There are myriad theories on the causes of mental health: pollution, culture, chronic stress, etc etc. Each of which are interesting and disturbing in their own right, but also fraught with blame or objectifying of folks.The treatment of mental illness (not sure how excited I am about that term, but I will use it here) as part of the problem as well.
There are two general reasons mental illness is treated, and they aren't exclusive: the symptoms of the illness are diminishing a persons quality of life (and it is important that this /ought/ to be up to the person experiencing it) and they wish to find relief; the second are cases in which the symptoms are interfering with ones ability to function in society, which is seen as detrimental to society (this is usually not up to the person affected).
The former is usually in cases of depression, anxiety, PTSD, and often more severe issues as well. In these situations it is important for there to be options and support. More often then not, these folks go to their PCP and are prescribed medication (which can be detrimental to quality of life in a million other ways) or folks self-medicate with nonprescriped drugs and/or alcohol (which are usually no different than what is prescribed, most anti-anxiety medication after all is just a pill form of alcohol). The scientific-medicalize view of a person is based upon chemical reactions, and works to solve the chemical problem, rather than a holistic view of a person that looks to address the ways their life is being affected. Other ways that ought to be utilized more are group counseling/therapy where people work on their sources of pain and discomfort themselves and together, having supportive people around and being willing to be that supportive person, setting up safety plans that address problems as they are arising rather then once they climax, removing sources of problems from a persons life. It is important that a persons autonomy be respected, that they aren't being passive victims of their condition or passive recipients of treatment, that act in and of itself can be quite healing (especially when the sources of anxiety or depression stem from issues of hopelessness or feeling out of control). None of these are particularly radical, and I think that is the important point. Heroic medicine has only exacerbated the problem and I think a switch to slow-moving, life-style oriented “treatment” is necessary, and medication (herbal or allopathic) can be one tool, but not the cure-all.
The latter, where function in society is the thing affected, is a whole other mess that brings up a lot of issues around consent: forcing a way of life and world view on a person who may not agree with or want that. Its a hard situation to handle, when one person's reality doesn't match yours, and when that different reality interferes with another's life. I am not going to address this much, because I don't know how one would handle such a situation other than on a cases by case basis, but would be curious as to other's experiences or thoughts. In /Locked Up/, Bonano has some great points about the move toward “treating mental illness” as another form of prison, and address the reality that as long as not /wanting/ to behave and function properly in society is seen as an a mental illness, radicals will never be 'sane'. (Check that book out.)