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ARTICLES
Pathological Lying: Theoretical and Empirical Support
for a Diagnostic Entity
Drew A. Curtis, Ph.D., and Christian L. Hart, Ph.D.
Objective: Pathological lying, originally called “pseudolo-
gia phantastica,” has an established history within clinical
practice and literature, although it has not been recog-
nized as a psychological disorder within major nosological
systems. With the movement in psychological sciences
toward theory‐driven, empirically supported diagnoses, the
current study sought to empirically test whether patho-
logical lying aligned with nosological definitions and could
be defined as a diagnostic entity.
Methods: A total of 807 people were recruited (January to
October of 2019) from various mental health forums, so-
cial media, and a university. Of those recruited, 623
completed the study. Participants responded to a lie fre-
quency prompt, questionnaires about lying behavior, the
Lying in Everyday Situations Scale, the Distress Question-
naire‐5, and demographic questions.
Results: Of the participants, 13% indicated that they self‐
identified or that others had identified them as pathological
liars (telling numerous lies each day for longer than 6
months). People who identified as pathological liars re-
ported 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.
Conclusions: The evidence supports establishment of
pathological lying as a distinct diagnostic entity. A defini-
tion of pathological lying, etiological considerations, and
recommendations for future research and practice are
presented.
Psych Res Clin Pract. 2020; 2:62–69; doi: 10.1176/appi.
prcp.20190046
The frequency with which people lie varies (1, 2). Consider-
able research has focused on the normative aspects of lying (1,
3–7). 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). 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). Although extensive research has
explored the normative aspects of lying among the general
population, and within psychotherapy (10–13), the patholog-
ical dimensions of deception have been neglected.
Pathological lying (PL) has been referenced in popular
culture, although some have suggested that psychiatrists and
psychologists know little about the phenomenon (14). PL,
originally termed “pseudologia phantastica,” was first recor-
ded 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). 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). 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.”
The DSM‐5defines a mental disorder as a syndrome that
causes significant distress and impairs functioning (16). 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). From these definitions, models of
HIGHLIGHTS
Pathological lying exists in a small percentage of people,
for whom it causes significant distress, impaired func-
tioning, and danger.
Pathological lying, distinct from normative lying and
prolific lying, has a prevalence of 8%–13%.
Evidence supports establishing pathological as a diag-
nostic entity.
62 prcp.psychiatryonline.org Psych Res Clin Pract. 2:2, 2020
abnormality have been suggested, such as the four Fs: frequency,
function, feeling pain, and fatal (18). 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). Therefore, to merge the key elements of the
previous definition with psychopathology criteria from classifi-
cation 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.
PL has not been classified within the DSM‐5or the
ICD‐10 (16, 17). 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 is one of 20 items used in the
Hare Psychopathy Checklist‐Revised (PCL) (19). However,
this item does not serve to provide a diagnosis but to assess
lying behavior related to psychopathy.
Research investigating PL is scant. One study of 1,000
young offenders found excessive lying among 15% of males
and 26% of females (15). 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 con-
trol participants and antisocial control participants (20).
Research on PL has mostly involved case studies. Delbrück
discussed five case studies, and Healy and Healy identified 12
case studies (15). Across the subsequent 100 years, other PL
case studies have been published (21–23). 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. Although evidenced in case
studies, the distinctiveness of PL has been debated (25–27),
with some arguing that PL is a unique disorder (14, 15).
The purpose of the current study was to explore a
theoretical model of PL as a distinct psychopathology that
meets major nosological definitions, namely a disorder
bearing the features of frequency, function, feeling pain,
and fatality. On the basis of this hypothesis, we made six
predictions: Our first prediction was about prevalence,
frequency of behavior, and duration of the condition. We
predicted that patients with PL would represent a smaller
percentage of the population reporting excessive lying,
would report PL as lasting for a longer time than would the
general population, and would report onset of the condi-
tion as occurring during adolescence. Our second predic-
tion was that patients with PL would report impaired
functioning in several areas. Our third prediction was that
patients with PL would report more distress from their
lying than would the general population. Our fourth pre-
diction was about fatality; we predicted that patients with
PL would be more likely to report that their lies put
themselves or others in danger. Our fifth prediction was
that patients with PL would indicate that their lying was
not entirely under their control and that it provided relief
from anxiety. Our sixth prediction was that patients with
PL would report telling lies for no specific reason and that
their lies would tend to grow from an initial lie more so
than those of people without PL.
