What’s in a name?

The list of possible names for Chronic Fatigue Syndrome (CFS) seems endless. The disease is constantly being re-named and re-adjusted as patients, researchers and advocates try to find international consensus. Most patients would agree that the term CFS makes trivial a debilitating and severe disease. In a cruel twist, it remains the most common and recognisable term for the illness.

The term for CFS has continuously changed along with our improved understanding of what the illness truly entails.

If you hate the term CFS just remember that in the early 1900’s, the term ‘nervous exhaustion’ was used to define the illness.

Thankfully, that is no longer the reality.

With each incremental step forward in research, we get closer to the perfect name. Unfortunately, international consensus is still a long way off.

Some, like the USA, want to create a name that acknowledges the illness as a disease (SEID). Many want to replace the term CFS with Myalgic Encephalomyelitis (ME). While others make huge distinctions between the two (CFS and ME). Still others simply use a forward slash and move on (CFS/ME).

This lack of international consensus may be hurting patients and diluting research.

CFS and ME share the same symptoms but their definitions are extremely variable. Are ME and CFS the same thing or are they significantly different? Each organisation, each country, each advocate will give a slightly different answer.

The potential harms that may occur if, in fact, ME and CFS are different diseases are twofold.

The first problem arises when CFS and ME are not regarded as different sides of the same coin.

Many definitions for CFS are broader than definitions for ME. Because of this, in many countries there are patients diagnosed with ‘CFS’ who may actually have ME and are going undiagnosed.

ME, unlike CFS, has objective diagnostic tests. For instance, brain scans can confirm an M.E. diagnosis with a high degree of accuracy. The problem is, treatments may not work for both CFS and ME and may actually harm patients if they are not considered independently.

The International Consensus Criteria (ICC) provides a possible solution:

Patients diagnosed using broader or other criteria for CFS….should be reassessed with the ICC. Those who fulfil the criteria have ME; those who do not would remain in the more encompassing CFS classification.

This would be a great way to begin categorising patients so they do not end up under a large umbrella of diagnosis.

The second problem occurs when CFS patients dilute ME research pools and vice versa.

These different definitions and criteria are big problems for investigators, because if case definitions have different symptoms, which are measured in different ways, then ‘criterion variance’ is introduced.

By diluting research pools, we may be getting no closer to treatments for either of the diseases.

If CFS and ME are treated under the same umbrella we may be shooting future research in its proverbial foot.

The Hummingbird’s Foundation for ME draws clear distinctions between CFS and ME. For instance, the website states:

CFS is not a distinct disease with a distinct cause and pathology. CFS is a mere diagnosis of exclusion (or wastebasket diagnosis).

The second part is true. At the moment, CFS is diagnosed through exclusion. However, that does not make the first claim true. In fact, multiple studies, like this and that, have shown robust evidence that CFS is a distinct disease.

The best way to explain the confusion surrounding CFS and ME is to examine the history of Hepatitis.

In 1975, researchers found a type of hepatitis which did not fit into the category of Hepatitis A (HAV) or Hepatitis B (HBV), despite having shared symptoms. None of the examined patients tested positive for proteins found in either disease. American and British researchers agreed that an unknown hepatitis virus must be the cause.

That meant for 15 years, Hepatitis C patients were diagnosed with ‘non-A, non-B Hepatitis’.

Talk about a wastebasket diagnosis.

It was not until 1989 that the virus was discovered and the disease became it’s own distinct entity: Hepatitis C (HCV).

This is very much what we see occurring today with CFS and ME. ME, like HAV and HBV, has a definitive diagnosis. CFS is, as HCV used to be, a wastebasket diagnosis. Does that, however, mean that CFS is not a distinct disease? No. HCV, even when it was called non-A and non-B, was still a disease, even if the unique pathology was unknown.

The main point here is that research continued despite the trivial ‘non-disease’ name.

In fact, it was eventually discovered that HCV was the most common cause of chronic hepatitis, cirrhosis, and liver cancer in the Western world.

Good thing we didn’t just throw our hands up and assume it was all psychological!

Today, scientists have identified five hepatitis viruses: A, B, C, D, and E. They are caused by different viruses but display similar symptoms.

The inability for researchers to untangle shared symptoms is one of the reasons diseases like Hepatitis and CFS are so difficult to diagnose and research.

One of the greatest difficulties CFS faces is its simultaneous over-diagnosis and under-diagnosis. Over-diagnosis often occurs because symptoms of CFS are shared with many other diseases and disorders. The diagnosis of CFS is made even more difficult by the fact that it shares comorbidities with disorders like depression. Over-diagnosis is dangerous for patients because it dilutes pools and hinders research into biological markers unique to CFS.

On the other hand, under-diagnosis of CFS also adversely affects patients. CFS patients who are not diagnosed with the the disease often receive fragmented medical care because their symptoms are not pieced together and identified as belonging to a distinct whole.

These are both harms that naturally come when a disease is qualified by the mere presence of symptoms that also occur in other diseases and disorders.

CFS remains a wastebasket diagnosis because we haven’t allocated enough funding to find out what the underlying ‘it’ is. Not because ‘it’ doesn’t exist. After all, the term HCV only came to fruition after the underlying virus was found.

It seems the only way to improve the accuracy of the name is to identify the underlying cause of CFS.

Yet funding for CFS remains abysmal. Last year, Medicare spent $4.5 billion on a Hepatitis C cure. In the same year, CFS received $5.4 million from the US government for research. It is no wonder that one of these diseases has shed its trivial name and the other hasn’t.

Just like non-A, non-B Hepatitis wasn’t exactly the perfect fit, neither is CFS. However, a trivial name should not mean the scientific community or the public should disregard this debilitating illness. The obscurity of CFS and its prevalence amongst the population (around 17 million people affected worldwide) begs for further research.