With medication and behavioural interventions, children with attention deficit hyperactivity disorder (ADHD) could better maintain attention and self-control by normalising activity in the same brain systems, according to a study.
Researchers from the University of Nottingham have shown that medication has the most significant effect on brain function in children with ADHD, but this effect can be boosted by complementary use of rewards and incentives, which appear to mimic the effects of medication on brain systems.
Although no cure exists for the condition, symptoms can be reduced by a combination of medication and behaviour therapy.
Methylphenidate, a drug commonly used to treat ADHD, is believed to increase levels of dopamine in the brain. This increase amplifies certain brain signals and can be measured using an electroencephalogram (EEG). Until now it has been unclear how rewards and incentives affect the brain, either with or without the additional use of medication.
Thus, researchers at Nottingham’s Motivation, Inhibition and Development in ADHD Study (MIDAS) used EEG to measure brain activity while children played a simple game. They compared two particular markers of brain activity that relate to attention and impulsivity, and looked at how these were affected by medication and motivational incentives.
The researchers found that when given their usual dose of methylphenidate, children with ADHD performed significantly better at the tasks than when given no medication, with better attention and reduced impulsivity. Their brain activity appeared to normalise, becoming similar to that of the control group.
Similarly, motivational incentives also helped to normalise brain activity on the two EEG markers and improved attention and reduced impulsivity, though its effect was much smaller than that of medication.
“When the children were given rewards or penalties, their attention and self-control was much improved. We suspect that both medication and motivational incentives work by making a task more appealing, capturing the child’s attention and engaging his or her brain response control systems,” said Dr Maddie Groom, first author of the study. Professor Chris Hollis, who led the study, believes the findings may help to reconcile the often-polarised debate between those who advocate either medication on the one hand, or psychological/behavioural therapy on the other.
The study has been published in the journal ‘Biological Psychiatry’.