METHODS
Participants
We recruited 807 people via Facebook, Reddit/samplesize,
Psych Forums, and a university in the southwestern
United States to participate in a study on lying behavior. A
total of 635 participants completed information beyond the
inclusion criteria. Three participants were removed
because of reporting an unlikely number of lies told, and
nine participants were excluded because they indicated
they had lied in response to some of the survey questions.
Thus, 623 participants were retained for the analyses.
Participants ranged in age from 18 to 60 years (mean
SD¼21.977.57) with more female (N¼374, 68%) partici-
pants than male. The majority of participants were Caucasian
and/or European American (N¼325, 59%), followed by
Hispanic and/or Latinx (N¼135, 25%); multiracial (N¼41,
8%); African American and/or Black (N¼20, 4%); Asian,
Asian American, and/or Pacific Islander (N¼19, 4%); and
Native American and/or Alaskan Native (N¼8, 2%). The
participants ranged in education, from having no high school
diploma (N¼6, 1%), a GED (N¼4, 1%), a high school diploma
(N¼210,38%), a college degree (N¼309, 56%), a master's
degree (N¼21, 4%), and a doctoral degree (N¼2, <1%). A
majority of participants indicated that their annual income
was under $25,000 (N¼456, 85%), with fewer reporting
annual incomes of $25,000 to $49,000 (N¼44, 8%), $50,000
to $75,000 (N¼18, 3%), and $75,000 or more (N¼22, 4%).
Although the complete sample of 623 participants drew from
a range of ages, ethnicity, education, and income, participants
were slightly younger, more Hispanic, more educated, and
had lower incomes than the general population.
Materials
Participants were asked about whether they considered
themselves to be pathological liars and whether others
considered them to be pathological liars. Additionally, par-
ticipants were given a lie frequency assessment (1, 2) (Figure 1)
and other questionnaires. The Survey of Pathological Lying
behaviors (SPL) is a nine‐item questionnaire about func-
tioning, feeling pain, and fatal risks of lying behavior that uses
a Likert‐type rating scale (1¼strongly disagree; 7¼strongly
agree) (see the online supplement accompanying this article).
Internal consistency for the SPL was acceptable (Cronbach's
α¼0.82). The Survey of Lying Behaviors is a seven‐item sur-
vey, reporting on the frequency, functioning, pain, and risks
the respondent perceives as related to lying behavior, and has
a Cronbach's αof 0.80. The Survey of Others' Pathological
Lying is an 11‐item questionnaire, reporting on the frequency,
CURTIS AND HART
Psych Res Clin Pract. 2:2, 2020 prcp.psychiatryonline.org 63
functioning, pain, and risks respondents perceive as related to
the lying behaviors of others (Cronbach's α¼0.83). The Lying
in Everyday Situations (LiES) Scale (28) is a 14‐item scale
designed to assess the propensity to lie. The LiES scale has
demonstrated high internal consistency, test‐retest reliability,
and concurrent validity and displayed high internal consis-
tency reliability in the current study (Cronbach's α¼0.88). The
Distress Questionnaire‐5 (DQ5) is a five‐item screen, with
suggested sensitivity and specificity cutoff points, used to
measure general psychological distress among individuals
with various psychological disorders (29) (Cronbach's
α¼0.83). A demographic questionnaire also was provided.
Procedure
The institutional review board of Angelo State University
approved the study. Following written consent, we pre-
sented the participants with a prompt and lie frequency
assessment (1) (Figure 1). We then asked three questions
which we used to identify assignment to the PL or non‐PL
condition. Participants in the PL condition completed the
SPL, LiES, DQ5, and the demographic questionnaire. Par-
ticipants in the non‐PL condition completed the Survey of
Lying Behaviors, LiES, DQ5, and the demographic ques-
tionnaire. Additionally, participants in the non‐PL condition
completed the Survey of Others' Pathological Lying if they
indicated that they knew someone whom they believed was
a pathological liar. All participants were debriefed after
participating in the study.
