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You want to take an active role in understanding your or your child’s
ADHD and new or emerging treatments. So you keep up with information
online, even scouring research published in journals. But how do you
evaluate whether what you read is valid, or that it actually applies in
your case?
ADHD is a popular topic in news reporting, but mainstream media may not
always convey the whole story. Studies highlighted in the news can
sometimes raise concern. If something you read or hear in the news
makes you question your or your child’s treatment plan or the way you
parent your child, it can be helpful to look at the original study on
which the news reports are based, rather than relying on the media to
translate the science for you. It is also important to discuss concerns
with your treatment provider, especially before making any changes to
your treatment plan.
The media sometimes cover and highlight studies that are sensational.
So being skeptical and questioning what you read or see is a healthy
response.
Here are some tips to help you understand research studies and how to
interpret their results.
Not all research studies are alike—Each study has a specific research question and comes with
limitations, which are seldom mentioned in news reports. Most research
begins with a hypothesis, a proposed explanation for the
phenomena under investigation. The researchers then test the hypothesis
in order to prove or disprove it. In some cases, the study is
considered successful if the hypothesis is disproven because it
eliminates one potential factor affecting the phenomena.
Who conducts the study—Some studies are conducted by researchers in government, university,
and non-profit organizations. These institutions usually have a
reputation for producing high quality studies with results that are
tested and reviewed by other experts in the field. Studies from these
sources are more likely to be trustworthy.
Who pays for the study—Pay attention to who is funding the studies. If the research is being
paid for by a political organization or a for-profit company, you
should be more critical of the outcomes. It’s possible that researchers
paid by these companies may avoid presenting results that do not
support the sponsors’ claims.
Correlation vs. causation—These two terms can be confusing. Correlation measures whether two items follow
the same trend—the more you find of one, the more (or less, the
inverse) the other occurs. One website provides humorous examples of
what are called spurious correlations—two events or factors that follow
the same trends but really aren’t related, either because a different
factor is involved or because of coincidence. For example, the divorce
rate in Maine seems to follow the same trends as the consumption of
margarine in the United States. One does not actually cause the other,
but they increase and decrease at the same time.
Causation, on the other hand, refers to two factors where one makes the other
happen. It can be difficult for researchers to determine whether one
factor causes another or if there is a third factor influencing the
results. It’s important to be mindful that some news reports may state
a causal relationship when it is just a correlation. For example, a
recent study found that the more critical parents are, the more severe
their children’s ADHD symptoms. However, the researchers could not
determine how these factors were related—are the parents more critical
because their children’s ADHD symptoms are so severe, or are the ADHD
symptoms more severe because the parents are more critical? The news
headlines, however, included such alarms as “Is Your Child’s ADHD Your
Fault?” and “Overly Critical Parents Lead to Persistence of ADHD in
Kids.”
What type of study was conducted
—There are many different types of studies. Some of the most common are
the following:
A meta-analysis
looks at the many previous studies for trends and common results. This
type of study is helpful in determining ADHD prevalence, understanding
symptom influences, and improving outcomes of children with ADHD.
Experimental design studies
can provide the strongest evidence of a particular treatment. They can
look at the effectiveness of a treatment and causal relationships.
Conditions are supposed to be controlled in an experiment to help
remove outside influence. However, many studies can be handicapped in
their conclusions because they haven’t controlled some key variables.
Think critically: what other factors—not “controlled” in this study—may
have influenced or caused the outcomes? It may also be difficult to
take the experimental conditions and apply them to real-world
conditions, known as the generalizability of the experiment.
Observational research
looks at related factors not in a controlled experimental study, but by
analyzing data from surveys, school records, or insurance claims.
Studies based on data collected over a long period of time can help
researchers look more closely at causation. These analyses of data also
help researchers assess trends as they formulate new studies that seek
more definitive or causal conclusions.
Where is the study published
—In addition to looking at the reputation of the researchers conducting
the study, it’s important to also look at the quality of the journal in
which the study is published. It can be difficult, unfortunately, to
determine the quality of a journal. Many scientific journals select the
articles they publish using peer-reviews, meaning a panel of experts
evaluates the study carefully before it is published. If done
correctly, this process helps to validate the research findings. Some
publications may also require authors to pay to have their studies
published, which is a controversial practice, and may mean that studies
published in those journals may not go through a critical review before
being included in the journal. Be aware though, that even journals that
have excellent reputations of quality can sometimes publish imperfect
studies.
How participants are selected and the number of participants in the
study
—If study participants are randomly selected from a particular school
district, hospital system, urban vs. rural area, etc., then study
results are probably generalizable to that specific population. It is
becoming increasingly difficult to acquire a random sample that is
representative of the general population. Pay attention to the
limitations that the researchers identify in their study.
Length of the study
—Some studies last only a few days. Other studies can follow people for
years to see how various treatments affect them. The longer the study,
the more researchers can examine the long-term effects of treatments.
But longitudinal studies also present a challenge of interpretation,
because it is not possible to control all relevant variables over the
course of the subjects’ lives.
Conclusions of the study
—Understanding whether and how the findings of the study are relevant
to you and/or your loved one can be difficult. This is particularly
important in studies that deal with treatment; in fact, CHADD’s
Professional Advisory Board has defined Levels of Evidence criteria for
assessing such studies. Nevertheless, it is critical to consult with
your treatment provider for interpretation and possible application to
your situation.
The studies CHADD cites in our articles, fact sheets, and newsletters
have typically been vetted by the NRC’s Health Information Specialists
and our Professional Advisory Board members. We take care to make clear
the implications to you of the findings therein.
Here are a few links for additional information on understanding
research studies:
9 Questions to Help You Make Sense of Scientific Research from the National Center for Complementary and Integrative Health
Understanding Research: Ten Tips by the Harvard Family Research Project
For information on evaluating treatments:
Complementary and Other Interventions