Staff absence due to stress, anxiety and other mental health-related problems rose by a fifth at the East Suffolk and North Essex Trust during the first coronavirus wave, figures show.

Mental health charity Mind said it is "worrying but not surprising" that mental health sick days among NHS staff increased across England when the crisis hit, as many frontline workers were forced to spend time isolated from their families.

And with the country in the grip of a second wave – and another lockdown – unions are calling for the Government to invest in increasing NHS workforce levels and staff pay to boost the morale of "exhausted health workers".

NHS Digital data shows the equivalent of 42,779 full-time staff days were lost due to sickness at East Suffolk and North Essex NHS Foundation Trust between April and June.

Of these, 9,427 (22%) were because of stress, anxiety, depression, or other psychiatric illnesses.

That was an increase of 20% compared to the same period last year, when 7,878 days were lost for these reasons.

Across England, the number of mental health sick days among NHS staff rose to nearly 1.5 million between April and June, up from 1.1 million in the same period last year.

Sara Gorton, head of health at public sector union Unison, said healthcare workers have "paid a heavy physical and psychological price" to keep the NHS running.

"Staff shortages, while dealing with the backlog of cancelled operations from the spring, and the stress and trauma of working through the pandemic have hit hard," she added.

"Kind words and applause can only go so far. The Government should do the right thing next week and boost morale with a significant pay rise before Christmas. This would make the world of difference to staff and the NHS during this punishing second wave."

Susan Masters, director of nursing, policy and public affairs at the Royal College of Nursing, said a rise in the levels of staff needing to take time off for stress and anxiety during the pandemic "should come as no surprise".

She added that fundamental investment is needed to "grow a depleted workforce" and avoid a further increase in stress and sickness levels.

Cough, cold or flu was the most common reason given for sickness absence at the East Suffolk and North Essex Trust between April and June, the figures show, accounting for 37% of days lost.

Emma Mamo, head of workplace wellbeing at Mind, said many healthcare staff I'told the charity they faced tough decisions around their personal lives during the first wave.

"Sometimes they felt conflicted between their duty to patients and their need to protect their family and friends, with some forced to live away from loved ones to minimise the risk of infection," she added, "Common misconceptions around resilience and immunity to poor mental health – the ‘superhero’ narrative – can actually prevent people asking for support when they need it, particularly from their manager or employer."

An NHS spokesperson said more than 400,000 NHS workers accessed a health and wellbeing programme encouraging staff to look after their physical and mental health during the first wave.

They added: "NHS staff have worked tirelessly to protect the health of the nation throughout this pandemic and it is vital that they are looked after too, which is why the NHS is investing an extra £15 million to expand and strengthen mental health support services available to staff."