Scots are almost twice as likely to commit suicide or kill others than people anywhere else in Britain because of alcohol or drug abuse, said a new study as quoted by media reports Monday.

The study, commissioned by the Scottish government and carried out by the University of Manchester, looked at all homicides and suicides in Britain.

"Lessons for Mental Health Care in Scotland" found there were 500 killings north of the border over five years and 5,000 suicides over six years.

Suicide rates in Scotland were 18.7 per 100,000 of the population, compared with 10.2 per 100,000 in England and Wales.

Of the 1,373 patient suicides in the report, there was a history of alcohol misuse in 785 cases, an average of 131 deaths per year.

There was a history of drug misuse witnessed in 522 cases, or 87 deaths per year.

About 28 percent of people who took their own life and 12 percent of killers had recently been mental health patients, the research said.

The findings suggested that alcohol and drugs lay behind Scotland's high rates of suicide and homicide, said research director Louis Appleby.

"Alcohol and drug misuse runs through these findings and it appears to be a major contributor to risk in mental health care and broader society."

"Our findings support the view that alcohol and drugs are the most pressing mental health problems in Scotland and mental health services can play their part."

The report came 24 hours before Scottish ministers are expected to announce a ban on under-21s buying alcohol at supermarkets and off-licences. They will still be allowed to drink in pubs and bars.

(Agencies via Xinhua June 16, 2008)