Leading psychiatrist Ruth Vine is the deputy chief medical officer appointed to oversee the mental health impacts of the pandemic.

Dr Vine said the cumulative effect of uncertainty and insecurity stemming from lockdowns and other restrictions were taking a toll.

"This has to be one of the most significant mental health crises we face," she told ABC radio on Monday.

"It's manifest by people feeling distressed, anxious, depressed and presenting both to helplines and to emergency departments."

Dr Vine said the number of young people presenting to emergency departments was up 30 per cent compared with two years ago.

"One of the most worrying factors has been the very significant rise in young people presenting to emergency departments."

Support service Lifeline experienced its busiest day last week with 3345 calls on Monday.

The federal government is spending $17.7 million to rapidly establish 10 mental health pop-up clinics in Sydney and other locked down parts of NSW.

It will also extend the operation of 12 similar clinics in Victoria until at least mid-next year.

Dr Vine said the clinics were free and catered for all ages across multiple disciplines.

She said it was important for people to keep structure in their day, stay connected with others and contact people who were isolated, lonely or at risk.

"It's really important to not lose sight of those common sense, normal ways of trying to keep ourselves buoyant and keep ourselves looking hopefully to the future," Dr Vine said.

Assistant Mental Health Minister David Coleman said young Australians could access support through Kids Helpline, the Butterfly Foundation, Beyond Blue and Headspace.

"My message to young Australians is that you're not alone," he said.

"It's important that young people who are having a hard time, facing increased stress or struggling to make it day-to-day, reach out for support."

Lifeline 13 11 14

beyondblue 1300 22 4636

Kids Helpline 1800 55 1800 (for people aged 5 to 25)

Australian Associated Press