The script was originally entitled "Expiacion" ("Atonement"), and it portrayed an all male cast (male Psychologist and male Patient).
The Spanish production of the same name, directed by Paco Plaza, opened in theaters in Spain on the same exact date that this Veronica opened in theaters in Mexico, on August 25th, 2017. Although, the two films have no connection between one another.
The original ending of the script is different from the one in the actual final cut.
The police officer character named in the final credits of the film appeared in the original ending of the script, but was later cut out in editing.
Even though the film was released in 2017, the circa of the story-line is supposed to take place in 2012, since there's a line in which Veronica explains that she was born in 1987 and is now 25 years-old. The reason the directors decided to keep the line like that is because they wanted to pay homage to the year the first draft of the screenplay was written: 2012.