Otago prison nurses are the first in the country to gain extra credentials in primary mental health.
All 10 nurses at the Otago Corrections Facility in Milburn have been working under a new programme developed by the New Zealand College of Mental Health Nurses.
It aims to ensure all prison nurses work to the college's standards and practise at a level comparable to that of nurses in the wider primary health sector.
The Department of Corrections hopes to implement the programme in other New Zealand prisons.
It requires prison nurses to demonstrate their knowledge and skills when working with inmates who have mental health issues.
The jail, as a workplace, also has to meet standards for providing professional support, access to supervision and training, and policies and procedures that support good practice.
Corrections said effective, early intervention for prisoners with mental health needs was essential to reduce the impact of their illness, improve recovery and aid rehabilitation.
Mental health problems are more prominent among the prison population than in the wider community.
Otago Corrections Facility health centre manager Jillian Thomson said the prison's nurses had found the programme helpful.
''They are gaining more resources to add to their toolboxes around assessment and management.
Nurses are feeling more confident when they encounter patients showing signs of mental illness and addiction issues,'' she said.
Corrections Minister Anne Tolley said healthy prisoners were more likely to engage in education and training programmes, which helped their rehabilitation and ultimately reduced re-offending.
''The Government has ensured that prisoner health, and particularly mental health, is addressed and dealt with appropriately.''
Mrs Tolley said the introduction in 2012 of a mental health screening process to identify prisoners' mental health needs meant they were referred for appropriate care as soon as possible.
She said in the past five years there had been a dramatic reduction in the number of self-harm incidents that threatened prisoners' lives, from 33 in the 2008-09 financial year to seven in the 2012-13 financial year.
Drop in ranking
The Otago Corrections Facility has dropped in national prison performance rankings.
The Department of Corrections publishes a quarterly prison performance table, indicating whether prisons are meeting targets or need improvement in respect of security, internal procedures and rehabilitation.
Between December 2012 and December 2013 the OCF's performance has fluctuated.
It started in the ''needs improvement'' category, moved up to ''exceeding'', then dropped down to ''effective''.
