Exercise in ADHD – From the Theory to the Lab and the Field

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 external 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. Physical activity is widely known to be a powerful stimulus of the hypothalamic-pituitary-adrenal (HPA) and noradrenergic systems, as well as a powerful stimulus to the release of CA and growth hormone (GH). The objective of our study in progress is to examine differences in catecholamine (CA) response to exercise between children with ADHD and controls. To test this, all children performed the MOXO distractors- Continuous Performance Test (d-CPT) before and after exercise, and CA and GH response to exercise was measured. Children with ADHD performed the protocol twice, with and without treatment. Our initial data suggests different patterns of CA and GH excretion after exercise in children with ADHD. This deficiency may be detected using a minimally invasive, non-pharmacologic challenge. In some ADHD children exercise leads to an improvement in the MOXO test.