Joker deals with the themes of mental illness and its both psychological and sociological effects.[223] While its depiction of the Joker has been described as reminiscent of those who commit mass shootings in the United States as well as members of the incel community,[224][225] Christina Newland of The Guardian concludes that Fleck is not an incel, but wrote that incels are likely to relate to him.[226] Vejvoda, Hammond and Newland interpreted the film as a cautionary tale—society's disregard of those who are less fortunate will create a person like the Joker.[192][196][226] Stephen Kent, writing for the Washington Examiner, described Arthur Fleck as blending shared aspects of mass shooters and interpreted its message as a reminder that society is riddled with men like the Joker.[224] Writing in People's World, Chauncey K. Robinson said the film "walks a fine line between exploration and validation" of Joker's character and is "ultimately an in-your-face examination of a broken system that creates its own monsters."[227]
Some writers have expressed concern that Joker's sympathetic portrayal of a homicidal maniac could inspire real-world violence.[228][229] Richard Lawson of Vanity Fair found the film was too sympathetic towards "white men who commit heinous crimes" and that the sociopolitical ideologies represented in the film are "evils that are far more easily identifiable" to people "who shoot up schools and concerts and churches, who gun down the women and men they covet and envy, who let loose some spirit of anarchic animus upon the world—there's almost a woebegone mythos placed on them in the search for answers."[230] Jim Geraghty of National Review wrote he was "worried that a certain segment of America's angry, paranoid, emotionally unstable young men will watch Joaquin Phoenix descending into madness and a desire to get back at society by hurting as many people as possible and exclaim, 'finally, somebody understands me!'"[231] Contrarily, Michael Shindler, reviewing the film in Mere Orthodoxy, while agreeing that Joker depicts a sympathetic wish fulfillment fantasy, contends (drawing on insights from Sigmund Freud and Jacques Lacan) that it is for precisely that reason that the film will, if anything, preemptively quell real-world violence by rendering "the Flecks of the world into meek somnambulists".[232]
British neurocriminologist Adrian Raine was impressed by how accurate the film's depiction of the psychology of a murderer was. In an interview with Vanity Fair, he described it as "a great educational tool" and stated that he planned to present film clips during his classes.[233] Psychiatrist Kamran Ahmed highlighted the factors in Arthur's childhood such as parental abuse and loss and family history of mental illness in the genesis of his condition.[234] American psychiatrist Imani Walker, who is known for her Bravo television series Married to Medicine Los Angeles and working with violent criminals with mental disorders, analyzed the Joker's apparent mental disorders and circumstances and noted that Arthur tries to find help before his downfall, only to be abandoned. She says of Arthur and others in poverty who have mental illness: "We as a society don't even pretend that they're real people and that's what this movie is about. He never had a chance."[235] Forensic psychiatrist Ziv Cohen criticized the film as misrepresenting the mentally ill as violent.[236] He argued the film conflates psychopathy (a lack of conscience) with mental illness, thereby creating a false impression of the mentally ill as dangerous.[236]
Micah Uetricht, managing director of Jacobin, opined in a review published by The Guardian that he was shocked that the media did not understand the movie's message: "we got a fairly straightforward condemnation of American austerity: how it leaves the vulnerable to suffer without the resources they need and the horrific consequences for the rest of society that can result"; Uetricht thus declares that Joker presents a world that has devolved into "barbarism".[237] Uetricht states that these themes are unsubtle to the extent that it was surprising that most media outlets had not identified them.[237] Ahmed also highlights the lack of funding for already-stretched mental health services worldwide being alluded to.[234]
The film's director and co-screenwriter, Todd Phillips, has stated that Joker is "certainly not a political film".[238] Phillips has also commented on discourse surrounding the film, pushing back on several criticisms surrounding its themes. He responded to critics who have expressed concerns over the film's violence, saying "Isn't it good to have these discussions about these movies, about violence? Why is that a bad thing if the movie does lead to a discourse about it?" Phillips also commented on political backlash to the film, saying "What's outstanding to me in this discourse in this movie is how easily the far left can sound like the far right when it suits their agenda. It's really been eye-opening for me."[239]
