Dependency on drugs and alcohol in Scotland is fuelling a suicide rate almost double that of the rest of the UK.

Edinburgh University researchers made the claim in a new study after they found the percentage of people taking their own life here is 79% higher than south of the Border.

And suicide is more prevalent in Scotland among people between the ages of 15 and 44.

The study found Scots in this age group are almost twice as likely to kill themselves as their English counterparts, with a suicide rate around 20 per 100,000 people in Scotland, compared to 11 per 100,000 in England.

The survey, in conjunction with Manchester University, found a high incidence of poor mental health, coupled with drug and alcohol use and socio-economic deprivation, are the main factors behind the higher suicide rate north of the Border.

Professor Stephen Platt of Edinburgh University's Centre for Population Health Sciences, who co-wrote the study, said: "There was a marked fall in the suicide rate in Scotland, about 14%, over the decade from 2000, coinciding with the implementation of an intensive suicide prevention strategy Choose Life.

"Nevertheless, the suicide rate in Scotland remains higher than that in England. Continuing action is required to reduce further the prevalence of the underlying risk factors for suicide in Scotland."

Researchers measured mental ill-health in relation to suicide on both sides of the border. They also looked at social, cultural and health factors in both countries.

The team found the factor most strongly linked to the differences in suicide rate between the countries was the rate of prescriptions in each country of medication for depression and other psychiatric illnesses.

The study concludes that differences in prescription rates for these drugs may be a result of a greater willingness among people living in Scotland to seek medical help.

However, it could also indicate that doctors in Scotland are more willing to offer drug treatment for mental ill-health.

Dr Roger Webb, of the University of Manchester's Centre for Suicide Prevention, said: "Any attempt to reverse the higher rate of suicide in Scotland will need concerted efforts to prevent and treat mental ill-health and to tackle alcohol and drug misuse."

Scotland has had a significantly higher suicide rate since at least the 1990s, with the number of suicides among men 50% higher than other UK countries. The rate for women has been double that of elsewhere.

Although the problem has been studied in detail, reluctance to talk about it means it rarely hits the headlines.

One exception was the deaths of two teenagers – Georgia Rowe, 14, and Niamh Lafferty, 15, residents at the Good Shepherd Centre care home in Bishopton, Renfrewshire.

They died in an apparent suicide pact after falling more than 100ft from the Erskine Bridge in October 2009.

A Fatal Accident Inquiry criticised the care home for having only two members of staff on duty when there should have been four.

Andrew Sim, executive director for the Samaritans in Scotland, said: "Suicide rates have generally been on the decline for the last decade and a lot of work is being done through programmes such as Choose Life to help prevent suicide.

"We know that recessions can have a negative impact on suicide rates. Unemployment, job worries and financial pressures can all increase the probability that someone will think their life isn't worth living.

"At Samaritans we've seen calls about financial problems double since the onset of the economic crisis. In 2011 one in five calls to the helpline were about money worries, compared to one in ten in 2008."

Details of the study are published online today in the Journal of Epidemiology and Community Health.