The psychiatric concept of paranoia is commonly traced to ancient Greece, where Hippocrates inaugurated it among several other mental maladies, coining the term from the Greek para (meaning “beside,” or “changed”) and nous (signifying “mind,” or “reason”).

Its etymology can also be traced back to Plato’s and Aretaeus’s identifications of “religious madness” and “divine mania,” or citations in the work of Francois Boissier de Sauvages (Pathologie Methodica, 1759) to transformative delusions in which patients believed they were being transformed into either animals or the opposite sex.

It was not until Etienne Esquirol’s Mental Maladies: A Treatise on Insanity (1845) and, later, Emil Kraepelin’s Textbook of Psychiatry (1883–1915) that the concept of paranoia, as it is understood today, began to take shape.

Esquirol’s descriptivist account catalogued, among others, erotic, reasoning, theomaniacal, incendiary, and homicidal monomanias. Paranoia was identified as a délire partiel (monomania), a folie raisonante (a reasoning madness).

Kraepelin’s influential definition of dementia praecox (early-onset dementia, now classed under the broad category of schizophrenia) most deeply informs the contemporary understanding of the concept as a delusional disorder that builds a highly organized, grandiose system that is held with great conviction.

From this tradition and that which followed, paranoia has come to be characterized by symptoms such as projective thinking, hostility, suspicion, centrality, delusions, fear of the loss of autonomy, and grandiosity. Even though paranoids are often able to achieve a high level of occupational functioning, unlike other psychoses, there is no pharmaceutical or therapeutic “cure” for paranoia.

The most famous case of paranoia, which has served as the basis for most of the major contributions on the study of the subject as well as being a remarkable autobiography of paranoia, is Daniel Paul Schreber’s Memoirs of My Nervous Illness (Denkwürdigkeiten eines Nervenkranken [1903]).

Schreber, a high-ranking German judge, describes the slow and torturous process of being transformed into a woman by God in order to bring forth a new race of men; being made into God’s sexual slave; and being the victim of a “soul murder” at the hands of Dr. Paul Emil Flechsig, the director of the psychiatric hospital in which he first stayed.

Sigmund Freud’s influential study of the case read paranoia as a defense against (unconscious) homosexuality, or homosexual attack. Although this theory has largely been cast aside, it is notable for Freud’s first theorization of projection.

Freud also argued that paranoia is a recuperative process, one in which the paranoid attempts to rebuild his or her world after a psychotic break through delusion. Interestingly, “paranoia” as a discrete medicalpsychiatric definition no longer exists. The current Diagnostic and Statistical Manual of Mental Disorders (DSM) instead classifies it as an aspect of other psychoses, such as schizophrenia.

The category of paranoia gradually moved beyond the psychiatric domain and began to be used by philosophers and social theorists to explain literary texts, social formations, and historical epochs.

The discourse of heroic “enlightenment”—which seeks to uncover, reveal, and disclose knowledges that are otherwise concealed, shrouded, and hidden—is firmly entrenched in Western philosophical traditions. The notion of “suspicion” as an interpretive strategy can be traced from academic and Pyrrhonian skepticism through to the work of Machiavelli, Rousseau, and Hobbes.

Paul Ricouer identifies Nietzsche, Marx, and Freud as the key proponents of a tradition that sought to redirect its Cartesian doubt from a regard of things, to doubt consciousness itself. In Crowds and Power (1962), Elias Canetti describes paranoia as an “illness of power” that can help to explain the nature of political power in general.

Canetti establishes an equivalence between paranoids like Schreber and despots and rulers such as Adolph Hitler and Genghis Khan. Richard Hofstadter’s famous 1964 essay, “The Paranoid Style in American Politics,” continues this genealogy by theorizing paranoia as a political style, rather than a pathological category.

Conducted under the banner of “Studies on the American Right,” it charted the paranoid style in U.S. political life since independence, through the central characteristic of persecution and its systematization in conspiracy theory.

Hofstadter sought to describe a generally right-wing style of mind, and chose to refer to it as “paranoid” because “no other word evokes the qualities of heated exaggeration, suspiciousness, and conspiratorial fantasy” that characterizes this mindset.

The concept of paranoia has dispersed into popular culture in a vast array of forms including films such as JFK (dir. Oliver Stone 1991) and Conspiracy Theory (dir. Richard Donner 1997), television programs such as The X-Files and Nowhere Man, pamphlets, rants, and tracts of every political color, magazines such as Paranoia, and books such as Jim Keith’s Secret and Suppressed: Banned Ideas and Hidden History (1993).

Rhetorics of paranoia can be identified in popular music, from Black Sabbath’s classic anthem “Paranoid” to Radiohead’s Paranoid Android, and Garbage’s “I Think I’m Paranoid.” The paranoid ethic of hypervigilance even extends to managerial advice books such as Andrew S. Grove’s Only the Paranoid Survive: How to Exploit Crisis Points that Challenge Every Company and Career (1999).

The cultural sensibility expressed in these works, one that has wholly digested Delmore Schwartz’s adage that “even paranoids have real enemies,” suggests that there is less danger in being paranoid than in not being paranoid enough.

Like the term “conspiracy theorist,” “paranoid” represents a heavily loaded political and epistemological description, one that is used at certain times as an ironic form of self-identification, and at others, as a condemnatory indictment.

In a fashion similar to the way “conspiracy theory” is used as a description of false history, the accusation of paranoia has become a powerful tactic in the marginalization of one’s ideological opponents.

Cultural critics and pop psychologists have in recent years taken up the psychiatric history of paranoia, and (consciously or not) Freud’s contribution to it, in their attempts to delegitimize those they consider conspiracy theorists.

The conspiracy theorist (or paranoid), it is argued, takes an object or figure that was once revered and transforms it into the focus of persecutory anxiety, so that their conspiracy theories tell us more about the subject’s own desire and fear than they do about anything in the world.

Paranoia, so the story goes, is a disease of disaffection: the WASP patriot, the militant feminist, and the Islamic fundamentalist are united by their marginality, one which organizes their thinking in a paranoid or conspiratorial fashion.

Other critics have argued that such theories form appropriate responses to actual circumstances: for example, the widespread belief in the African American community of the early 1990s that the government was spreading drugs such as crack cocaine in poor black communities should not be read simply as “paranoid,” but as a dramatization of very real fears of an institutionally sponsored program of genocidal neglect, one that is based on the historical revelation of actual conspiracies such as COINTELPRO and the Tuskegee syphilis experiments.