"We are seeing more students all the time; they are getting more severe."
Andrews said she wanted trained counsellors not only in high schools but in primary and intermediate schools.
The increasing problems in younger children seemed to coincide with the introduction of National Standards, which have now been ditched, she said.
Youthline Otago manager Brian Lowe said his organisation - geared towards 12-to-24-year-olds - had observed an increase in calls from teens and people in their 20s dealing with depression and anxiety.
Societal and technological change were contributing factors, he said.
Andrews said she thought society was "less healthy in some ways".
"It's really simple things like having a well-nourishing diet and getting enough sleep."
When it came to younger people, technology contributed to a loss of connection and had changed the face of bullying, Lowe said.
Lowe and Andrews both said expectations on young people to have a particular body image and a "perfect life" - including academic success and life experiences such as travelling the world, or having a perfect job - were also stressful.
"We are teaching people that life should be constantly happy, so people are struggling when they find that their life experience is different," Lowe said.
Last month, the university's student health service said its mental health and wellbeing team had reported a 46 per cent increase in direct contact with students this year, compared with 2017.
On the positive side, part of the phenomenon could be young people now felt more comfortable asking for help, Lowe said.
Otago Polytechnic communications director Mike Waddell said the polytechnic was aware of the issue, and was working with the Otago Polytechnic Students' Association to ensure all students were supported.
Student services team leader Brayden Murray said a staff mental health working group had been started this year.
The polytechnic has counsellors whose work equates to 1.8 fulltime equivalent staff, and has ties with support organisations including the Otago Mental Health Trust.
Student Jordan Dargaville, the students' association representative on the polytechnic council, said he thought the change of season was a stressor for students, bringing financial struggles and "freezing flats".
He was keen to have public story boards up where students could write about their own experiences, to raise awareness, and also to work more closely with organisations such as Youthline.
• Lifeline: 0800 543 354 (available 24/7)
• Suicide Crisis Helpline: 0508 828 865 (0508 TAUTOKO) (available 24/7)
• Youthline: 0800 376 633
• Kidsline: 0800 543 754 (available 24/7)
• Whatsup: 0800 942 8787 (1pm to 11pm)
• Depression helpline: 0800 111 757 (available 24/7)
• Rainbow Youth: (09) 376 4155
• Samaritans 0800 726 666
• If it is an emergency and you feel like you or someone else is at risk, call 111.