PATIENTS convicted of violent offences were among the first to win appeals to be transferred out of the high-security state hospital, Carstairs, to lower security institutions.

Some 18 patients from the first 100 successful appeals, made between 2006 and 2008, had convictions for crimes involving violence – including three for murder, four for culpable homicide and 11 for attempted murder or serious assault.

The figures are reported in a new study examining the first 100 cases brought under the Mental Health (Care and Treatment) (Scotland) Act 2003.

The act is unique to Scotland and introduced a provision for patients at the state hospital to appeal against being treated in conditions of excessive security, in line with the European Convention on Human Rights.

It was introduced after doctors found some patients did not need to be held in restrictive conditions.

The paper, which has just been published in the Journal of Forensic Psychiatry and Psychology, found 44% of the first 100 cases were approved by the Mental Health Tribunal, 23% rejected and 23% withdrawn. The remaining 10% were either cancelled or adjourned.

The act contributed to the shake-up of forensic mental health services in Scotland and to the introduction of three medium-secure units.

If patients win their appeals they are transferred to medium-secure units where they are subject to less stringent rules and eventually allowed out on their own.

Professor Lindsay Thompson, medical director at Carstairs and co-author of the paper, said the developments had led to improvements in the system, with benefits for both patients and the public. She said: "We are truly now a high-security hospital and, along with the development of the three medium-secure units, I believe this is a major step forward for public safety.

"Before the act patients were with us and then went to a lower secure unit which was really just a locked ward in a local hospital. Now we have proper levels of security appropriate to patients' needs."