Green Party health spokesman Kevin Hague has said the ministry was forced to act after Stevens' death and other incidents.
Today, he said that although some of the circumstances of Stevens' death were different from the death of the 24-year-old woman, there were also "sufficient similarities to cause me to wonder if her death could have been avoided".
Derek Wright, executive director of the DHB's mental health and addictions service, said: "We can't confirm the exact circumstances of this woman's tragic death, due to patient and family privacy.
"The matter will be referred to the coroner and the DHB will conduct a serious-event review into the death.
"We can say that she was an informal patient who was transitioning to live in the community." She died while on unescorted leave the night before she was to be discharged home, Wright said.
"Once it was clear that she had not returned as arranged, and was not in the immediate environs of the Henry Rongomau Bennett Centre, the police were notified and staff worked closely with the police and family in attempting to locate her.
"We have been closely engaged with the family over this woman's care. Any death like this is a tragedy for the family and we are now supporting them through this difficult time, as well as supporting our staff. The family are happy with the care she received and have asked that their privacy be respected at this time."
The police said the woman's body was found on July 7 and her death had been referred to a coroner.
In April, the ministry's investigation report highlighted short-staffing and staff burn-out at the DHB's mental health services. The report said the DHB needed to focus on immediate staffing relief in critical areas to reduce "staff burn-out and churn, fill vacancies and improve staff retention".
The ministry said many of the report's recommendations supported changes already planned by the DHB.
In the wake of the Waikato review, the Greens demanded a nationwide inquiry into mental health services.
Earlier in April, a report on the Northland DHB mental health inpatient unit at Whangarei Hospital found it was crisis-driven, practised a medication-driven model of care and staff felt overworked, undervalued and unsafe.
The Northland DHB said many of the recommendations made in the report were already planned.
Hague said DHBs' mental health services were under-resourced, under-staffed and faced increased numbers of patients.
" ... practically every day brings a fresh story to my office of something that has gone disastrously wrong in mental health services from everywhere around the country. The problem is not just in one or two DHBs, and there is sufficient frequency and consistency about these stories to suggest strongly that the problems are systemic, not idiosyncratic.
"Some obvious measures required are a major funding lift, direction and oversight restored through reinstatement of the Mental Health Commission, reintroduced mental health targets -- and an urgent, nationwide inquiry along the lines of the Mason inquiries."
Health Minister Jonathan Coleman has highlighted the Government's increased funding for mental health and addiction services. It had risen from from $1.1 billion in 2008/9 to more than $1.4 billion for 2015/16. The May Budget added $12 million over four years to increase support for primary care and social services to enable people to access mental health help earlier.
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.
