An in-depth analysis of new ONS data by employment law firm Clifton Ingram has revealed a sharp rise in sickness absence due to mental health conditions, with the number of mental health-related sick days increasing by 40% in just 12 months.

Drawing on data published by the Office for National Statistics (ONS), the firm’s researchers examined annual sickness absence trends across the UK labour market. The dataset details working days lost to sickness by region, sex, age group, employment type, and illness category, providing a broad view of how absence has affected workplaces nationwide and how those patterns have changed over time.

The firm’s research shows that, in 2024, 1 in 5 sick days in the UK were taken for mental health reasons, marking a dramatic leap from the previous year. In fact, while minor illnesses still account for the highest number of absences overall, mental health now represents the fastest-growing category of reported sickness, overtaking musculoskeletal and respiratory conditions in year-on-year change.

Alison Gair, Senior Associate and Head of Employment at Clifton Ingram, commented:

“This steep rise in mental health-related absence may be a reflection of increasing pressure across many sectors, particularly in public-facing or emotionally demanding roles."

“It may also indicate progress - a growing willingness among employees to speak up and report mental health struggles more honestly, rather than disguising them as physical complaints. That’s a societal step forward - but it also places new responsibilities on employers.”

The figures show that women are more likely than men to take sick leave for mental health conditions, with reported cases increasing significantly over the past decade. At the same time, women’s reports of minor illness have declined - further supporting the theory that mental health is becoming less stigmatised and more accurately reported.

Notably, the data paints a contrasting picture for men. While they were 18% more likely than women to take time off for minor illnesses, they were far less likely to report mental health-related absences. This disparity may reflect the ongoing stigma men face when it comes to acknowledging and reporting mental health challenges.

Some regions appear to be more impacted than others. Wales, Scotland, and the North of England - where public sector employment is higher and socio-economic pressures are more acute - consistently reported higher sickness absence rates overall, with mental health likely playing a significant role.

In addition, in the South East, women’s sickness absence has climbed to a decade high of 2.7% in 2024, up from 2.3% in 2014. Commenting on this, Gair said:

“The rising cost of living in the area may be placing increased financial and emotional pressure on women, particularly those balancing work with caregiving responsibilities. Childcare in the South East is amongst the most expensive in the country, and with women more likely to take on primary caregiving roles, this added burden can lead to burnout and a greater likelihood of needing time off work."

“Employers in every region and sector need to take a hard look at whether their current policies truly support mental wellbeing - not just on paper, but in everyday culture."

“Training, flexible work, early intervention programmes, and open communication are no longer nice-to-haves - they’re essential for safeguarding productivity and protecting your team.”