Some suspiciousness is healthy. If we get a text, for example, we may resent the intrusion and question its legitimacy. What do they want? Access to an account? Our money?

Too much suspicion sends other signals. Paranoia is that unwarranted feeling that people are out to do us harm.

To rise to the level of psychiatric concern, symptoms must be out of proportion to any evidence; e.g., a grandfather suspects his 33-year-old grandson Eric asking questions about family generations. Grandpa casts malevolent motives and begins to shun visits, despite that he has known his grandson his entire life, which has included mission work and studying for a Ph.D. in sociology (hence curiosity about family).

When the grandpa tells his assisted living nurse that Eric wants money, she’s concerned, but given her training, the patient’s 73 years and physical decline, she engages him in Socratic questioning, determining that exploitation is unlikely. Grandfather doubles down with, “Well, he could rip me off.”

According to the DSM-5 TR, criteria for paranoid personality disorder includes elements of cognition and behavior that reach back to one’s early adulthood and present in a variety of contexts as indicated by at least four criteria:

• Suspects, without sufficient basis, that others exploit, harm, or deceive.
• Is preoccupied with unjustified doubts about loyalty and trustworthiness of friends/associates.
• Is reluctant to confide in others because of unwarranted fears that information will be used against them.
• Reads into the benign something demeaning or threatening.
• Persistently bears grudges even for minor slights.
• Perceives attacks on character or reputation that are not apparent to others and is quick to anger or counterattack.
• Has recurrent suspicions, without justification, regarding fidelity of a spouse or partner.

Also pivotal to diagnosis, symptoms do not occur during schizophrenia, bipolar or depressive episodes with psychotic features, or other psychotic disorders or general medical conditions to which descriptors may apply.

If our scenario’s grandpa had Lewy body dementia or Parkinson’s, he would not qualify for the disorder, unless he exhibited symptoms long before.

Research Into Paranoia

German researchers reproduced a U.K. study, enlisting Germans ages 18-65 who self-reported no brain diseases. The average study participant was 35 years old; the sample included 437 females, 362 males and three diverse individuals. Mental disorders were not excluded. Of these, depression was the most reported.

All were given multiple scales/surveys to measure coping, beliefs, and ideas of social reference and persecution. They also administered a screening questionnaire with 15 items assigned to one of four subscales: interpersonal sensitivity, mistrust, ideas of reference, and persecutory ideas.

Ideas of reference involve the misinterpretation of ordinary events, even a coincidence, as having a deeply personal meaning. For instance, when hearing strangers laugh, one might conclude this happens at his expense or that a news story or book targeted them without knowing the author’s inspiration. The German study concluded that paranoia is common and hierarchical, aligning with what little research exists and called for future studies to explore etiology.

Paranoia Exists on a Spectrum

Not everyone who exhibits symptoms meets criteria for a disorder. Given privacy rules and ethics surrounding diagnosis, we don’t always know for sure.

One example, based upon investigative reporting (e.g., Bob Woodward/Carl Bernstein) is former president Richard Nixon. Nixon’s speeches are rife with high obsession with enemies (the press), evident in his 1952 Checkers speech and 1962 gubernatorial loss. This predates the release of secret tapes during the 1960s/’70s that countless experts and historians pored over to conclude unwarranted paranoia, in some form, existed. As Nixon led in the 1972 election, historians believe the surveillance of the DNC Watergate offices was wholly unnecessary.

Nonetheless, in everyday life, it’s challenging to be in relationship or to work with someone super suspicious. Rather than self-recognize faults, a partner’s blame invades interpersonal dynamics. When a woman with paranoid tendencies gets a supervisory correction, she’ll insist management prejudiced her. If one’s default is that others manipulate, the easy conclusion leads to misread words, deeds, even human emotion as manipulative. So too, one might rationalize one’s own poor behavior, striking first out of threat. Like falling dominos, paranoia can start a chain of mistakes.

Expectations of Paranoid Ideation

Dr. Martin Kantor, M.D., author of Understanding Paranoia and a clinical book on passive aggression, believes by increasing one’s knowledge of this the general public “will be better positioned to create a less paranoid society,” and harkening to our scenario that caregivers “will know more precisely how, when, and where their friends and family go astray and so be better positioned to help both those they love and those who victimize them.”

Kantor writes compassionately, “We must always remember that: paranoia is disorder of the mind, not a flaw of the character.” He calls attention to subtle signs such as the person appearing to be tense, excessively reserved, withdrawn or having flat affect, or eccentric. “Paranoid individuals are angry people. Typically, they use others as ready-made lightning rods for their own rage, then complain that, and act as if, other people are responsible for setting off landmines.”

Healthier people with paranoia have the capacity to wait until their anger subsides; the less healthy express it in counterproductive ways. Little to no Self-awareness along with proper judgment exists.

“As a result they fully believe their distortions of reality,” Kantor writes, later adding they “often do act on their false beliefs because they are convinced that they are justified in doing so.” And he warns that the breadth of a delusional system is not always a reliable indicator of judgment in that “some patients reality-test even the most extensive delusional complexes and suppress any behavior driven by delusion.” Conversely, delusions may go untested and lead to unproductive, even dangerous consequences.

Benefits of Knowledge

Paranoia is one of the least studied Mental health conditions, largely because those with it do not present for treatment. Still, it’s wise to have rudimentary knowledge for one’s own self-protection as well as to help others. Kantor incorporates quality research.

Of the eccentric paranoid, he notes that they become countercultural, often on the fringe, with “their own version of science and become persuasive quacks, rainmakers, music men and gurus, who shamelessly foist questionable theories on the public, possibly doing considerable damage to their followers’ pocketbooks, health, and even lives.”

Key takeaways include that paranoid individuals feel threatened by people they think are on to them (media/investigators) and they dislike/hate anyone dishonoring, putting them down or exercising traditional authority. As well, Kantor advises we watch for the overestimation of someone’s true worth and ideas along with their potential for false accusations, or worse, violence.

Copyright © 2025 Loriann Oberlin, MS.