RESULTS
Identification of Pathological Lying
We assigned participants to the pathological lying condition
if they considered themselves pathological liars or if others
considered them pathological liars. Statistics for normally
distributed data are likely to be unreliable for handling lie
distributions, which have consistently been shown to be
positively skewed (1, 2). Thus, we conducted a negative
binomial regression to examine the fit of the frequency of
lies with self‐identified PL, because it is a robust method for
handling overdispersed count data (30). The likelihood ra-
tio chi‐square test indicated that the model was a significant
improvement in fit over a null model (p<0.001). Thus, the
self‐identification of a PL and non‐PL model was found to
be a better fit and was retained.
Of the 623 participants, 83 (13%) indicated that they or
others considered themselves pathological liars (35 indi-
cated only self, 27 indicated only others, 12 indicated both,
and nine affirmed self or others). A chi‐square analysis
revealed a statistically significant difference between people
in the PL and non‐PL conditions (χ
2
¼335.23, N¼623, df¼1,
p<0.001). Of the 589 participants who responded to the
question that asked about having been formally diagnosed
by a mental health professional with a psychological disor-
der, 49 (8%) indicated they were pathological liars. Thus,
our prediction was confirmed that PL would occur within a
relatively small percentage of the sample (8%–13%).
FIGURE 1. Screen shot of lie frequency assessment
a
a
Source: Serota et al. (1).
THEORETICAL AND EMPIRICAL SUPPORT FOR PATHOLOGICAL LYING AS A DIAGNOSTIC ENTITY
64 prcp.psychiatryonline.org Psych Res Clin Pract. 2:2, 2020
We conducted a chi‐square test of independence to
compare the frequency of formal psychiatric diagnoses
among the PL group and those in the non‐PL group and found
no significant association (χ
2
¼4.42, N¼553, df¼2, p¼0.11).
Thus, participants in the PL group were no more likely to
have a psychiatric diagnosis than those in the non‐PL group.
We conducted an independent samples t‐test to examine
whether there were differences in age between the PL group
and non‐PL group and found no statistically significant dif-
ferences (t¼–0.62, df¼519, p¼0.54). Chi‐square tests of in-
dependence found no significant association for sex
(χ
2
¼0.92, N¼551, df¼2, p¼0.63), education (χ
2
¼0.89,
N¼552, df¼5, p¼0.97), income (χ
2
¼2.77, N¼540, df¼3,
p¼0.43), or ethnicity (χ
2
¼12.05, N¼548, df¼6, p¼0.06). To
examine whether education (inclusion of a college sample)
resulted in the differences, we created an education variable
to differentiate between those with a college degree or higher
and those with a high school education or less. In addition,
we used a multivariate analysis of variance (MANOVA) to
compare education across lying frequency, distress, func-
tioning, and danger and found no statistical significance for
the PL group (F¼1.97, df¼7 and 58, p¼0.07) or the non‐PL
group (F¼0.49, df¼7 and 424, p¼0.84).
Frequency (Prediction 1)
To further test prediction 1, we used a chi‐square test to
examine duration of engagement in PL, which demonstrated
statistical significance (χ
2
¼59.18, N¼78, df¼24 p<0.001). A
majority of participants in the PL group reported engaging in
PL for 6 months or longer (N¼68, 87%), with more than half
(N¼42, 54%) indicating they had engaged in frequent lying
for more than 5 years (Table 1).
We conducted an independent samples t‐test to examine
the difference in the number of lies told by participants in the
PL group compared with the non‐PL group and found a
statistically significant difference (t¼7.52, df¼588, p<0.001).
As predicted, participants in the PL group indicated telling
more lies within a 24‐hour period (mean¼9.9911.17, me‐
dian¼7, mode¼1, N¼82, maximum¼66 lies, 95% confidence
interval [CI]¼7.5–12.44, skewness¼2.27 [SE¼0.27], and kur‐
tosis¼7.20, [SE¼0.53]) than participants in the non‐PL
group (mean¼3.096.86, median¼1, mode¼0, N¼499,
maximum¼80 lies, 95% CI¼2.49–3.70, skewness¼6.79
[SE¼0.11], kurtosis¼58.43 [SE¼0.22]). We conducted a one‐
sample t‐test on the PL condition, and a test value of five
revealed a statistically significant difference (t¼4.04, df¼81,
p<0.001). Confirming our hypothesis, a majority of partici-
pants in the PL group (N¼49, 60%) reported telling five or
more lies within the past 24 hours. Furthermore, the PL
group told more lies in person (mean¼6.357.75) than over
the phone or in writing (mean¼3.885.82, t¼2.85, df¼76,
p¼0.006). We conducted a MANOVA to determine to whom
the participants in the PL group reported telling lies and
found statistical significance (F¼13.71, df¼5 and 76, p<0.001).
