The introduction of a more stringent test to assess eligibility for disability benefit in England may have taken a “serious” toll on the nation’s mental health, concludes research published online in the Journal of Epidemiology & Community Health.

Since 2010 the test, known as the Work Capability Assessment (WCA), has been used to assess the eligibility of claimants of the main out of work disability benefit, in a bid to get more people back into the workplace and help curb the government’s rising welfare bill.

But areas with the greatest use of the WCA to assess existing claimants have seen the sharpest rises in reported suicides, mental health issues, and antidepressant prescribing, the findings show, prompting the researchers to question the wisdom of introducing this policy.

Doctors and disability rights organisations have voiced fears that use of the tough new criteria to measure incapacity to work is undermining the mental health of claimants. However, up till now, there has been no hard evidence to substantiate these concerns.

To find out if there was any link between use of the WCA and a rise in the prevalence of mental health issues, the researchers analysed the numbers of disability assessments carried out in 149 local authorities in England between 2004 and 2013.

They looked at local trends in suicide rates among 18 to 64 year olds; antidepressant prescribing patterns; and Labour Force Survey data on self-reported mental health issues among the working population in each local authority.

Between 2010 and 2013, more than one million (1.03) people claiming disability benefit were reassessed using the WCA. A higher proportion of people living in areas of deprivation were reassessed.

The analysis showed that in those areas with higher rates of reassessment, there was a corresponding increase in suicides, mental health issues, and antidepressant prescribing.

After taking account of the impact of baseline deprivation, economic trends, and long term trends in mental health, the researchers calculated that, there were around six extra suicides, 2700 more cases of mental ill health, and an extra 7020 prescriptions for individual antidepressants for every 10,000 people reassessed during this period.

This adds up to a total of 590 additional suicides, 279,000 extra cases of mental ill health and 725,000 more prescriptions for antidepressants across the country as a whole that were associated with the reassessment policy between 2010 and 2013..

This is an observational study, so no firm conclusions can be drawn about cause and effect. None the less, the researchers point out that they were at pains to adjust for other potentially influential factors, and that the observed increases in mental ill health followed–rather than preceded–the reassessment process.

The findings have important implications for policy, they say, particularly as this was introduced without any evidence of its potential impact or any plans to evaluate its effects, added to which a further 1 million people will have been reassessed in 2015.

The policy also raises ethical issues for the doctors involved, given that they have professional and statutory duties to protect the health of patients and the public, they add.

“Our study provides evidence that the policy in England of reassessing the eligibility of [disability] benefit recipients using the WCA may have unintended but serious consequences for population mental health, and there is a danger that these adverse effects outweigh any benefits that may or may not arise from moving people off disability benefits,” they write.

“Although the explicit aim of welfare reform in the UK is to reduce ‘dependency,’ it is likely that targeting the people living in the most vulnerable conditions with policies that are harmful to health, will further marginalise already excluded groups, reducing, rather than increasing, their independence,” they conclude.