A survey of more than 10,000 Australian workers found the number of workers who reported experiencing a mental health condition in 2020 had risen by 9 percentage points.

The study, Australia's largest on workplace mental health, also found over a quarter of those who experienced ill mental health did so for the first time during the pandemic.

National mental health organisation SuperFriend's Indicators of a Thriving Workplace Report asked respondents about work stresses, supports, and the impact of the pandemic on their professional life.

They found productivity was lower for many respondents, more were extremely stressed at work, and more were hesitant to change jobs even if they hated them.

Almost 60 per cent of those surveyed said they had been less productive this year because of mental health concerns, and 26 per cent reported work was extremely stressful or very stressful for them this year.

Workers from the transport, postal and warehousing industries reported being under the most strain, followed by those in public administration and safety and retail.

The survey also found more people are staying in jobs despite fewer finding their work interesting or important, due to fears over rising unemployment.

The survey found that casual workers were the least "thriving" cohort, and that half had their work hours cut involuntarily.

"Casual workers have very little job security, and fewer opportunities to access workplace mental health programs and resources compared with their securely employed peers," SuperFriend chief executive Margo Lydon said in a statement.

But it wasn't all negative. Nearly half of the respondents said the pandemic has resulted in a better work-life balance and a range of mental and physical health benefits.

Almost 30 per cent of respondents said they'd become more productive during the pandemic, thanks to a reduced commute to work (38.4 per cent), more comfortable clothing (31.3 per cent) and flexible work hours (29.4 per cent).

"Time usually spent getting ready for work, commuting and attending unnecessary meetings is instead spent with loved ones, exercising, pursuing personal interests or getting more sleep - all known factors to improve wellbeing and increase productivity," Ms Lydon said.

The research also found that working remotely had boosted workplace connectedness for many.

Ms Lydon said the mental impacts of the period were clear, and it is "hugely disappointing" to note more than half of workplaces - 55.1 per cent - had not implemented initiative to support workers' mental wellbeing.

"Lost productivity due to mental ill health is estimated to cost the Australian economy between $10 billion to $18 billion every year, but on the flip side, every dollar invested into workplace mental health is estimated to deliver a return on investment of five to one," she said.

However the survey also found one in three workplaces had implemented new initiatives since March to support workers' mental health, such as paid mental health days off, sick pay for casual workers, meeting-free blocks of time and substantially longer break times.

Australian Associated Press