A global team led University of New South Wales (UNSW), Sydney aims to track the long-term impacts of COVID-19 on the mental health of thousands of people - from the womb to old age.

The team will explore for the first time what they describe as this pandemic's toxic combination of two extreme psychological stressors: existential threat and social isolation.

They are hoping to recruit around 3,000 people from Australia, the UK and US to evaluate their mood before and after the onset of the pandemic, and to track their cognitive function and social networks over the coming months.

It has a special focus on two subgroups thought to be especially vulnerable to the shock of enforced isolation: adolescents and pregnant women.

"The COVID-19 pandemic has changed people's lives so drastically that it is difficult to know how protracted the effects may be," said study's chief investigator Dr Susanne Schweizer from UNSW's School of Psychology.

"We're particularly interested in younger people because they are at a time of social reorientation away from the family towards their peers which is all of a sudden being disrupted by social distancing," Schweizer added.

The research team are concerned that the longer-term effects of social isolation in this group may come at a cost to their cognitive development due to schools being closed as they are in the US and the UK, or drastically changed as in the case of Australia.

According to the researchers, initially, participants will be asked to complete an hour-long survey online in a laptop or smartphone browser to assess mood before and after the pandemic.

They will be asked to evaluate their connections to people in their social network and will also be invited to complete tasks that assess working memory – the ability to store information in memory for short amounts of time.

After three months – and then again after six – participants will again be asked to fill in a shorter survey to track progress in mood, cognitive function and social network.

"We hope that by the end of the study, we will have reliable and accurate data so that we can qualify the longer-term effects of this pandemic," Schweizer said.

"By working together with other research teams at the universities of Oxford and Cambridge in the UK and Oregon and Pittsburgh in the US, we are able to ask these questions across different populations," Schweizer added.

"By investigating the impact of the pandemic on mental health and what happens when the protection of a social support network suddenly disappears, we will be much better positioned to respond to the future health care needs of our national and global populations," she noted.