Nearly a third of fit notes issued by GPs are for psychiatric problems, says an NHS report.

This makes them the most common reason for people to take time off work, ahead of musculoskeletal diseases.

There was a 14% rise in notes relating to anxiety and stress between 2015-16 and 2016-17.

The Royal College of Psychiatrists said the findings were "alarming" and pointed to a need for more to be done to help get people back to work.

Fit notes is the formal name given to what were once called sick notes.

The new data analysed more than 12 million of them, issued over almost two and a half years from GP practices across England.

Around half of the notes had a known diagnosis.

It was the first time this information had been collected from GPs and analysed.

Simon Stevens, the chief executive of NHS England, said: "These figures explain why the NHS is now putting mental health front and centre, in what was recently independently described as 'the world's most ambitious effort to treat depression, anxiety and other common mental illnesses'."

Longer periods off work

The NHS Digital report also revealed that fit notes for psychiatric problems were being issued for longer periods of time than other types of illness.

For example, more than one in five psychiatric sick notes were issued for longer than 12 weeks, compared to only 3% of notes for diseases of the respiratory system.

Jed Boardman, from the Royal College of Psychiatrists, said not enough was being done to facilitate a person's return to work.

"GPs will write suggestions on the fit note, such as staggered work days or agreeing specific goals for the returning employer - both parties need to be more active in tailoring these suggestions to that person," he said.

Dr Boardman said the data "may underestimate the scale of the problem" as discrimination can mean those with mental health issues are out of the labour force completely.

"Almost half of benefits claimants of Employment and Support Allowance in England are receiving payments as the result of mental and behavioural disorders," he pointed out.

A spokeswoman from the Department for Work and Pensions said: "We're helping thousands of people to remain in, or get back into work after a period of ill-health.

"We're determined to go further, and these statistics will provide us with a better understanding of why people take sickness absence in different areas across the country."