Of course it is (the delusion that's really true)

William Burroughs described the paranoid man as one ‘who knows a little of what's going on’. In that rare beast, a mainstream Hollywood film that portrays schizophrenia with humanity and without a murder, A Beautiful Mind (2001), John Nash (Russell Crowe) irritates his wife when he says he heard the garbage truck outside at night. He has been hospitalised with psychosis and in that movie convention much imitated in life, anything he says must be taken as fantasy, unless proven otherwise. But the garbage guys are outside and thus begins a process where she (and the audience) begin to trust and identify with Nash again. This is the exception that proves the rule. When a filmic character with mental illness reports the ‘unfortunate event’ on which the film turns, nobody believes him/her: The Couch Trip (1988), Twelve Monkeys (1995), Independence Day (1996), Conspiracy Theory (1997) and K-Pax (2001) all milk this conceit for its full comic potential. Director Alan J. Pakula's paranoid trilogy Klute (1971), The Parallax View (1974) and All the President's Men (1975) project the angst of the unbelieved onto a battered American audience, reeling from Vietnam and Nixon. A flavour of paranoia excites modern science fiction (Total Recall, 1990 and the Matrix trilogy, 1999–2003), and infuses the contemporary celebrity film, The Truman Show (1998).

Melodramas take the ‘unbelievable mental patient’ a stage further. Gaslight was a popular drama (filmed twice: 1940, 1944), where a scheming husband tries to convince his dutiful wife that she is losing her mind by making things go bump in the night. The hero-journalist of Shock Corridor (1963) feigns psychosis to gain admission to the asylum. He identifies the murderer but no one believes him; his continued incarceration drives him insane. The parents of Claudia Draper in Nuts (1987) conspire to undermine her testimony against a murder charge. Despite her histrionics, Claudia (Barbara Streisand) wins out. Her battle with a bullying psychiatrist is mirrored in The Changeling (2008). A woman's child goes missing but the Los Angeles police return the wrong boy. To avoid further embarrassment to the police, an unscrupulous psychiatrist declares her insane.

Where A Beautiful Mind succeeds is in drawing in the audience into seeing and believing the content of Nash's delusions. By the time the film demarcates reality from illness, we have been seduced by his experiences, and we feel his confusion and loss. True empathy.