Parents need to know that Motherless Brooklyn is a noir crime drama set in 1950s New York that's based on the novel by Jonathan Lethem. It follows a private investigator (Edward Norton, who also directs) who has Tourette syndrome and obsessive-compulsive disorder. Lionel is called "freak show" by his friends for his neurological tics, which cause his body to jerk or uncontrollably shout word clusters, many of which are profane. Lionel isn't alone in swearing: Characters curse constantly, with "f--k" being the favorite word. It's rare to see a lead character who has Tourette syndrome, and while Lionel represents an extreme manifestation, the film facilitates a compassionate understanding for what it's like to live with the disorder. To calm his symptoms, Lionel smokes pot, and many characters smoke cigarettes (accurate for the era). Bloody violence comes from guns, beatings, and a long fall; a rape is discussed. Sexual content includes allusions to sexual activities and kissing. Upon the death of his friend and boss, Lionel's obsessive mind keeps "pulling on the thread" of curiosity to find out who killed his friend and why; in the pursuit of truth, he shows courage and perseverance. While the story is fiction, it's based on real instances of housing discrimination at the hands of the city government.