You may have noticed that the media seem to report on a new treatment for ADHD frequently. If so, you may wonder why so many alternative treatments exist for ADHD, and why they so easily gain credibility with the general public. One reason is that, as opposed to such medical conditions as diabetes, the results of a given treatment for ADHD are difficult to measure objectively—that is, there is no blood, urine, or other laboratory test that can prove conclusively that the treatment has worked. Instead, as you will see, the effectiveness of treatments for ADHD are judged through rigorous studies of groups undergoing the treatment compared with those who are not.
Because effects of these treatments are determined through relatively subjective methods, such as changes in teachers’ and parents’ observations, and ratings of behaviors over time—not by objective blood, urine, or magnetic resonance imaging studies—it is often more difficult, even with careful statistical analysis, to clearly establish that any proposed standard or alternative treatment for ADHD is wellfounded. If a treatment cannot quickly and objectively be proven effective, it is easier for its proponents to just claim that it works. Thus claims for a particular approach can be greatly exaggerated and widely disseminated long before it has been sufficiently studied.
Yet there is a standard, reliable process for deciding whether a new treatment is effective. This process is called the scientific method, and through it investigators can subject any treatment approach to a reliable series of tests or studies to evaluate its effectiveness. There is a great deal written these days about “evidence-based medicine,” which is a set of procedures, resources, and information tools for appraising the strength of the scientific evidence to assist practitioners in applying research findings to the care of individual patients. The medical community now expects treatments strongly recommended for the treatment of ADHD to meet these standards of evidence-based medicine. Studies of treatments for ADHD conducted according to the scientific method make use of research tools, including structured observations, rating scales, and objective tests of the child’s functioning, whenever possible. They are structured so that extraneous factors that might influence results are taken into account and designed so that they can be reproduced by other researchers to make sure similar results are achieved.
According to the scientific method and evidence-based medicine, we can only rely on the results of studies relating to a particular treatment if the researchers have
- Formulated a clear hypothesis. The researcher must state what she wants to determine through the study. For instance, she might state the hypothesis, “Because diet and nutrition are known to affect brain development, a diet fortified with extra vitamins will have a positive effect on ADHD symptoms.” This then will be proved or disproved by a wellconducted study.
- Created a detailed plan to test the hypothesis. The researcher must then define the nature of the treatment (for example, state which vitamins will be administered, at what dose, and how frequently), how it will be administered (by parents, by a physician, by the children themselves), how it will be monitored (by counting the number of pills left in the bottle at the end of the study), and how the effects will be measured (through a daily dosage checklist, parents’ reports, physicians’ records, teacher observations, etc). In this way, the study results can be systematically explained (perhaps it did not work because the children reported taking the vitamins but did not always do so, for example), and other researchers can confirm the results by using the same methods with different sets of children.
- Defined the group to be tested. This is an important and sometimes difficult part of creating a reliable study. Can a child be allowed to participate in the study solely on the basis of whether he looks hyperactive to the researchers? Must he have been diagnosed by his pediatrician? Or have the researchers made their own diagnosis according to rigorous research criteria? The group under study must also be large enough for the treatment results to apply to the population as a whole—1, 6, or even 100 children may not be enough, depending on the research question. The group receiving the treatment must be compared with a group not receiving the treatment, and/or another group or groups receiving a different type of treatment for ADHD. The members of the groups under study should otherwise be as similar as possible, and children who might be affected by extraneous influences, such as coexisting disorders, high or low extremes in intelligence, and unusual family circumstances, are sometimes screened out. Depending on the question to be answered, the researcher must limit as many other variables as possible, aside from the treatment under study.
- Eliminated the power of suggestion. One way to test whether a treatment is effective is to compare the proposed treatment with a placebo treatment. People often tend to respond to placebos—inactive medications or treatments they believe may work— whether or not the treatment is actually effective in the long run. A person with a headache who is given a “sugar pill,” believing it is pain medication, may report that the headache is gone a short time later. In many studies placebos can be shown to be somewhat or very effective. One way to test whether a treatment for ADHD is effective, for example, is to make sure that the subjects do not know whether they are really receiving the proposed treatment or a placebo treatment. In the vitamin treatment example, then, half of the subjects in the study might receive actual megavitamins and the other half would receive an inactive, neutral, but identical-looking pill. Depending on the type of investigation, the study design may work even better if used in a “double-blind” experiment—that is, if the subject, his family, his teacher, and the researcher do not know whether the actual pill or a placebo was used in a particular patient until the study has ended. That way there is no danger that the researcher has inadvertently communicated this information to the subject, his family, or teacher, or that he misinterpreted the results because of what he knew. Of course, if the treatment has specific effects, such as an unusual taste difficult to mimic in the placebo, it may be impossible to keep everyone in the dark about which person got the experimental treatment.
Placebo treatments are more difficult to create when the treatment involves a procedure, such as psychotherapy, rather than a pill. Still, researchers must make every effort to make the real treatment and the placebo treatment equally convincing to the subject. Having independent evaluators who are unaware of the treatment being used, called blinded, to whether the treatment is the megavitamin or the placebo preparation improves the accuracy of the study.
- Provided a valid means of evaluating the results. Some treatment results are easier to evaluate than others. As you’ve already read, in the case of ADHD, results can be difficult to judge because they cannot be measured through precise laboratory tests or other fully objective measures. Still, researchers can standardize test results through such techniques as quantifying behaviors (having teachers report how many times per day a child interrupted a conversation, got out of his seat without permission, or failed to hear someone talking to him), using standard rating scales, comparing the study subjects’ performance to that of the other groups in the study who received different treatments, and measuring changes in the behaviors being studied at predetermined intervals throughout the course of the investigation. Treatments can be evaluated by standardized tests (such as performance on standardized math tests), as well as in terms of the child’s performance in the real world (measures of classroom behavior or improvements in family relationships). Rigorous statistical techniques are then used to find any significant differences in results among the groups in the study. The methods and results of any study are then reviewed by other experts in the field. This process, called peer review, is required before the study is published in a reputable scientific journal. If a treatment proves successful, it is also helpful to follow up with the children on the treatment for longer than the period that was studied to make sure that the beneficial results continue and do not cause any serious long-term side effects.
Which Treatments Have Been Shown to Work?
The treatments for ADHD supported by the strongest evidence are stimulant medications and behavior therapy techniques, often used together. These forms of treatment have been the most studied and validated by the types of rigorous scientific research described previously. For this reason, pediatricians can feel secure in recommending these approaches as proven, safe, and effective, evidence-based, first-line treatments for ADHD.
Many other forms of treatment for ADHD have been tested in studies using the scientific method. Some, such as traditional psychotherapy and cognitive therapy, have been shown through convincing research not to demonstrate positive results in treating the condition’s core symptoms. Another group of potential treatments for ADHD has been tested to some extent, but the studies have been too few in number or were conducted with some flaws in study designs, or the results were too ambiguous to prove that the treatment works. Evidence of a treatment’s effectiveness may be insufficient if the
- Studies involve too few subjects, so that results cannot be generalized to the ADHD population at large
- “Proof” relies on anecdotal evidence, such as parents’ testimonies or one physician’s experience with his own patients, rather than on a large group that has been part of a well-designed scientific study
- Study results have not been subjected to the scrutiny of experts who would have reviewed the study prior to publication to identify any possible flaws in the study design or the results