Participants in the PL group reported lying more to friends
and social acquaintances than to other people (Table 2).
We used an independent samples t‐test to compare scores
on the LiES between the PL and non‐PL groups and found a
statistically significant difference (t¼7.09, df¼78, p<0.001).
Those in the PL group reported a greater propensity for
telling lies in their everyday lives (mean¼50.8018.00) than
those in the non‐PL group (mean¼34.8812.59).
A frequency analysis revealed that a majority of partici-
pants in the PL group indicated onset of PL during adoles-
cence (10‐20 years) (N¼48, 62%). A chi‐square analysis
showed a statistically significant difference between devel-
opmental periods (χ
2
¼35.62, N¼78, df¼2, p<0.001), with
most participants reporting that the earliest age they were
considered a pathological liar was in adolescence (N¼48).
Impaired Functioning (Prediction 2)
To assess impaired functioning, we conducted a MANOVA
with areas of functioning as the dependent variable and
the lying condition as the between groups variable. A
statistical significance was shown (F¼24.09, df¼4 and 549,
p<0.001). Univariate tests indicated statistical significance
between the PL and non‐PL groups' impairment in func-
tioning in occupation (F¼15.32, df¼1 and 552, p<0.001),
social relationships (F¼83.88, df¼1 and 552, p<0.001), fi-
nances (F¼27.42, df¼1 and 552, p<0.001), and legal con-
texts (F¼29.04, df¼1 and 552, p<0.001). Within the PL
group, a repeated measures MANOVA showed statistical
significance in areas of functioning (F¼16.16, df¼3 and 72,
p<0.001). Pairwise comparisons found the greatest
impairment in social relationships (p<0.001) (Table 3).
Feeling Pain (Prediction 3)
Participants in the PL group reported greater distress from
their lying (mean¼3.042.02) compared with those in the
non‐PL group (mean¼2.211.65, t¼3.44, df¼94, p¼0.00).
Participants in the PL group reported greater general
psychological distress (mean¼15.76 5.11) than the non‐PL
group (mean¼14.504.63, t¼2.15, df¼539, p¼0.03). By
using DQ5 suggested cutoff points for sensitivity (≥11) and
specificity (≥14), 9% (N¼59) and 8% (N¼50) of the overall
sample were identified as those in the PL group who
experience psychological distress, respectively.
Fatal Danger (Prediction 4)
We used an independent samples t‐test to compare the PL
and non‐PL groups on scores of whether their lying put them
or others in danger. A statistically significant difference was
TABLE 1. Duration of engagement in pathological lying
among participants considered pathological liars (N¼78)
a
Duration N %
3 months 10 13
6 months 8 10
1 year 4 5
1–5 years 14 18
>5 years 42 54
a
Data missing for five of the 83 participants considered pathological liars.
CURTIS AND HART
Psych Res Clin Pract. 2:2, 2020 prcp.psychiatryonline.org 65
found (t¼5.53, df¼82, p<0.001). Participants in the PL group
reported that their lying had placed themselves or others in
danger (mean¼2.762.16) more so than participants in the
non‐PL group (mean¼1.381.00).
Compulsivity (Prediction 5)
To assess compulsivity, we conducted a MANOVA on two
items (feeling out of control and for relief from anxiety)
and found statistical significance (F¼90.47, df¼2 and 563,
p<0.001). Participants in the PL group indicated that their
lying was out of their control more (mean¼3.292.25)
than did individuals in the non‐PL group (mean¼1.38
0.93, p<0.001). Additionally, the PL group felt less anxious
after lying (mean¼3.512.23) compared with the non‐PL
group (mean¼1.951.55, p<0.001).
