Relapse!

With the insane, it's not so much how they behave, it's about what sort of conversation they're having with themselves. It's kind of silly in a way, but their behavior largely depends on their imaginary companion(s). These relationships, bordering on the parasitic, inhibit normal social interaction to varying extents. It's a lot like having a neurotic muppet latched to your face that you're compelled to obey. Episodes as such can range from mounting kittens with bottles, to believing in one's innate ability to fly off steep ledges. A serial killer, for example, would simply be sexually repressed manchild with a particularly enthusiastic imaginary companion.

On my run this morning, I saw a hobo having a very stimulating conversation with his imaginary companion; something to do with dental hygiene. These varietals are mostly harmless, except for that one off moment of lucidity every month or so when they start clawing at you for loose change and the nutritious muck off your boot.

But the other kind, I think their imaginary companions do really bad things to them. They go on a regular basis from being distraught and miserable, to angry, and finally violent, flailing their hands in the air at the imaginary terror muppets. Most of the time their ravings are largely ineffectual, but as the terror muppet latches on tighter and tighter every passing day, they become drawn deeper into the psychosis. Soon enough they're either monstrously deranged sociopaths, or drooling zombies.

So my idea is this, if we could somehow beat these imaginary mops into submission, we could ideally have a world full of socially acceptable mad people. And then we'd move on to producing billboards specifically aimed at selling products for imaginary people. That's like a whole new target demographic!