Ran across this definition of mental health, supposedly from the WHO

[TreasonousBastard]

3. What's wrong with that?

We are a social species, and mental health is largely meaningless outside of how we work within the society.

As with physical health, there is "functioning" measure of whether or not we're "working" as in able to, say, feed ourselves or get around, but we have always looked a mental health as largely an ability to properly socialize.

Perhaps at some point we can properly distinguish the two, as we do with physical health and fitness.