Research Suggests that ADHD Is Not a Single Disorder
Researchers at the Oregon Health & Science University have concluded that ADHD is not a single disorder, but rather an “entire family of disorders.” Their findings could impact the way patients are diagnosed and treated as well as the way future research is conducted.
Led by OHSU scientists Damien Fair, Ph.D., assistant professor of behavioral neuroscience, psychiatry, and the Advanced Imaging Research Center; and Joel Nigg, Ph.D., professor of psychiatry, behavioral neuroscience and pediatrics, the recently completed study suggests that ADHD is similar to cancer in that there are many different subtypes.
To reach their conclusions, the research team measured a number of cognitive skills (e.g. memory, inhibition, attention, comprehension, etc.) in a large sample of ADHD patients and a control group. The results, which are published in Proceedings of the National Academy of Sciences, were reported in Medical News Today (MNT).
In essence the researchers found a wide variation in both the ADHD and control groups; neither group consistently was found to have the same strengths and weaknesses. In addition, according to MNT, the findings showed “that ADHD patients can be subcategorized depending on their deficits and relative strengths, showing unique subgroups among all children with ADHD.” Dr. Fear explained the implications:
Traditionally, physicians and psychologists have diagnosed patients through the use of the Diagnostic and Statistical Manual of Mental Disorders, commonly known as the DSM.
The problem with this approach is that it often relies on secondary observations of parents or teachers, where even if the descriptions are accurate, any given child may be behaving similarly, but for different reasons. Just as if there might be many reasons why someone might have chest pain, there might be many reasons why a child presents with ADHD. However, unlike diagnosing countless other well-understood diseases, there is no one test that can differentiate individuals when it comes to psychiatric and developmental conditions like ADHD. The data here highlights ways to recognize such individual variability and shows promise that we might be able to identify why any given child presents with ADHD, thus allowing for future examinations of more personalized treatments.
Based on this and future research, those who evaluate patients for ADHD may soon be able to replace observation with a battery of cognitive tests, which will allow them to determine strengths and weaknesses of their patients, categorize them accordingly, and tailor treatments for various subcategories.