Brain scans of children who have parents or siblings
with the illness reveal a neural circuitry that is
hyperactivated or stressed by tasks that peers with
no family history of the illness seem to handle with
ease.
Image reflects brain activation abnormalities in
children and adolescents with a family history of
schizophrenia, themselves at greater risk for
schizophrenia. Image source: Aysenil Belger, PhD.
Because these differences in brain functioning
appear before neuropsychiatric symptoms such as
trouble focusing, paranoid beliefs, or
hallucinations, the scientists believe that the
finding could point to early warning signs or
“vulnerability markers” for schizophrenia.
Individuals who have a first degree family member
with schizophrenia have an 8-fold to 12-fold
increased risk of developing the disease. However,
there is no way of knowing for certain who will
become schizophrenic until symptoms arise and a
diagnosis is reached. Some of the earliest signs of
schizophrenia are a decline in verbal memory, IQ,
and other mental functions, which researchers
believe stem from an inefficiency in cortical
processing – the brain’s waning ability to tackle
complex tasks.
In this study, Aysenil Belger, PhD, associate
professor of psychiatry at the UNC School of
Medicine and her colleagues sought to identify what
if any functional changes occur in the brains of
adolescents at high risk of developing schizophrenia.
She performed functional magnetic resonance imaging
(fMRI) on 42 children and adolescents ages 9 to 18,
half of which had relatives with schizophrenia and
half of which did not.
Study participants each spent an hour and a half
playing a game where they had to identify a specific
image – a simple circle – out of a lineup of
emotionally evocative images, such as cute or scary
animals. At the same time, the MRI machine scanned
for changes in brain activity associated with each
target detection task.
Belger found that the circuitry involved in emotion
and higher order decision making was hyperactivated
in individuals with a family history of
schizophrenia, suggesting that the task was
stressing out these areas of the brain in the study
subjects.
“This finding shows that these regions are not
activating normally,” she says. “We think that this
hyperactivation eventually damages these specific
areas in the brain to the point that they become
hypoactivated in patients, meaning that when the
brain is asked to go into high gear it no longer
can.”
Belger is currently exploring what kind of role
stress plays in the changing mental capacity of
adolescents at high risk of developing schizophrenia.
Though only a fraction of these individuals will be
diagnosed with schizophrenia, Belger thinks it is
important to pinpoint the most vulnerable people
early to explore interventions that may stave off
the mental illness.
“It may be as simple as understanding that people
are different in how they cope with stress,” says
Belger. “Teaching strategies to handle stress could
make these individuals less vulnerable to not just
schizophrenia but also other neuropsychiatric
disorders.”
The research was funded by the National Institute of
Mental Health and the National Institute of Child
Health and Human Development. Study co-authors from
UNC include Sarah Hart, PhD, postdoctoral fellow;
Joshua Bizzell, MS, lab engineer; Carolyn Bellion,
study coordinator; and Diana Perkins, MD, MPH,
professor of psychiatry.
For more information
Altered fronto–limbic activity in children and
adolescents with familial high risk for
schizophrenia
(MDN)
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