JOY Ford's son started smoking cannabis at the age of 14 - six years later he jumped to his death.

Mrs Ford, who lives in Blewbury, believes those two events were directly connected.

Her new book, One in Four, tells Edward's story, his descent into schizophrenia and the family's struggle to get help.

Edward Best spent Easter 2002 with his family in Blewbury.

Encouraged by voices in his head, he tried to cut his own throat.

He was transferred to the Fairmile mental health hospital, near Cholsey, but went missing.

Hours later, he jumped from a multi-storey car park at Reading railway station and died from his injuries the next day.

Four years on, Mrs Ford began writing her book, both as a tribute to her son and a warning to other families.

She first discovered her son was using cannabis when he was 17 and, despite her objections, he continued.

She said: "In December 2000, he had a complete breakdown. He thought when he was in hospital he was in prison. He thought doctors were poisoning him and there was a Government plot to brainwash him.

"At one point he thought he was the Messiah."

Edward spent four months in hospital, but after his release he relapsed and was diagnosed with paranoia schizophrenia.

"When the doctors found out he started smoking cannabis at 14 they were quite certain that was what had triggered it," Mrs Ford said.

"But Edward saw it as self-medication because it calmed him down. I really feel that cannabis started all this."

One in Four - the title reflects the number of people with a mental illness who commit suicide - will go on sale on April 5 and will be available to purchase at and in bookshops.

Proceeds from the book will be donated to the mental health charity the Chipmunka Foundation