Series on Men and Woman suffering PTSD. Nicholas Hodge.

Nicholas Hodge, who suffers from PTSD. Photo: Melissa Adams

Nicholas Hodge pauses as he opens the door into the ''war room'' at the end of his Chifley home. Before us, his proud military and Australian Federal Police careers are on display - awards, memorabilia and mementoes from his overseas deployments compete for space on the walls.

But that life is over, and Mr Hodge will never serve his country overseas again. The strain of what he saw and experienced has left him suffering severe anxiety, depression and post-traumatic stress disorder.

He is one of the first of a new generation of PTSD sufferers emerging from modern conflicts involving Australian soldiers and peacekeepers, such as those deployed to Afghanistan, Iraq, the Solomon Islands and East Timor.

New research on PTSD, known by a host of different names given to it by each generation of sufferers, suggests Australia and its military might be unaware of the scale of the problem likely to be faced by soldiers and other personnel deployed to war zones. More than 1700 military personnel who have served in recent combat or peacekeeping missions have been diagnosed with PTSD.

But former soldiers, support groups and experts interviewed by Fairfax Media as part of a special report on the issue expect the number to grow significantly in the coming decades.

The director of the Australian Centre for Post-Traumatic Mental Health, Professor David Forbes, said much of the recent research into PTSD had led to a rethink on the late onset of symptoms, sometimes decades after the actual trauma.

The Defence and Veterans' Affairs departments have significantly increased their expenditure on support services and research to understand the condition better.

But Professor Forbes said new evidence suggested those harbouring a deep trauma might be unlikely to experience difficulties until after leaving the military, and show little to no evidence of damage immediately upon their return from deployment.

''It can be a case of a precipitant or trigger event much later in that person's life, even leaving the military, that causes that initial trauma to come to the surface,'' he said.

Support group Soldier On co-founder John Bale said he expected thousands more to seek help for psychological injuries from deployments in Iraq and Afghanistan, and although the military was aware of the problem, it was poorly understood in the wider community.

Picking Up The Peaces co-founder Katie Tonacia said the stigma of being labelled mentally ill meant many young PTSD sufferers stayed away from support services.

''There has been a lot of work to treat and identify PTSD, but it's that stigma that still hasn't been addressed fully, and until we get past that, they won't feel supported enough to come forward.''