Those making submissions are most likely to be women, to be close to someone who suffers from a mental illness or to have one themselves — and they are fed up.

The submissions have arrived in less than a month to help shape the terms of reference for the Mental Health Royal Commission, which was announced by Premier Daniel Andrews before the November election.

Even at this early stage, it is more than four times the number of people who made submissions to Victoria's family violence royal commission.

Figures supplied to The Age reveal that more than 75 per cent of those who have lodged a submission are women.

More than 80 per cent of respondents have used mental health services in Victoria in the past five years, or have someone close to them who has, and more than a quarter of respondents were aged 26 to 35.

Their three top priorities for the royal commission were:

Experts have long raised the need for more funding for people suffering mental illness.

In June a report warned that tens of thousands of Victorians with serious mental illness were receiving no support.

The Australian Medical Association's Victorian chair of psychiatry, Dr Ajit Selvendra, said there was "huge unmet need among consumers and carers".

"Victoria has for over a decade underfunded mental health services. It's the lowest per capita spend in Australia."

Patrick McGorry, the executive director of Orygen, the National Centre of Excellence in Youth Mental Health, said the overwhelming response "vindicates the Premier's decision to call a royal commission".

"This is the first government that's listened," he said. "I've been trying to talk about this stuff for 10 or 15 years."

Professor McGorry said that in an ideal world, governments would fund enough mental health services to cater for between 3 and 10 per cent of the population; in Victoria the level had fallen to 1 per cent.

"There has been a total collapse in the system," he said.

The government had asked people to rate the importance of various aspects of the mental health system, to help it draft the royal commission's terms of reference.

It will continue to take submissions on the terms of reference until January 27, and announce both the terms and the commissioners next month. Members of the public will be able to make broader submissions once the royal commission begins in March.

Announcing the inquiry in October, Mr Andrews said it would save lives.

“This year, 3000 Australians will take their own lives. Countless more are trying to cope,’’ he said. “If this were any other cause or condition, we would call it what it is: a national emergency.”

The Premier said the government would implement all recommendations made by the royal commission.

Acting Mental Health Minister Jenny Mikakos said that each year one in five Victorians would experience a mental illness.

"We know we don’t have all the answers to improve the system ... only a royal commission will help us do just that.”

On Wednesday, the federal government announced that mental health services across Australia would share in $1.45 billion under a funding model shake-up that offers local organisations, staff and patients greater long-term certainty.