Official forecasts have shown the cost of sickness benefits will rise by more than a third.
The Office for Budget Responsibility (OBR) expects spending on health and disability benefits to rise from £65.7bn this year to £90.9bn in 2028-29.
It comes as employers are struggling to fill approximately 900,000 vacancies across the country.
Meanwhile, taxpayers are feeling the strain from a combination of more people out of work and the rising benefits bill.
The comments made by Mel Stride MP was met with a backlash
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There has been a sharp rise in claims for mental health conditions and back pain among all ages, with a £6.2bn increase in the amount spent on child health and disability benefits. Claims related to ADHD have climbed 23 per cent to almost 64,000.
Children with behavioural disorders has already trebled over the past five years to more than 150,000, while the number claiming support for boys and girls with learning difficulties has increased by 37 per cent to 303,000.
It comes as Work and Pensions Secretary Mel Stride said there was: "A real risk now that we are labelling the normal ups and downs of human life medical conditions which then actually serve to hold people back and, ultimately, drive up the benefit bill."
However, the MP's comments were met with a backlash from doctors, including the president of the Royal College of Psychiatrists Dr Lade Smith who slammed the comments as "disappointing" slamming the MP for Central Devon's comments as "diminish[ing] and misrepresent[ing] people with mental illness."
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Rishi Sunak’s official spokesman refused to repeat Stride’s comments
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Dr Smith said: "This is not simply a ‘culture’ that will go away on its own. People are not pretending to be sick – they really are sick."
A spokesperson for Rishi Sunak told The Telegraph that the Prime Minister welcomed the fact that "as a society we are more comfortable discussing mental health" while seeking to "tackle the underlying issues" behind the increase in claimants.
The overall benefits bill, which also includes things like the state pension and housing support, is forecast to rise to £360bn in five years’ time, or more than 11 per cent of total economic output.
A total of 9.25 million people of working age are classed as economically inactive because they are neither in work nor looking for a job. However, employers have more than 900,000 jobs available but are struggling to fill vacancies.
Meanwhile, separate analysis from the Institute of Fiscal Studies (IFS) showed middle and high-income families have been left worse off by frozen tax brackets and high inflation.
The IFS said the data failed to capture "the true increase in deprivation" during the cost of living crisis, as millions more people struggled to afford food and heating.
A government spokesman said: "Our landmark welfare reforms will help an extra one million people break down the barriers to work, as this government makes work pay – cutting taxes for the average worker by more than £900.
"The OBR estimates our recent Budget measures will see an extra 200,000 people into work, while our £2.5bn Back to Work plan will help thousands find jobs.
"This is bolstered by our changes to disability benefits as we focus on what people can do, not what they can’t – cutting the number of people due to be put on the highest tier of incapacity benefits by 370,000 and helping everyone to reap the rewards of work."