"I want to be a health minister that stands up for people with mental illness," he said at his first press conference as minister at Canberra Hospital's new cancer centre.

Mr Corbell said his own experience with depression had made him "very very acutely aware" of the issue. "I know that all too often it's still an issue of shame and stigma in our society and it shouldnt be. Mental illness is just that, it's an illness and it can be managed and people can recover."

He also pointed to an "enormous" obesity problem in Canberra, with more than half of Canberrans overweight or obese.

"Leadership from me as the health minister is going to be critical," he said. "I'm very, very committed to addressing that because we need to stop that growth. And we need to stop seeing people getting unwell, facing all the challenges that brings and ending up putting more and more pressure on our health system."

Mr Corbell and Chief Minister Andrew Barr toured the cancer centre and met patients, including Phyllis, who has been receiving treatment for leukaemia for five years, and who told Mr Corbell he had very cold hands. Cold hands but a warm heart, he assured her.

He takes on a portfolio plagued with unprecedented demand on the emergency department and controversy over management at the hospital maternity unit. He will also oversee the delivery of a new public hospital at the University of Canberra. He takes on the job as the government begins a three-year squeeze on health funding, bringing it back from annual growth of 6.2 to 6.4 per cent to 5 per cent, the same as education. Mr Corbell said he would have to keep spending under constant review to contain growth at 5 per cent.

He shouldered the bulk of the workload in the reshuffle announced on Friday, also keeping his job as Attorney-General, albeit with some of the portfolio carved off into a new justice portfolio that went to the Greens' Shane Rattenbury, and police and emergency services, which went to Joy Burch. Ms Burch is the territory's first police minister.

Mr Barr will look to a wider reshuffle after former chief minister Katy Gallagher's vacancy in the Assembly is filled in January. He plans to appoint a sixth minister then, and has already indicated that the person likely to win Ms Gallagher's seat, Meegan Fitzharris, will go first to the backbench. That makes Yvette Berry the most likely Labor backbencher to be elevated to the ministry, perhaps taking on a role such as education and sparking a wider reshuffle of ministries.

Mr Corbell received health after putting the view to Mr Barr that it should remain with a senior Labor minister. "I said to Andrew that it needs to be a senior minister and it needs to be something that is critical to Labor's mission as a government and as a party. This is heart and soul business for the Labor Party."

It remains to be seen whether he will aim for as ambitious and reformist change in health as he has led in renewable energy and in his cast-iron commitment to the tram line. He has led the government's target of 90 per cent of the city's energy use from renewable sources by 2020, a target that has seen the launch of large-scale solar, wind and other renewable projects in the city.

As well as taking on justice, Mr Rattenbury keeps his current portfolios of Territory and Municipal Services, Aboriginal affairs, sport and corrective services.

Mr Barr keeps Treasury, housing and tourism and takes on the Mr Fluffy buyback.

Ms Burch keeps education, disabilities, arts, multicultural affairs, and racing and gaming.

Mick Gentleman keeps planning, community services and industrial relations.