A report on Wellington's mental health services highlights flaws in the system for the whole country, the Mental Health Foundation's chief executive says.
A review of the region's mental health services was set up after five mental health patients were involved in attacks, four of them fatal, between 2015 and the end of March 2016.
The review found specific problems in each case, and identified that in at least one of them no psychiatric assessment was carried out.
Mental Health Foundation chief executive Shaun Robinson said the report showed a lack of funding and staff was eroding the quality of the services and how they were co-ordinated.
"These were very unwell people at the time and the mental health system really let them down. They needed more support, a better standard of care and co-ordination of that care and had that happened, it's quite probable that these tragic events would have been avoided."
The report recommended, among other things, that a psychiatrist should assess all new patients within two weeks of their admission to mental health services.
Mr Robinson said some DHBs were reluctant to adopt that recommendation.
"Capital & Coast DHB has indicated that they don't think that is necessary. Well I think that is quite appalling to say that longer than a two-week wait is acceptable. It is simply not and it is a symptom of some of the deep problems that are emerging in the public mental health system."
In response to the report, the Capital & Coast DHB said some issues were being worked on, such as improving electronic record keeping.