Ms Thomas said she was in the last six months of her doctorate and had enrolled for study on the understanding that she would be able to access a student allowance to fund her living costs.
She said she would now have to borrow living cost on her student loan, which would leave her with $70 less to live on each week.
"We were really concerned about the lack of discussion and awareness about these changes even though they were signalled in the May Budget. They weren't clear at the time; it was only in September I'd realised that I won't be able to get the student allowance next year.
"We're also concerned about the impact this is going to have on people. It's causing quite a bit of financial distress and this is leading to lower mental health wellbeing.
"We think this needs a lot more discussion and lot more consideration by the minister.''
Ms Duncan said she had planned her area of study, and when she found out in May her allowance would be cut she had a big decision to make.
"I decided to stay. I didn't want to abandon my plan, and the death of Sir Paul Callaghan, whose legacy was trying to keep talent in New Zealand, influenced me.''
Tertiary Education Minister Steven Joyce said savings needed to be made, and it made sense to cut allowances to the group of people that would be some of the highest income earners after graduating.
"If you're looking for savings, then it would seem only fair that those that stand to gain the most from the system - those at postgraduate level who stand to earn the best incomes when they leave on average - it would seem only fair that they are the people that would make a bit of extra contribution,'' he said.
He didn't think the cut to allowances would force students overseas, where he said they would face higher fees. He urged postgraduate students to stay in New Zealand.
The survey asked how changes to student allowances would affect people's study choices, and gathered comments on how the changes would impact on people on an individual level.
The main concern was New Zealand would no longer be able to offer world class research, expertise or be innovative due to fewer people choosing to take part in postgraduate study.
Those surveyed were asked:
- How will changes to student allowance affect you?
- How has the student allowance contributed to helping your postgraduate study?
- How does this affect your future study choices?