His books have helped thousands of people cope with life, but until now Patrick Whiteside has avoided the limelight.

Now the author of The Little Book of Happiness and The Little Book of Bliss has revealed his true identity.

His real name is Larry Culliford and he is consultant rehabilitation psychologist at the Buckingham Road Community Mental Health Centre in Brighton.

Dr Culliford came up with the pseudonym by combining his birthday, St Patrick's Day, with the name of prize-winning Australian author Patrick White.

The Little Book of Happiness has sold more than 100,000 copies since it was published in 1998 and The Little Book of Bliss was an instant hit when it came out two years later.

Dr Culliford's latest book, a full-length work called Happiness - The 30 Day Guide, reached the shops in March.

After training as a doctor at Cambridge University and Guy's Hospital, Dr Culliford specialised in psychiatry at St George's Hospital in London.

He has also practised in Australia and New Zealand.

The format of the books was inspired by the runaway success of Paul Wilson's The Little Book of Calm.

The Little Book of Happiness drew on Dr Culliford's ideas about emotions and mental health, built up over many years.

He said: "The thoughts had been going around my head for a long time about how people could make themselves more relaxed and be in a happier state of mind, so the book more or less wrote itself.

"I finished the book in about three hours over one long weekend. I write for about an hour a day, producing about 4,500 words."

Dr Culliford has no literary background but finds writing fulfilling and relaxing.

He said: "I believe there's an enormous hunger for wisdom and spiritual guidance in contrast to the loud and inescapable messages confronting us day after day through TV, advertising and the media."

Dr Culliford says he is able to keep the two distinct strands of his life separate.

He said: "The book writing is more of a hobby. I sit down and become in my own mind Patrick Whiteside before starting to write. It makes things easier."