These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
It's implied that many of the higher ups in the government are also off their meds. Dupont's office is filled with art which is banned and his villainous gloating towards Preston has the sound of very real malice. He even tells him that he feels.
The man who tests Preston for emotion also utters "Oh shit!" before Preston kills the guards in the room, as do many of guards in the Nethers who utter "Oh fuck!" when Preston unleashes on them.
There could also be an interpretation akin to the RPG Paranoia, where none of the characters are on the meds, and some hide it better than others.
Small Reference Pools: They're burning a painting? Make it the (original) Mona Lisa! Man stumbles for the first time on music? The Ninth Symphony! Just imagine how the movie would've progressed if he'd found a Philip Glass record instead.
Yeah, he'd have gone back on Prozium and wiped out the Resistance singlehandedly.
Special Effects Failure: The face-cutting scene looks as believable as some early Flash/CGI animation. Worse, if you look closely when Preston leaves the room, you can actually see Brandt's face on the floor; it's clearly a photo printed on a piece of paper. (Also, in the photo, he's smiling).