Exercise Effects in Children With Attention Deficit Hyperactivity Disorder

A leading pathophysiologic hypothesis of attention-deficit/hyperactivity disorder (ADHD) is based on the notion of a catecholamine [CA; norepinephrine (NE), epinephrine (EPI), and dopamine (DA)] dysfunction. This hypothesis suggests that the CA response to environmental stimuli is attenuated in ADHD and is derived primarily from observations that drugs such as methylphenidate and amphetamine - considered to be CA agonists - are effective in treating the symptoms of ADHD. Despite this compelling evidence, a definitive role of CA responsiveness in ADHD remains controversial. Physical activity is widely known to be a powerful stimulus of the hypothalamic-pituitary-adrenal (HPA) and noradrenergic systems. On the basis of the nation of a CA dysfunction in ADHD, we reasoned that the normal robust increase in circulating CA seen in response to exercise would be blunted in children with ADHD.

The objective of this study is to examine the possibility that exercise program and testing might be useful in differentiating CA responses to stress between children who had received a diagnosis of attention-deficit/hyperactivity disorder (ADHD) and age- and gender-matched controls.

This study will take place in 'Children and adolescence health and sports center' in Meir Medical Center, Kfar-Saba, Israel. Forty-five children, boys and girls between the ages 6 and 18, with newly diagnosed ADHD that not receiving any drugs will be assigned to the intervention group. Age and gender matched children with ADHD, receiving Ritalin and not engaged in regular exercise, or healthy children's without ADHD will serve as controls. The intervention group will participate in an exercise program, including aerobic and anaerobic components, twice a week, for 3 months. Exercise testing, blood sampling and cognitive assessment will be performed at the start and in the end of this study.