Brain Scans Reveal Why Children with ADHD Have Difficulty in Concentrating

by Thilaka Ravi on Jan 6 2011 3:11 PM

 Brain Scans Reveal Why Children with ADHD Have Difficulty in Concentrating
Scientists studying brain scans have shown for the first time why children with attention-deficit/hyperactivity disorder (ADHD) have difficulty in concentrating.
Researchers at the University of Nottingham, who performed brain scans of children with ADHD using a 'Whac-a-Mole' style game, have found evidence that kids affected by the condition require either much greater incentives or their usual stimulant medication to focus on a task.

ADHD is the most common mental health disorder in childhood. Children with ADHD are excessively restless, impulsive and distractible, and experience difficulties at home and in school.

Although no cure exists for the condition, symptoms can be reduced by medication and/or behavioral therapy. The drug methylphenidate is commonly used to treat the condition.

The default mode network (DMN) in the brain is usually active when we are doing nothing, giving rise to spontaneous thoughts or 'daydreams', but is suppressed when we are focused on the task before us.

However, in children with ADHD, it is thought that the DMN may be insufficiently suppressed on 'boring' tasks that require focused attention.

The researchers compared brain scans of 18 children with ADHD, aged between 9 and 15 years old, against scans of a similar group of children without the condition.

By studying the brain scans, the researchers were able to show that typically developing children switched off their DMN network whenever they saw an item requiring their attention.

However, unless the incentive was high, or they had taken their medication, the children with ADHD would fail to switch off the DMN and would perform poorly.

The findings were published in the Journal of Child Psychology and Psychiatry.