The number of 111 calls that police code as related to either "mental health" or "attempted suicide" has soared by nearly 50 per cent in four years, according to the People's Mental Health Review.
The review is a project of psychotherapist Kyle MacDonald, comedian Mike King and others calling for people to share their experiences of the mental health system.
The review team said data they had obtained from the police showed that the number of 111 calls coded primarily as "mental health" or "attempted suicide" was 31,059 in the 2011/12 financial year. In 2015/16, it was 45,476 - an increase of 46 per cent.
"This represents one call every twelve minutes, every day of the year in New Zealand," the review team said.
"The police communication centre can only assign one code to each call, and these figures represent those calls primarily coded as either 'mental health' or 'attempted suicide'.
"Given there are a wide range of reasons people with mental health need to call the police, these numbers likely also under-represent the volume of mental health work that the New Zealand police are asked to do.
"It seems like yet another red flag among many, and frankly comes as no surprise," says MacDonald.
"Our submissions are showing a clear trend of people being unable to access services in a timely manner, and of a workforce feeling overwhelmed by demand. It makes sense the NZ police would also be seeing increased demand."
He cited the police statement last week outlining increased training for communication centre staff to enable them to better deal with mental health calls. The increase in such calls explained why the extra training was needed.
"I think it's a great initiative; anything that improves the services that people experiencing mental illness get has to be a good thing.
"But it's also another sticking plaster on a gaping wound. Once again other services are picking up the pieces because our core mental health services, especially acute and emergency services, are unable to meet demand.
"In our view this is yet further evidence of the need for a comprehensive, independent national review into public mental health services."
The Green Party has been calling for a national inquiry for months.
Health Minister Jonathan Coleman has ruled out holding such an inquiry.
Where to get help
• 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)
If it is an emergency and you feel like you or someone else is at risk, call 111.