Billy Liar is a tall tale teller who lives in the world of Ambrosia.

He is in a relationship with two girls. He is desperate to get out of the dead-end town of Stradhoughton where he lives with his working-class family and where he has a luxury calendar under his bed that he should have uploaded nine months ago.

He kept the postage money and lied about it. He would like to become a comedy writer in the capital. One of his girlfriends asked if he was actually going to London.

Billy Liar is a book that records a day in the life of a hero. Pretending was seen as a game of genteel amateurism back then.

In a new book, two American psychologists propose that pathological lying should be included in the Diagnostic and Statistical Manual of Mental Disorders. What is going to happen with that?

Britain of the 50s was fueled by fabrication. Politicians who "misspeak", spin doctors who massage the facts, and professionals who "editing" their CVs are some of the examples. It is so easy to be found out that you couldn't or shouldn't make it up in social media.

We don't know where to draw the line. When does a "little white lie" become a disease? Would we be lying if we said it wasn't worth it?

Christopher Massimine, a former theatre director in Salt Lake City, is on a regimen of cognitive behavior therapy to stop lying. Billy Liar was featured in the New York Times and Massimine's story is always funny. Massimine has brought him prestige, power and dollars because of the darkness that surrounds him. Is he smart or sick.

Massimine said he was born in Italy. His birthday is in September. He told his wife that he was having an affair with KimKardashian and that he had invented awards to add to his resume. He caught a minnow and then it became a swordfish.

All of her husband's Facebook posts and email accounts were reviewed, as well as dummy email accounts, elaborately forged correspondences, and mocked up photos. She is reported to be wondering who this person is. "Who did I get married to?" The husband has been diagnosed with a personality disorder. Dr Jordan W Merrill, a psychiatrist who treated Massimine last year, said his former patient was abenign liar. It is not trying to take anything from you.

Massimine resigned from the job he was hired to do and negotiated a $175,000 settlement with his previous employer.

There was this wonderful character of me, and he did things nobody else could do. In some ways, I’m sad to see him go

Massimine is allergic to the truth. Research done in 2010 was used to calculate how many Americans lie. It showed that most people said they didn't tell any lies the day before. In the previous 24 hours, people told an average of 1.65 lies. They lied an average of 15 times a day. Two doctors put together a psychological profile that they want included in the DSM MM.

According to the psychologists, these liars are needy, eager for social approval, and don't have a criminal history. Many were plagued by guilt and remorse and deserved better research, treatment and a chance to tackle their "toxic" compulsion

Now her husband's addiction to fiction is recognised as an illness, she is less angry. Massimine seems to be wavering in his recovery now that his days are done. He says that there was a wonderful character of him. I'm sad to see him leave.

In an age of rampant mendacity, narcissism and a chronic lack of self-awareness, pathological liars are a tiny minority. Who are we supposed to believe?

Yvonne Roberts writes and broadcasts.