March 26 (HealthDay News) -- Compared with other children, those with attention-deficit hyperactivity disorder (ADHD) have more inconsistent responses when doing short-term memory tasks, a new study finds.
"Our study helps explain why working memory may be fine at one moment and poor at another, just as one day a child with ADHD seems to be able to learn and focus in class and on another day seems distracted and not paying attention," study author Julie Schweitzer, an associate professor of psychiatry and behavioral sciences at the University of California, Davis, said in a news release from the school. The study was done while Schweitzer was at the University of Maryland.
"We think poor working memory is a characteristic present in many children and adults with ADHD," she said.
The study included 25 children with ADHD and 25 children without the disorder. All of them performed a computer task involving numbers and addition. Children with ADHD were much less consistent in their response times, but their answers were as accurate as those from the other group.
The researchers also found that higher levels of hyperactivity, restlessness and impulsivity were associated with slower reaction times among the children with ADHD.
The findings support the idea that the inability of a child with ADHD to consistently respond during a working memory task is what underlies impaired working memory.
Schweitzer hopes to study whether behavioral therapy or medication might help reduce working memory variability in children with ADHD. She noted that this variability means that children cannot generalize what they learn in one situation to another.
"Improving consistency in how children with ADHD respond to the environment should help them generalize what they learn in clinical interventions, improving their skills across situations," she said.
The study was published online in Child Neuropsychology.
SOURCE: University of California, Davis, news release, March 24, 2009