The Great Recession that began in late 2007 resulted in about 12,940 suicides in North America and Europe - and many of them could have been prevented, researchers said.
As far back as 1897, French sociologist Emile Durkheim observed the link between economic hardship and suicide.
"It is a well-known fact that economic crises have an aggravating effect on suicidal tendency," he wrote in his book Suicide: A Study in Sociology.
In the following decades, researchers have documented time and again that suicides become more frequent during recessions and depressions.
The new study, published on Wednesday in the British Journal of Psychiatry, reveals that in the US, the suicide rate was rising even before the subprime loan crisis sent global financial markets into a tailspin.
But data from the Centres for Disease Control and Prevention show the rate accelerated by 4.8 per cent after the meltdown, resulting in 4,750 "excess suicides" between 2007 and 2010.
In Europe, the suicide rate had been falling in the years before the recession, according to data from the World Health Organisation.
That trend reversed after the meltdown - the suicide rate rose 6.5 per cent, which translates into 7,950 "excess suicides" between 2007 and 2010, the researchers wrote. The story was similar in Canada, where a once-declining suicide rate wound up rising 4.5 per cent between 2007 and 2009.
That resulted in 240 "excess suicides" nationwide, according to the study.
The researchers blamed the deaths on the Great Recession by pointing to New Zealand, a rare example of an industrialised country that "escaped unscathed from the financial crises".
They found the suicide rate among New Zealanders didn't rise in the years after 2007.
The good news is that the researchers - sociologists and public health experts from the University of Oxford and the London School of Hygiene and Tropical Medicine - seem convinced that at least some suicides could be prevented in the next economic calamity.
One reason they cited is that Austria and Sweden managed to avoid any significant change in suicide rates despite being swept up in the Great Recession.
Perhaps those countries have adopted policies that mitigate the effect of economic hardship on suicidal behaviour.
Sweden, in particular, must be doing something right - in the recession of the early 1990s, it was one of two European countries that saw suicides fall even as unemployment rose. The other country was Finland.
Also, the increase in suicide was about four times greater in men than in women. This may reflect the fact that losing a job poses a greater "status threat" for men than for women, but perhaps this could change if there were "greater gender equity in the workplace", the study authors wrote.
The researchers offered two specific policy proposals that might buffer the effects of future recessions on mental health. One was to expand programmes to help unemployed workers find new jobs.
The other suggestion was for doctors to step up their prescriptions for antidepressants.
The majority of people who commit suicide suffer from clinical depression, so treating depression more aggressively ought to make a difference.