Additionally, close to 700,000 have sustained injuries, according to new research from business insurer QBE.

For the first time, QBE research shows the cost to the UK construction industry from poor mental health. QBE surveyed 362 UK construction workers about their mental health at work.

The results indicate that they are likely to continue to work even with the increased risk of injury.

Three-quarters of UK construction workers with poor mental health said at some point, they continued to work in a dangerous situation despite the increased risk involved.

In addition, more than one-quarter of construction workers (27%) have taken time off in the last 12 months due to poor mental health, with almost half of them (46%) taking at least one week off.

The research also shows that in the UK construction industry, more than five million working days were lost to poor mental health last year.

This compares to 18 million working days for the whole UK economy. The construction sector is one of the largest in the UK economy – employing 3.1 million people or over 9% of the workforce.

According to government reports, stress, depression, or anxiety account for almost half (49%) of all work-related ill health.

It is the biggest cause of lost workdays in the UK, with work-related ill health accounting for over half (54%) of lost working days.

Key findings from the research include:

• Half of the workers in the industry, or 1.5m people, have worked in a dangerous environment while experiencing poor mental health.
• More than one in five (22%), or 682,000 workers, report having suffered an injury at work because of poor mental health.
• For those who have continued to work with mental ill health, the majority (76%) agree that mental ill health increases the risk of injury.
• Mental health costs the UK construction industry at least £1.2b per annum, with 1.7 days lost per worker and 5.1m lost working days last year.
• More than one-quarter of respondents (27%) are uncomfortable discussing mental health with their employer.
• One-third (32%) of workers said their employer has never once checked in with them about their mental health.
• Absent construction workers are likely to lie about the reason if it is related to mental health and give a different reason for their time off. Over a third (38%) of respondents said they told an employer the reason they were absent from work was due to a physical condition when it was, in fact, due to poor mental health.
• 36% have been prevented from speaking openly about their mental health by workplace stigma.