Is it possible that increasing children's time spent
in natural green
settings could be an effective method for diminishing ADHD symptoms?
This question was addressed in a study published in a recent issue of
the
American Journal of Public Health
(Kuo, F.E., & Faber Taylor, A. (2004). A potential natural
treatment for ADHD: Evidence from a national study.
AJPH, 94, 1580-1586).
This provocative study is based upon research conducted with non-ADHD
populations in which it has been shown that inattention and impulsivity
are reduced after exposure to natural views and settings. An
explanation for this finding proposed by environmental psychologists is
that tasks and situations that require one to direct attention or
inhibit unwanted stimuli, thoughts, or impulses cause the attention
system to fatigue.
Natural environments are suggested to assist in the recovery from
"attention fatigue", in part, because they "engage the mind
effortlessly, providing a respite from having to deliberately direct
attention." This may explain the feelings of freshness and
rejuvenation that is commonly experienced after one spends times in
natural settings.
The authors of this study reasoned that if exposure to natural settings
enhances attention and focus in those without ADHD, it could
potentially play a role in diminishing inattentive behavior in children
with ADHD. They cite preliminary work (reviewed in Attention
Research Update at http://www.helpforadd.com/2002/july.htm ) in which
96 parents rated a variety of leisure activities with respect to
whether their child's ADHD symptoms were "better than", "worse than",
or the "same as usual" after engaging in those activities.
Results indicated that symptoms were better than usual (i.e., less
problematic) after the child engaged in activities in relatively green
settings.
RESEARCH DESIGN
The current study built on this prior work by collecting data from a
large, national sample using a web-based survey. Participants
were 452 parents of children ages 5 to 18 who were recruited through
ads in national newspapers and a posting on the CHADD website.
(CHADD is the national support organization for children and adults
with ADHD). These parents represented approximately 60% of those
who visited the survey site, and who met the eligibility criteria to
participate (i.e., the child had been formally diagnosed with ADHD by a
physician, psychologist, or psychiatrist). The parents who
participated were diverse in terms of their socioeconomic status, age
of their child, community type they lived in, and region of the country
they were from. The severity of their children's ADHD symptoms
was also diverse, and both males (80%) and females (20%) were
represented.
In the survey, parents rated 49 common after-school and weekend
activities in terms of whether it made their child's symptoms "much
worse than usual", "worse than usual", "same as usual", "better than
usual", or "much better than usual" for an hour or so after the
activity ended. The symptoms that parents were asked about were:
- Difficulty remaining focused on unappealing tasks;
- Difficulty completing tasks;
- Difficulty in listening and following directions;
- Difficulty in resisting distractions;
Activities were described as occurring in either green outdoor settings
(i.e., any mostly natural area - a park, a farm, or just a green
backyard of neighborhood space), "built" outdoor settings (i.e., mostly
human made space - parking lots, downtown areas, or just a neighborhood
space that doesn't have much greenery) or indoor settings. The
after effects of several activities were rated when they occurred in
different settings. For example, "reading" could take place
indoors, in a relatively green outdoor setting, or in a built outdoor
setting.
Parents knew nothing about the purpose of the study. Thus, their
ratings are unlikely to have been biased by the knowledge that the
authors were interested in documenting that spending time in natural
settings is associated with a reduction in children's ADHD
symptoms.
RESULTS
The authors examined the aftereffects of activities conducted in green
settings with those occurring in built or indoor settings. The
analysis controlled for children's gender, income, and severity of ADHD
symptoms. The authors also controlled for whether children lived
in rural vs. urban settings.
For the sample as a whole, parents' ratings indicated that children's
ADHD symptoms were significantly better (i.e., less problematic) after
participating in green outdoor activities compared to activities that
occurred indoors, or in build outdoor spaces. This pattern of
results was found for virtually all subgroups the authors examined
(i.e., boys vs. girls, older vs. younger children, higher vs. lower
income families, etc.). It was also evident regardless of which
region of the country children were from and whether they lived in
rural or urban environments.
