&gt; I&#x27;m saying the question deserves further investigation.<p>My mistake.<p>&gt; You seem to be claiming that it&#x27;s settled.<p>No. There are doubtless many rare variants of human ailment we haven&#x27;t understood or discovered yet. Literally, you could come up with at least one ailment for every enzyme and cell-surface molecule on the human body, at least.<p>My issue is that every few years there comes up a new anxiety&#x2F;depression fad: some subset of folks with anxiety and depression with attribute it to some new undiagnosed condition (almost always musculoskeletal), and whip up a frenzy.<p>Is it possible that there are these large numbers of usually-musculoskeletal rare disease variants that all happen to look like anxiety and depression?<p>Well, yes, there could be. But considering how woefully under-diagnosed and under-treated mental health is in this country, and that between anxiety disorder and MDD you have a twelve-month prevalence in the US of &gt;20%, you are far, far, far more likely finding people with anxiety&#x2F;depression and a dollop of either denial or misunderstanding[1].<p>All of medicine comes down to the Bayesian discipline of figuring out what the most likely cause of an issue is, and collecting evidence to support&#x2F;disprove that until it&#x27;s no longer the most likely cause, or until the ordering stops changing. That&#x27;s it. Jumping down the list is medically irresponsible. Every treatment, at that point, is unethical: you can&#x27;t justify cost vs. benefit of treatment benefits and side-effects when there&#x27;s every likelihood the patient doesn&#x27;t have that rare thing.<p>So, before inventing new diseases every handful of years, we need to stop and say &quot;is there any good evidence that this is a 1&#x2F;1,000,000 new illness, vs. the anxiety&#x2F;depression for which there&#x27;s a &gt;20% chance it is?&quot; In this case, the sum total of evidence for novel disease amounts to the possibility of &quot;possible injury to nasal sensory neurons creates a little numbness in the nose; subject of anxious obsession by pts w&#x2F; anxiety.&quot;<p>I don&#x27;t argue this because it amuses me to say &quot;no, silly rabbit, you&#x27;re not allowed to have your own new disease.&quot; It&#x27;s because these people are suffering terribly, in dire need of help, and when we expend our resources chasing new diagnoses (in the absence of good reason to believe there&#x27;s a new illness), we&#x27;re &quot;validating&quot; them at the expense of actually helping them.<p>[1](Yes, patients with anxiety can just genuinely not understand they have it. Anxiety can come on as strictly somatic symptoms, and the common layperson can rationally say &quot;I don&#x27;t feel anxious or panicked at all; I&#x27;m just having trouble breathing. Non-sense!&quot; It&#x27;s a poorly named disease.)