Can you compare a walk with ADHD drug?

A stroll in the park is as good at calming children as the Attention Deficit Hyperactivity Disorder (ADHD) drug Ritalin, according to a report in the Daily Mail today.

But the reliability of the study it weas based on is open to question. The study was small (on only 17 children) and made no direct comparison of exercise and the drug. It relied on a comparison with previous studies, which may have been carried out very differently.

The newspaper report said the study showed that children who took a 20-minute walk in a city park showed improvements in concentration "on a par with a daily dose of drugs for ADHD".

The study found significant improvements in concentration on children who took a walk in the park compared with when they took urban walks.

But whether the results could be replicated, sustained in the long-term, or produced in everyday situations is uncertain.

The question of whether ‘a walk in the park’ is as good as drugs for ADHD remains unanswered and requires further research. Nevertheless, all children benefit from fresh air and exercise and this should be encouraged wherever possible.

Where did the story come from?

Andrea Faber Taylor and Frances E. Kuo of the University of Illinois carried out this research. The study reported no sources of funding and was published in the Journal of Attention Disorders, a peer-reviewed medical journal.

What kind of scientific study was this?

This was a within-subject randomised crossover trial where a group of children with ADHD were each exposed to a guided 20-minute walk to see how each of the walks affected subsequent concentration. These walks, given in a random order, were in either a city park, downtown area, or an urban neighbourhood.

This study was adding to investigations into why performance related to attention can vary so much in children with ADHD, and what may influence this. This study explored how the idea that individuals experience a sense of rejuvenation after exposure to the natural environment might apply to managing symptoms of ADHD.

Children with professionally diagnosed ADHD were recruited through advertisements. The children were aged 7-12 years, and were on average 9.2 years of age. The final sample included 17 children – 15 boys and two girls, reflecting the male predominance of ADHD. Each of the walks were carried out on separate occasions, in the daytime in warm summer weather, and the children were individually accompanied by a guide, whom they had some time to get to know before the session started.

Although half of the children were taking daily medication for ADHD, none took this on the day of the walk. A series of puzzles were completed before the start of the walk designed to cause some degree of lapsed attention during completion. Following this, a 20-minute relaxed walk was taken with the guide, with minimal conversation during the walk.

After the walk the child then completed tests of concentration administered by a person who was unaware of where the walk had taken place.

The children also related their experience of the walk, rating options such as fun, relaxed, boring etc. The children were all told that they could receive a toy from a treasure chest after completing the tests.

What were the results of the study?

Children with ADHD had significantly improved concentration following the walk in the park compared with the walks in two urban settings. The park walk resulted in improved performance in one test on numbers.

There were no significant differences in concentration between the two urban walks. Children also rated the park walk as ‘fun’ significantly more often than the two urbanised walks.

Previous studies have shown that children with ADHD have lower scores on the concentration number test than for those without ADHD. The researchers say the effect of the park walk is "roughly equal and opposite to the performance deficit due to ADHD".

Comparing the effect on concentration to studies of the ADHD drug methylphenidate (brand name Ritalin) that had used anther 'roughly comparable' test they suggest that the effect of the park walk was ‘roughly equal’ to that of the medication.

What interpretations did the researchers draw from these results?

The researchers conclude that children with attention deficits have better concentration after walking in a park than two other urban settings.

They also say that the effect of ‘a dose of green’ was substantial, and roughly equal to that seen following extended-release methylphenidate such as Ritalin. They also conclude that a walk in the park was a positive experience for the child.

What does the NHS Knowledge Service make of this study?

This study has demonstrated the benefits of a park walk compared to walking in two urban settings on a measure of concentration. However, there are important points to bear in mind:

• The sample size was very small, including only 17 children with attention disorders. A larger study would give more reassurance that the walks resulted in improvements in concentration.
• Additionally, randomisation of larger groups of children to experience only one type of walk (instead of all three in a random order) allowing comparison between the groups would be beneficial.
• The study did not compare walks against treatment with Ritalin or other drugs for ADHD, and made only indirect comparisons. This is not an adequate method for comparing treatments for a number of reasons, including different study methods, different measures of attention and different populations of children.
• The results are only from a single exposure to the park environment. Questions remain unanswered as to whether results could be replicated, sustained in the long-term (i.e. attention maintained for hours or days following the exposure), or how regular the walks would need to be to maintain benefit.
• It is also unclear whether the same effect would be seen if the child was out on their own/playing with friends rather than the more artificial scenario of being under silent supervision of a guide whom they did not know particularly well.
• As the researchers acknowledge, their study is also unable to assess whether environmental exposure has any effect on impulse control, which is another important aspect of ADHD.
• It is unclear whether improvement in concentration or impulse control resulting from environmental exposure would have an effect on academic performance or peer group/family situations.

The question of whether ‘a walk in the park’ is as good as drugs for ADHD requires further research. Nevertheless, all children benefit from fresh air and exercise and this should be encouraged whenever possible.

Sir Muir Gray adds...

Where possible, walking should be a therapy prescribed for all chronic conditions.