Mythomania is a mental disorder characterized by persistent, compulsive lying that goes far beyond ordinary dishonesty. Also called pathological lying or pseudologia fantastica, it involves the creation of elaborate, exaggerated stories that the person often genuinely believes to be true. Estimates place the prevalence of pathological lying at 8% to 13% of the population, making it more common than many people assume.
How Mythomania Differs From Ordinary Lying
Everyone lies sometimes. A normal lie has three components: you know it’s false, you’re doing it on purpose, and you have a specific reason. You call in sick to skip a meeting. You tell someone their haircut looks great. The lie serves a clear goal.
Mythomania works differently. The fabrications are disproportionate to any obvious benefit, often appearing completely purposeless to outside observers. Even when there is some external motive, the lies are so wildly out of scale with the perceived payoff that most people would consider them senseless. People with mythomania construct detailed, believable stories woven into a framework of real events, spanning personal history, career achievements, and relationships. These stories persist over months or years, growing more elaborate over time.
The most striking feature is that people with mythomania frequently believe their own fabrications. Rather than deliberately calculating a deception, they sincerely perceive their stories as genuine truths. This is a key distinction from delusions, though: when confronted with clear factual evidence, a person with mythomania can usually acknowledge that what they said isn’t true. Someone experiencing a fixed delusion cannot.
What Drives the Behavior
Ordinary lies aim for external rewards: money, status, avoiding consequences. In mythomania, the reward is internal and often unconscious. The lying itself appears to be its own gratification. Research shows that people with pathological lying report that the act of telling lies reduces their anxiety, and that they feel their lying is out of their control. Their lies also tend to snowball, with each fabrication growing from an initial one into something larger and more complex.
This compulsive quality is central to the condition. People with mythomania score significantly higher than non-pathological liars on measures of lying “for no specific reason” and on the tendency for lies to expand beyond the original story. The behavior contains clear elements of compulsiveness: it’s repetitive, feels difficult to stop, and provides temporary emotional relief.
Brain Differences in Pathological Liars
Brain imaging studies have found structural differences in people who lie pathologically. One study published in the British Journal of Psychiatry compared brain scans of pathological liars, people with antisocial behavior who were not pathological liars, and typical controls. The pathological liars had 23% to 36% more connective tissue (white matter) in specific areas of the prefrontal cortex, the brain region involved in planning, impulse control, and decision-making.
The increases were concentrated in the lower and middle portions of the frontal brain, with the largest difference (32% to 36%) in the lower frontal region. Notably, there was no difference in gray matter volume, the tissue responsible for processing information. This suggests that the brains of pathological liars may be wired with more connections between different areas, potentially making it easier to link unrelated ideas into convincing, complex narratives. The extra wiring in decision-making areas could also help explain why the fabrications feel so natural and fluid to the person telling them.
Conditions That Often Overlap
Mythomania is not currently a standalone diagnosis in the DSM-5, the main diagnostic manual used in psychiatry. Instead, deceptive behavior appears as a feature of several recognized conditions. Antisocial personality disorder includes persistent lying, though those lies are typically calculated for external gain and accompanied by a history of behavioral problems starting in childhood. Factitious disorder involves deception specifically aimed at assuming a sick role. Malingering involves lying driven entirely by obvious external incentives like financial compensation.
Mythomania frequently co-occurs with personality disorders, particularly narcissistic, borderline, and histrionic types. It can also appear alongside anxiety and mood disorders. The relationship runs in both directions: underlying conditions may fuel the lying behavior, and the consequences of chronic fabrication can worsen anxiety and depression.
How It Affects Daily Life
The consequences of mythomania accumulate over time and tend to be severe. Because lies grow from initial fabrications into increasingly elaborate stories, maintaining them becomes an all-consuming effort. Relationships erode as partners, friends, and family members discover inconsistencies. Professional credibility collapses when coworkers or employers catch contradictions.
People with mythomania often experience significant distress, not from guilt in the traditional sense, but from the anxiety of managing a web of fabrications and the fallout when deceptions are uncovered. Relational conflict is one of the most commonly reported sources of suffering. The compulsive nature of the behavior means that even after painful consequences, the person may find themselves unable to stop, which creates a cycle of lying, discovery, conflict, and further anxiety that drives more lying.
Treatment Options
Because mythomania lacks a formal standalone diagnosis, there is no standardized treatment protocol. Therapy typically focuses on the underlying conditions that accompany it, such as personality disorders, anxiety, or trauma. Cognitive behavioral therapy can help a person identify the triggers and thought patterns that precede lying episodes, develop alternative coping strategies, and gradually build tolerance for the anxiety that arises when they resist the urge to fabricate.
One of the biggest barriers to treatment is that many people with mythomania don’t seek help on their own. The nature of the condition, where the person often believes their own stories, means they may not recognize the behavior as a problem until relationships or careers have already been damaged. When they do engage in therapy, progress depends heavily on building enough self-awareness to catch the impulse to fabricate before the story takes shape. This is a slow process, often spanning years, but people who stay engaged in treatment can develop significantly more control over the behavior.