However, the extended timespans at sea, prolonged periods of social isolation and port restrictions arising from Covid-19 have probably acted together to exacerbate the mental health pressures for seafarers.

Researchers found that 37.3% of seafarers in the study had at least one of three key PTSD symptoms, and 11.8% showed all three symptoms.

Overall, 12.4% of the seafarers were found to exhibit symptoms of anxiety and 14.1% showed depressive symptoms.

The report says the findings for seafarers can be compared with a study of frontline healthcare workers during the coronavirus crisis which showed 29% with anxiety symptoms, 26.3% with depressive symptoms and 20.7% with PTSD.

The researchers also found that the prevalence of depressive symptoms was significantly greater among officers, married seafarers, and those who had served the longest time onboard the current vessel during the pandemic.

Factors such as long periods of separation from loved ones and concern about their health, pressure from family members to get home, limited medical facilities, and less access to medical care ashore might also have adverse effects on the psychological status of seafarers.

The study calls for further research into the reasons why extended periods at sea were linked with higher rates of depressive symptoms. It also highlights evidence suggesting that seafarers may be trying to reduce PTSD symptoms of hyper-vigilance and avoidance by working even longer hours every week.

It also warns that even before the Covid crisis there was a lack of agreed data on the mental health of seafarers, and it calls for other researchers to do more to examine all aspects of their psychological health during Covid-19, to ensure that all stakeholders in the maritime industry have the necessary information to tackle the problems faced by those at sea.