claims that immune response can be manipulated through classical conditioning. One book claims this as a placebo response mechanism. This is a much narrower claim than "affected by a patient's psychological state of mind".

Hence my using the broadest category, leaving open the specific etiology of such an effect. "Can be affected by a patient's psychological state of mind" is necessarily a less burdensome assertion than "can be manipulated through classical conditioning", because the former is true if the latter is true, but not vice versa (not iff).

They were still experiencing reduced grip strength. They were feeling subjectively better, but that was at odds with a functional measurement of their condition.

I'm not making the claim that placebo works for objectively quantifiable symptoms that aren't subject to the perception of the patients. Discomfort, however, is.

Conditions requiring medical treatment are not, to my knowledge, exclusively subjective.

There are indeed kinds of e.g. tinnitus that have a component that can be objectively measured. However, if placebo can effectively treat subjective components, that in itself would justify their usage. For many disease complexes, medication will only address partial symptoms. Which is fine. No need for a panacea.

Of course there in an involuntary cause to subjective symptoms, at least involuntary to a first approximation. The effectiveness of placebos does not preclude the effectiveness of other, actual medicine, such as lidocaine. Also, effectiveness implies only a reduction, not a cessation ("not able to convince themselves that their tinnitus is gone")

Damn, after all this tinnitus talk now I'm cognizant of my own tinnitus. Better take another sip of my, um - (suspending disbelief) - "special" water.