A comprehensive analysis of 72 case studies ( 24) showed that PL was equally represented among men and women of average to above average intelligence, typically beginning in adolescence, with some people committing crimes. Across the subsequent 100 years, other PL case studies have been published ( 21, 22, 23). Delbrück discussed five case studies, and Healy and Healy identified 12 case studies ( 15). Research on PL has mostly involved case studies. A recent imaging study found that 12 participants who endorsed the PL item from the PCL showed an increase in prefrontal white matter and reduction in gray matter and white matter ratios compared with normal control participants and antisocial control participants ( 20). One study of 1,000 young offenders found excessive lying among 15% of males and 26% of females ( 15). However, this item does not serve to provide a diagnosis but to assess lying behavior related to psychopathy. PL is one of 20 items used in the Hare Psychopathy Checklist‐Revised (PCL) ( 19). The DSM‐5 mentions that deception is a symptom of antisocial personality disorder and is used for external incentive (malingering) and to assume a sick role (factitious disorder) ( 16). PL has not been classified within the DSM‐5 or the ICD‐10 ( 16, 17). Therefore, to merge the key elements of the previous definition with psychopathology criteria from classification systems, we suggest that PL should be defined as a persistent, pervasive, and often compulsive pattern of excessive lying behavior that leads to clinically significant impairment of functioning in social, occupational, or other areas causes marked distress poses a risk to the self or others and occurs for longer than 6 months. In comparison with contemporary models of psychopathology, the definition of PL put forth more than a century ago does not fully capture aspects of pathology ( 15). From these definitions, models of abnormality have been suggested, such as the four Fs: frequency, function, feeling pain, and fatal ( 18). Similarly, the ICD‐10 defines a disorder as a 'set of symptoms or behaviour associated in most cases with distress and with interference with personal functions' ( 17). The DSM‐5 defines a mental disorder as a syndrome that causes significant distress and impairs functioning ( 16). They defined PL as “falsification entirely disproportionate to any discernible end in view, may be extensive and very complicated, manifesting over a period of years or even a lifetime, in the absence of definite insanity, feeblemindedness or epilepsy.” Today, there is little consensus for a definition of PL, but many continue to use a definition proposed by Healy and Healy more than a century ago ( 15). PL, originally termed “pseudologia phantastica,” was first recorded in 1891 by psychiatrist Anton Delbrück in discussions of several cases of people who told so many outrageous lies that the behavior was considered pathological ( 15). Pathological lying (PL) has been referenced in popular culture, although some have suggested that psychiatrists and psychologists know little about the phenomenon ( 14). Although extensive research has explored the normative aspects of lying among the general population, and within psychotherapy ( 10, 11, 12, 13), the pathological dimensions of deception have been neglected.

Two recent studies, however, discovered that a majority of people reported telling no lies within the past 24 hours, whereas a small subset reported telling numerous lies ( 1, 2). Deception has been defined by Vrij ( 3) as “a successful or unsuccessful deliberate attempt, without forewarning, to create in another a belief which the communicator considers to be untrue.” Some studies report that people tell an average of two lies per day ( 4, 8, 9). Considerable research has focused on the normative aspects of lying ( 1, 3, 4, 5, 6, 7). The frequency with which people lie varies ( 1, 2). Pathological lying, distinct from normative lying and prolific lying, has a prevalence of 8%–13%.Įvidence supports establishing pathological as a diagnostic entity. Pathological lying exists in a small percentage of people, for whom it causes significant distress, impaired functioning, and danger.

Compulsive liar test