You're asking me to suppose a great deal! :-D
Are you speaking from personal experience, or do you know someone - anyone - whose reaction to waking up from naivité and growing up to become a responsible man, instead of remaining a child mentally, was to kill everybody in sight, including himself?
I don't know ANYONE who's reacted the way you describe.
On the other hand, your description is EXACTLY how the NWO spokespeople would express themselves to describe the "reason" why Martin Bryant killed so many people at Port Arthur, or why Robert Steinhauser in Erfurt, Germany went on a mass killing rampage.
In fact, that's exactly how they're describing chess genious Bobby Fischer: "a lunatic, paranoid, who thinks the CIA is out to get him". Well, they WERE! He sat in solitary confinement for 8 MONTHS in Japan, before the Islandic government offered him a citizenship to get him out.
Why did the Americans do this? Because Fischer is popular, has access to mass media by being a world-famous chess master, and last but certainly not least, he is a dissenter with facts in his hands and he's not afraid to voice his opinion on American foreign and domestic policy.
Actually, Jesus said "my Kingdom is NOT of this world", which leads me to suspect that Satan has put it in the heads of the mentally asleep to achieve it here, on earth...
"The road to Hell is paved with good intentions." Don't remember who said that, but it's very relevant.
My version of mental health is very easy: like I said before, if one is able to scale away all the social conditioning, mind control, memes, 'slide reactions', false doctrines, propaganda, etc., we would get genuine mental health.
Reading the Sacred Wisdom of the Traditional World would lead Modern Western civilization out of this pit.
For every false doctrine we expose and discard we get more mentally healthy. By thinking logically and trying to see with the Eye of the Heart. We can cure our "mental disorder" imposed on us by the Modern World, but not by any modern means!
Turning away from the Modern World and it's false concepts and manifestations, and turning either towards the World of Tradition, or looking ahead towards a new Golden Age.
Three things are sacred to me: first Truth, and then, in its tracks, primordial prayer; Then virtue–nobility of soul which, in God walks on the path of beauty. Frithjof Schuon