One day, people just stopped caring. History had seen cases of people not caring, but this was different. This time it actually caused something other than the alienation of one’s surroundings. This time it actually had consequences. It was called Psylence.
Psylence was the physical manifestation of people not caring. It resembled catatonia and certain cases of comas but there was no apparent cause, which is why it took so long to be properly diagnosed. When a person reached the phase where he didn’t care anymore, he just stopped. Stopped talking, stopped reacting to the world around him, stopped living. Except for their vital functions, they were essentially dead.
The main problem with Psylence was that once a person stopped caring, he couldn’t be brought to care again. And things were tried; all types of stimuli were applied, but nothing worked. The process of one’s downward spiral towards apathy was irreversible. It made people mad. It made them stop caring. Psylence was contagious.

I think the biggest problem with this passage is you have no character. It's like you're giving us a lecture.