SMCI Comment on the Institute of Medicine Report—Part 4 of 5

By Suzanne D. Vernon, PhD, SMCI Scientific Director

This is Part 4 of 5 of a blog series that breaks down the Institute of Medicine (IOM) report, “Beyond Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: Redefining an Illness.” This post focuses on unrefreshing sleep, the third diagnostic criteria recommended by the IOM committee.

Sleep is essential to recovery and rejuvenation of every system in the body—immune, nervous, muscular, etc. It is the time when our body builds up and replenishes the molecules that are essential for the body to function when awake. Yet sleep disorders and diseases are very common and almost everyone experiences disturbances, including problems falling and staying asleep, waking up early, sleeping all day and staying awake all night. We now know that left untreated, severe and chronic sleep disorders increase the risk of developing other chronic diseases such as heart and cardiovascular diseases.

Unrefreshing sleep, which is described as “feeling as tired upon waking as before going to bed,” is one of the most common symptoms reported by ME/CFS/SEID patients. The graph below is from a study conducted by DePaul University of SolveCFS BioBank participant responses to the DePaul Symptom Questionnaire1. The black portion of each bar corresponds to responses from ME/CFS patients; the gray portion from healthy control patients. Unrefreshing sleep and fatigue are the two most common symptoms in more than 90 percent of ME/CFS/SEID patients.

Click on image to see full-size.

There has been research on unrefreshing sleep in ME/CFS, but like other research, ME/CFS/SEID sleep studies have suffered from small size, different designs and measures and including different patients defined by various case definitions. In general, in studies that used polysomnography to find possible causes of the unrefreshing sleep, ME/CFS patients had normal sleep study. Therefore, whether unrefreshing sleep is a cause or a consequence is unknown.

But since sleep is required for the body to rejuvenate and recover and since ME/CFS/SEID patients have chronically poor sleep that does not replenish their bodies, clearly this puts ME/CFS patients at significantly increased risk for a number of other diseases such as heart disease. Chronic unrefreshing sleep causes fatigue, brain fog, increased pain sensitivity, irritability and depression. Research has not identified the cause(s) of unrefreshing sleep in ME/CFS, and it is not clear if unrefreshing sleep may be the root cause of ME/CFS.

The IOM committee relied largely on patient-reported information to decide on unrefreshing sleep as one of the ME/CFS diagnostic criteria. After a review of the data and peer-reviewed biomedical evidence, they concluded:

“Despite the absence of an objective alteration in sleep architecture, the data are strong that the complaint of unrefreshing sleep is universal among patients with ME/CFS when questions about sleep specifically address this issue. While PSG (polysomnography) is not required to diagnose ME/CFS, its use to screen for treatable sleep disorders when indicated is appropriate. Diagnosis of a primary sleep disorder does not rule out a diagnosis of ME/CFS.”

The IOM committee recommended that medical providers ask about unrefreshing sleep when taking the medical history diagnosis. Example questions to ask include:

  • Do you have any problems getting to sleep or staying asleep?
  • How do you feel in the morning or after you’ve slept?
  • Do you need too much sleep?
  • Do you need to take more naps than other people?

Questionnaires that can be used to determine the frequency and severity of unrefreshing sleep include the Pittsburgh Sleep Quality Index (PSQI) and the Epworth Sleepiness Scale. Certain medications, diet and behavioral changes can be used to treat sleep disorders and have been shown to help ME/CFS symptoms.

The fifth and final blog post in this IOM series will address the final two “either/or” diagnostic criteria: orthostatic intolerance and cognitive impairment. To ensure you receive notification of each future blog post as it is published, simply sign up for notifications in the grey and blue “Sign Up” box on the top right of this page.


1. Jason LA, Sunnquist M, Brown A, Evans M, Vernon SD, Furst J, Simonis V. Examining case definition criteria for chronic fatigue syndrome and myalgic encephalomyelitis. Fatigue. 2014 Jan 1;2(1):40-56.