Psychologists say there's emerging evidence of long-term and in some cases 'severe' effects from time spent in MIQ, brought on by a lack of control, autonomy and social contact.
While many returnees relish the two-week hotel stint, others say they're being caught completely unprepared by the mental health toll.
Debbie described her time in the Crowne Plaza hotel in July as being "stuck in a strange altered reality" where she had no idea how angry, distressed and "weird" she would feel.
"I really hit the bottom. I just sat and cried at the wire fence. I just couldn't move and I just felt like I couldn't do it - and this was only on day 2," she said.
"If it had been like staying in a hotel - I don't go to a hotel with an expectation of support. I just stay there, do what I have to do and I leave. I thought it was going to be that simple but it wasn't... it really is a strange reality of trying to fit into a set of rules, but you don't know what the rules are."
For Carrie-Ann it was a feeling of being lost and unmotivated - and she was still a bit rattled one month later.
Last month she and her three-year-old daughter spent two weeks in Auckland's Grand Mercure, following a trip to the UK to see her ill father.
Carrie-Ann expected it to be a relaxing few days, but the rest of the country went into lockdown and she started to panic about catching the virus after learning about potential transmission at the Crowne Plaza.
She said she struggled without opening windows and was fearful about turning on her air-con.
"I did break a few times in there. I can see how anybody's mental health would really struggle, especially people with kids. You're stuck in there trying to look out for the wellness of your children while you try to keep your own sanity," she said.
"You try to keep positive, but then I just had no motivation. And normally I'm quite active - I like to get out with my kids, doing things. All of a sudden I'm stuck in this room and I just had no motivation to do anything with my daughter. I felt like I was lost."
MIQ officials say there's a mental health clinician on hand at each hotel and nurses available 24/7, if returnees are worried about their own mental wellbeing or someone in their whanau.
The welcome pack given to returnees includes free support helplines, websites and services, while nurses are directed to ask about people's mental health and wellbeing as part of daily health checks.
But RNZ has spoken to several recent returnees who said that didn't happen at their hotels.
Debbie said staff seemed too overworked and too busy to check in on her mental health.
"Each day they took my temperature, checked for COVID-19 symptoms, and then left," she said.
Another returnee who left the Four Points by Sheraton today and asked not to be named: "I haven't been asked how I'm coping, just simply if we have symptoms... I believe there is supposed to be an on-site wellness team... I haven't heard from them once."
Clinical psychologist Jacqui Maguire warned the impacts of MIQ on some people's mental health are "not to be underestimated".
RNZ
Where to find help and support:
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- Lifeline - 0800 543 354 or (09) 5222 999 within Auckland
- Youthline - 0800 376 633, text 234, email talk@youthline.co.nz or online chat
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- Depression Helpline - 0800 111 757
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- Shakti Community Council - 0800 742 584
