Psychologists use the term “pathological” to refer to thoughts, behaviors, or other phenomena that are “a departure from what is considered healthy or adaptive,” according to the American Psychological Association’s Dictionary of Psychology.

Right now, there is no broadly accepted definition of pathological lying, but experts are working on it.

In one study, Curtis and other researchers argued that pathological lying should be established as a diagnosable disorder. They also attempted to define it.

“The short definition is it’s excessive lying for six months or longer that’s causing marked distress for the individual and an impairment in functioning,” Curtis says.

In some of his work, he and colleagues have attempted to track people’s daily lies. He says that, according to this work, lying five times or more in a 24-hour period would qualify as “excessive.”

But even if someone is lying excessively, he says, it might not meet his group’s definition of pathological lying if the lies don't cause the person distress or negatively affect their life or daily activities.

“You can have excessive lying that’s not pathological,” he explains. “There are individuals who are lying a lot, but the lies are serving them some purpose.”

He points out that salespeople or politicians may lie, but these lies enhance — rather than impair — their functioning. In other words, their lies are being rewarded or reinforced.

Once again, there is no formal psychological definition of compulsive lying. But the APA’s dictionary defines a compulsion as a behavior or mental act a person feels “driven or compelled to perform” to reduce anxiety or distress (compulsive lying is typically different from the compulsions that are part of obsessive-compulsive behavior).

“With compulsive lying, like any compulsive disorder, there’s usually some kind of anxiety aroused, and the compulsive behavior reduces the anxiety, at least in the moment,” Curtis says.

Almost any social situation could arouse this compulsion to lie, he explains. He offers an example: “Someone asks about your favorite band, and you feel anxious about giving the right socially acceptable answer. You respond with some lie to resolve that anxiety, and in the moment there’s some relief, but then later on you feel remorse or regret about the lie.”

He says that compulsive lying is very often a feature of pathological lying. But not always.

Some people may lie compulsively to reduce anxiety, but not so much or so outlandishly that it causes them distress or interferes with their ability to function. That form of compulsive lying wouldn’t meet his group’s proposed definition of pathological lying.

On the other hand, someone may lie excessively — enough to cause them distress and mess with their life — but they’re not lying to reduce anxiety or discomfort. This pattern of lying could meet all the criteria for “pathological,” but it wouldn’t strictly qualify as “compulsive,” Curtis says.

Again, Curtis says that many people lie in order to reduce anxiety or awkwardness, especially in social situations.

“Impression management” — basically, trying to make people think more highly of you — is also a driver of dishonesty, he says.

Even people who don’t normally lie may be dishonest if they feel especially anxious, or they’re keen to make a positive impression, he says. First dates or job interviews are some common scenarios in which people who normally tell the truth may lie or exaggerate, he explains.

People also lie because of failures of executive functioning, he says. One article defined executive functions as a set of “future-oriented” brain operations that allow people to plan ahead and make choices that will benefit them down the road.

If a person’s executive functioning is not well-developed, or is somehow impaired, Curtis says lying may become more frequent. “With pathological lying, we see that planning or forethought is often lacking,” he says.

Interestingly, teens lie more than people of any other age group, Curtis notes. Research shows that executive functioning is still developing throughout adolescence and even into young adulthood.

Finally, he says that lying is also a feature of some formal psychological disorders. “With both psychopathy and antisocial personality disorder, you often see dishonesty without remorse,” he says. “The cold, Machiavellian, calculating liar — these people are out there.”

But these people would not be considered pathological liars because their lying causes them no distress.

Because pathological lying has not been formally recognized as a disorder, Curtis says it’s hard to say with confidence what works or doesn’t work. He does have some suggestions, though, based on his own work.

If you think you’re dealing with a pathological liar, rewarding honesty can be helpful, Curtis says.

“You want to reinforce honest behavior, and one way to do that is by praising it,” he explains. That could be as simple as saying, “Thanks for being honest with me,” he adds.

For people who are in a relationship with a compulsive or pathological liar, Curtis says couples therapy or family therapy can be helpful.

If you feel you may be a pathological or compulsive liar yourself, he recommends working with a therapist who specializes in habit reversal training. “This technique helps you gain awareness of when you lie — the situations when your propensity to lie is greatest — and it helps you identify competing behaviors to replace the lying,” Curtis explains.

Cognitive behavioral therapy (CBT) can also support this kind of recognition and behavioral adjustment, he says.

“The goal of treatment is not to eliminate the lying completely,” Curtis says. “The goal is to reduce that lying behavior to the point where you can function again.”