Motivation and Growth of Lies (Prediction 6)
We conducted an independent samples t‐test to examine
whether the participants in the PL group were more likely
than those of the other group to report that they told lies
for no reason. A significant difference was found (t¼6.13,
df¼92, p<0.001). Participants in the PL group told lies for
no reason (mean¼3.732.30) more than participants in the
non‐PL group (mean¼2.091.64). Additionally, we used an
independent samples t‐test to examine group differences
in the belief that their lies grew. The results showed a
statistically significant difference (t¼6.46, df¼91,
p<0.001), with those in the PL group indicating their lies
grew from an initial lie (mean¼3.812.22) more so than
did those in the non‐PL group (mean¼2.151.15).
Pathological Liars Versus Prolific Liars
Prolific liars were identified from the non‐PL sample in a
manner similar to Serota and Levine's (2) by using an index of
dispersion (D) to decide whether the data fit a distribution.
We used a negative binomial regression because of over‐
dispersed data (30). To achieve a dispersion closest to 1, we
divided the sample into two groups: those who told zero to
two lies (mean¼0.660.77, D¼0.89) and those who told three
or more lies (prolific liars) (mean¼7.5110.09, p<0.001).
Thus, prolific liars were coded into a new condition variable.
An independent samples t‐test found no significant dif-
ference in number of lies told between the PL group and the
prolific lying group (p¼0.09). However, a significant dif-
ference was seen on the LiES (t¼6.12, df¼224, p<0.001).
Participants in the PL group reported greater propensity for
telling lies (mean¼50.8018.00) compared with partici-
pants in the prolific lying group (mean¼38.3212.03).
We used a MANOVA to analyze areas of functioning be-
tween participants assessed as pathological liars and those
assessed as prolific liars and found a statistical significance
(F¼8.86, df¼4 and 230, p<0.001). Univariate tests indicated
statistical significance for lower functioning among PL partici-
pants in occupation (F¼4.40, df¼1 and 233, p¼0.037), social
relationships (F¼28.44, df¼1 and 233, p<0.001), finances
(F¼7.43, df¼1 and 233, p¼0.007), and legal contexts (F¼12.51,
df¼1 and 233, p<0.001). An independent samples t‐test found a
significant difference between the PL group (mean¼3.04
2.02) and those classified as prolific liars (mean¼2.491.63)
with regard to lying causing distress (t¼2.08, df¼127, p¼0.039).
Lying was also reported to be more dangerous by the PL
group (mean¼2.762.16) than by the prolific liar group
(mean¼1.581.19, t¼4.49, df¼100, p<0.001).
Perceptions of Pathological Liars
Of the participants who did not indicate being a pathological liar,
162 indicated that they knew someone they considered a path-
ological liar. Participants estimated that these individuals had
told an average of approximately 10 lies within the last 24 hours,
with five lies as the most frequent response (mean¼9.9615.47
lies told, median¼5, mode¼5, N¼127, maximum¼130 lies, 95%
CI¼7.24–12.68, skewness¼5.53 [SE¼0.22], kurtosis¼37.13
[SE¼0.43]). A majority of participants reported either that
the person did not have a formal diagnosis (N¼67, 42%) or
that they did not know whether the person had a formal
diagnosis (N¼73,46%. Most of these participants reported
TABLE 2. Lies told by participants considered pathological
liars (N¼75), by relationship
a
Relationship M SD
Family member (face‐to‐face) 1.40 2.59
Family member (writing or
phone or internet)
1.11 2.48
Friends or other people you
know socially (face‐to‐face)
2.07 2.71
Friends or other people you
know socially (writing,
phone, or Internet)
1.53 2.32
People you work with or
know as business contacts
(face‐to‐face)
1.37 3.12
People you work with or
know as business contacts
(writing, phone, or Internet)
0.59 1.53
People you do not know but
might see occasionally
(face‐to‐face)
0.83 1.92
People you do not know but
might see occasionally
(writing, phone, or Internet)
0.28 0.91
Total strangers (face‐to‐face) 0.76 2.48
Total strangers (writing,
phone, or Internet)
0.37 1.08
a
Data missing for eight of the 83 participants considered pathological liars.
TABLE 3. Pairwise comparisons of impairment in areas of
functioning among participants considered pathological liars
(N¼75)
a
Function M SD p
Occupation 2.01 1.46
Social relationships
b
3.52 2.09 <0.001
Finances
c
2.32 1.83 0.02
Legal contexts 1.88 1.57
a
Data missing for five of the 83 participants considered pathological liars.
b
p<0.001 for all other areas of functioning.
c
p<0.05 compared with legal contexts.
