Pseudologia fantastica: the truth about pathological liars

by Heather Kranz, MEd, CRC on September 21, 2012 · 8 comments

in pathological lying

Some of us are experts at picking up on it, others find themselves victims of it, but we are all guilty of it: It’s the common experience known as lying.

White lies, big lies or simple exaggerations are common to the human experience; they may be temporarily problematic but typically do not have lasting repercussions on our lives.

Sometimes, however, lying can become excessive, with lies becoming so intricate, so extreme and interwoven that they almost blur the line between one’s concept of reality and fantasy. Individuals who engage in extensive lying are known as pathological liars.

Pseudologia fantastica

There is no consensus on the definition of pathological lying, referred to diagnostically as pseudologia fantastica. Furthermore, the condition is not recognized as a diagnosable disorder in the Diagnostic Statistical Manual for Mental Disorders (DSM).

Healy and Healy argued that the condition of pathological lying should stand independently as a diagnosis, believing that pathological lying patterns develop over time in the absence of a medical condition such as epilepsy or a mental disorder such as schizophrenia.¹ Others argue that pathological lying is a result of a “psychopathic personality.”² There are also conflicting ideas about whether pathological lying is a willful act or more of an automatic (and thus unintentional) behavior.

Diagnostic interference

Suspected lying can present a formidable challenge in conducting the Structured Clinical Interview for the DSM-IV (SCID). Since the interview relies almost entirely on self-report, suspected lying can interfere with the interpretation of symptoms. Complicating matters is the brevity of interaction with the patient and the inability to check the veracity of a patient’s accounts with family members or friends (many of whom also struggle to gauge the accuracy of a patient’s statements).

An accurate history is critical to diagnoses. For example, according to the DSM, a diagnosis of posttraumatic stress disorder (PTSD) requires a history of exposure to traumatic events, with the following criteria being met: the person experienced, witnessed or was confronted with an event or events that involved actual or threatened death or serious injury, or a threat to the physical integrity of self or others AND the person’s response involved intense fear, helplessness or horror. One can see the diagnostic difficulties that may present when the legitimacy of a patient’s traumatic experience is called into question.

However, many patients do experience extreme adversities, some of which seem so outlandish that they are difficult to accept as truth but, in fact, are real. At other times a patient’s exaggeration of symptoms, or intentional flight from the truth, can be a deliberate attempt to garner sympathy or attention, or to externalize blame.

Research results

What sets pathological liars apart from the rest of us?  Well, biologically speaking, studies suggest that pathological liars suffer from structural brain abnormalities, specifically, an increase in prefrontal white matter and a reduction in prefrontal grey/white ratios, compared with normal and antisocial controls.³ These findings suggest that prefrontal impairment might play an important role in the phenomenon of pathological lying.

Still other research studies suggest that people suffering from compulsive lying have the possibility of impaired reality testing – similar to those experiencing psychosis. Some authors propose that the impulse to lie is connected to a type of “wishful psychosis,”4 a desire to live in a fantasy life that can be gratifying to the person, blurring the line between desired fantasy and reality to the point that the person can no longer distinguish between the two.

This concept is challenged, however, by the fact that many pathological liars express sound judgment in all other areas of life and do not typically experience the same functional limitations someone with a psychotic disorder might show. Furthermore, when confronted about their lies, pathological liars are able to acknowledge the falseness of their stories, which suggests they are consciously aware of their lying and therefore not delusional (i.e. not psychotic).

There remain many unanswered questions about pathological lying, including:

  • Does it warrant a diagnosis?
  • Is it a willful act?
  • Is it associated with detectable brain abnormalities?

Limited research into this fascinating topic renders many plausible hypotheses about pathological lying.

While there is much dispute about the etiology of this condition, it can be agreed upon that individuals who experience pseudologia fantastica face many difficulties in their personal relationships and even professional careers as a direct result of their lying.

Editor’s note: If you enjoyed this post, check out some of Heather’s other blog posts:


  1. Healy, W., & Healy, M. (1926). Pathological Lying, Accusation, and Swindling. Boston: Brown, Little. 
  2. Selling, L. (1942). The psychiatric aspects of the pathological liar. Nerv Child, 335-350. 
  3. Yang, Y., Raine, A., Lencz, T., Bihrle, S., Lacasse, L., & Colletti, P. (2005). Prefrontal white matter in pathological liars. The British Journal of Psychiatry, 320-325. 
  4. Dike, C., Baranoski, M., & Griffith, E. (2005). Pathological Lying Revisted. The Journal of the American Academy of Psychiatry and the Law, 342-349.
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{ 6 comments… read them below or add one }

Ed Webber October 9, 2017 at 7:33 pm

Ever since the president has taken office there have been rummors that he is a little to a lot a bit odd. Some have said he is abnormal and therefore dangerous.
I just looked up the term “pseudo logia fantastica” and it makes me wonder if this possibly could be the case. Without pointing fingers – could you check out this idea? Thank you.

Liar Liar May 5, 2016 at 1:22 pm

I am a liar.. NO really.. I lie a LOT.. Sometimes for no real reason; or sometimes I start a lie and catch myself at it halfway through the story.. WHere do I go for help? What do I do? It’s impossible to live and function like this!

lorna hobson August 1, 2015 at 6:08 am

ive been with my partner for 4 years and just found out he has been lying to me all these years he told me his wife died way cancer and he had four kids to the same woman ,in april is ex partner and daughter turned up at my door which she has two kids to him and his wife that was supposed to be dead stays in Edinburgh with her son which is his youngest,he also has another daughter to someone else.i have always known about his kids but its the thought of him lying to me about his wife been dead,i also new he had been lying to me but could not get anything out of him and I still think he his lying about something else when I try to talk to him he puts it all on me what can I do

Stacy W April 9, 2014 at 7:12 am

My ex-boyfriend Brett Gyllenskog is a pathological liar. I never knew what to believe. He verbally abused me, cheated on me and separated me from my family but his lying was the worst. I’m glad he’s gone.

LadyPsych September 30, 2012 at 1:30 am

Any views on the lying commonly associated with ADHD – a psychological reaction related to feeling inadequate and being unable to do things, or associated with this brain-based disorder?

Leetal September 24, 2012 at 3:31 pm

Would you conside a sociopath would use this condition to get what he wants?

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