Stress Hormone Linked to Severe Aggression in Boys
Jan. 13, 2000 (Indianapolis) -- A study published in the January edition of
the Archives of General Psychiatry indicates that low levels of the
stress hormone cortisol in the saliva may be an indicator of persistent
aggression in boys. This may indicate a lasting biological component to this
type of aggression, meaning that it's not just initiated by parental or
environmental factors. <
A group of 38 boys, aged 7-12, who were referred to a clinic for disruptive
behavior were studied for up to four years. The researchers conducted
psychiatric evaluations on the boys and interviewed family members and teachers
looking for symptoms of aggressive behavior such as starting fights, using
weapons, and being cruel to people or animals. In addition, classmates were
surveyed and asked to name the three children they thought best fit each of
five categories: likes most, likes least, fights most, meanest, and most shy.
Nominations from the 'fights most' and 'meanest' categories were monitored for
two years to determine which boys had peer aggression.
Researchers found that low levels of cortisol, a hormone normally secreted
by the brain in response to stressful or threatening situations, is associated
with persistent and early aggression. Boys with low cortisol concentrations
exhibited three times the number of aggressive symptoms and were named most
aggressive by peers three times more often when compared with boys who had
higher cortisol levels at either sampling time.
"What we think may be going on with these kids is their system doesn't
react to stress very quickly or easily," says lead author Keith McBurnett,
PhD, assistant professor of psychiatry at the University of Chicago. "If
they don't experience internal stress or anxiety about being punished or
retaliated against, that may be reflected in their low levels of stress
hormone. This may also explain why punishment doesn't seem to change the
aggressive behavior in these kids."
According to McBurnett this may soon lead to a way to separate those who
will be aggressive into adulthood from those who may just be "going through
a phase." The former is much harder to treat. McBurnett suggests that the
findings might also lead to developing new methods to channel that
aggressiveness in a way that is better tolerated by society.
Patricia Brennan, PhD, assistant professor of psychology at Emory University
in Atlanta, doesn't think the study will have an immediate impact on the
treatment of aggressive boys, but she does think that it will provide some
guidance for future research.
"There is no comparison to a normal control group which means you cannot
use the cortisol level as a predictor until more research is completed,"
Brennan tells WebMD. "You also cannot say anything about stress being a
cause because [the study] did not follow children for a long enough period of
time. Concerning treatment, it might suggest something different in terms of
responsiveness to stress and how to handle it could be considered."
- Low levels of the stress hormone cortisol in the saliva are associated with
persistent aggression in boys.
- Researchers suspect that these aggressive children don't react to stress
quickly or easily and don't experience internal stress in response to being
- The findings might eventually lead to new ways to treat aggression in