We have a saying in Pulmonary Medicine, “all that wheezes is not necessarily asthma.” What that means is that as a physician, when you have a patient with wheezing, while asthma is the first diagnosis that might cross your mind, one also has to think of other possible causes of wheezing, such as congestive heart failure, gastro-esophageal reflux, occult sinus infections and a myriad of other diagnoses. The bottom line is that you have to look at the big picture and not have tunnel vision.
The same is true for Attention Deficit Hyperactivity Disorder (ADHD). Just because your child is hyperactive or has difficulty with his or her school work does not mean they have ADHD. Even if your child truly has ADHD, they may also have other disorders that contribute to, exacerbate or mimic ADHD. Specific learning differences may exist such as dyslexia, visual or auditory perceptive disorders and a host of other learning disabilities may be present. Hyperactivity may be a reflection of boredom, anxiety or other psychiatric or neurologic disorders.
The American Psychiatric Association estimates the incidence of ADHD in school-aged children at 3-7%. Many if not most of these children are placed on stimulant medications to treat their ADHD. Many of these children’s symptoms of ADHD improve on these medications, but a significant proportion of these children not only does not improve with stimulants, but suffer from side effects and / or show little or no improvement at all. On top of that, these medications are often not covered by insurance and they can be very expensive.
There is another saying in medicine that we teach our medical students, interns and residents early on in their careers, “If you hear the sound of hoof beats, think horses, not zebras”. In other words, think of something common before you think of an exotic or uncommon diagnosis. Unfortunately, as a sleep disorders specialist, I see far too often, a child that has been labeled with a diagnosis of ADHD without their pediatrician or family physician having also considered 2 common disorders as possible causes or contributing factors to their symptoms of ADHD. The two common disorders that I refer to are obstructive sleep apnea (OSA) and restless limb syndrome (RLS).
In the pediatric population, the prevalence of OSA has been estimated at 2-3% of otherwise normal children. Unlike in adults, whose primary symptom is excessive daytime sleepiness, sleepiness is a rather uncommon complaint in children with OSA. Think about what happens to children who do not sleep well at night, the main consequence of OSA. They are cranky and irritable, they don’t pay attention, they act out, they won’t sit still, and they frequently perform poorly in school. These are many of the same symptoms that occur in children with ADHD.
RLS is a disorder in part manifest by an irresistible urge to move the legs and therefore often confused with ADHD. The National Institutes of Health estimate that 1 million school-aged children in the US have RLS, with one-third having moderate to severe symptoms. In addition, 80-90% of patients with RLS also have Periodic Limb Movements during Sleep (PLMS), a disorder that disrupts sleep (often without the patient themselves knowing it). Just like the sleep disruption occurring in OSA, the disturbance associated with PLMS causes daytime symptoms mimicking the inattentiveness, difficulty with concentration, poor school performance, behavioral difficulties and hyperactivity of ADHD. To further support the overlap between RLS and ADHD, a deficiency in Central Nervous System iron has been found in both disorders and treating patients with iron supplements has been found to improve symptoms of both RLS and ADHD.
The point of this article is not to debunk a diagnosis of ADHD. ADHD is a very real disorder affecting a significant number of children every year. What I would like you to take away from this article is that two common disorders are often confused with ADHD and should be considered in any diagnosis of ADHD. There is a great deal of overlap in the symptoms of ADHD, OSA and RLS. Furthermore, all of these diagnoses can co-exist in the same child, and frequently do. Treating only ADHD without considering the possibility of co-existing OSA and / or RLS is a prescription for failure and denies your child the greatest opportunity to succeed in school and life in general.
What should you do if you or a loved one has been diagnosed with ADHD? See your doctor and ask about the possibility of co-existing OSA and / or RLS. Ask your doctor for a referral to a Board Certified Sleep Specialist at an Accredited Sleep Disorders Center. You will be glad that you did.