Thirty-one patients have absconded from Canberra's mental health units over the past year, health authorities have revealed.
A majority of the patients who absconded were those who were out on approved leave and failed to return to their unit at the appointed time.
A spokesman from Canberra Health Services said the number of patients who absconded accounted for fewer than 2 per cent of admissions to the ACT's mental health units.
The spokesman said it was important to remember the vast majority of those with a mental illness do not pose any risk to the community.
"Approved leave from mental health inpatient units is an important aspect of a person's therapeutic pathway and journey," the spokesman said.
"We have appropriate treatment plans, behavioural management plans and risk mitigations in place for all patients and these plans are regularly updated to ensure they remain relevant to their stage of recovery."
Leave policies in the territory's public mental health units have been criticised for being too complex.
A board of inquiry held last year into the Dhulwa Mental Health Unit found there were concerns leave approvals were "unnecessarily prescriptive and, if strictly applied, could lead to unintended consequences and consumer frustration".
But the leave policies have also been highlighted following an alleged stabbing at the Australian National University last month. Alex Leonard Ophel, 24, was arrested and accused of stabbing two women. He was staying at Gawanggal and was on an unescorted walk when the alleged stabbing happened.
The territory's chief police officer, Neil Gaughan, has previously said it was "quite a common occurrence in the ACT" for a patient from a facility to go missing.
Staff from Dhulwa have said patients have returned from leave under the influence of drugs or alcohol, the ABC has reported.
Managers from the facility have reportedly asked for an urgent review of search policies and the possibility of using sniffer dogs at the secure mental health unit.
ACT Minister for Mental Health Emma Davidson was asked last week about how often contact was lost with those who were on approved leave.
She took the question on notice but said the reasons varied as to why it might be hard to contact someone.
"Sometimes it can be because they actually have a health issue while they are on leave," Ms Davidson said.
"That is something that clinicians need to think about when they are trying to work out whether leave is appropriate and for how long and for what activity.
"Quite often, people who are receiving mental health treatment also have physical health conditions at the same time, and all these things need to be taken into account together."