THEORETICAL AND EMPIRICAL SUPPORT FOR PATHOLOGICAL LYING AS A DIAGNOSTIC ENTITY
66 prcp.psychiatryonline.org Psych Res Clin Pract. 2:2, 2020
that the earliest stage of development when the person was
perceived as a pathological liar was adolescence (N¼83, 52%) or
that they did not know (N¼42, 26%). A majority of these
participants also reported that the person they knew had been
telling numerous lies for >6 months (N¼121, 76%) or that they
did not know (N¼35, 22%). A MANOVA revealed a statistically
significant difference in areas of functioning (F¼590.35, df¼4
and 154, p<0.001). Participants indicated that the person's lying
had resulted in impaired functioning more in social
relationships (mean¼5.932.14) than in occupation
(mean¼3.932.14), finances (mean¼3.842.24), or legal con-
texts (mean¼3.272.15). An independent samples t‐test was
used to compare distress between the PL group (mean¼3.04
2.01) and participants in the non‐PL group who reported
knowing someone they considered a pathological liar
(mean¼4.242.00), finding a statistically significant difference
(t¼ 4.32, df¼223, p<0.001). An independent samples t‐test
also showed a statistically significant difference in danger be-
tween those in the PL group (mean¼2.762.16) and those the
participants' considered pathological liars (mean¼5.641.49,
t¼ 10.59, df¼115, p<0.001).
DISCUSSION
The historical discussion of PL has been robust. Documented
case studies have supplied ample evidence of patients with PL
behavior in clinical practice. Yet, nosological systems have not
classified PL as a distinct entity. Attending to the credence
of theory‐driven, empirical approaches to psychopathology
(31–33), the current study provides evidence for PL as a disorder
and aligns with the requirements set forth by the American
Psychiatric Association for the addition of a new diagnostic
category (34). By applying definitions and criteria from psy-
chopathology models, a distinguishable group of people emerges
who lie excessively for extended periods and experience
impaired functioning, significant distress, and increased danger.
Our findings showed that the participants classified as
pathological liars reported telling about 10 lies per day on
average, and most reported telling one lie per day. This average
is greater than the number of lies told by a normative sample,
in the current study, and in previous research (1–4, 7, 8).
Additionally, those in the PL group indicated a greater pro-
pensity to tell lies, and the excessive lying had persisted for
longer than 6 months, a duration similar to that of other DSM‐
5disorders (16). Estimates of PL in the current sample ranged
from 8%–13%. This range represented those who reported no
psychological disorder (8%), those who currently met the
DQ5 specificity criteria for distress (8%), and those who self‐
identified (13%) as pathological liars.
Our results indicate a distinction between prolific and
pathological liars, with the latter endorsing greater distress,
impaired functioning, risk of harm, and propensity to lie. The
area of greatest impairment in functioning for those in the PL
group was in social relationships. This finding was not sur-
prising, because deception often damages trust, especially
when used to conceal a transgression (35, 36). Our results
provide a strong argument that a definition of PL should
hinge not solely on the frequency of the lying behavior, but on
the indices of psychopathology.
Participants in the PL group reported experiencing
more distress from telling lies. Classic research indicates
that lying can reduce distress when behavior is discrepant
from beliefs, acting as a distress‐relieving mechanism (37,
38). However, lying can cause distress because it requires a
justification for its use (4, 39). For pathological liars, the
distress may result from telling lies for no apparent reason,
with lies growing from an initial lie, and from concern
about discovered deceptions and relational conflict. Addi-
tionally, the PL condition indicated greater psychological
distress, suggestive of a distinct mental disorder.
The fatal criterion was met because PL was more likely
to put oneself or others in danger. An example of lying that
may pose a threat to one's safety is if one conceals suicidal
ideation during psychotherapy (40).
In addition to the pathological distinctions, we found
that those in the PL group indicated that telling lies reduced
their anxiety and that their lying was out of their control.
Furthermore, PL behavior involves telling lies without a
specific reason, with lies growing from an initial lie. Thus,
PL contains elements of compulsiveness. The subsequent
growth of lies, however, tends to cause more distress.
