The findings, published in the British Journal of Psychiatry, show that suicide rates rose significantly in the EU, Canada and the USA after 2007, with the increase being four times higher among men.

The research team analysed recently released suicide data from the World Health Organization covering 24 EU countries and two North American countries. They observe that the downward trend in suicide rates in the EU reversed when the economic crisis began in 2007, rising by 6.5% by 2009 and remaining at the higher level through to 2011. In Canada, suicides rose by 4.5% between 2007 and 2010, while in the USA, the rate increased by 4.8% over the same period.

Report authors Aaron Reeves, Martin McKee and David Stuckler argue that there were at least 10,000 additional suicides due to the economic hardship experienced in EU countries, Canada and the USA. They describe their figure as a 'conservative' estimate and say the rise in suicides is substantially over and above what would be expected.

They found that there were 'marked' differences in suicide rates across countries affected by the same recession. This leads them to conclude that, in theory, increased suicides during an economic crisis are 'avoidable'.

The study finds that job loss, home repossession and debt are the main risk factors leading to suicide during economic downturns.

The study says while most suicides occur among people with clinical depression, to date there is little evidence to show the benefits of treatments, such as antidepressants, for protecting individuals against the risk of suicide. However, the study notes that prescription rates rose markedly in some countries during the recent recession. In the UK, a rise of 11% in antidepressant prescribing between 2003 and 2007 went up to 19% between 2007 and 2010.

The study suggests that nations that invest in active labour market programmes reduce the risk of suicide. The authors estimate that for each US$100 spent per capita on programmes offering such assistance for the unemployed, the risk of suicide reduced by 0.4%.

The authors highlight that Sweden, between 1991 and 1992, and Finland, between 1990 and 1993, both experienced rises in unemployment at the same time as the rate of suicide decreased. In the most recent recession, suicide rates remained stable in Sweden and Finland, while the rate declined in Austria, despite rising unemployment.

Lead author Dr Aaron Reeves, of Oxford University's Department of Sociology, said: 'There has been a substantial rise in suicides during the recession, greater than we would have anticipated based on previous trends. A critical question for policy and psychiatric practice is whether suicide rises are inevitable. This study shows that rising suicides have not been observed everywhere, so while recessions will continue to hurt, they don't always cause self-harm. A range of interventions, from return to work programmes through to antidepressant prescriptions, may reduce the risk of suicide during future economic downturns.'

Co-author Professor David Stuckler, also from the University of Oxford, added: 'Suicides are just the tip of the iceberg. These data reveal a looming mental health crisis in Europe and North America. In these hard economic times, this research suggests it is critical to look for ways of protecting those who are likely to be hardest hit.'