Mental health experts agree that while predicting suicide is often difficult, a prior attempt is one of the clearest signs that an individual will try to take their own life again.

Yet, a Legislative Assembly inquiry into youth suicide heard earlier this year that the majority of youth suicides in the ACT since 2004 came after a previous attempt.

ACT Children and Young People Death Review Committee member and paediatrician Sue Packer said that was one of the most disturbing findings to have emerged from her group's research.

She said more needed to be done to ensure proper follow-up and support for those who were known to be at risk of suicide and their families.

"So looking at what is available in terms of services and supports in families for young people who have attempted suicide," Dr Packer said.

"I think this is something we can do quite quickly."

It's a problem that's been known for years.

In 2014, the National Mental Health Commission Review warned the federal government that those who attempted suicide were not all receiving sufficient support and follow-up to prevent further attempts.

That was particularly so in the high-risk period after hospital discharge, the commission found, describing it has a missed opportunity to reduce suicide rates.

Beyondblue told this year's Legislative Assembly inquiry that a previous attempt was "the most significant risk factor for suicide", yet those who presented at hospitals and medical facilities often had poor experiences.

Beyondblue warned that many received inadequate support and reported being treated in a "stigmatising way".

"In addition, follow-up may be absent, poorly communicated, poorly co-ordinated or poorly timed," the organisation wrote in its submission.

"As a result, many young people either do not attend appointments or attend only briefly and are lost to follow-up."

Beyondblue urged better safety planning and after-care, and measures to ensure emergency departments were able to better deal with those who had self-harmed or attempted suicide.

Typically, when a young person attends a hospital after self-harm or a suicide attempt in the ACT, they are first treated for physical injuries and seen by a mental health nurse, who will then discuss the case with psychiatrists.

If deemed necessary, the individual can be detained involuntarily in the inpatient unit or emergency department.

A safety plan is put in place if they are discharged, and the hospital notifies community-based mental health teams or the Child and Adolescent Mental Health Services.

The issue of youth mental health has become an area of contention in the federal election in recent days, amid concerns that changes to funding arrangements could threaten the headspace youth support service, a proven model for early intervention.

Health Minister Sussan Ley has denied that the changes will see funding reduced for the headspace network.

On Sunday, Opposition Leader Bill Shorten used his campaign launch to pledge Labor would keep open the existing 95 headspace centres at their current locations.

He also announced $72 million for 12 regional suicide prevention projects and $9 million for a new suicide prevention fund, designed to reduce the social stigma around depression.

Headspace is struggling to meet surging demand in the ACT, which has been growing by 10 per cent annually.

The service, which deals with mild to moderate cases, has been without a federal funding increase for four years.

The Legislative Assembly youth suicide inquiry heard that the two headspace centres in the region, in Belconnen and Queanbeyan, are overstretched, lack adequate resourcing, and currently have wait times stretching out to eight weeks.

If you need help or support contact, Lifeline: 13 11 14, beyondblue: 1300 22 4636, Kids Helpline: 1800 55 1800 (24/7 crisis support), or headspace: 1800 650 890 www.headspace.org.au.