1984 (2004)
Prozac found in drinking water (Link 2). Level not revealed - Government dismisses it, arguing it's just trace amounts.
Uhhh...it doesn't matter if it's a trace amount. Because, well, it's still enough to have neurolochemical consequences over time. But possibly more importantly, we can take this as the MOST RELIABLE INDICATOR ever devised (economists everywhere would kill for a Prozac-drinking water dataset) of just how unhappy, bored, fragmented, divided, frightened, and generally anomized your society really is (and will be)
I am so moving to the 3rd world.