Chiropractors have an urge to manipulate your bones to "fix" all kind of ailments, of which they think that they are caused by "the bones". And the psychologists think that anything that (at the moment!) lacks a "medical" explanation must be caused by the psyche, and therefore they must manipulate the psyche to "help", as much as an chiropractor must manipulate the bones to "help".
Seriously, they have "biopsychosocial models", "psychosomatic models" and "somatoform disorders" to explain pain and fatigue – where is the evolutionary sense in that?
"Nothing in Biology Makes Sense Except in the Light of Evolution."Psychology needs to get evolutionary roots, or it will have to be up-rooted.
-- Theodosius Dobzhansky
And isn't it amazing that sub-specialites of the medical sciences, that are so heavily build on confirmation bias, can still thrive today?