Vulnerable Peter Barnes, 32, vanished after going for a cigarette and was found hanged a week later just 30 yards from his psychiatric hospital’s front door.
Peter had been allowed out unescorted for a 30-minute break despite previously talking about killing himself.
A senior clinician at the Bradford hospital had not been told by nurses about marks seen on his neck or how he had been heard talking about ending his life with shoelaces days before.
One nurse told police investigating his disappearance “I think he will be sat somewhere with a couple of cans of Stella”, the inquest heard.
Post-mortem examinations showed he was likely to have died just hours after he went missing.
An inquest heard he was let down by “gross failures and neglect” at Cygnet Hospital Wyke, on October 13, 2011, an inquest was told.
His mother, Karen Barnes, 54, said she couldn’t believes how close her son had been to the front door and still nobody had found him. Mrs Barnes, of Lincoln, said she hoped lessons learned from her son Peter’s death will stop other tragedies.
She said: “At long last Peter’s voice has been heard through his inquest. We have heard what he was feeling – making himself heard was something he had to fight for all through his illness.
“He was failed by Cygnet. We now hope what happened to Peter and the outcome of the inquest will be used as a precedent and lesson to be learned stopping any other families going through the agony we have suffered.
“It is just heartbreaking these people are in the profession of looking after vulnerable people and yet they haven’t got any compassion. There is nothing they can say to make me feel any better.
“A former member of staff came up to me and told me they had planted a tree in the grounds for Peter and one member of staff who died, and I just looked at her and thought that’s really apt, isn’t it. Have they got no sense?”
Mother-of-three Mrs Barnes said her son suffered from paranoid schizophrenia and was psychotic.
She explained he was diagnosed at 16 and has been in and out of hospitals since then.
She said he was put on an intensive care secure unit at Cygnet after he attacked a doctor and was there for just over three weeks before he hung himself.
After the jury returned its unanimous findings on Wednesday, Assistant Bradford Coroner Neil Cameron said he would write to the hospital about his concerns.
The jury in the inquest held in Bradford, decided Mr Barnes had taken his own life while the balance of his mind was disturbed.
They also stated in their findings that the hospital’s systems and methods of communication ensuring his clinician had all the information needed to decide whether or not to allow unescorted ground leave had been “inadequate” and had led to an error which gave him the opportunity to take his own life.
The response of the hospital and its staff to him going missing was also “untimely and inappropriate” they said in regard to the efforts they made to find him and the time and the nature of information passed on to police.
The jury foreman concluded: “His death was contributed to by neglect, namely by the aforementioned gross failures of hospital systems and the failure to communicate and identify significant events which led to him wrongly being granted unescorted ground leave.”
The inquest had heard Dr Keith Rix had allowed Peter unescorted leave because he hadn’t been warned that he had marks on his neck or had talked about killing himself.
Neither had those details been flagged up by nurses to the ward manager responsible for safety.
In a statement after the inquest a Cygnet spokesman expressed sympathy for Mr Barnes’ family and friends and added: “We have already made numerous changes to further improve our services. Communication inside Wyke has been totally overhauled.”