Source: University of
Washington Posted: June 16, 2006
http://www.sciencedaily.com/releases/2006/06/060616135015.htm
Physiological
Markers For Cutting, Other Self-harming Behaviors By Teenage Girls Found
Non-fatal,
self-inflicted injuries by adolescent and young adult females are major public
health problems and researchers have found physiological evidence that this
behavior may lead to a more serious psychological condition called borderline
personality disorder.
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University
of Washington psychologists have discovered that adolescent girls who engage in
behaviors such as cutting themselves have lower levels of serotonin, a hormone
and brain chemical, in their blood. They also have reduced levels in the
parasympathetic nervous system of what is called respiratory sinus arrhythmia,
a measure of the ebb and flow of heart rate along with breathing.
"A
low level of this measure of the parasympathetic nervous system is
characteristic of people who are anxious and depressed and among boys who are
delinquent. But this is the first study to show it among adolescent girls who
engage in self-harming behavior," said Theodore Beauchaine, UW associate
professor of psychology.
The
findings come from a study that also uncovered sharp disparities in the number
of self-harming events and suicide attempts reported by the girls and their
parents.
The
research, headed by Sheila Crowell, a UW psychology doctoral student, focused
on girls because self-harming behavior affects females far more often than it
does males. The study included 23 girls, ages 14 to 18, who engaged in what
psychologists call parasuicidal behavior. Participants were included if they
had engaged in three or more self-harming behaviors in the previous six months
or five or more such behaviors in their lifetime. An equal number of girls of
the same ages who did not engage this behavior were enrolled as a comparison
group.
The
adolescents in the parasuicide group reported far more incidents of
self-harming behavior than did their parents. Individuals engaged in this kind
of behavior between 11 and 839 times. Their parents, however, reported a range
of 0 to 205 incidents. Similarly, the girls reported more than three times the
number self-harming behaviors with intent to die, 310 events versus 90, than their
parents did. However, the girls and their parents were very close on the number
of times an adolescent required medical attention.
Twenty
of the girls, or 87 percent, reported at least one attempted suicide, but
Crowell said this number is not that surprising in this population.
"You
need to understand a person's intent and the lethality of their attempts,"
she said. "Did they take a small number of Tylenol or were they holding a
loaded gun to their head?"
She
noted cutting was the most common self-harming behavior in which the girls
engaged. Eight-two percent of girls used instruments ranging from paper clips
to kitchen knives and razors with the intent of hurting themselves.
"These
attempts have to be taken seriously," said Beauchaine. "These girls
may be really at risk for later suicide, and in the long term there needs to be
studies of the progression of self-harm attempts."
To
find physiological markers of self-harming behavior, the UW researchers showed
both groups of adolescents a three-minute film clip from the movie "The
Champ" depicting a boy with his dying father. Previous studies have shown
the film can induce sadness. A number of different psychophysiological measures
were collected from each of the girls before, while and after viewing the film
clip. Following the viewing a small blood sample was taken to measure
whole-blood serotonin.
The
girls who engaged in self-harming behavior had lower levels of respiratory
sinus arrhythmia in their parasympathetic nervous system while watching the
film clip. These measures, the researchers argue, support the idea that the
inability to regulate emotions and impulsivity can trigger self-harming
behavior.
"This
research supports the primary theory that borderline personality disorder is
caused by an inability to manage emotions. These girls have an excessively
strong emotional reactions and they have extreme difficulty in controlling
those emotions," said Beauchaine. "Their self-harming behavior serves
to distract them from these emotions."
Borderline
Personality Disorder is far more serious than self-harming behavior and people
with the condition have a very high suicide rate. An estimated 5.8 million to
8.7 million Americans, mostly women, suffer from borderline personality
disorder. People with the condition have a multiple spectrum of disorders that
are marked by emotional instability, difficulty in maintaining close
relationships, eating disorders, impulsivity, chronic uncertainty about life
goals and addictive behaviors such as using drugs and alcohol. They also have
major impact on the medical system by being among the highest users of
emergency and in-patient medical services.
Co-authors
of the study are Elizabeth McCauley, UW professor of psychiatry and behavioral
science; Cindy Smith a former psychiatrist at Children's Hospital who is now in
private practice; Adrianne Stevens, an incoming UW psychology graduate student,
and Patrick Sylvers, a former UW student who is now a graduate student at Emory
University. The study, published in the journal Development and
Psychopathology, was funded by Seattle Children's Hospital, the National
Foundation for Suicide Prevention and the National Institute of Mental Health.