High stress is pushing workers into sick leave, with just one in four (27%) saying mental health is genuinely prioritised and supported at work, the latest Burnout Report from Mental Health UK found.
The report, based on YouGov polling of more than 4,500 UK adults, showed one in five (20%) workers took sick leave due to poor mental health caused by stress, staying at the same level as last year.
Two in five (39%) 18 to 24-year-olds took time off for the same reason.
Nine in 10 (91%) adults reported high or extreme stress over the last year.
Over one in three (35%) workers said they did not feel comfortable talking to a manager about high or extreme stress, up 3% from the previous year.
Among 18 to 24-year-olds, this figure rose to 39%, an increase of 5%.
One in four (27%) workers who took time off due to extreme stress did not get any support on their return to work, and only 17% had a formal return-to-work plan.
18% said mental health is treated as a tick-box exercise, while nearly one in three (29%) said their employer raises awareness about mental health but managers lack time, training and resources to offer real support.
The main causes of workplace stress were high or increased workloads, experienced by 42% of workers, unpaid overtime (33%) and fears around redundancy and job security (32%).
Outside work, poor sleep (59%), money worries (48%) and poor physical health (38%) were top drivers of stress.
Younger workers aged 18 to 24 were most likely to have stress from high workloads (57%), unpaid overtime (47%), feeling isolated at work (45%) and job security worries (43%). Money worries were a major issue for this group (64%), just behind the 25 to 34 age group (65%).
Brian Dow, CEO of Mental Health UK, said: “Burnout is fast becoming one of the UK’s most serious shared challenges.
“We all want a thriving economy that benefits employers and workers alike, but unless we tackle chronic workplace stress and help people perform at their best, we are effectively trying to accelerate with the handbrake on.
“This year’s report highlights continuing concerns about high levels of absence among younger workers.”
Dow added: “This group is facing pressures both inside and outside work, alongside an uncertain job market where AI is increasingly seen as a threat to some entry-level roles.
“For many, the social contract that rewarded previous generations for hard work is breaking down.
“While young people are often seen as championing better attitudes towards mental health at work, our survey shows many are staying silent about their own stress levels.”
He said: “Our workplace training team reports that young people do value regular check-ins on workload and wellbeing, when managers create the right environment for discussion.
“As the Keep Britain Working review makes clear, employers have a vital role in helping people stay in work, but we know that managers often feel unsure about starting conversations on stress and mental health.
“If we want to see a thriving workforce, organisations must move faster in supporting managers to act early, before stress and poor mental health turns into burnout and people are pushed out of work.”

