Joker by DC Comics
It's based on the character Joker from the Batman comics.
Synopsis:
A socially inept clown for hire - Arthur Fleck aspires to be a stand-up comedian in his small job, dressed as a clown holding a sign for advertising. He takes care of his mother- Penny Fleck, and as he learns more about his mental illness, he learns more about his past. Dealing with all the negativity and bullying from the society he heads downwards on a spiral, in turn showing how his alter ego "Joker", came to be.
Recommendation:
A film for crime, drama and suspense lovers. This film is hard to watch, it's based on the supervillain of Superman who has psychosis. A very well-done interpretation from the actor who makes you understand what is like having this mental illness. If you want to watch it have in mind these facts.