Limitations
The current study had some limitations. Participants were
recruited from forums that may attract people interested in
psychological disorders, which may have increased the PL
sample, resulting in a slightly larger prevalence than what
may be expected in the general population. However, this
method of recruitment was necessary to reach the target
sample, because PL is not an official classification within the
DSM‐5. Although PL is not a formal diagnostic entity, it has
been widely discussed by mental health professionals and
people who maintain difficulty with lying behaviors. Addi-
tionally, our sample included an age range of 18‐60, with an
average age of about 22 and many having advanced educa-
tion. Although we found no statistical difference in a com-
parison of education levels, use of this sample may have
underestimated some of the negative life consequences of PL
compared with individuals who are older or less educated.
Another potential concern was the self‐report. We used this
method because PL has not been established as a diagnostic
entity. Additionally, self‐reporters are most likely to seek out
treatment. When asking people to report on their lying be-
haviors, there may be concern that the self‐reports are lies.
However, evidence suggests that self‐reports of lying
behavior are valid and reliable (1, 2, 41). Halevy and col-
leagues found that self‐reported frequency of lying behaviors
was not significantly correlated to variable response incon-
sistency or true response inconsistency scales of the multi-
dimensional personality questionnaire‐brief form, with no
significant differences found between subjects who
were categorized as valid and invalid respondents (41).
CURTIS AND HART
Psych Res Clin Pract. 2:2, 2020 prcp.psychiatryonline.org 67
Finally, although many of the participants indicated they had
never been formally diagnosed with a psychological disorder,
the current study did not specifically compare PL to various
other psychological disorders. Future studies may examine
assessment profiles of people with PL behavior to determine
convergent and discriminant validity related to other
psychopathologies.
Future Directions
If PL is recognized as a diagnostic entity, researchers would
be positioned to examine additional features, etiology, and
effective and efficacious treatments. Research may also
benefit from exploring clinicians' experiences in treating
individuals having PL. Future analyses at the biological level
may lead to a deeper understanding of PL. Recognizing PL
would equip practitioners to diagnose and treat the condi-
tion, thus allowing people to seek treatment. Because PL is
not a formally recognized disorder, no systematic studies on
the effectiveness of psychotherapy in treating PL have been
conducted (27). The utility of implementing cognitive‐
behavioral therapy and pharmacotherapeutic options for
treating PL is worth consideration (27).
In addition to supporting recognition of PL as a diagnostic
entity, the current research adds to deception literature by
establishing parameters that distinguish pathological lying
from normative lying. The current study showed that cate-
gorical distinctions can be made between normative, prolific,
and pathological lying. Thus, this study will assist re-
searchers investigating the range of lying patterns.
CONCLUSIONS
In sum, the current evidence and theory built on existing case
studies support establishment of PL as a diagnostic entity.
The findings support PL as meeting criteria for a mental
disorder, with evidence of a unique, valid, and reliable group
of symptoms. We have provided theoretical criteria, etio-
logical markers, and a definition of PL, which should guide
clinicians in identifying PL. There are individuals who
clearly recognize and report concerns about their own
excessive, persistent, and problematic lying behavior.
Currently, there is no diagnostic label for these individuals
and no specific treatment. Features of PL are distinct and
found beyond the forensic population. Definition of a diag-
nosis of PL would pose low risk of harm and would allow
practitioners to formally identify PL and to provide treat-
ment for people looking for relief from its symptoms.
AUTHOR AND ARTICLE INFORMATION
Department of Psychology and Sociology, Angelo State University, San
Angelo, Texas (Curtis); Department of Psychology and Philosophy,
Texas Woman’s University, Denton (Hart).
Send correspondence Dr. Curtis (drew.curtis@angelo.edu).
The authors report no financial relationships with commercial interests.
This is an open access article under the terms of the Creative Commons
Attribution License, which permits use, distribution and reproduction in
any medium, provided the original work is properly cited.
© 2020 The Authors. Psychiatric Research and Clinical Practice pub-
lished by Wiley Periodicals LLC. on behalf of the American Psychiatric
Association.
Received December 29, 2019; revisions received March 9 and April 18,
2020; accepted May 12, 2020; published online June 22, 2020.
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