Many families have reported that, when they have told a health care provider about a symptom their loved one with Down syndrome is experiencing, the provider has, in effect, said, “It is just Down syndrome.” No further assessment or treatments were offered. The symptom was attributed to Down syndrome, and it was assumed there was no treatment.
My first experience with this occurred just a few weeks after the Adult Down Syndrome Center opened in 1992. The mother of an adult man with Down syndrome called and informed us he had a cough that had been present for about three weeks. She had taken him to two different health providers, and each had informed her that, “It was just Down syndrome.” Admittedly, I knew little about Down syndrome at that time, but I had never heard of cough being caused by Down syndrome and could find no information in the available books (no Internet available to us at that time!). We asked the man with Down syndrome to come in for an appointment, listened to his lungs, and ordered a chest x-ray. All the findings were consistent with pneumonia. The cough resolved after we prescribed and he took appropriate antibiotics. While respiratory infections (including pneumonia) are more common in people with Down syndrome, the cause of the cough was due to pneumonia, not Down syndrome.
Overshadowing is a term used to describe this misdiagnosis or underdiagnosis of co-occurring conditions. The definition of overshadow (from the Free Dictionary) is "to cast a shadow over; to darken or obscure" or "to render insignificant or less important in comparison." In medical care, when a provider overshadows with regards to Down syndrome, he or she focuses primarily (or only) on the fact that the person has Down syndrome and de-emphasizes the possibility of a co-occurring, often treatable condition. While this approach can fail to address physical health problems, it is often even more limiting for diagnosis and treatment of mental health problems. The person with Down syndrome or his/her family are told that the behavior, mood, or other mental health change are not diagnosable or treatable mental health conditions but just features of Down syndrome.
There are a couple other areas in the care of people with Down syndrome in which overshadowing occurs. It is well known that Alzheimer’s disease is more common and occurs at a younger age in people with Down syndrome. However, there are many reasons a person with Down syndrome may lose some skills. Many of these causes, if diagnosed and treated, can be reversed. However, when a person with Down syndrome loses skills, often it is assumed it is caused by Alzheimer’s disease and little assessment or treatment for reversible causes are provided. This can be quite detrimental to people with Down syndrome because, unfortunately, as of the time of the writing of this article, there is no cure for or reversibility of Alzheimer’s disease. In not assessing for other causes or even conditions that may also co-exist with Alzheimer’s disease, the opportunity to improve function, maintain function, or delay decline is missed.
Another area where overshadowing occurs is in the assessment of mental illness in people with Down syndrome. The focus may be on the mental illness only and the opportunity to assess for potentially contributing, underlying physical health problems is missed. Many physical health conditions of people with Down syndrome can present as mental health or behavioral health conditions or complicate mental health or behavioral health. If assessment is not done for physical health conditions, mental illness may be over diagnosed, treatment options may be missed, and treatment may be less successful.
When assessing a change in health in a person with Down syndrome, it is very important to consider that people with Down syndrome often have co-occurring physical and mental health conditions. A thorough assessment of possible causes has great potential to improve diagnosis and treatment.
With time and research, some common features or conditions in people with Down syndrome have been found to be preventable or to have treatments. For example, while immunodeficiency is a common feature of Down syndrome, immunizations can be quite effective in preventing infections. Similarly, zinc supplementation may reduce skin infections in some individuals. Mild kidney dysfunction is common in the people we see at our clinic, and we suspect this is related to the lower number of kidney cells in people with Down syndrome that a few studies found. However, the effect of this anatomical difference can be reduced by good hydration.
Accepting dysfunction without assessing for and promoting measures to optimize function can be considered a form of overshadowing. More study is needed to better understand what features of impaired health in people with Down syndrome may be prevented or optimized. Research should help us understand optimal doses or amounts of the intervention, potential benefits and risks, and what co-occurring conditions may make prevention or treatment more or less likely to be successful.