Mr Olley, 26, leapt from the 10th floor of Lister Hospital, Stevenage, Hertfordshire, in April. In an earlier fall, from the sixth floor of a car park, he suffered severe facial wounds. A few minutes before his death Mrs Olley heard his social worker ask a nurse at the Lister, where he was an in-patient, to keep a close eye on him. He had become furious during a meeting with his parents because they had failed to bring his guitar. The Lister has been under scrutiny recently because seven in- patients killed themselves in a six-month period up to last summer.
Mrs Olley accepts there was a high risk her son would commit suicide. One of the most stable periods in his four years of illness was when he was transferred to a secure unit at Fairfields Hospital, near Letchworth, Bedfordshire. He could only leave the ward if accompanied by a staffer.
During his final stay at the Lister he would leave unaccompanied to visit a friend in town. Mrs Olley said: ''We can't go back to Victorian asylums. But there are people who need to be in an institution-type atmosphere for some periods.''
A review was carried out into seven suicides at the Lister. It found problems with supervision and staff shortages and it recommended improvements. But North Herts NHS Trust, which runs the Lister, defended its supervision of patients.
Chief executive Heather Lawrence has said: "Each patient is being assessed. Either they are being observed the whole time, which can be distressing for them, so we try to avoid it, or they are monitored every 15 minutes or, if they are near discharge, they have a lot more freedom."