The economic recession across Europe has had a profound impact on people with mental health problems, research from King's College London suggests.
Between 2006 and 2010, the rate of unemployment for those with mental health problems rose twice as much as for other people - from 12.7% to 18.2%.
Men and those with low levels of education were particularly affected, the study said.
The authors warn that social exclusion could increase among the mentally ill.
Scientists collected data from 20,000 people across 27 EU countries using the Eurobarometer survey, which looked at mental health, attitudes to those with mental health problems and current employment rate.
For those without mental health problems, the unemployment rate increased from 7.1% in 2006 to 9.8% in 2010 - half the increase compared with the previous group.
In addition, the study identified that men with mental health problems were particularly vulnerable. The unemployment rate for this group increased from 13.7% in 2006 to 21.7% in 2010.
The researchers, from the Institute of Psychiatry at King's College London, found that negative attitudes to people with mental health problems were a factor in the rise in unemployment.
The study said: "Living in a country where a higher proportion of individuals believe that individuals with mental illness are dangerous was associated with a higher likelihood of unemployment for people with mental health problems, but did not influence employment rates for those without mental health problems."
It is thought that unemployed people with mental health problems may also be less likely to seek help and and may need specific outreach support.
Dr Sara Evans-Lacko, lead study author and lecturer at the Institute of Psychiatry, said the study did not have unemployment rates for individual EU countries. She suggested the trend was a general one across Europe which was not specific to any one culture.
"During a recession people who already have mental health problems find their economic and social position gets worse.
"We don't exactly know why, but it's harder for people to get a job if there's already a gap on their CV and if employers need to cut staff then these people might be more vulnerable."
The danger is that economic hardship can intensify the social exclusion of vulnerable people, such as those with mental health problems, the study said.
Prof Graham Thornicroft, also from the research team at the Institute of Psychiatry, said there were steps which could be taken to prevent this happening.
"Governments need to be aware of these risks, and employers need to be aware of their legal duty to comply with the Equality Act to support people with mental health problems coming into, and staying in, employment," he said.
Beth Murphy, head of information at mental health charity Mind, said the findings were worrying.
"Mental well-being depends on many factors, including employment status, working conditions and financial security, all of which can be affected during a recession.
"Since 2008, the Mind Infoline has received an increasing number of enquiries from people concerned about the impact of money and unemployment on their mental health, which could well be attributed to the economic downturn.
"Specifically, redundancy is known to trigger depression and suicidal thoughts, as is the case with debt."
She added: "Losing your job is a sudden change and there can also be financial implications through loss of income, which in itself can cause anxiety. We'd urge anybody struggling with their mental health to seek support."