Never fear, I got the whole pre vs post-test probability thing down. My point is that "Fatigue" as an isolated symptom is generally not symptomatic enough to go fishing with an isolated ANA and a high proportion of the general population will come back positive to begin with. The statement "there is a reason it frequently gets ordered in the presence of some symptoms" is so vague as to be useless. Yes, symptoms of an autoimmune disease...and you should know what you're going to do with a + ANA if it comes back.
Fish up some papers showing that checking an ANA in people with chronic fatigue as an isolated symptoms yields much more than saying "you have a positive ANA" in a bunch of them and we can figure out the pre-test probability of finding something actionable in fatigue + positive ANA.
By definition CFS is not a question of fatigue as the only symptom, and in reality, how often are you having patients present to psychiatry with literally only overwhelming fatigue as the symptom they are complaining of? I think I can count on 1 hand how many times I have actually seen a patient complaining of fatigue and only fatigue without something identifiable (new parent, cut back on coffee, etc) being the cause of just plain old fatigue. Invariably these patients have other complaints.
I guess I disagree, that in that presence of symptoms, and by the definition of the discussion we are having, the symptoms cannot be better accounted for by a psychiatric diagnosis, such as depression, we are talking about overwhelming fatigue plus other complaints, not otherwise accounted for. That to me begs ruling out autoimmune etiologies in addition to other things. As a psychiatrist, really your job is to 1) help rule out somatic causes of symptoms such as fatigue and 2) diagnose psychiatric causes of symptoms, for which you often have to do Step 1.
Now I know I am telling you what you already know of your job. And your points are good.
But where I disagree, is that in your patient so profoundly fatigued they are seeking psychiatric care, typically because they meet criteria for impairment of major life function(s), where a somatic or psychiatric diagnosis is not immediately apparent, I feel that immune etiologies *must* be investigated.
Now, I am not saying the psychiatrist should be the one to order an ANA.
I've heard different things from rheumatologists. Some say that ordering the "standard panel" for inflammatory disease is not really helpful, they know which ones they want when they see the patient. Others would say, it can speed things up when the blood tests they would most likely order to work up an immune etiology is already ordered and they can review the results with a patient.
I agree that what an ANA does NOT do, is that for the psychiatrist I'm not sure it changes management, does it? You tell me. Sounds like these patients are appropriate referrals to rheum regardless of the blood test results, so ANA doesn't add much there.
My argument is more, the idea that ANA is useless in these patients or that inflammatory disease does not need to be investigated. Which may not be your point, that's fine. But it is my point.
Just, an attitude like why bother with these people. Some of them will have identifiable conditions, some will have inflammatory disease, and some may be diagnosed as CFS, which we can then debate if that is "real". My understanding is that typically it is the rheumatologist that diagnoses that, even if in the long term they do not manage it ongoing.
The impairment is "real." I have no doubt the fatigue is also "real." As to whether we can diagnose it or treat it, I'm not sure.
I think that is more a failure of medicine (we don't know enough, or these issues are more complex or are not appropriate for what a medical approach currently can address) than that this isn't "real."
I almost never find a physician pose the question of whether or not a patient's symptoms are "real" posed in any way that is less than somewhat contemptuous or dismissive or blaming of the patient and it bothers me.
I still disagree that a rheum work up and that will probably include bloodwork, is not indicated. If your point is just the psychiatrist shouldn't order that, again, I do think that is debatable.
