Truman Syndrome is a form of psychological delusion in which the patient believes that he or she is trapped inside in a reality television show, or that people are monitoring his or her every move. The name for this syndrome is a reference to The Truman Show, a 1998 film which revolved around a character who was living his entire life on camera without being aware of it. To those of sound mind, Truman Syndrome might sound a bit ludicrous, but not dangerous, although this is not, in fact, the case: this condition can actually be very dangerous for the people who suffer from it.

Psychologists have suggested that Truman Syndrome is a culture-based delusion, noting that it tends to arise in developed nations where there is a high level of surveillance, and where reality television shows are easy to access. Many people living in such societies have a certain amount of nervousness about being under surveillance or watched by the government, but people with Truman Syndrome take it to a whole new level, subverting very real concerns into a complex delusion.

Patients with this condition often specifically reference The Truman Show, along with other films and books with similar premises. They claim that they are living in an entirely artificial world where nothing is real and every action is carefully documented on a camera and watched by a television audience or government agency. Like the title character in The Truman Show, they think that they are slowly breaking through to the truth, but no one believes them.

Aside from the fact that delusions in general can be psychologically harmful, Truman Syndrome can also be dangerous. For example, people may think that specific actions will release them from the show, allowing them to win prizes, and these actions may involve dangerous activities. People may also become frustrated by the repeated denials of their delusions, lashing out at friends and strangers alike in an attempt to get people to admit that they are inhabiting an artificial world. Some people also have difficulty coping with real-life events, believing that these events were manufactured as part of the reality shows they inhabit.

Treating Truman Syndrome is complex. The use of anti-psychotic drugs and anti-depressants can help, but ultimately extensive talk therapy is the best option. Because the entire delusion rests on the premise that the world isn't real, the treating psychiatrist or psychologist may struggle initially to be accepted, especially if he or she is confrontational with the patient, and this is a good thing to keep in mind.