At the time the memo was written, there were 189 long-term inpatients stranded in acute units around the country, against a national capacity of roughly 600 beds. A quarter of them had been in the short-stay facilities for longer than six months.
"This means 30 per cent of acute inpatient capacity is unavailable for acute use," the officials said.
Waikato had 44 long-term patients in its acute facilities, Waitematā 24 and Auckland 18.
The Government has promised to upgrade mental health facilities around the country, but those investments will not relieve the pressures on the system unless there are also better transitional structures in the community, mental health experts say.
In the memo, officials told the Health Minister that resolving the backlogs of long-term patients will require "significant resourcing and new services and workforce established".
Acute mental health inpatient units exist to provide a secure therapeutic space for people with urgent problems that can't safely be treated in the community. Around 9800 people are admitted to these facilities every year, just over 5 per cent of mental health service users, and they stay for an average of 18 days, according to government figures.
Demand for beds is increasing as more New Zealanders develop severe problems requiring intensive support, but many of the inpatient facilities are deficient after decades of underinvestment in the sector.
Last year, a Ministry of Health audit of hospital buildings examined 24 mental health units and found that 11 were in poor condition and four in very poor condition. The audit described a multitude of problems, including that the units are too small, design flaws that compromise patients' safety and privacy, and poor maintenance.
Overcrowding in some units has reached the extent that they have become unsafe and distressing environments for both patients and staff. In some facilities, patients have been made to sleep in meeting rooms or seclusion rooms because there aren't enough beds — a practice that the Ombudsman, Peter Boshier, has warned is a violation of the UN convention against torture.
Pressure for beds results in some patients being sent home earlier than they should be, given their health needs, to free up beds for incoming patients. In some of those cases, patients deteriorate after they're released and end up being readmitted to acute facilities again.
And then there is the growing group of patients with complex problems who are not being discharged because they have nowhere to go.
Health authorities are reluctant to discharge these patients if they will be homeless, but for some there are no options for placement in the community — and so they stay, taking up beds for months and worsening the strain on the overburdened units.
Ideally, patients should be transferred when they are no longer acutely unwell to a stable environment in the community where they can access constant support and treatment.
One example of "best practice" cited by the officials in the briefing to the Health Minister is placing someone in a standalone community house with "one to one or two to one staffing 24 hours a day, seven days a week from the health system".
In practice, DHBs are delaying discharging some people because there is a shortage of affordable community housing or because the placements available in the community are too expensive, the memo said.
In a recent review of its mental health services, the Waikato DHB said it had dozens of patients with high and complex needs who were "effectively living in the acute and forensic wards".
"The 'opportunity cost' of this situation is vast," the report added.
Waikato has plans to build a new mental health inpatient unit to relieve the pressure on its specialist services, but the experts who conducted the review warned that this new facility would be "severely compromised" without more "sub-acute" options in the community to provide patients a pathway out of inpatient care.
In November, the Ombudsman said that, while it was admirable that mental health staff aren't discharging people into homelessness, acute facilities should not be housing patients for long periods. "It is not suitable accommodation for those who do not require care in an acute inpatient setting," Boshier said.
In a statement to the Herald, the Ministry of Health said the challenge of discharging long-term patients "is an issue that has been acknowledged for a long time and one that the Ministry talks about regularly with DHBs".
It is running a pilot programme in Auckland and Waikato aimed at helping around 100 people transition from acute mental health units into the community by providing housing support and other services.
HELP US INVESTIGATE THE MENTAL HEALTH SYSTEM
If you or a family member have been affected by problems in the mental health system, or you work in the sector and have information you would like to share, we want to hear from you. Contact us in confidence at investigations@nzherald.co.nz
Where to get help:
• 0800 543 354 (0800 LIFELINE) or free text 4357 (HELP) (available 24/7)
• https://www.lifeline.org.nz/services/suicide-crisis-helpline
• YOUTHLINE: 0800 376 633
• NEED TO TALK? Free call or text 1737 (available 24/7)
• KIDSLINE: 0800 543 754 (available 24/7)
• WHATSUP: 0800 942 8787 (1pm to 11pm)
• DEPRESSION HELPLINE: 0800 111 757 or TEXT 4202
• NATIONAL ANXIETY 24 HR HELPLINE: 0800 269 4389