In popular culture, the term paranoia is usually used to describe excessive concern about one's own well-being, sometimes suggesting a person holds persecutory beliefs concerning a threat to themselves or their property and is often linked to a belief in conspiracy theories.
In psychiatry, the term paranoia was used by Emil Kraepelin to describe a mental illness in which a delusional belief is the sole, or most prominent feature. This usage is now largely obsolete and the term is more typically used in a general sense to signify any delusion, or more specifically, to signify a delusion involving the fear of persecution. The exact use of the term has changed over time, and because of this, psychiatric usage may vary.
Farrell, John. Paranoia and Modernity: Cervantes to Rousseau (Cornell University Press, 2006).
Freeman, D. & Garety, P.A. (2004) Paranoia: The Psychology of Persecutory Delusions. Hove: Psychology Press. ISBN 1-84169-522-X
Harper, David J. (1999) Deconstructing Paranoia: An Analysis of the Discourses Associated with the Concept of Paranoid Delusion.
Igmade (Stephan Trüby et al, eds.), 5 Codes: Architecture, Paranoia and Risk in Times of Terror", Birkhäuser 2006. ISBN 3-7643-7598-1
Kantor, Martin. (2004) Understanding Paranoia: A Guide for Professionals, Families, and Sufferers. Westport: Praeger Press. ISBN 0-275-98152-5
Munro, A. (1999) Delusional disorder. Cambridge: Cambridge University Press. ISBN 0-521-58180-X
Sims, A. (2002) Symptoms in the mind: An introduction to descriptive psychopathology (3rd edition). Edinburgh: Elsevier Science Ltd. ISBN 0-7020-2627-1
Siegel, Ronald K. (1994) Whispers: The Voices of Paranoia. New York: Crown.
Harper, D.J. (1996). Deconstructing 'paranoia': Towards a discursive understanding of apparently unwarranted suspicion. Theory & Psychology, 6, 423-448. Final draft