Justice Minister Amy Adams wants more money spent on mental health services for those appearing and being sentenced in the country's courts.
Photo: RNZ / Alexander Robertson
But the Ministry of Health says mental health services are already under strain and there is little scope to do what the minister wants.
Figures compiled by justice officials show 11 percent of the general population had sought mental health treatment, compared with 40 percent of those who appeared in court and 50 percent for those on community sentences.
Ms Adams said her ministry was picking up the pieces and she wanted the health sector to take more responsibility.
"The justice system is picking up where the health system hasn't really addressed some of these issues, and I need them to change their thinking in the same way we have to change ours," Ms Adams said.
She wanted the Ministry of Health to take a more holistic approach and consider the benefits across the entire system, not just the health sector.
"They need to be assessing the cost benefit analysis, if you want to put it in fiscal terms, right across the whole of the sector," she said.
But the Ministry of Health told justice officials its services were already under pressure.
In a statement to justice officials it said: "The Ministry of Health advises that mental health services are under significant demand pressure so there would be very limited scope to shift their focus towards reducing offending. The resource of a rather limited cognitive behavioural therapists trained workforce so expanding it would take time".
Labour Party health spokeswoman Annette King said it was the first time she had seen the ministry publicly admit how pressured mental health services were.
"You don't solve it by telling them that they need to do more unless you're going to back it up with a budget allocation, so you've got an impasse here really, a minister saying we're going to have data and we want this to happen and a ministry of health saying well we can't do that because we're already under huge pressure," Ms King said.
Ms Adams said she was confident the Ministry of Health would change its stance.
"As better information becomes available to tell us more about the value of these interventions across the government system, I think that would change the prioritisation discussions," Ms Adams said.
But Ms King doubted that would be the case.
"Part of the problem for the Ministry of Health is the government no longer has made mental health one of their priorities, they have targets, it doesn't include mental health," Ms King said.
Health Minister Jonathan Coleman said spending on mental health for inmates was essential and health and justice worked closely together.
Ms King said the annual increase of $50 million a year for mental health was introduced when Labour was last in power eight years ago, and the funding levels had not changed, despite increasing demands on the sector.
She said the increasing number of media reports about failings in the mental health system showed how underfunded the sector was.
