Exercise as it relates to Disease/Effects of physical activity on ADHD

This in an analysis of the journal article “The association between physical education and symptoms of Attention Deficit Hyperactivity Disorder” by Barnard-Brak, Davis, Sulak, & Brak (2011)

What is the background to this research?
The World Health Organisation defines physical activity as “any bodily movement produced by skeletal muscles that requires energy expenditure”. Whilst physical activity has been shown to improve overall physical health, current studies are evaluating its effects on Attention Deficit Hyperactivity Disorder (ADHD) symptoms.

Affecting a majority of classrooms across the United States, children with ADHD symptoms can often prove a challenge for teachers and support staff. Disruptive traits including excessive talking and motor activity, often translate to an overall increase in behavioural problems and lower academic achievements , when compared to their peers.

Common treatments for children with ADHD symptoms include pharmacological therapy and behavioural interventions. Despite proven benefits of drug prescription, parents are less favoured to this type of treatment for their children. Previous research has shown many children are reluctant to take medication, with another study identifying over fifty per cent of their sample (of children with ADHD) would cease taking medication if provided the choice. This poses a gap in literature to further explore the benefits of behavioural interventions, particularly that of physical activity.

Where is the research from?
Barnard-Brak & Brak are with the Department of Educational Psychology, Texas Tech University, Lubbock, Texas. Davis and Sulak are with the Department of Educational Psychology, Baylor Univeristy, Waco, Texas. The sample was taken from the pre-existing Early Childhood Longitudinal Study-Kindergarten (ECLS-K), with children from across the United States. Article was published in the Journal of Physical Activity and Health.

What kind of research was this?
This is a qualitative research study, involving a longitudinal survey comprised of child assessments and responses from parents, teachers and school administrators.

Level of evidence was sufficient, with a large sample group (>17,000 persons). A subsample of 25 per cent was chosen in order to cross-validate results, which returned statistically similar results, enabling the use of the original model.

What did the research involve?
The study consisted of 17,565 children from the ECLS-K database (children commencing kindergarten in Autumn 1998). Gender participation was even (between males and females) with the major ethnicity groups identifying as white non-Hispanic, Africa American, and Hispanic.

To assess ADHD symptoms, teachers and parents rated children’s behaviour on 4 variables using a 4-point frequency scale (i.e. never, sometimes, often, and very often). The variables are outlined below in Table 1. This methodology was also acquired from the ECLS-K, which has been replicated in numerous studies due to its cross-validation. Table 1: Variables assessing ADHD symptoms To measure physical activity, sport classes were implemented into the school program (varying duration per student). Additional non-curriculum-based activity was not monitored.

The main limitation of this study was the diagnosis of ADHD. The ECLS-K database used provided children with ‘symptoms of ADHD’, with diagnosis not noted.

What were the basic results?
Barnard-Brak, Davis, Sulak, & Brak found that structured physical activity is associated with lower levels of symptoms of ADHD across time. Whilst the mechanisms leading to these results are unclear, previous research has supported this papers’ additional hypotheses.

The leading hypothesis notes that issues with the cathecholamine system contribute to ADHD symptoms. Physical activity is a strong stimulus for this system, and thus may have prompted a decrease in ADHD symptoms amongst children in this study.

Another theory proposed by Barnard-Brak, Davis, Sulak, & Brak suggests the physical activity may have fatigued the children, with a calming effect, and consequently reduce ADHD symptoms. Although this would minimise the long-term effect of physical activity on ADHD symptoms, it still proves to be an intervention that should be monitored and adapted accordingly.

The researchers do not over emphasise the results, however, highlight numerous opportunities for further study within the area.

What conclusions can we take from this research?
This study concludes the correlation between physical activity and ADHD symptoms. Incorporating more physical activity into the children’s school curriculum lead to a reduction in ADHD symptoms. Further results were limited, however supported by previous research.

A 2016 systematic review compared multiple ADHD domains and their effectiveness in treating ADHD. Barnard-Brak, Davis, Sulak, & Brak’s study was highlighted under the behavioural domain, with numerous studies reflecting similar results; a positive correlation between physical activity and reduction in ADHD symptoms.

Practical advice
ADHD interventions vary, with parents tending to favour behavioural interventions over pharmacological interventions for their children. This highlights the importance of this research for parents and support persons of those with ADHD, especially for persons seeking alternative treatment methods. Although medication is often successful in reducing ADHD symptoms, it is frequently over-prescribed or accompanying side-effects.

Physical activity offers an additional option to assist in the reduction of ADHD symptoms. Whether it is alongside pharmacological treatment or not, exercise proves beneficial for overall health and fitness.

A holistic approach to treatment of ADHD symptoms, including both pharmacological and behaviour interventions, has resulted in the best outcomes (when compared to exclusive interventions). Barnard-Brak, Davis, Sulak, & Brak identify the need for further research in this area, and the specific structure of physical activity that proves most beneficial for children.

Further information/resources
For further reading regarding Attention Deficit Hyperactivity Disorder please visit the following links:
 * Medlineplus - ADHD
 * Raising Children - ADHD
 * Kids Health Info - ADHD an overview
 * Health direct - ADHD Australian Health Advise
 * ADHD Support Chat Room