Research released by the Department of Corrections shows that prisoners were considerably more likely to have substance abuse difficulties than is found among the general population, and their mental health was also worse.

The research involved interviews with over 1200 prisoners across 13 prisons between March and July 2015.

The report into the interviews, Comorbid substance use disorders and mental health disorders among New Zealand prisoners, has now been released. It is the first time in 17 years that such a study has been conducted. Results in both the 1999 and 2015 studies are broadly similar, although there has been an increase in rates of mood and anxiety disorders.

The 2015 research has found that in the 12-month period leading up to the interview:

• 62% of prisoners were found to have either a mental disorder or substance use disorder, and 20% had both.
• 7% of prisoners reported experiencing psychotic symptoms (eg, hearing voices, seeing things that were not real, delusions).
• 24% had some form of mood disorder, such as depression.
• 23% met the criteria for an anxiety disorder (eg, panic, post-traumatic stress).
• 6% had attempted suicide.
• 46% of prisoners with mental health or substance use disorders had received some form of treatment.

With release of the research findings, Corrections Minister Judith Collins has announced that the Justice Sector Fund will provide $13,797,000 to purchase mental health services for offenders in prison and in the community over the next two years.

The Police have also received $350,000 in funding to enhance information sharing on mental health.

"This is a significant increase in support for offenders suffering from mental illness," Ms Collins says. 

"Offenders' mental health needs can escalate quickly and tragically. We want to get them the help they need early, and reduce the likelihood of them harming themselves or those around them.