Victoria's fourth lockdown in 14 months has sparked new mental health concerns, especially for women and people dealing with chronic conditions.

Experts are bracing themselves for a spike in domestic violence and mental health crises, as Victoria goes into its fourth lockdown in 14 months.

A seven-day lockdown will begin from 11.59pm on Thursday as Victorian health authorities race to contain a COVID-19 cluster imported from South Australian hotel quarantine.

Monash University psychiatry professor Jayashri Kulkarni expects to see a spike in people, particularly women, seeking help for chronic conditions and domestic violence.

"The added stresses and strains of a lockdown can make something that's a bit fragile like a relationship, for example, really explode," she told AAP.

Following Melbourne's 112-day lockdown, there was a spike in new referrals for help with anxiety, depression, eating disorders, substance abuse, post-traumatic stress and domestic violence.

Prof Kulkarni is hopeful a shorter lockdown means "some of these explosive situations will not necessarily reach the peaks that they reached last year".

People should be kind and gentle with themselves, University of Melbourne research fellow and Australian Red Cross resilience expert Kate Brady urged.

"It's really important just to stop and say, 'I'm feeling overwhelmed because this is an overwhelming situation. I'm feeling stressed because this is an objectively stressful situation to be in'," she said.

Dr Brady also encouraged people to focus on what they could control and things they enjoyed, such as cooking, gardening or getting into a book they'd been meaning to read.

"What most of us were experiencing is that we were getting back to a sense of normality and things starting to settle down a bit," she said.

"When these things come about so quickly, they're a real reminder of how fragile that is and how much is out of our control."

The lockdown announcement came as Victoria's outbreak grew to 26 cases, with 11 new infections linked to the City of Whittlesea outbreak in Melbourne's north.

More than 150 exposure sites, and more than 10,000 primary and secondary contacts of positive cases have been identified.

People will only be able to leave home to get food and supplies, give or receive care, get vaccinated, and for exercise or authorised work.

A 5km travel limit will be reimposed, and face masks will be mandatory indoors and outdoors.

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