Mr Farmer, who is chief executive of mental health charity Mind, said: “Opportunities are missed to prevent poor mental health and ensure that employees who may be struggling get the support they need.
“In many instances, employers simply don’t understand the crucial role they can play, or know where to go for advice and support.”
The review makes 40 recommendations for how to support employees to remain at work, including creating an online wellbeing portal and using digital technology to support workers in the gig economy.
Companies are also being encouraged to include a section on employee mental health in their annual reports. Currently only 11% of companies do this, the report said.
Prime Minister Theresa May, who commissioned the report, said it showed “we need to take action”. The civil service has agreed to take on the report’s recommendations.
One employer the report praised is the insurer, Aviva.
James Tringham, who has worked for the company for seven years, said it helped him get his life back on track after suffering with bipolar disorder.
“In 2009, I’d reached crisis point with my mental health, and I gave up my career as a solicitor,” he says.
“I was unable to work for over a year – the prospect of returning to work was just so frightening and not something that I could imagine.”
Eventually he got a job in the insurer’s contact centre. “They gave me a way back into employment and I have worked my way back up.
“Aviva have been brilliant in supporting me to manage my mental health at work, and have given me my confidence back.
“There’s an understanding, which means little things like adjusting my workload when I’m feeling on the low side can really help. And the staff – both officially and unofficially – form a great support network.”
The review says employers should:
Create a mental health at work plan
Build mental health awareness by making information and support accessible
Encourage open conversations
Provide good working conditions and ensure employees have a healthy work-life balance
Promote effective people management, with line managers holding regular conversations about health and well-being with their staff
Routinely monitor employee mental health
The review said that people with long-term mental health problems were leaving jobs at twice the rate of colleagues with no such issues, although it did say that some people may be counted twice – if they left one job, returned to work elsewhere after a break but were then unable to continue in their new post.
The report also pointed out the cost to employers, estimating they were losing £42bn each year because of staff suffering from mental health problems.
Mrs May said: “It is only by making this an everyday concern for everyone that we change the way we see mental illness, so that striving to improve your mental health – whether at work or at home – is seen as just as positive as improving our physical well-being.”