A bit ambivalent in that the discrimination (it's not stigma it's overt, clearly bigoted discrimination) originates within the medical and psychological professions. Although it would be more fair to say that medicine, especially neurology and psychiatry, have a lot more blame here than psychology, psychologists could play a big role in denouncing what happened and how failure to address has been largely a choice in the pursuit of psychosomatic ideology, and they have played a big role in the establishment of the psychosomatic model that is 100% to blame for this failure.
And the health care industry being highly conservative, this is probably the closest it can get to that. Which is still very little, a mild muttering of "that wasn't ideal" isn't the proper response to the deliberate detonation of a nuclear bomb in a large city, which just about captures the scope and disaster of what has been done to tens of millions of us for decades, but although it fails to place proper blame where it deserves to be, it's otherwise pretty direct and unequivocal.
Where does the BPS stand on the NICE guidelines? Of course they can't affect how MDs do their work, but they certainly could have a big impact if they chose to.