.
They are of often involved in risky behavior
such as shoplifting, drug and alcohol abuse and
risky sexual activities. People with bulimia have
low-self worth and depend on the approval of others
to feel good about themselves. They are aware that
their behavior is abnormal. After a binge/purge session,
they are ashamed and vow never to repeat the
cycle, but the next time they are unable to control the
impulse to eat and purge. They also tend to have a
black-or-white, all-or-nothing way of seeing situations.
Major depression, obsessive-compulsive disorder,
and anxiety disorders are more common among
individuals who are bulimic.
Social factors.
The families of people who develop
bulimia are more likely to have members who have
problems with alcoholism, depression, and obesity.
These families also tend to have a high level of open
conflict and disordered, unpredictable lives. Often
something stressful or upsetting triggers the urge to
diet stringently and then begin binge/purge behaviors.
This may be as simple as a family member as
teasing about the person’s weight, nagging about
eating junk food, commenting on how clothes fit,
or comparing the person unfavorably to someone
who is thin. Life events such as moving, starting a
new school, and breaking up with a boyfriend can
also trigger binge/purge behavior. Overlaying the
family situation is the false, but unrelenting, media
message that thin is good and fat is bad; thin people
are successful, glamorous, and happy, fat people are
stupid, lazy, and failures.
Signs and symptoms
Binge/purge cycles have physical consequences.
These include:
-teeth damaged from repeated exposure to stomach
acid from vomiting; eroded tooth enamel;
-swollen salivary glands; sores in mouth and throat
-dehydration
-sores or calluses on knuckles or hands from using
them to induce vomiting
-electrolyte imbalances revealed by laboratory tests
-dry skin
- fatigue
-irregular or absent menstrual cycles in women
-weight, heart rate and blood pressure may be normal
