A study has linked a spike in mental-health problems among the unemployed with the rollout of universal credit and other government welfare changes.
The number of unemployed people with psychological distress rose 6.6% between 2013 and 2018, it suggests.
And this represents an extra 63,674 people in England, Wales and Scotland - 21,760 of whom became clinically depressed over the period.
The government highlighted the study found no causal link.
Prof Dame Margaret Whitehead, of the University of Liverpool, who co-authored the Lancet Public Health Journal study, said it had found "observational associations" rather than "cause and effect".
The spike in mental-health cases could also have been influenced by the broader range of welfare changes, she said.
But the study added to the "mounting evidence of substantial mental-health harms related to universal credit".
And it was crucial the government conducted robust health-impact assessments of all welfare changes, including universal credit.
The researchers found no links to any impact on physical health, however, or any evidence universal credit had led to an increase in the number of claimants finding jobs.
Launched in 2013, universal credit, which combines six benefits into one, was an attempt to simplify the welfare system and get more people into work.
But its implementation has been criticised for introducing long delays and a tougher use of sanctions.
Numerous concerns have been raised by MPs, charities and select committees and there have been several cases of vulnerable individuals killing themselves after having problems with the new system.
The researchers followed more than 52,000 working-age people between 2009 and 2018, who were taking part in Understanding Society, the UK Household Longitudinal Study.
A Department for Work and Pensions spokesman said: "People coming into the job centre are often doing so at a difficult time in their lives and there is a range of support available for those with mental-health conditions."