On the wall in Detective Downs' bedroom is a poster from the film "Tomb Hackers" which was Anthony Thurman's first animated short film.
During the opening credit sequence, it's supposed to be Rolando Downs who is looking up the information about Depression.
At the beginning when Rolando Downs looks in the mirror, his reflection is distorted because he doesn't see himself to be as attractive as others see him. His own mental image regarding himself is distorted. He later reaffirms this point when he washes his hands at the police station and avoids looking at his reflection in the mirror.
The idea for the Depression Meter was inspired by all the meters that are usually seen in video games.
The director originally thought about showing the bullet enter Detective Downs' body at the end of the film, but didn't do it after realizing how shocking it might be for children to see.