From the balcony of a luxury cruise liner anchored off the coast of Japan, Trudy Clement shouts to another Canadian couple a floor above to exchange tidbits of news.

It's a rare bit of human contact on the 19-storey ship, where 2,666 passengers have been holed up since Tuesday — after a man tested positive for the coronavirus after disembarking in Hong Kong.

Outside the ship is a sea of media and cameras ready to capture any developments in the fast-changing saga. Ambulances come and go as infected passengers are taken off the ship for treatment. Inside, the halls are patrolled by guards so that guests remain inside their rooms.

"We're not in jail, but it sort of feels like it," Clement said from inside her suite. "My husband and I are starting to feel the walls closing in."

This is the Diamond Princess, a luxury ship, now a massive floating quarantine site, where passengers will remain confined to their rooms for two weeks. There's no getting off the vessel until at least Feb. 19. So far, more than 61 passengers have been confirmed infected, including seven Canadians.

WATCH | Canadians quarantined amid coronavirus outbreak:

More than 250 Canadians have been quarantined in their cabins on a cruise ship near Japan. Two Canadians on board are among the 20 passengers who have tested positive for coronavirus. 2:07

"Mentally you think you've got it [together]. Then you call home and you lose it. You talk to the grandkids or children and it just hits you that we're not free to come and go."

The fear: who might be next?

Dr. Laura Hawryluck, associate professor of critical care medicine at the University of Toronto, co-authored a 2012 study on the psychological effects of quarantine on SARS patients. She says the short-term effects can lead some to feel stressed, anxious and depressed.

Those feelings can be exacerbated when information is lacking from authorities, making timely updates an important part of getting through time in quarantine.

"It can be very scary when you know you've been exposed, you've got a period of time before you know if you're going to be in the clear or not, but you don't have access to accurate and consistent information about this new illness," said Hawryluck.

Other studies have shown the long term-effects can include nightmares and flashbacks, Hawryluck said.

'We're not in jail, but it sort of feels like it,' says quarantined passenger Trudy Clement 'My husband and I are starting to feel the walls closing in.' (CBC)

Kerry Bowman, a bioethicist and professor of global health at the University of Toronto, was among those quarantined during the 2003 SARS outbreak.

He says "many people did react with depression."

"Many people found quarantine very, very hard going, alienating, worrisome. Alone with their thoughts, the fear setting in," he told CBC News.

Bowman was fortunate enough to be quarantined in the comfort of his home, but says the experience on a ship is very different.

"If you're quarantined at home, you don't have to worry about contagion from other people," he said. "The concern with the ship is the number of cases has risen and the testing of passengers is not complete and it may rise again. So with that, the fear factor will rise."

WATCH | Prof. Bowman says those in quarantine need contact with outside world:

Jennifer Lee, a Canadian who is among several thousand passengers quarantined on board the Diamond Princess off-shore from Yokohama, Japan, gives the latest news on the situation, and how she and her fellow passengers are coping. 5:19

It's critical to make sure people have access to mental health resources, he said.

Canadian officials have said mental health services will be provided to those who were airlifted from the key outbreak zone of Wuhan, China, now quarantined at CFB Trenton in Ontario.

Health Minister Patty Hajdu has said the evacuees experienced a "tremendous amount of stress," anxiety and boredom during the lockdown in Wuhan. Many have been separated from their children or had to leave loved ones behind.

And while social interaction will be limited on the military base, officials are taking steps to keep people occupied, including setting up play centres for kids.

WATCH | Canadian describes what it's like on quarantined ship:

The 176 Canadians who came from Wuhan will enter a 14-day quarantine period at CFB Trenton in Ontario. Bioethicist Kerry Bowman was under quarantine for SARS in 2003 and says people in such conditions can show symptoms of depression and even PTSD. 6:03

The Quarantine Act gives Ottawa extensive powers to detain people in order to halt the spread of a communicable disease, according to Michael Bryant, executive director of the Canadian Civil Liberties Association. The government does not require consent.

On the Diamond Princess, the free Wi-Fi has become a lifeline for Clement, who's been passing the time videoing with family in Canada, watching plenty of movies and reading.

Room cleaning and laundry service has ceased, with few supplies available to passengers, says Clement, who has been washing her clothes in the sink.

Those on board are required to check their temperature regularly, with any passengers coming in over 37.5 C required to report to medical officials.

"It's extremely scary," said Clement.

WATCH | Clincal psychologist Dr. Steven Taylor on mental toll of quarantine:

Psychologist talks about the mental toll that quarantine might have on the Canadians in Trenton, Ont. 3:40

But another fear, is what happens after Feb. 19.

So far, Clement says Canadian officials haven't said whether passengers will be allowed to board their flights back home, or if they will face another quarantine on home soil.

For now, Clement is trying to remain positive, and reminding herself that she's one of the lucky ones. Not everyone on board has access to a balcony — some don't even have a window.