Mythomania or Pseudologia Fantastica: Lying as a Disease

Mythomania or pseudologia fantastica is the pathological tendency to lie. Do you want to know why it appears and how it's treated?
Mythomania or Pseudologia Fantastica: Lying as a Disease
Laura Ruiz Mitjana

Written and verified by la psicóloga Laura Ruiz Mitjana.

Last update: 08 May, 2023

Do you know someone who lies compulsively and many times without realizing it? Perhaps you suffer from mythomania, also called pseudologia fantastica, a disorder in which the person lies pathologically.

Pathological lying, according to Pérez and Ramírez (2013), is a picture characterized by the continuous fabrication of gross falsehoods, disproportionate in regard to any advantage that could be obtained.

The mythomaniac person includes false fantasies in their stories that can end up configuring a true, complex, and systematic deception. In other words, they disguise their life, and behind the lies are hidden pathological motivations and various psychopathological mechanisms on which today we will shed a little light.

Although we all lie to a greater or lesser extent (much more than people think!), in mythomania, the limits exceed this type of habitual behavior. What else do we know about the disorder? Are these individuals lying consciously or unconsciously? What groups tend to resort more to pathological lying? Discover it here!

The origin of mythomania

Before explaining what mythomania consists of, we’re going to delve a little into its origin and its conception as a clinical entity. It’s a very old term. According to a study by Rivera and Zamarro (1990), mythomania or pseudologia fantastica was described as a specific clinical entity, but now it is considered a syndrome or a symptom.

Regarding its origin, the concept of mythomania was described by Dupré in 1900; a definition that we find in his very old work Etude psychologique et medico-legale du mensonge et da la fabulation morbide (cited in Burgin et al, 1986). However, other authors attribute its origin to the Swiss doctor Anton Delbrück, who would describe it for the first time in 1891.

People with mythomania aren't always aware of their lies.
Regarding the awareness of pathological lying, it’s not clear if people do it on purpose or on impulse, without realizing it.

What is mythomania?

Mythomania or pseudologia fantastica can be defined as the pathological tendency to lie. Its main characteristic is the conscious and demonstrable invention of events that are difficult to verify, as well as disproportionate falsehoods.

With their lies, the mythomaniac doesn’t obtain an apparent gain (although there are more intrinsic and unconscious reasons or benefits to doing so); that is, an impulse to lie appears whose purpose is to build a false identity. Later, we’ll investigate a little more about its possible causes.

Mythomania, which can be considered a syndrome or a symptom, isn’t classified as a specific entity in the “Diagnostic and Statistical Manual of Mental Disorders” (DSM-5). That is, it is not independent; however, it is usually included as part of the symptoms of antisocial personality disorder.

Other features

According to Pérez and Ramírez (2013), the prevalence of mythomania in the general youth population is 1%. Its onset is usually in adolescence, but the lying behavior becomes chronic. Diagnosis can take years to arrive.

Who suffers from mythomania?

Mythomania often occurs in people with maladaptive personality traits or who have a personality disorder such as antisocial (or a mental disorder). Many of them don’t even know why they do it, that is, they don’t seek personal benefits and they do it unconsciously.

“People with antisocial personality disorder have an inability to experience the pain of others or the guilt over the harmful consequences of their actions.”

-Edorta Elizagárate-

On the other hand, people with narcissistic, borderline, or histrionic personality disorder are also another group in which mythomania is more likely to appear. However, a person can manifest mythomania without presenting another underlying mental or personality disorder that explains these behaviors.

The causes of mythomania

According to River and Zamarro (1990), the motivations of the person with mythomania must be sought in the individual biography of each one, although we can think of some common points, such as a lack of acceptance of their own personal reality and substitution for a fiction that makes it more acceptable to themself and others.

On the other hand, in an article by Pérez and Ferrero (2013), psychiatrists explain that 40% of the cases of mythomania have a previous alteration in the central nervous system (CNS), such as epilepsy, pathological findings in the electroencephalogram, traumatic history, or infection. In addition, it has been suggested that certain people have a predisposition to lie.

On the other hand, there are mythomaniacs who use more conscious strategies and who lie according to the circumstances in order to achieve an immediate benefit (or avoid being controlled). However, there are those who act impulsively and almost without being aware that they’re lying.

The vision of psychoanalysis

To talk about the possible causes of mythomania, Freud (1972) mentions the realization of certain desires through this syndrome or symptom. According to the author, when we find ourselves in a daytime fantasy, we find ourselves at a midpoint of balance in all senses.

On the one hand, we can express the realization of wishes more directly than in a dream, and, on the other, interpretation is less necessary in order to understand it.

A man taking off a mask.
The causes of mythomania are varied and it’s important to investigate the biographical personal history to find the origin.

Treatment of mythomania

People with mythomania or pseudologia fantastica rarely seek professional help. If they do, they allude to other causes that justify asking for help. For example, they can go for medical-legal reasons or for other types of consequences derived from their lies. In addition, it’s common for them to break the therapeutic bond at the slightest frustration.

There’s no specific treatment for this disorder. However, a cognitive behavioral approach could bring positive benefits for the patient. As a noteworthy fact, its worth mentioning that the underlying disease that explains the pseudologia fantastica, if it exists, is usually treated, making use of the most validated therapies in each case.

Finally, it will always be important to delve into the causes that explain the need that the patient manifests to resort to lying to decorate or disguise their reality (or identity). We’ll have to explore the areas of their life, what factors maintain the problem, and, above all, how it started and why.

In addition, it will be important to work with insight, so that they can become aware of their actions and what’s leading them to act in such a way. The motivation for change will also be essential.

“If you really have your own identity, you’ll continue to do what you think is really right for you, and you’ll also understand the next step you want to take.”

-Helmut Lang-



  • Burgin, C. & Feillaro, J. (1986). “Histoire sans nom”. A propos de la Mythomanie. Evol. Psychiat., janu-mars, 51(1): 187-204.
  • Casas Rivera, R. & Zamarro Arranz, L. (2011). La mitomanía en la clínica actual. A propósito de un caso. Revista AEN.
  • Freud, S. (1972). Obras completas. Ed. Biblioteca Nueva. Madrid, 1972. Tomo IV: La novela familiar del neurótico, págs. 1.361-1.363.
  • Freud, S. (1972). Obras completas. Ed. Biblioteca Nueva. Madrid, 1972. Tomo 11: La interpretación
    de los sueños. “la realización de deseos”: 680-693.
  • Rivera, R. y Zamarro, M. (1990). La mitomanía en la clínica actual. A propósito de un caso clínico. R.A.E.N., 10(34): 345-353.
  • Valdés, M. (2005). Los trastornos de la personalidad desde la perspectiva evolucionista. En Sanjuán, J. & Cela Conde, C.J. La profecía de Darwin: Del origen de la mente a la psicopatología. Madrid: Ars Médica.

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