Australia's Defence community must change its culture and end negative stereotypes about mental health to ensure members and veterans get the help they need, a national report has found.

The National Mental Health Commission has released a review of suicide and self-harm by veterans and members of the Australian Defence Force (ADF) and made 23 recommendations.

The report was commissioned by the Federal Government and has been welcomed by Veterans Affairs Minister Dan Tehan, who has promised immediate action in response.

Some aspects of Defence culture are reinforcing negative stereotypes about mental health, the commission's chief executive Dr Peggy Brown said.

The report also revealed that many ADF members and veterans have not sought assistance because they fear doing so may restrict their career opportunities.

Mr Tehan said the Government had listened to the 3,200 people who contributed to the report and said he would look to provide additional funding for services in the May budget.

"The Government has a responsibility to the men and women who defend our nation and we are committed to addressing veteran and ADF suicide," he said.

"We have made mental health treatment free for depression, anxiety, post-traumatic stress disorder and drug and alcohol misuse conditions for anyone who has served one day in the ADF."

Government needs to do more to help young veterans, commission says

The commission called on the ADF to resolve a tension between encouraging members to seek help early while keeping mental health counselling on a "need-to-know" basis from an operational perspective.

Health Minster Greg Hunt said the Government would immediately release $3 million for a suicide prevention trial program in Townsville, where a significant number of veterans live.

He said the Government needed to do more to assist those leaving the armed forces, particularly given those who leave the armed forces at a young age are at greater risk of suicide.

"Those veterans who do leave, particularly the youngest ones, often face a very hard transition and that means we have to do more in terms of services and to be more personal," Mr Hunt said.

Chief of Navy Tim Barrett said the armed forces needed to ensure that veterans were comfortable seeking help for mental health issues.

"To all those who serve and who are currently wearing the uniform of Army, Navy or Air Force, we must learn that there is no stigma in raising issues," he said.

"We must also remember that for those who do have an issue, you should feel comfortable about putting your hand up and seeking the help of the services we do provide."

The report found there was a lack of awareness about mental health services, and better communication between the Defence and Veterans Affairs Departments would reduce the prevalence of suicide.

The risk of suicide increased greatly once people left the armed forces, Dr Brown said.

"What that study demonstrated is that if you are a current-serving member of the Defence Force, that your risk of suicide is 50 per cent less than your age-matched cohort in the general population," she said.

"But if you're a former serving member you are at high risk of suicide and that's particularly so in those from the age of 18 to 30."