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10 Facts About Pathological Lying

A big problem for a small minority, and their friends and families.

Key points

  • Pathological lying lacks a consensus definition and appears to be compulsive and without reason.
  • Pathological lying can result in greater distress, impaired functioning, and more dangerous situations for those who do it.
  • Even those who lie frequently (i.e., prolific liars) may not be pathological liars.
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Even though the term pathological liar gets bandied about in everyday conversation, the actual phenomenon affects only a minority of people. Pathological lying has been noted as a psychological disorder since 1891, when it was called pseudologia phantastica by psychiatrist Anton Delbrück. He coined the term concerning cases of those who uttered so many outrageous lies that the behavior was deemed pathological.

Although the term lacks a consensus definition, more than a century ago, Healy and Healy characterized it as “falsification entirely disproportionate to any discernible end in view, may be extensive and very complicated, manifesting over the years or even a lifetime, in the absence of definite insanity, feeblemindedness or epilepsy.” This definition still applies.

Let’s take a look at ten facts about pathological lying.

  1. Various articles were written about pathological lying in the first half of the 20th century. Nevertheless, interest in the subject waned, and modern research is scant.
  2. Pathological lying lacks classification per the DSM‐5 or the ICD‐10. The DSM‐5, however, notes that deception is a symptom of antisocial personality disorder and is used as a means of external incentive (i.e., malingering) and when undertaking a sick role (i.e., factitious disorder). Lying also appears in the DSM-V as a symptom or diagnostic criteria in narcissistic personality disorder, borderline personality disorder, conduct disorder, gambling disorder, and oppositional disorder.
  3. Pathological lying is one of 20 items utilized in the Hare Psychopathy Checklist‐Revised (PCL). However, the item on this test does not indicate a diagnosis but rather assesses lying behavior related to psychopathy.
  4. There exists emerging support for the establishment of pathological lying as a diagnosis. For instance, in a 2020 study published in Psychiatric Research and Clinical Practice, Drew A. Curtis and Christian L. Hart found that when investigating lying behaviors in 807 participants, 13% indicated that they self-identified as pathological liars or that others had identified them as such. Pathological lying was defined as telling various lies each day for longer than six months.
  5. According to the authors of the aforementioned study, “People who identified as pathological liars reported greater distress, impaired functioning, and more danger than people not considered pathological liars. Pathological lying seemed to be compulsive, with lies growing from an initial lie, and done for no apparent reason.”
  6. Various hypotheses have been suggested to explain pathological lying. For instance, lie-telling becomes so habituated it turns into a natural response, and the liar no longer distinguishes on a conscious level between what is true and what is false. Other contributing factors may include cognitive/social immaturity, maladaptive problem-solving strategies, and a strategy to perpetuate antisocial behavior.
  7. Many people who lie are not pathological liars per se. Some research has demonstrated that people lie on average twice a day. Other research shows that most people report telling no lies within the past 24 hours, while a small number have told many lies. Ultimately, pathological lying is distinguished from normative or, even, prolific lying.
  8. In a study published in the British Journal of Psychiatry, Yaling Yang and co-authors investigated white matter volumes at the level of four prefrontal subregions via structural MRI in ten pathological liars, 14 antisocial controls, and 20 normal controls. They found that liars demonstrated a relatively widespread increase in white matter (23-36 percent) at the level of orbitofrontal, middle and inferior, but not superior, frontal gyri versus antisocial and normal controls. Higher levels of white matter may predispose some individuals to pathological lying, per the authors.
  9. Pathological lying has been compared with the “pseudolying” or the fantasy of children. Such lies in children, however, are essential in self-development and self-protection. When such lying extends into adulthood, however, things can become pathological.
  10. No drug is available for the treatment of pathological lying. Although psychotherapy may help, the patient may start telling lies to the therapist, thus undermining this treatment option. Ultimately, although they recognize pathological lying as an issue of concern, mental-health professionals still lack a clear understanding of this pathology. Much more research needs to be done.

Bottom line

Pathological lying is a clear problem for some people and seriously erodes the quality of life and social interactions. Nevertheless, not all people who lie are pathological liars, so it’s best not to label or be dismissive/flippant with the term.

Facebook image: Dmytro Zinkevych/Shutterstock


Curtis DA, Hart CL. Pathological lying: Theoretical and empirical support for a diagnostic entity. Psychiatric Research and Clinical Practice. 2020;2(2):62-69. doi:10.1176/appi.prcp.20190046.

Talwar V, Crossman A. From little white lies to filthy liars. Advances in Child Development and Behavior. 2011:139-179. doi:10.1016/b978-0-12-386491-8.00004-9.

Yang Y, Raine A, Narr KL, et al. Localisation of increased prefrontal white matter in pathological liars. British Journal of Psychiatry. 2007;190(2):174-175. doi:10.1192/bjp.bp.106.025056.

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