Almost 1,500 people in Gwynedd receiving benefits due to mental health problems.
The Employment and Support Allowance is for people struggling to work due to long-term health conditions. It is for those unable to work completely, and for people whose hours are limited by their condition.
Department of Work and Pensions figures show 1,455 people in Gwynedd claimed ESA due to mental or behavioural conditions as of last summer – 46% of the 3,171 claimants in the area.
These conditions accounted for almost half of the 1.6 million people claiming the benefit across Britain and were the most common reason in every area and region.
In Gwynedd, they were followed by 'musculoskeletal' diseases – which includes issues with joints, bones and muscles – with 370 people receiving ESA.
These figures show the primary diagnosis when people are first assessed for the ESA – there may be more people with mental health problems as a secondary condition which are not counted in the data.
Megan Pennell, head of public affairs and campaigns for Mind, said a lack of mental health support – including lengthy waiting lists for NHS services – was keeping people out of the job market.
"We are concerned about the increasing rhetoric suggesting benefits for disabled people and people experiencing long-term health conditions should be reduced. At the time of a cost-of-living crisis, this is unconscionable.
"People need to be offered tailored support from experts if they are to return to work, not threats of losing what little money they currently have to live on."
Fewer people are claiming the ESA as the Government moves towards using Universal Credit for those with health conditions.
As of December 2023, two million people were on Universal Credit health benefits, including 3,288 in Gwynedd - a rise from 1.6 million (2,616 in Gwynedd) a year earlier.
Data on medical conditions for those receiving the benefit is less complete than for the ESA, making it difficult to know the true number of people missing work due to issues with their mental health.
However, DWP figures show 72% of claimants starting on Universal Credit health benefits from 2022 to November 2023 were suffering from a mental health problem – even if this was not the main reason they were struggling to work.
The Joseph Rowntree Foundation – an anti-poverty charity – said these benefits are "inadequate" and can make people with mental health problems feel worse.
A DWP spokesperson said: "We are taking the long-term decisions to help everyone who can work to do so, improving lives and growing the economy.
"Our landmark welfare reforms will cut the number of people due to be put onto the highest tier of incapacity benefits by over 370,000 and instead give them personalised support, while our Chance to Work Guarantee will mean people can try work without fear of losing their benefits.
"In total our £2.5 billion Back to Work Plan will help over a million people to break down barriers to work, including those with disabilities and long-term health conditions."