From “Serenity” (movie based on Firefly):
It’s the Pax. The G-23 Paxilon Hydrochlorate that we added to the air processors. It was supposed to calm the population, weed out aggression. Well, it works. The people here stopped fighting. And then they stopped everything else. They stopped going to work, they stopped breeding, talking, eating. There’s 30 million people here, and they all just let themselves die.
You’re welcome :) (https://freerepublic.com/focus/news/4023616/posts?page=19#19)