Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a complex, multifaceted disorder characterized by extreme fatigue and a host of other symptoms that can worsen after physical or mental activity, but do not improve with rest. In addition to extreme fatigue, people with ME/CFS may also experience:
Effects of the illness can range from moderate to debilitating, and can substantially impact everyday functioning. Routine daily activities such as cooking meals, brushing teeth, and caring for children become difficult. Additionally, sensitivity to environmental factors (e.g., noise, light, chemicals) may force many individuals with ME/CFS into seclusion or withdrawal from society.
The onset of ME/CFS symptoms may be sudden—for example, immediately following a viral illness such as the flu—or gradual, with no discernible attachment to a specific event or time. The U.S. Centers for Disease Control and Prevention (CDC) reports over 1 million adults with ME/CFS in the United States, and recent evidence has shown a higher prevalence in females compared to males. Certain racial/ethnic groups have also been found to be at an increased risk for ME/CFS; most notably Native American and African American populations. The economic burden of ME/CFS, including annual health care costs, is estimated to be between $1.9 billion and $7.2 billion.
There are many aspects of ME/CFS that are problematic. First, the underlying mechanisms are unclear. There are differing views as to whether ME/CFS is a central nervous system, metabolic, infectious or post-infectious, cardiovascular, immune system, or other type of disorder. Second, there is little agreement among clinical and research professionals, as well as patient groups, regarding the name of the illness. The name myalgic encephalomyelitis or ME is more commonly used in Europe and Canada, while the name chronic fatigue syndrome or CFS is used more often in the United States and Australia. Yet the acronym ME/CFS is increasingly being used worldwide. Third, no laboratory tests exist for diagnosing ME/CFS, and its diagnosis is one of exclusion. All other illnesses with overlapping symptoms must be ruled out prior to an ME/CFS diagnosis. Fourth, there are no drugs or therapies approved by the U.S. Food and Drug Administration (FDA) to treat ME/CFS. Clinical trials to test drug or therapy effectiveness, and drug development to target the underlying cause, are difficult to conduct because of the unknown causes, varied symptom profile, and lack of concurrence regarding diagnostic criteria. Lastly, medical professionals disagree on many aspects of ME/CFS, including whether the illness is real, and there is no definitive answer about the effectiveness of current therapies (e.g., diet, use of off-label or experimental drugs).
The 2014 Pathways to Prevention Workshop: Advancing the Research on Myalgic Encephalomyelitis/Chronic Fatigue Syndrome sought to clarify:
The workshop was co-sponsored by the Trans-NIH Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) Research Working Group.
Initial planning for each Pathways to Prevention workshop, regardless of condition, is coordinated by a Working Group that nominates panelists and speakers, and develops and finalizes questions that frame the workshop. After finalizing the questions, an evidence report is prepared by an Evidence-based Practice Center, through a contract with the Agency for Healthcare Research and Quality (AHRQ). During the 2-day workshop, invited experts discuss the body of evidence, and attendees have opportunities to provide comments during open discussion periods. After weighing evidence from the evidence report, expert presentations, and public comments, an unbiased, independent panel prepares a draft report that identifies research gaps and future research priorities. The draft report is posted on the ODP website, and public comments are accepted for 4 weeks.