But the statistical approach to diagnosis only seems to be used in certain illnesses and conditions.
My father, back in the late 80s or early 90s, was diagnosed with high blood pressure. He suffered severe side effects on the first treatment. So it was changed, then changed again. In total it took nearly 2 years and five different treatment protocols before his blood pressure was reduced AND his side effects were tolerable. This wasn't considered odd by his doctor nor did he assume my father was attention-seeking or depressed or anxious or mad.
Contrast the above experience with thyroid treatment for so many, and the difference is stark. Symptoms and side effects count for nothing. If you don't tolerate synthetic levothyroxine then you are clearly deranged.
I did read one paper looking at symptoms - this one published online March 2013 :
where 48.6% of people preferred animal thyroid treatment, 32.9% had no preference, and 18.6% preferred levothyroxine.
"DTE therapy did not result in a significant improvement in quality of life; however, DTE caused modest weight loss and nearly half (48.6%) of the study patients expressed preference for DTE over l-T4. DTE therapy may be relevant for some hypothyroid patients."
This conclusion is a whitewash of their own results. If nearly 50% preferred DTE then clearly it did give a significant improvement in quality of life. So how can they possibly say otherwise? Just because being hypothyroid makes some people gain weight doesn't mean that is all they care about. You mentioned reductionism. I think the conclusion of this paper is reductionism taken to absurd levels.
I think my problem, and the problem of so many of us, is simply understanding why thyroid treatment is treated so very differently from, for instance, high blood pressure and diabetes. Diabetics require insulin. So why are there over 80 entries in the BNF for medications related to diabetes and its side effects. For hypothyroidism there are 2 - levothyroxine and liothyronine - with a couple of sub-types accounting for the need for liquid and injectable preparations of these two treatments. That is all. There is no logic to this so many of us start building conspiracy theories. And sometimes I have a lot of sympathy with them!