A paranoid schizophrenic may have died because his prescribed medication intensified the effects of heroin, an inquest heard.

Simon Green, 35, who had a history of alcohol abuse and mental health problems, was found dead in his room at The Knowl, a psychiatric care home, in Stert Street, Abingdon, on February 8.

Tests found relatively low levels of heroin in his blood. Dr David Davies, a consultant pathologist at the John Radcliffe Hospital, Oxford, said the combined effect of heroin and prescribed anti-depressant and anti-psychotic drugs could have caused Mr Green's death, rather than one individual substance.

The last person to see him alive was Jaqueline Mayo, of The Knowl, who saw him the night before his body was found.

She told the Oxford hearing Mr Green had told her he was going to visit friends in Bicester the morning before he died. When she saw him again that evening, she noticed his eyes looked different.

She said: "He said he had a confession to make. When I asked him, he just pointed to his arm, so I presumed he had injected himself with something."

Ms Mayo said Mr Green said he had taken drugs in the past but she had only ever known him use cannabis occasionally.

Simon Newton, project manager at The Knowl, said staff gave Mr Green his prescribed medication and kept a check on signs of illicit drug abuse because of his history.

He said Mr Green was making good progress. Alcohol abuse had been identified as a risk but he had made efforts to stop drinking.

Coroner Nicholas Gardiner recorded a verdict of accidental death.