The number of police calls out for suicide and mental health issues has risen by nearly a quarter in the last five years.
And while they're often the first port of call, police say they don't receive specialist training to deal with severely mentally ill patients.
Police have added mental health as one of their core "drivers of demand", which are at the heart of the police "prevention first" operating strategy.
Mental health's addition as the sixth driver creates a strategic direction throughout the organisation, with officers encouraged to show how they're addressing the issue.
Police headquarters mental health team manager Senior Sergeant Matthew Morris said police attended mental health calls in good faith and to the best of their ability, but there were obvious problems.
"The general feedback we get [from frontline officers] is that they find mental health incidents tricky, and difficult to resolve.
"The primary reason is that police are not mental health professionals.
"We have limited training, and we are dealing with complex social and mental issues, and that's not our core role."
Figures released under the Official Information Act show that police call-outs for suicide and mental health issues are steadily increasing, with mental health calls to police jumping 22%, from 22,438 in 2012/13, to 27,429 in 2016/17.
To deal with the increase, the police Mental Health Team was formed in 2013.
In August 2014 a two-hour mental health training session was created for recruits at police college, and in October 2016 three more mental health e-learning modules were released for frontline staff.
Morris said that training focused on destigmatisation and how to de-escalate situations with people in crisis.
"We can't match the years of training that they [mental health professionals] get.
"And we have to keep in mind, that we have to train police for a vast array of jobs.
"It's one of the beauties of police work, is that we go to many different situations and we have to train for all of them."
In August the Government announced a new mental health package, which included $8m for a multi-agency co-response service, meaning those who called 111 in distress would have people from police, ambulance, and mental health, dispatched to help them.
Morris said the scheme was now in the early stages of planning, and he hoped it would mean officers could move into a supporting role to mental health professionals.
"It's fair to say that we're the first port of call. And that's understandable, because we're 24/7, and we will go.
"The co-response model means a more wrap around service.
"There'll be less jumping around between the agencies for the individual, there'll be more treatment at home, it will lead to less admissions to emergency departments, and less detentions in police cells.
"We attend in good faith to many incidents every day.
"But often we arrive first on the scene, and we're there by ourselves. And, of course, when we come to a job by ourselves we bring a police perspective to it.
"That isn't the perfect perspective. If we wanted to bring the perfect perspective, we would think about the medical needs and mental health needs.
"So by having every single person there, they can advise much better on what to do when we first arrive."
Mental Health Foundation chief executive Shaun Robinson said there had been a "far increased" demand on mental health services throughout New Zealand.
"Services from police and mental health services are struggling to keep pace.
"By and large, it's more appropriate for mental health professionals to come and assist people in mental health crises.
"We don't think we'll ever get to a place where police aren't ever necessary, sometimes it's for the safety of everybody involved, then a police response can be very helpful.
"But for the most part, an arrest is not an appropriate pathway to care.
"Really, the health system needs to be stepping up here."
Robinson said the idea of an emergency co-response team was good, but they would reserve judgement until they saw what the final arrangement looked like.
"I think most of us are raised to think that if the police are coming, we're in trouble. That's a difficult thing.
"I think anything that makes sure we have a health response to someone who's having a mental health problem is a good thing."
He said the next test would be whether enough mental health professionals were on the ground to be part of the co-response teams.
Robinson said mental health funding hadn't kept pace with demand and population growth, and unions had been vocal about the fact there weren't enough people to do the work.
Drivers of demand (formerly the drivers of crime)
Alcohol: To foster a culture of responsible drinking, reduce incidents of alcohol-related offending and victimisation.
Youth/Rangatahi: To keep vulnerable children and young people safe and decrease the number of young people represented in the criminal justice system.
Families/Whānau: To support and protect vulnerable and dysfunctional families, lift the veil of secrecy around family violence, child abuse and expose familial organised crime groups.
Roads: To reduce death and serious injury on our roads
Organised crime and drugs: To reduce the social impact of gangs and drugs
Mental health: To work closely with providers of health services to ensure those suffering mental distress are not a danger to themselves or others.
• 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.