The definition for mental 'health" is based on an assumption that, in the absence of what has been diagnosed as 'unhealthy" what remains is a mentally healthy personality. We then measure these behaviors across the population and find the "mean" showing that a majority exhibits this behavior. We call this the "norm' and those that fall in the range as "normal."
Another way of looking at this is to say that there really is no definition of mental health. As a consequence our mental health system is forced to focus on intervention rather than prevention. There is no effective way to identify unhealthy behavior unless they have been diagnosed are documented in literature like the DSM which is considered the mental health's system bible.
The fatal flaw in this approach is that the DSM, much like the Bible, continues to be revised. One example of this is homosexuality which was once diagnosed as a disorder and later removed from the DSM and is now considered healthy behavior. Why? Well, homosexual behavior is now seen as "normal" behavior in our society by a majority of the population. Even the Bible is being revised to conform with the norm.
Looking at this flawed approach in a different context take our view of homicide which is defined as; 1. The killing of one person by another. 2. A person who kills another person. If the act is premeditated (planned in advance) it is considered sociopathic behavior deserving a more severe punishment; execution which is another way of saying legal homicide because the very same definition applies. 1. The killing of one person by another. 2. A person who kills another person. Why is one act of homicide consider a mental disorder while the other is looked at as completely normal? The only difference is that the latter act is accepted by the majority of society as "normal" behavior.
Mental health is relative to time, place, and situation. What the Romans did to Christians was considered normal and healthy behavior whereas today it would be considered abhorrent, vile, disgusting, sick, psycho, crazy behavior (at least I would hope so).
If we accept that mental health is defined by what the majority of the population considers to be normal (healthy) behavior then we are on a very slippery slope these days. An example of this are the "stand your ground" laws passed in several states. If the norm is that you can kill someone if you "perceive" a threat then the killing of a teenager for playing his car radio too loud be considered "healthy' behavior. If we believe that a soccer mom from Newtown Connecticut should be allowed to own military grade weapons if they "perceive' a threat then tragedies like the Newtown massacre will sooner or later become common place.
By shutting down our public mental health system over the last 3 decades we have in essence given the keys to the asylum to the inmates and there seems to be a large enough number of them to turn our country into a large graveyard.