http://dailytelegraph.news.com.au/story/0,20281,16613386-5001028,00.html
ADHD kids ‘have brain dysfunction’
By Janelle Miles
September 15, 2005
ADOLESCENTS with attention deficit hyperactivity disorder (ADHD) have dysfunction in areas of the brain which help people ignore distractions and maintain focus, Australian research has found.
Child psychiatrist Alasdair Vance, of the University of Melbourne, and others, studied the brains of 14 boys aged 12 to 16 using magnetic resonance imaging (MRI) scans as they performed a working memory task.
The scans of seven children with ADHD were compared with a control group of healthy adolescents matched for age.
They were shown a three-dimensional cubed object and then four others, one of which was the same as the first, but rotated.
When asked to select the one which matched the original, the healthy adolescents performed significantly better than their ADHD counterparts.
Associate Professor Vance found that in the ADHD children, the connections between the parietal and frontal lobes of the brain which are important for holding information, were not as active as in the control group.
By comparison, the children with ADHD had increased activation in central areas of the brain linked to object recognition and motivational shifting of attention.
“Children with ADHD do have subtle, clear abnormalities in those brain systems that involve balancing the external inputs they get from their environment with the internal inputs that occur in their body and brain,” Prof Vance said.
“What that means is the factors that place children at risk for ADHD are both … biological and environmental.
“Our environment shapes the neural networks that we form.
“For example, in ADHD I’ve got no doubt that there is a group of vulnerable individuals who’ll never develop the disorder because they’ve had a particularly helpful environment at critical early stages of life.
“That same individual placed in an at-risk environment may develop full-blown ADHD.”
Details of the Melbourne study have been published in this month’s British Journal of Psychiatry.
Prof Vance said vulnerability to ADHD may begin with biological events in the womb, probably during the second trimester of pregnancy when neural networks begin to develop.
“This may set children up to have the onset and progression of ADHD as they try and cope with increasingly complex environments throughout life,” he said.
Children with ADHD often have inattention, concentration difficulties, planning and organisational problems and impulsive behaviour.
Prof Vance said learning more about how the brains of ADHD sufferers were affected would hopefully lead to improved medications and psycho-social treatments.
“Currently, there is no psychological or social intervention that helps ADHD children uniquely,” he said.
“However, we do know that positive reinforcement for desired behaviour and focusing on the positive rather than on punishment is helpful.”
Many children with ADHD are prescribed Ritalin.
A recent Australian study found daily doses of fish oil helped calm those with the disorder.