Preventative care is of the utmost importance in medicine. Why wait until an amputation or daily insulin shots are needed to treat diabetes when early weight management could prevent it in the first place? Why wait and deal with the catastrophic consequences of a stroke to look at the brain instead of doing so regularly and hopefully catching the clot? Preventative care is emphasized in order to ideally prevent problems from arising in the first place. Unfortunately, this emphasis seems to be mostly placed on classically somatic ailments.
This is an unfortunate norm as mental health care could greatly benefit from more preventative care, early and effective intervention being paramount to avoiding serious risks later on. Let's identify a risk for depression before the suicide attempt or manage the anxiety before it compromises work or school. This is a lofty, almost whimsical goal granted the inherent difficulty in identifying the conditions themselves, much less treating them. My intention is not to be glib or patronizing, merely to acknowledge the need for preventative care while honoring it's difficulty. Obviously it's not as easy as giving someone medication and off they go, but rather identifying treatment methods, not even necessarily medication, that can ameliorate symptoms or teach patients constructive, healthy ways to cope.
The operative question at this point is how.
Education is key, first and foremost. I volunteer as a crisis counselor and one of our key functions is some semblance of psycho-education, in the vein of providing callers with tools to manage their mental health. Often times these people aren't subject to any pathology but simply have no idea how to manage their own emotions or aren't privy to constructive coping mechanisms (i.e. talking, exercising, breathing). Emotional intelligence needs to be as equally valued as it's empirical counterpart.
Another component in this equation is the integration of therapy with medication. Often folks will be medicated for their AD(H)D or BPD but not necessarily properly assisted in assimilating or processing the changes it can have on their personality or sense of self. This tends to lead to a great deal of dissonance regarding the medication, I remember someone once telling me that they wanted to stop taking it because it made them "a whole different person."
These are just examples from my own experience and by no means exhaustive nor professionally informed but they are some starting points for brainstorming and conversation. Preventative treatment for mental health is not as simple as testing, diagnosing, and medicating but some education and early diagnosing could go a long way in turning inevitable catastrophes into expected, but manageable conditions.