One possible explanation for the apparent superiority of "green"
activities in reducing ADHD symptoms may be the nature of the
activities themselves. That is, activities that occur in natural
settings may systematically differ from those that occur in other
settings, and it may be the type of activity rather than where it takes
place that accounts for the findings reported above.
To examine this possibility, the authors examined differences in parent
ratings for activities that occurred in both green and other
settings. Results from this supplemental analysis indicated that
even when the activities were identical, they were associated with
greater reduction in attention problems when they took place in green
settings.
SUMMARY AND
IMPLICATIONS
Results from this study suggest that exposure to ordinary natural
settings in the course of common after-school and weekend activities
may be helpful in reducing attention difficulties in children with
ADHD. This advantage of green outdoor activities over activities
conducted in other settings was consistent for children across a wide
range of individual and residential characteristics, and was found even
when the activities conducted in different settings were highly
similar. This suggests that the benefits of green outdoor
activities cannot be wholly attributed to differences in the activities
themselves.
Because the "green" advantage was found among children living in
diverse communities in different parts of the country, it seemed to
hold despite what must have been wide variation in the specific "green
outdoor", "built outdoor", and "indoor" settings available to different
children. In addition, because the "green" advantage was also
found for children living in rural environments, where exposure to
nature is plentiful, the apparent benefits of green spaces are unlikely
to simply reflect the relative novelty of such spaces for children
raised in urban environments. According to the authors, the
findings are thus consistent with the hypothesized restorative effect
that exposure to natural settings can have on our ability to focus and
attend.
The authors are cautious to note that their findings need to be
supported with additional research and randomized controlled trials in
which the impact of exposure to green settings can be more carefully
evaluated. For example, it would be important to document via
methods other than parent report that exposure to natural settings is
associated with a reduction in attention problems following the
activity. In particular, gathering information from teachers
about whether outdoor time in natural settings improves children's
attention in the classroom would be especially interesting data.
Similarly, does exposure to green settings result in children being
better able to work productively and accurately on school
assignments? This is a very important avenue to pursue, as it is
the classroom where many children with ADHD experience their most
profound struggles.
In regards to the need for additional controlled research, it is worth
noting that the authors discuss an as yet unpublished study that
appears to provide further support for the benefits that exposure to
green settings may have on children with ADHD. In this study,
children with ADHD completed three guided walks that differed in the
extent to which natural or urban elements predominated. The
20-minute walks were counterbalanced for order, and controlled for time
of day, day of week, walking guide, and walking pace. Routes were
chosen to involve roughly comparable amounts of noise and pedestrian
density. After each walk, an evaluator unaware of which walk the
child had just completed administered several objective measures of
attention. Children's performance on these measures was said to
significantly better after walking in the greenest setting than in the
other settings. The summary of this study sounds promising,
although it will be necessary to carefully review the
paper, once it is published, so that the meaning of the results can be
better
understood.
Should these provocative findings hold up in future research,
particularly in studies that examine the impact of exposure to natural
settings on classroom behavior, what might be the implications?
The authors suggest that "daily doses" of green time could potentially
supplement medication and behavioral approaches to treating ADHD. These
"doses" could take several forms, including doing class work or
homework at a window with a relatively green view, or playing in a
green yard or ball field at recess and after school. Of course,
even if this were shown to be helpful, there would be many
children - those living in densely populated urban settings -
where exposure to natural environments during the day may just not be
practical. For these children, one wonders whether watching
videos of natural landscapes could serve a similar function.
Although more work remains to be done, it is encouraging to see that
rigorous scientific work on such a novel approach to assisting children
with ADHD is being conducted. In my view, it is too early
to know whether exposure to natural settings will provide clinically
meaningful benefits to children with ADHD. However, because this
is certainly an inexpensive intervention that is unlikely to have any
adverse effects, it would be reasonable for parents to see whether they
notice any benefits for their child, and the authors have certainly
opened up an exciting new line of research.