Munir Majothi, 26, a caterer, of Strensall, York, stopped breathing and fell unconscious in a special seclusion unit at Clifton Hospital, despite attempts to resuscitate him.
The inquest, in York, was told that his death followed a series of sedative drug injections in 'unusual quantities' over a short space of time.
The verdict was praised by Mr Majothi's family. Their solicitor, Michael Benzimra, said that they intended taking civil proceedings against York Health Authority.
The hearing was told that the drug Droperidol was administered to Mr Majothi first at Bootham Park Hospital, and later in repeated doses at Clifton. He was given 230mg of the drug in the 15 hours leading up to his death, in June last year, and a further 100mg 40 minutes before he died.
The inquest was told that the recommended 15-hour dosage of the drug was 40mg - 10mg every four to six hours. The dosages have since been revised.
Mr Majothi was admitted to hospital after his family became fearful that he would suffer a repeat nervous breakdown. At Clifton he became violent but repeated intra-muscular doses of Droperidol failed to calm him.
He was eventually given an intravenous dose of the drug. He calmed down but within 15 minutes had stopped breathing.
The inquest was also told that Mr Majothi had a heart problem, which contributed to his death. A post- mortem examination found that he had died from Droperidol intoxication and coronary artery atheroma (furring of the arteries); one artery was 70 per cent blocked.
The mental health charity, Mind, called for an immediate ban on the use of psychiatric medication above recommended levels, and for improved training for psychiatrists in safe prescribing practice.
Liz Sayce, the charity's policy director, said: 'This is a tragic case which demonstrates the need for this practice to stop.'Reuse content