Attention-Deficit Hyperactivity Disorder Attention (ADHD) is a common childhood neurobehavioral disorder characterized by hyperactivity, impulsivity, and attention deficits.
Awareness about the disorder has been rapidly increasing, and more and more children are being diagnosed with and treated for ADHD. While pharmacological interventions are an option, they may not always be viable or effective in treating ADHD. Due to the fact that ADHD often co-occurs with other developmental disorders, and due to the heterogeneity of symptoms, the efficacy of medication varies from child to child. Even if the medication has a good success rate, many parents look at drugs with a wary eye, not wishing to put their children at risk of growing dependant on medication. Over the past couple years, the debate on whether ADHD medication is over-prescribed has gained momentum in the U.S, and several valid questions have been raised. While over-prescribed pills and increased rates of addiction to ADHD medication may not yet be a serious concern in India, it is definitely something worth looking into before it is too late.
Pharmacological intervention and cognitive training are commonly used to treat children with the disorder. But, could regular physical exercise help alleviate the major symptoms of ADHD?
While parents of children diagnosed with ADHD report that regular physical activity induces positive behavioural changes in their children, there is not much evidence to support these statements. In a pilot exploratory study, conducted by researchers at the University of North Carolina and Southern Illinois University, parental perceptions of the effects of exercise on behavior in children and adolescents with ADHD were studied. 96 participants were surveyed, of which 68 met the requirements of the study. The findings suggest that physical activity generally helped diminish symptoms in children diagnosed with ADHD. 85% of the sample was using pharmacological treatment for ADHD, which suggests that physical activity helps contribute to the efficacy of pharmacological treatment too. It can be concluded that chronic exercise does exacerbate ADHD symptoms to an extent, and that it can be even more effective if used in conjuction with pharmacological intervention.
This study was published in the Journal of Sport and Health Science 2013.
It is commonly perceived that regular physical activity could improve attention in children with ADHD. However, “common perception” is no concrete scientific evidence. Is there any neurophysiological evidence to show the link between impaired motor function and attention deficits?
In a recent study, published in Neuroimage Clinical 2014, the neural correlates of motor networks were studied in children with Developmental Coordination Disorder and ADHD. DCD is often found comorbid with ADHD in children. Neuroimaging research provides evidence that motor circuitry is disrupted in children diagnosed with these disorders, which could explain the high rate of co-currence.
In this functional neuro-imaging study, resting-state fMRI was compared between seven children with DCD, 21 with ADHD and 18 with DCD+ADHD and 23 controls. Specifically, the activity of the primary motor cortex was compared between each group and the control group, with age as a co-factor. Results revealed that children with DCD and/or ADHD had similar reductions in functional connectivity between the primary motor cortex and the bilateral inferior frontal gyri, right supramarginal gyrus, angular gyri, insular cortices, amygdala, putamen, and pallidum. It was also found that age had an effect on the pattern of connectivity in children with DCD and/or ADHD, when compared with the control group. These findings suggest that disruptions in motor circuitry occur in children with ADHD and/or DCD, which could be the contributing factor to diminished motor function and attention. The results provide a link between motor and attention problems, which could be attributed to common underlying neurophysiological substrates.
While functional neuroimaging provides an excellent means to study the neurophysiology of ADHD and its relationship with physical activity, clearer, neurobiological evidence is required to conclusively prove the same. This can be obtained via animal studies. The cerebellum, which is involved in motor learning, motor coordination and control by maintaining a balance and muscle tension, shows functional impairment in children with ADHD. Animal experiments and subsequent microscopic and biochemical analysis of brain samples provide great insight into understanding the etiology of the disorder.
In a study, published in Journal of Exercise Rehabilitation 2014, the effect of treadmill exercise on ADHD was studied in spontaneous hypertensive rats. Spontaneous hypertensive rats were used at the ADHD animal model as they exhibit the major symptoms of ADHD. The experiments were conducted on four group of 15 rats each: control group, ADHD group, ADHD and methylphenidate (MPH)-treated group, ADHD and treadmill exercise group. The Purkinje cells of the cerebellum and the astrocytes were microscopically studied. Motor coordination and balance were determined. It was found that ADHD significantly decreased balance, and exhibited clear loss of Purkinje cells. In contrast, treadmill exercise and MPH alleviated balance and reduced Purkinje cell loss and astrocyte reaction. Hence, results suggest that treadmill exercise might alleviate symtoms of ADHD, through reduction of Purkinje cell loss and astrocytic reaction in the cerebellum.
So far, only a handful of studies have been conducted on the effects of physical exercise and sports on ADHD. However, from the current research, we can safely say that physical activity does help alleviate the symptoms of ADHD, at least to some extent. While there is not enough evidence to conclusively state that physical exercise can be used as an alternative to pharmacological treatment, it definitely worth a shot to encourage children with ADHD to engage in sports and outdoor games.