St John has responded to nearly 20,000 mental health crisis call outs in the past six months.
And the number of elderly Kiwis dialling 111 for mental health issues is rising, the charity said.
St John Ambulance released its emergency workload statistics for 2019, which showed a 10 per cent increase in mental health call outs last year.
The group with the largest increase were those aged 70 to 79, and men made up nearly half of all callers, rising 8 per cent on the year before.
Almost seven thousand suicide attempts were recorded.
Director of operations Norma Lane told Newstalk ZB that sadly, the numbers reflected a culture with alcohol and drug issues.
Last year, St John responded to over 440,000 incidents, almost 18,000 more than the year before.
Most of these were to respond to falls, breathing problems, chest pain, people unconscious or passing out and GP referrals.
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Traumatic injuries were also on the rise, up 14 per cent from 2018.
"Māori and Pacific people with these injuries are likely to be younger and in higher areas of deprivation than other ethnic groups," Lane said.
As well as a growing number of emergency responses, paramedics also faced more complex jobs with patients who had multiple health issues, increasing the time that the job took, Lane said.
"It can take time to stabilise and treat patients with serious and complex conditions, meaning ambulances are not available to respond as quickly to the next call."
Over 10,000 people suffering stroke needed emergency ambulance response, up nearly 12 per cent from 2018.
Call-handlers at the St John 111 communication centres in Auckland and Christchurch answered more than half a million calls – 46,000 more than in 2018.
Ninety-two per cent of ambulance emergency calls were answered immediately, and 95 per cent within 15 seconds.
But despite the increasing demand the charity faced, Lane said St John was working hard to improve outcomes for patients as well as the safety for ambulance officers.
Single-person ambulance call-outs are to be replaced by fully crewed ambulances by next year.
"Ambulances are now fully crewed 97 per cent of the time and we are on track for all ambulances being double crewed in 2021."