A worldwide jump in deaths by suicide in 2009 was probably linked to the global economic crisis that began the previous year, a new study suggests.

Researchers based in the UK and Hong Kong set out to investigate the impact of the 2008 economic crisis on international trends in suicide. They compared the actual number of suicides in 2009 with the number that would be expected based on suicide trends before the crisis, specifically the years 2000-2007.

They also looked at different age categories, to see if the crisis hit people of certain ages more than others.

The study looked at 54 American and European countries worldwide, including Ireland.

It noted that all countries in Europe recorded an increase in unemployment in 2009 and 2010, while unemployment rates started rising in the US and Canada in 2008, followed by big increases in 2009 and 2010.

The study found that in 2009, there were almost 5,000 excess suicides worldwide compared with the number that would have been expected based on 2000-2007 trends. In the 27 EU countries, the increases in suicide occurred mainly in men and the age group most affected was 15-24 years.

In American countries, men in the 45-64 age group were most affected.

There was no overall change in suicide rates among women in Europe and only a small increase among American women.

"Rises in national suicide rates in men seemed to be associated with the magnitude of increases in unemployment, particularly in countries with low levels of unemployment before the crisis," the study found.

In Ireland, 82 excess suicides were recorded in 2009 among men and 15 among women. This means that almost 100 deaths by suicide in Ireland in 2009 were likely related to the economic crisis.

The researchers insisted that these findings probably underestimate the true impact of the economic crisis on suicide rates. They noted that for every completed suicide, as many as 30 or 40 people attempt suicide, while many more have suicidal thoughts.

"Our findings show that economic crises pose considerable suicide risks, though previous studies suggest that these risks are not inevitable. Research has shown that active labour market programmes can help to offset the impact of economic recession on suicide, as successful re-employment has been found to substantially reduce, and in some cases eliminate, mental health risks of job loss," the researchers said.

They warned that in many countries, government austerity ‘is resulting in further job losses, posing additional suicide risks'.

"Urgent action is needed to prevent the economic crisis leading to further increases in suicides," they added.

Details of these findings are published in the British Medical Journal.