Compulsive lying disorder, also known as pseudologia fantastica or mythomania, is a condition that describes the behavior of a habitual liar.

​While compulsive lying disorder is actually not included in the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV), except as a symptom of factitious disorder, many psychiatrists and psychologists consider it a distinct mental disorder.

In the past two decades countless hours of research and multiple papers have been written regarding this issue, though it remains one of the most under researched psychiatric conditions. Individuals with the disorder simply cannot stop themselves from misrepresenting the truth.

People with the disorder are not able to control their lies and experience no guilt regardless of how the lies may affect themselves and others. The lack of guilt is frequently the result of the fact that the individual becomes so caught up in the lie that they are telling, they begin to believe it themselves. If confronted with a lie they have told in the past or one that they are presently telling, they will be insistent that they are speaking the truth.

Over time, the individual will become so adept at lying that it will be very difficult for others to determine if they are, in fact, telling the truth. There are no exact figures regarding the number of people that suffer from this disorder, but has been found to be equally common in men and women and usually becomes very apparent in the late teens.

The defining characteristics of compulsive lying disorder are:

The stories told are not entirely improbable and often have some element of truth. They are not a manifestation of delusion or some broader type of psychosis: upon confrontation, the teller can admit them to be untrue, even if unwillingly.

The fabricative tendency is long lasting; it is not provoked by the immediate situation or social pressure as much as it is an innate trait of the personality.

A definitely internal, not an external, motive for the behavior can be discerned clinically: e.g., long-lasting extortion or habitual spousal battery might cause a person to lie repeatedly, without the lying being a pathological symptom.

The stories told tend toward presenting the liar favorably. For example, the person might be presented as being fantastically brave, knowing or being related to many famous people.

Dike, Charles C. (June 1, 2008). Pathological Lying: Symptom or Disease? 25 (7).

​Currently, there are several theories as to what causes an individual to develop compulsive lying disorder. There has been research completed that indicates it is the result of neurological imbalance, particularly in the frontal lobe. A study published in the British Journal of Psychiatry reported that pathological liars have an increase in the amount of white matter in the brain predisposing them to the condition. The Journal of Neuropsychiatry and Clinical Neurosciences reported that brain scans had found that those with this disorder suffered from right hemithalamic dysfunction. There are also various psychiatric theories regarding the cause.

Many psychiatrists and psychologists believe that individuals with low self-esteem who are looking, whether knowingly or unknowingly, for attention, popularity, love, or to cover up a failure are prone to developing the disorder. Finally, there is speculation that it is a reaction to childhood trauma or neglect or failure of the parents to establish realistic limits and provide guidance. It is important to note that many experts believe that habitual lying is a symptom of a larger personality disorder including borderline personality disorder and antisocial personality disorder.

As a result of not being included in the DSM-IV, there is no actual diagnostic criteria for a compulsive liar. However, many psychiatrists and psychologists will diagnosis based on behavioral patterns as reported by loved ones and through observation of the individual. There is no magic cure for this disorder. Therapy can be beneficial to the sufferer if they will admit that there is an actual problem. If the person does not recognize that they suffer from this condition, therapy will be of no consequence.

There are treatment options for this disorder, but they can only be effective if the compulsive liar agrees to treatment. In most cases, friends and family will have to learn to adapt to the situation in order to maintain a relationship. As you are probably aware, compulsive lying disorder can have a tremendous effect on the sufferer as well as those that care about them.

If therapy is initiated it will likely be geared towards the addictive aspect of the disorder as well as helping the person understand their behavior and how it impacts others. Later, there will be measures taken to help the individual change their way of thinking. Some psychiatrists may prescribe antidepressants to treat underlying issues with depression and self-esteem. Also, the prescription of anti-anxiety medications may be used to decrease the feelings of anxiety that may unconsciously prompt the individual to lie.

Again, it must be noted that therapy will only help the individual if they admit they do have a problem.​ Maintaining a relationship of any kind with a person suffering from compulsive lying syndrome can be complicated. In fact, relationships are almost certain to end without the involvement of a trained third party, such as a therapist.

Loved ones can benefit from attending therapy and counseling with the sufferer and individually. This allows them to gain insight into the disorder, express their feelings openly, and bring up important issues such as trust without the sufferer feeling as if they are being attacked. There is no guarantee that a relationship will survive, but the chances are increased with the amount of energy that is out into treatment. ​

Compulsive lying disorder is a complicated condition that requires a great deal of effort and determination on the sufferer to change their behaviors. Ultimately, it is entirely up to the person with the disorder as to whether or not they are able to regain their ability to tell the truth consistently.