I probably wrote this is the wrong place, so copy it here.
I read the original article and was amazed to see the significant number of methodological flaws:
First- you can't create your own questionnaire and use it in serious research without validating it first. (Not to mention that you don't usually diagnose diseases by questionnaires of this sort. quite likely if he used a similar questionnaire in patients with pancreatic cancer, lymphoma or thyroid disorders and not CFS patients, he would have reached similar conclusions, but he didn't validate his questionnaire on any control group of that sort).
Second- when you compare one group of patients to another group of patients, you have to use clear criteria to define those groups. And as the distinction between normal sadness and depression is still not well-defined, using a group of patients with the diagnosis of depression as a group of comparisson is at the least problematic. (also as I have mentioned many diseases can be mistakes for depression, because of significant overlap in many symptoms; also to complicate matters even more, having a serious/debliltating illness is many times accompanied by a normal reactive sadness/depression).
Third-the above is even more important when you have mixed and overlapping symptoms of diagnoses. Or else you can easily enter a loop of proving your hypothesis with what you have to prove. (which is basically what happened here).
Fourth- you can't use a heterogenous group of patients with symptoms varying from mild eye symptoms to being on a respirator in the ICU (such as myasthenia gravis) as your group of comaparisson without clearly defining the severity of the illness in your group of patients. There is no mention of how many had a mild disease, how many had only limb involvement, how many had bulbar symptoms, how many had respiratory problems and sleep disturbances? He also didn't take into account (and probably didn't know) that myasthenia itself (now known to be an autoimmune and rarely a genetic disease) was initially thought to be a non-organic illness (hysteria) because there were no anatomic findings in this disease.
Further more, patients with atypical variants of myasthenia, or unrecognized respiratory muscle involvement are often diagnosed as suffering from psychiatric problems. In general it is exceedingly common for patients with neurological illnesses to also "have" psychiatric problems. (which in other words means that some of their symptoms are atypical and can't be explained by the current knowledge and understanding of their illness).
So, the only valid conclusions that can be reached from this paper are that patients with CFS are in many ways similar to patients with less typical forms of myasthenia. And that neurologists commonly attribute symptoms they do not have a good explanation for to psychiatric problems, such as "depression" and "anxiety".
This does not prove or disprove the validity of this approach and only shows what was already known without this study.
Without realizing it, the non-organic nature of the disease studied was based on the initial assumption of the non-organic nature of this disease. The fact that there was significant overlap with symptoms of patients with depression did not prove or disprove this assumption. This overlap was obvious without the study, as it was the original hypothesis based on wessley's (right or wrong) observations and impressions, which were validated by his own questionnaire.
The fact that others readily agreed with his findings and this paper was cited numerous times, only proves (again) the ingeniousness of Lewis Carol in the "Hunting of the Snark" -
"Just the place for a Snark!" the Bellman cried,
As he landed his crew with care;
Supporting each man on the top of the tide
By a finger entwined in his hair.
"Just the place for a Snark! I have said it twice:
That alone should encourage the crew.
Just the place for a Snark! I have said it thrice:
What i tell you three times is true."
