Mental health-related sickness absence costs UK workforce 17 million working days 

Mental health-related sickness absence is continuing to place significant pressure on UK employers, with new figures highlighting the scale of long-term absence linked to stress, anxiety and depression across the workforce. 

Research from MetLife UK found nearly half (47 per cent) of HR directors and senior decision makers say mental health conditions are now among the leading causes of long-term sick leave within their organisation. 

The findings coincide with Office for National Statistics data showing 17.1 million working days were lost to mental health-related sickness absence in 2025, making it one of the largest drivers of workplace absenteeism in Britain. 

Women accounted for the majority of those lost days, with mental health linked to 10.2 per cent of all sickness absence days among women, compared with 7.3 per cent among men. 

While other health conditions may account for a greater number of days lost overall, mental health-related absence is often more prolonged and complex, creating wider implications for workforce resilience, productivity and operational pressure. 

The research suggests employers increasingly view early intervention and workplace support as central to tackling long-term absence. Nearly one third (31 per cent) of HR leaders surveyed said mental health support was the single most effective measure for preventing sickness absence lasting more than four weeks. 

Anthony Sly, lead medical service consultant at MetLife UK, said: “Unlike physical illness or injury, mental health issues can be trickier to manage or spot in that they are more silent and less visible. Yet, with mental health conditions being one of the top reasons for employee absence, it is becoming a significant business risk. 

“Too often poor mental health is caught too late. Mounting pressure transpires into burnout or something more physical, resulting in time needed off work. It’s imperative that early action is taken by employers to help intervene before things like stress, anxiety, or depression escalate into long-term illness. When people feel supported early, they recover faster and stay connected to work. Early intervention is the only real prevention.” 

Sly said employers should focus on recognising behavioural changes early, encouraging supportive conversations and ensuring employees have access to practical adjustments and specialist support before issues escalate into prolonged absence. 

The research was conducted by Censuswide among 1,000 HR directors, business owners and senior decision makers in the UK between 7 and 13 May 2025.