Funny you should put it that way, because Psychiatry as a field historically evolved directly out of the witch hunts of the Inquisition.[1]

[1]https://www.amazon.com/Manufacture-Madness-Comparative-Inqui...

>I think it's a distraction from the actual topic

Precisely my point.

>that may be true but you'd have to give supporting cases.

There are countless examples throughout history if you'd like to learn.

Runaway slaves, gays, masturbators, marijuana smokers, and political dissidents have all been classified as mentally ill and oppressed as a result of their lifestyles.

For more comprehensive, historically cited writeup, check out The Manufacture of Madness

https://www.amazon.com/Manufacture-Madness-Comparative-Inqui...

>more like a state-supported official religion

You might find The Manufacture of Madness: A Comparative Study of the Inquisition and the Mental Health Movement by Dr. Thomas Szasz interesting[1].

In this book Dr. Szasz historically shows the startling revelation of how modern psychiatry evolved out of and is the modern day equivalent of the Inquisition. As the church lost its control over the state during the Enlightenment, witches were relabeled as crazies and the role of social control was taken over by the psychiatric state.

[1]https://www.amazon.com/Manufacture-Madness-Comparative-Inqui...

> There are many many contexts in which we, as a society, determine that someone is mentally unfit to make decisions

And in many of those contexts those determinations are routinely unjustified, and have resulted in massive institutionalized civil rights violations over generations. You can read Thomas Szasz for heartbreaking details (e.g. http://www.amazon.com/Manufacture-Madness-Comparative-Inquis...). Hopefully someday we can look back on such policies with similar horror to how we now see 17th century Bedlam. Instead of using them as arguments for further authoritarianism.