Two fifths (41%) of businesses are reporting a growing number of mental health problems over the past 12 months, according to the CIPD, the professional body for HR and people development.

In 2009, just 24% of organisations reported an increase in things like anxiety and depression in the workplace, but 2015 is the sixth year in a row that that figure has been above 40%.

Reported increases are most likely in large and medium-sized organisations, with 69% and 51% respectively showing rises, the CIPD said. They’re also associated with long working hours and the extent to which operational demands take precedence over employee wellbeing.

Ahead of World Mental Health Day on 10 October, Ben Willmott, head of public policy at the CIPD, said: “Unfortunately, this year’s survey shows the number of reported mental health problems has increased for many employers, and after over half a decade at these levels, we can’t afford to let this issue continue to grow any longer. As a nation we’re getting better at opening up the conversation around mental health, but there is still a long way to go.

“So what more can employers do? Manager training is crucial, as they are often employees’ first point of call for reporting an issue, but only 30% of organisations currently provide it. There needs to be a lot more focus on this going forward, as well as tailored support for line managers from HR and signposting employees to appropriate support. Employers also need to look at how well their corporate culture supports good mental health and employee wellbeing.”

The report also found the private sector particularly lacking in managing and supporting employees with mental health problems, with 28% admitting they weren’t taking any action to support employees. Just 32% currently offer a counselling service, compared to 70% of public sector organisations. Similarly, only 21% said they were increasing awareness of mental health issues across the workforce as a whole, compared to over double that (47%) in the public sector.

Emma Mamo, head of workplace wellbeing at Mind, said: “These figures show just how common mental health problems are in the workplace and highlight why it’s so important that businesses make promoting staff mental wellbeing a priority. Given how prevalent poor mental health is among staff, employers can no longer afford to bury their heads in the sand when it comes to tackling the causes of stress and poor mental health for their employees.

"It’s positive to see more staff opening up to their employers if they are struggling with their mental health. The stigma surrounding mental health is beginning to dissipate, as awareness increases, with more people coming forward. But we know that many people still don’t feel comfortable disclosing, and sometimes those who do aren’t offered the right support at the right time."