Aw, poke away. We may poke back, but there is no mental health / psychiatry perspective that’s any kind of sacred cow on this board 
I’m an escapee (escaper? I didn’t get escaped from, I did the escaping). Variously diagnosed as paranoid schizophrenic w/delusions of grandeur (most lurid one, I guess); manic-depressive psychosis (nowadays known as bipolar disorder); schizotypal personality disorder; borderline personality disorder. Two incarcerations, both private bins: Vista Sandia Psychiatric Hospital outside Albuquerque 1980, and Deer Park Hospital outside Houston 1982. “Voluntary” in the same sense as the OP on the first one, voluntary in a bit more embarrassing sense in the second instance. Also twice held very short-term on an involuntary basis on psych floors of mainstream facilities, once in Athens GA and once in New York. Resident of special psychiatric shelter for homeless (Creedmoor, Queens) followed by “halfway house” facility in New York (Residental Care Center for Adults, Creedmoor grounds), 1984-5.
I don’t believe in “mental illness”, at least not without an asterisk and five pages of disclaimers and elaborations. Certainly there are commonalities among the folks who have been so labeled, and it seems likely that there are physiological manifestations (perhaps in neural structure, perhaps in biochemistry), although they are not necessarily causal. Politically, a difference is not an illness if sufficient numbers of the people who have the difference like being that way.
Nurse’s training (LPN), Georgia 1982-3, incl. rotational placement on two psych floors @ general hospitals.
Myriad visits as advocate and/or friend, various facilities usually in New York, 1984-present, including opportunities to view treatment of residents.
Participation in the movement variously called “psychiatric inmates’ liberation movement”, “mental patients’ liberation movement”, “expatients-consumers-survivors’ movement (C-S-X)”, etc; member, Project Release of NY, Long Island Treatment Resistance, National Association of Psychiatric Survivors, and New York Organization For Human Rights and Against Psychiatric Assault.
I’m harshly critical of the state of psychiatric treatment (dark ages, stone knives and bearskins, trephination, blah blah blah), lots of lying about the excellence of the pharmaceuticals & other tx modalities, but for those who want it, I’m fine with a free and unimpeded market. (I do think LSD and other mood-modifying substances should be equally availalble to those who find them useful and efficacious, so I’m being consistent there). Where I’m inflexible and totally polarized against psychiatric practice is forced treatment, which I totally oppose.
Hentor the Barbarian is correct: I have my screeds ready, and I carry my own soapbox to stand on. I’m partisan. But I don’t think that means I cannot learn from folks with other perspectives, and I hope you are open in a similar fashion.