Post-traumatic stress disorder is easy to understand but incredibly complex to treat, says a University of Victoria counselling psychologist.

Tim Black, UVic professor of counselling psychology, said manuals of mental illness define PTSD as a reaction to traumatic stress. And traumatic stress is defined as experiencing, witnessing or hearing about anything that threatens life, limb or integrity of the person.

But it gets tricky to treat, or sometimes even recognize, when you consider every person is a unique individual, each with their own past history, relationships and viewpoints, said Black, who also administers the Vancouver Island component of the Veteran's Transition Program.

"It's very complex but it's also very understandable when you dig into the 'why,' " he said.

For example, a military unit of 20 people can come under fire, but only one man [and they are mostly men] later suffers PTSD.

Perhaps he was the only person who saw a unit member killed. Or perhaps he saw the body afterward and it reignited a childhood trauma of stumbling across a body. Or perhaps he couldn't return fire for some reason and feels guilty. Maybe he was later chewed out by the sergeant major and shamed in front of his unit colleagues.

"It's not a simple dose-response thing where you get a dose of trauma and you get PTSD," Black said.

Similarly, he said individual symptoms of PTSD can vary widely, from trouble sleeping, to difficulty with concentration, to nightmares and night sweats. The movie stereotype of the trauma victim shivering, shaking or blacking out are rare, however.

Often, a returning service person can languish for years, never understanding what's happening. Perhaps they self-medicate with alcohol or drugs and never seem to reach their potential.

It's why Black likes to concentrate on transition to civilian life rather than overt treatment of PTSD when it comes to helping veterans. All veterans leaving the military community have some transition issues to overcome when leaving military life.

For example, at work a military person might take time to fix a machine perfectly because he has been taught lives are at stake. But the civilian has to get that machine up and running as quickly as possible, perfect or not, because money is lost when production stops or slows.

Or a job foreman with a military background might insist his civilian crew stay on the job until all work is done. But that attitude can earn trouble with workers who clock out when their shift is over, or with company managers who object to any surprise overtime expenses.

"PTSD is just part of the transition," Black said. "There is a whole host of other things around transition. And society has a responsibility to receive them back well and help them in this society."

Black noted society helped out in the past. Second World War veterans came home welcomed as heroes with parades. And they were presented with an entire continent committed to rebuilding, moving into a civilian economy, putting veterans to work and into affordable homes.